// formrt.c -- DVX BASIC form runtime implementation
//
// Bridges BASIC programs to the DVX widget system. All widget types
// are discovered dynamically via WgtIfaceT interface descriptors
// registered by .wgt DXE files. No hardcoded control types.

#include "formrt.h"
#include "../compiler/codegen.h"
#include "../compiler/opcodes.h"
#include "dvxDialog.h"
#include "dvxWm.h"
#include "widgetBox.h"
#include "thirdparty/stb_ds_wrap.h"

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>

// ============================================================
// Defines
// ============================================================

#define DEFAULT_FORM_W       400
#define DEFAULT_FORM_H       300
#define MAX_EVENT_NAME_LEN   128
#define MAX_LISTBOX_ITEMS    256
#define MAX_FRM_LINE_LEN     512
#define MAX_FRM_NESTING      16
#define MAX_AUX_DATA         128

// ============================================================
// Per-control listbox item storage
// ============================================================

typedef struct {
    char   *items[MAX_LISTBOX_ITEMS];
    int32_t count;
} ListBoxItemsT;

// ============================================================
// Auxiliary data table for listbox item storage
// ============================================================

typedef struct {
    BasControlT   *ctrl;
    ListBoxItemsT *items;
} AuxDataEntryT;

static AuxDataEntryT sAuxData[MAX_AUX_DATA];
static int32_t       sAuxDataCount = 0;

// Module-level form runtime pointer for onFormClose callback
static BasFormRtT   *sFormRt = NULL;

// ============================================================
// Prototypes
// ============================================================

static BasStringT *basFormRtInputBox(void *ctx, const char *prompt, const char *title, const char *defaultText);
static BasValueT callCommonMethod(BasControlT *ctrl, const char *methodName, BasValueT *args, int32_t argc);
static BasValueT callListBoxMethod(BasControlT *ctrl, const char *methodName, BasValueT *args, int32_t argc);
static WidgetT  *createWidget(const char *wgtTypeName, WidgetT *parent);
static void      freeListBoxItems(BasControlT *ctrl);
static BasValueT getCommonProp(BasControlT *ctrl, const char *propName, bool *handled);
static BasValueT getIfaceProp(const WgtIfaceT *iface, WidgetT *w, const char *propName, bool *handled);
static ListBoxItemsT *getListBoxItems(BasControlT *ctrl);
static void      onFormActivate(WindowT *win);
static void      onFormClose(WindowT *win);
static void      onFormDeactivate(WindowT *win);
static void      onFormResize(WindowT *win, int32_t newW, int32_t newH);
static void      onWidgetBlur(WidgetT *w);
static void      onWidgetChange(WidgetT *w);
static void      onWidgetClick(WidgetT *w);
static void      onWidgetDblClick(WidgetT *w);
static void      onWidgetFocus(WidgetT *w);
static void      onWidgetKeyPress(WidgetT *w, int32_t keyAscii);
static void      onWidgetKeyDown(WidgetT *w, int32_t keyCode, int32_t shift);
static void      onWidgetKeyUp(WidgetT *w, int32_t keyCode, int32_t shift);
static void      onWidgetMouseDown(WidgetT *w, int32_t button, int32_t x, int32_t y);
static void      onWidgetMouseUp(WidgetT *w, int32_t button, int32_t x, int32_t y);
static void      onWidgetMouseMove(WidgetT *w, int32_t button, int32_t x, int32_t y);
static void      onWidgetScroll(WidgetT *w, int32_t delta);
static void      parseFrmLine(const char *line, char *key, char *value);
static void      rebuildListBoxItems(BasControlT *ctrl);
static const char *resolveTypeName(const char *typeName);
static bool      setCommonProp(BasControlT *ctrl, const char *propName, BasValueT value);
static bool      setIfaceProp(const WgtIfaceT *iface, WidgetT *w, const char *propName, BasValueT value);
static BasValueT zeroValue(void);

// ============================================================
// basFormRtBindVm
// ============================================================

void basFormRtBindVm(BasFormRtT *rt) {
    BasUiCallbacksT ui;
    memset(&ui, 0, sizeof(ui));

    ui.getProp    = basFormRtGetProp;
    ui.setProp    = basFormRtSetProp;
    ui.callMethod = basFormRtCallMethod;
    ui.createCtrl = basFormRtCreateCtrl;
    ui.findCtrl    = basFormRtFindCtrl;
    ui.findCtrlIdx = basFormRtFindCtrlIdx;
    ui.loadForm    = basFormRtLoadForm;
    ui.unloadForm = basFormRtUnloadForm;
    ui.showForm   = basFormRtShowForm;
    ui.hideForm   = basFormRtHideForm;
    ui.msgBox     = basFormRtMsgBox;
    ui.inputBox   = basFormRtInputBox;
    ui.ctx        = rt;

    basVmSetUiCallbacks(rt->vm, &ui);
}


// ============================================================
// basFormRtCallMethod
// ============================================================

BasValueT basFormRtCallMethod(void *ctx, void *ctrlRef, const char *methodName, BasValueT *args, int32_t argc) {
    (void)ctx;
    BasControlT *ctrl = (BasControlT *)ctrlRef;

    if (!ctrl || !ctrl->widget) {
        return zeroValue();
    }

    // ListBox-specific methods (AddItem/RemoveItem/Clear/List)
    BasValueT result = callListBoxMethod(ctrl, methodName, args, argc);

    if (result.type != 0 || strcasecmp(methodName, "AddItem") == 0 ||
        strcasecmp(methodName, "RemoveItem") == 0 ||
        strcasecmp(methodName, "Clear") == 0 ||
        strcasecmp(methodName, "List") == 0) {
        return result;
    }

    // Interface descriptor methods
    const WgtIfaceT *iface = ctrl->iface;

    if (iface) {
        for (int32_t i = 0; i < iface->methodCount; i++) {
            if (strcasecmp(iface->methods[i].name, methodName) != 0) {
                continue;
            }

            const WgtMethodDescT *m = &iface->methods[i];
            WidgetT *w = ctrl->widget;

            switch (m->sig) {
                case WGT_SIG_VOID:
                    ((void (*)(WidgetT *))m->fn)(w);
                    return zeroValue();

                case WGT_SIG_INT:
                    if (argc >= 1) {
                        ((void (*)(WidgetT *, int32_t))m->fn)(w, (int32_t)basValToNumber(args[0]));
                    }
                    return zeroValue();

                case WGT_SIG_BOOL:
                    if (argc >= 1) {
                        ((void (*)(WidgetT *, bool))m->fn)(w, basValIsTruthy(args[0]));
                    }
                    return zeroValue();

                case WGT_SIG_STR:
                    if (argc >= 1) {
                        BasStringT *s = basValFormatString(args[0]);
                        ((void (*)(WidgetT *, const char *))m->fn)(w, s->data);
                        basStringUnref(s);
                    }
                    return zeroValue();

                case WGT_SIG_INT_INT:
                    if (argc >= 2) {
                        ((void (*)(WidgetT *, int32_t, int32_t))m->fn)(w, (int32_t)basValToNumber(args[0]), (int32_t)basValToNumber(args[1]));
                    }
                    return zeroValue();

                case WGT_SIG_INT_BOOL:
                    if (argc >= 2) {
                        ((void (*)(WidgetT *, int32_t, bool))m->fn)(w, (int32_t)basValToNumber(args[0]), basValIsTruthy(args[1]));
                    }
                    return zeroValue();

                case WGT_SIG_RET_INT: {
                    int32_t v = ((int32_t (*)(const WidgetT *))m->fn)(w);
                    return basValLong(v);
                }

                case WGT_SIG_RET_BOOL: {
                    bool v = ((bool (*)(const WidgetT *))m->fn)(w);
                    return basValBool(v);
                }

                case WGT_SIG_RET_BOOL_INT: {
                    if (argc >= 1) {
                        bool v = ((bool (*)(const WidgetT *, int32_t))m->fn)(w, (int32_t)basValToNumber(args[0]));
                        return basValBool(v);
                    }
                    return basValBool(false);
                }
            }
        }
    }

    // Common methods (SetFocus, Refresh)
    return callCommonMethod(ctrl, methodName, args, argc);
}


// ============================================================
// basFormRtCreate
// ============================================================

BasFormRtT *basFormRtCreate(AppContextT *ctx, BasVmT *vm, BasModuleT *module) {
    BasFormRtT *rt = (BasFormRtT *)calloc(1, sizeof(BasFormRtT));

    if (!rt) {
        return NULL;
    }

    rt->ctx    = ctx;
    rt->vm     = vm;
    rt->module = module;

    sFormRt = rt;
    basFormRtBindVm(rt);
    return rt;
}


// ============================================================
// basFormRtCreateCtrl
// ============================================================

void *basFormRtCreateCtrl(void *ctx, void *formRef, const char *typeName, const char *ctrlName) {
    (void)ctx;
    BasFormT *form = (BasFormT *)formRef;

    if (!form) {
        return NULL;
    }

    // Resolve VB name to DVX widget type name
    const char *wgtTypeName = resolveTypeName(typeName);

    if (!wgtTypeName) {
        return NULL;
    }

    // Create the widget
    WidgetT *parent = form->contentBox ? form->contentBox : form->root;

    if (!parent) {
        return NULL;
    }

    WidgetT *widget = createWidget(wgtTypeName, parent);

    if (!widget) {
        return NULL;
    }

    wgtSetName(widget, ctrlName);

    // Initialize control entry
    BasControlT entry;
    memset(&entry, 0, sizeof(entry));
    entry.index = -1;
    snprintf(entry.name, BAS_MAX_CTRL_NAME, "%s", ctrlName);
    arrput(form->controls, entry);
    form->controlCount = (int32_t)arrlen(form->controls);
    BasControlT *ctrl = &form->controls[form->controlCount - 1];
    snprintf(ctrl->name, BAS_MAX_CTRL_NAME, "%s", ctrlName);
    ctrl->widget  = widget;
    ctrl->form    = form;
    ctrl->iface   = wgtGetIface(wgtTypeName);

    // Wire up event callbacks
    widget->userData   = ctrl;
    widget->onClick    = onWidgetClick;
    widget->onDblClick = onWidgetDblClick;
    widget->onChange    = onWidgetChange;
    widget->onFocus    = onWidgetFocus;
    widget->onBlur     = onWidgetBlur;

    return ctrl;
}


// ============================================================
// basFormRtDestroy
// ============================================================

void basFormRtDestroy(BasFormRtT *rt) {
    if (!rt) {
        return;
    }

    if (sFormRt == rt) {
        sFormRt = NULL;
    }

    for (int32_t i = 0; i < rt->formCount; i++) {
        BasFormT *form = &rt->forms[i];

        if (form->formVars) {
            for (int32_t j = 0; j < form->formVarCount; j++) {
                basValRelease(&form->formVars[j]);
            }

            free(form->formVars);
        }

        for (int32_t j = 0; j < form->controlCount; j++) {
            freeListBoxItems(&form->controls[j]);
        }

        arrfree(form->controls);

        if (form->window) {
            dvxDestroyWindow(rt->ctx, form->window);
            form->window = NULL;
        }
    }

    arrfree(rt->forms);

    // Free .frm source cache
    for (int32_t i = 0; i < rt->frmCacheCount; i++) {
        free(rt->frmCache[i].frmSource);
    }

    arrfree(rt->frmCache);
    free(rt);
}


// ============================================================
// basFormRtFindCtrl
// ============================================================

void *basFormRtFindCtrl(void *ctx, void *formRef, const char *ctrlName) {
    (void)ctx;
    BasFormT *form = (BasFormT *)formRef;

    if (!form) {
        return NULL;
    }

    for (int32_t i = 0; i < form->controlCount; i++) {
        if (strcasecmp(form->controls[i].name, ctrlName) == 0) {
            return &form->controls[i];
        }
    }

    return NULL;
}


// ============================================================
// basFormRtFindCtrlIdx
// ============================================================

void *basFormRtFindCtrlIdx(void *ctx, void *formRef, const char *ctrlName, int32_t index) {
    (void)ctx;
    BasFormT *form = (BasFormT *)formRef;

    if (!form) {
        return NULL;
    }

    for (int32_t i = 0; i < form->controlCount; i++) {
        if (form->controls[i].index == index && strcasecmp(form->controls[i].name, ctrlName) == 0) {
            return &form->controls[i];
        }
    }

    return NULL;
}


// ============================================================
// basFormRtFireEvent
// ============================================================

bool basFormRtFireEvent(BasFormRtT *rt, BasFormT *form, const char *ctrlName, const char *eventName) {
    return basFormRtFireEventArgs(rt, form, ctrlName, eventName, NULL, 0);
}

bool basFormRtFireEventArgs(BasFormRtT *rt, BasFormT *form, const char *ctrlName, const char *eventName, const BasValueT *args, int32_t argCount) {
    if (!rt || !form || !rt->vm || !rt->module) {
        return false;
    }

    char handlerName[MAX_EVENT_NAME_LEN];
    snprintf(handlerName, sizeof(handlerName), "%s_%s", ctrlName, eventName);

    const BasProcEntryT *proc = basModuleFindProc(rt->module, handlerName);

    if (!proc) {
        return false;
    }

    if (proc->isFunction) {
        return false;
    }

    // Strict parameter matching: the sub must declare exactly the
    // number of parameters the event provides, or zero (no params).
    if (proc->paramCount != 0 && proc->paramCount != argCount) {
        return false;
    }

    BasFormT  *prevForm     = rt->currentForm;
    BasValueT *prevVars     = rt->vm->currentFormVars;
    int32_t    prevVarCount = rt->vm->currentFormVarCount;

    rt->currentForm = form;
    basVmSetCurrentForm(rt->vm, form);
    basVmSetCurrentFormVars(rt->vm, form->formVars, form->formVarCount);

    bool ok;

    if (argCount > 0 && args) {
        ok = basVmCallSubWithArgs(rt->vm, proc->codeAddr, args, argCount);
    } else {
        ok = basVmCallSub(rt->vm, proc->codeAddr);
    }

    rt->currentForm = prevForm;
    basVmSetCurrentForm(rt->vm, prevForm);
    basVmSetCurrentFormVars(rt->vm, prevVars, prevVarCount);
    return ok;
}


// ============================================================
// basFormRtFireEventWithCancel -- fire an event that has a Cancel
// parameter (first arg, Integer). Returns true if Cancel was set
// to non-zero by the event handler.

static bool basFormRtFireEventWithCancel(BasFormRtT *rt, BasFormT *form, const char *ctrlName, const char *eventName) {
    if (!rt || !form || !rt->vm || !rt->module) {
        return false;
    }

    char handlerName[MAX_EVENT_NAME_LEN];
    snprintf(handlerName, sizeof(handlerName), "%s_%s", ctrlName, eventName);

    const BasProcEntryT *proc = basModuleFindProc(rt->module, handlerName);

    if (!proc || proc->isFunction) {
        return false;
    }

    // Must accept 0 or 1 parameter
    if (proc->paramCount != 0 && proc->paramCount != 1) {
        return false;
    }

    BasFormT  *prevForm     = rt->currentForm;
    BasValueT *prevVars     = rt->vm->currentFormVars;
    int32_t    prevVarCount = rt->vm->currentFormVarCount;

    rt->currentForm = form;
    basVmSetCurrentForm(rt->vm, form);
    basVmSetCurrentFormVars(rt->vm, form->formVars, form->formVarCount);

    bool cancelled = false;

    if (proc->paramCount == 1) {
        BasValueT args[1];
        args[0] = basValLong(0); // Cancel = 0 (don't cancel)

        BasValueT outArgs[1];
        memset(outArgs, 0, sizeof(outArgs));

        if (basVmCallSubWithArgsOut(rt->vm, proc->codeAddr, args, 1, outArgs, 1)) {
            cancelled = (basValToNumber(outArgs[0]) != 0);
            basValRelease(&outArgs[0]);
        }
    } else {
        basVmCallSub(rt->vm, proc->codeAddr);
    }

    rt->currentForm = prevForm;
    basVmSetCurrentForm(rt->vm, prevForm);
    basVmSetCurrentFormVars(rt->vm, prevVars, prevVarCount);
    return cancelled;
}


// ============================================================
// basFormRtGetProp
// ============================================================

BasValueT basFormRtGetProp(void *ctx, void *ctrlRef, const char *propName) {
    (void)ctx;
    BasControlT *ctrl = (BasControlT *)ctrlRef;

    if (!ctrl || !ctrl->widget) {
        return zeroValue();
    }

    // Common properties (Name, Left, Top, Width, Height, Visible, Enabled)
    bool handled;
    BasValueT val = getCommonProp(ctrl, propName, &handled);

    if (handled) {
        return val;
    }

    // "Caption" and "Text" map to wgtGetText for all widgets
    if (strcasecmp(propName, "Caption") == 0 || strcasecmp(propName, "Text") == 0) {
        const char *text = wgtGetText(ctrl->widget);
        return basValStringFromC(text ? text : "");
    }

    // "ListCount" for any widget with item storage
    if (strcasecmp(propName, "ListCount") == 0) {
        ListBoxItemsT *lb = getListBoxItems(ctrl);
        return basValLong(lb ? lb->count : 0);
    }

    // Interface descriptor properties
    if (ctrl->iface) {
        val = getIfaceProp(ctrl->iface, ctrl->widget, propName, &handled);

        if (handled) {
            return val;
        }
    }

    return zeroValue();
}


// ============================================================
// basFormRtHideForm
// ============================================================

void basFormRtHideForm(void *ctx, void *formRef) {
    BasFormRtT *rt   = (BasFormRtT *)ctx;
    BasFormT   *form = (BasFormT *)formRef;

    if (!form || !form->window) {
        return;
    }

    dvxHideWindow(rt->ctx, form->window);
}


// ============================================================
// basFormRtInputBox
// ============================================================

static BasStringT *basFormRtInputBox(void *ctx, const char *prompt, const char *title, const char *defaultText) {
    BasFormRtT *rt = (BasFormRtT *)ctx;
    char buf[256];

    buf[0] = '\0';

    if (defaultText && defaultText[0]) {
        strncpy(buf, defaultText, sizeof(buf) - 1);
        buf[sizeof(buf) - 1] = '\0';
    }

    if (!dvxInputBox(rt->ctx, title, prompt, defaultText, buf, sizeof(buf))) {
        return NULL;
    }

    return basStringNew(buf, (int32_t)strlen(buf));
}


// ============================================================
// basFormRtLoadForm
// ============================================================

void *basFormRtLoadForm(void *ctx, const char *formName) {
    BasFormRtT *rt = (BasFormRtT *)ctx;

    // Check if form already exists
    for (int32_t i = 0; i < rt->formCount; i++) {
        if (strcasecmp(rt->forms[i].name, formName) == 0) {
            return &rt->forms[i];
        }
    }

    // Check the .frm cache for reload after unload
    for (int32_t i = 0; i < rt->frmCacheCount; i++) {
        if (strcasecmp(rt->frmCache[i].formName, formName) == 0) {
            // Re-parse the cached .frm source (creates window, controls, fires Load)
            return basFormRtLoadFrm(rt, rt->frmCache[i].frmSource, rt->frmCache[i].frmSourceLen);
        }
    }

    // No cache entry — create a bare form (first-time load without .frm file)
    WindowT *win = dvxCreateWindowCentered(rt->ctx, formName, DEFAULT_FORM_W, DEFAULT_FORM_H, true);

    if (!win) {
        return NULL;
    }

    win->visible = false;

    WidgetT *root = wgtInitWindow(rt->ctx, win);

    if (!root) {
        dvxDestroyWindow(rt->ctx, win);
        return NULL;
    }

    BasFormT entry;
    memset(&entry, 0, sizeof(entry));
    arrput(rt->forms, entry);
    rt->formCount = (int32_t)arrlen(rt->forms);
    BasFormT *form = &rt->forms[rt->formCount - 1];
    snprintf(form->name, BAS_MAX_CTRL_NAME, "%s", formName);
    win->onClose     = onFormClose;
    win->onResize    = onFormResize;
    win->onFocus     = onFormActivate;
    win->onBlur      = onFormDeactivate;
    form->window     = win;
    form->root       = root;
    form->contentBox = NULL;
    form->ctx        = rt->ctx;
    form->vm         = rt->vm;
    form->module     = rt->module;

    // Allocate per-form variable storage and run init code from module metadata
    if (rt->module && rt->module->formVarInfo) {
        for (int32_t j = 0; j < rt->module->formVarInfoCount; j++) {
            if (strcasecmp(rt->module->formVarInfo[j].formName, formName) == 0) {
                int32_t vc = rt->module->formVarInfo[j].varCount;

                if (vc > 0) {
                    form->formVars     = (BasValueT *)calloc(vc, sizeof(BasValueT));
                    form->formVarCount = vc;
                }

                // Execute per-form init block (DIM arrays, UDT init)
                int32_t initAddr = rt->module->formVarInfo[j].initCodeAddr;

                if (initAddr >= 0 && rt->vm) {
                    basVmSetCurrentForm(rt->vm, form);
                    basVmSetCurrentFormVars(rt->vm, form->formVars, form->formVarCount);
                    basVmCallSub(rt->vm, initAddr);
                    basVmSetCurrentForm(rt->vm, NULL);
                    basVmSetCurrentFormVars(rt->vm, NULL, 0);
                }

                break;
            }
        }
    }

    return form;
}


// ============================================================
// basFormRtLoadFrm
// ============================================================

BasFormT *basFormRtLoadFrm(BasFormRtT *rt, const char *source, int32_t sourceLen) {
    if (!rt || !source || sourceLen <= 0) {
        return NULL;
    }

    BasFormT    *form    = NULL;
    BasControlT *current = NULL;

    WidgetT *parentStack[MAX_FRM_NESTING];
    int32_t  nestDepth = 0;

    // Track Begin/End blocks: true = container (Form/Frame), false = control
    bool    isContainer[MAX_FRM_NESTING];
    int32_t blockDepth = 0;

    const char *pos = source;
    const char *end = source + sourceLen;

    while (pos < end) {
        const char *lineStart = pos;

        while (pos < end && *pos != '\n' && *pos != '\r') {
            pos++;
        }

        int32_t lineLen = (int32_t)(pos - lineStart);

        if (pos < end && *pos == '\r') {
            pos++;
        }

        if (pos < end && *pos == '\n') {
            pos++;
        }

        char line[MAX_FRM_LINE_LEN];

        if (lineLen >= MAX_FRM_LINE_LEN) {
            lineLen = MAX_FRM_LINE_LEN - 1;
        }

        memcpy(line, lineStart, lineLen);
        line[lineLen] = '\0';

        char *trimmed = line;

        while (*trimmed == ' ' || *trimmed == '\t') {
            trimmed++;
        }

        if (*trimmed == '\0' || *trimmed == '\'') {
            continue;
        }

        // "VERSION DVX x.xx" (native) or "VERSION x.xx" (VB import)
        if (strncasecmp(trimmed, "VERSION ", 8) == 0) {
            const char *ver = trimmed + 8;

            if (strncasecmp(ver, "DVX ", 4) != 0) {
                double vbVer = atof(ver);

                if (vbVer > 2.0) {
                    return NULL; // VB4+ form, not compatible
                }
            }

            continue;
        }

        // "Begin TypeName CtrlName"
        if (strncasecmp(trimmed, "Begin ", 6) == 0) {
            char *rest = trimmed + 6;
            char  typeName[BAS_MAX_CTRL_NAME];
            char  ctrlName[BAS_MAX_CTRL_NAME];

            int32_t ti = 0;

            while (*rest && *rest != ' ' && *rest != '\t' && ti < BAS_MAX_CTRL_NAME - 1) {
                typeName[ti++] = *rest++;
            }

            typeName[ti] = '\0';

            while (*rest == ' ' || *rest == '\t') {
                rest++;
            }

            int32_t ci = 0;

            while (*rest && *rest != ' ' && *rest != '\t' && *rest != '\r' && *rest != '\n' && ci < BAS_MAX_CTRL_NAME - 1) {
                ctrlName[ci++] = *rest++;
            }

            ctrlName[ci] = '\0';

            if (strcasecmp(typeName, "Form") == 0) {
                form = (BasFormT *)basFormRtLoadForm(rt, ctrlName);

                if (!form) {
                    return NULL;
                }

                // contentBox is created lazily (see below) after
                // form-level properties like Layout are parsed.
                nestDepth = 1;
                current   = NULL;

                if (blockDepth < MAX_FRM_NESTING) {
                    isContainer[blockDepth++] = true;
                }
            } else if (form && nestDepth > 0) {
                // Create the content box on first control if not yet done
                if (!form->contentBox && form->root) {
                    if (form->frmHBox) {
                        form->contentBox = wgtHBox(form->root);
                    } else {
                        form->contentBox = wgtVBox(form->root);
                    }

                    form->contentBox->weight = 100;
                    parentStack[0] = form->contentBox;
                }
                WidgetT *parent = parentStack[nestDepth - 1];

                const char *wgtTypeName = resolveTypeName(typeName);

                if (!wgtTypeName) {
                    continue;
                }

                WidgetT *widget = createWidget(wgtTypeName, parent);

                if (!widget) {
                    continue;
                }

                wgtSetName(widget, ctrlName);

                {
                    BasControlT ctrlEntry;
                    memset(&ctrlEntry, 0, sizeof(ctrlEntry));
                    snprintf(ctrlEntry.name, BAS_MAX_CTRL_NAME, "%s", ctrlName);
                    snprintf(ctrlEntry.typeName, BAS_MAX_CTRL_NAME, "%s", typeName);
                    ctrlEntry.index  = -1;
                    ctrlEntry.widget = widget;
                    ctrlEntry.form   = form;
                    ctrlEntry.iface  = wgtGetIface(wgtTypeName);
                    arrput(form->controls, ctrlEntry);
                    form->controlCount = (int32_t)arrlen(form->controls);

                    // Re-derive pointer after arrput (may realloc)
                    current = &form->controls[form->controlCount - 1];
                    widget->userData   = current;
                    widget->onClick     = onWidgetClick;
                    widget->onDblClick  = onWidgetDblClick;
                    widget->onChange     = onWidgetChange;
                    widget->onFocus     = onWidgetFocus;
                    widget->onBlur      = onWidgetBlur;
                    widget->onKeyPress  = onWidgetKeyPress;
                    widget->onKeyDown   = onWidgetKeyDown;
                    widget->onKeyUp     = onWidgetKeyUp;
                    widget->onMouseDown = onWidgetMouseDown;
                    widget->onMouseUp   = onWidgetMouseUp;
                    widget->onMouseMove = onWidgetMouseMove;
                    widget->onScroll    = onWidgetScroll;
                }

                // Track block type for End handling
                const WgtIfaceT *ctrlIface = wgtGetIface(wgtTypeName);
                bool isCtrlContainer = ctrlIface && ctrlIface->isContainer;

                if (isCtrlContainer && nestDepth < MAX_FRM_NESTING) {
                    parentStack[nestDepth++] = widget;

                    if (blockDepth < MAX_FRM_NESTING) {
                        isContainer[blockDepth++] = true;
                    }
                } else {
                    if (blockDepth < MAX_FRM_NESTING) {
                        isContainer[blockDepth++] = false;
                    }
                }
            }

            continue;
        }

        // "End"
        if (strcasecmp(trimmed, "End") == 0) {
            if (blockDepth > 0) {
                blockDepth--;

                // Only decrement parent nesting for containers (Form/Frame)
                if (isContainer[blockDepth] && nestDepth > 0) {
                    nestDepth--;
                }
            }

            current = NULL;
            continue;
        }

        // Property assignment: Key = Value
        char key[BAS_MAX_CTRL_NAME];
        char value[MAX_FRM_LINE_LEN];
        parseFrmLine(trimmed, key, value);

        if (key[0] == '\0' || !form) {
            continue;
        }

        if (current) {
            // Control array index is stored on the struct, not as a widget property
            if (strcasecmp(key, "Index") == 0) {
                current->index = atoi(value);
                continue;
            }

            BasValueT val;

            if (value[0] == '"') {
                int32_t vlen = (int32_t)strlen(value);

                if (vlen >= 2 && value[vlen - 1] == '"') {
                    value[vlen - 1] = '\0';
                }

                val = basValStringFromC(value + 1);
            } else {
                val = basValLong(atoi(value));
            }

            basFormRtSetProp(rt, current, key, val);
            basValRelease(&val);
        } else if (nestDepth > 0) {
            // Form-level property -- strip quotes from string values
            char *text = value;

            if (text[0] == '"') {
                text++;
                int32_t len = (int32_t)strlen(text);

                if (len > 0 && text[len - 1] == '"') {
                    text[len - 1] = '\0';
                }
            }

            if (strcasecmp(key, "Caption") == 0) {
                dvxSetTitle(rt->ctx, form->window, text);
            } else if (strcasecmp(key, "Width") == 0) {
                form->frmWidth = atoi(value);
            } else if (strcasecmp(key, "Height") == 0) {
                form->frmHeight = atoi(value);
            } else if (strcasecmp(key, "Left") == 0) {
                form->frmLeft = atoi(value);
            } else if (strcasecmp(key, "Top") == 0) {
                form->frmTop = atoi(value);
            } else if (strcasecmp(key, "Resizable") == 0) {
                form->frmResizable = (strcasecmp(text, "True") == 0);
                form->frmHasResizable = true;
            } else if (strcasecmp(key, "Centered") == 0) {
                form->frmCentered = (strcasecmp(text, "True") == 0);
            } else if (strcasecmp(key, "AutoSize") == 0) {
                form->frmAutoSize = (strcasecmp(text, "True") == 0);
            } else if (strcasecmp(key, "Layout") == 0) {
                if (strcasecmp(text, "HBox") == 0) {
                    form->frmHBox = true;
                }
            }
        }
    }

    // Apply accumulated form-level properties
    if (form) {
        // Ensure content box exists even if form has no controls
        if (!form->contentBox && form->root) {
            if (form->frmHBox) {
                form->contentBox = wgtHBox(form->root);
            } else {
                form->contentBox = wgtVBox(form->root);
            }

            form->contentBox->weight = 100;
        }

        // Set resizable flag
        if (form->frmHasResizable) {
            form->window->resizable = form->frmResizable;
        }

        // Size and position the window
        if (form->frmAutoSize) {
            dvxFitWindow(rt->ctx, form->window);
        } else if (form->frmWidth > 0 && form->frmHeight > 0) {
            dvxResizeWindow(rt->ctx, form->window, form->frmWidth, form->frmHeight);
        } else {
            dvxFitWindow(rt->ctx, form->window);
        }

        // Position: centered or explicit left/top
        if (form->frmCentered) {
            int32_t scrW = rt->ctx->display.width;
            int32_t scrH = rt->ctx->display.height;
            form->window->x = (scrW - form->window->w) / 2;
            form->window->y = (scrH - form->window->h) / 2;
        } else if (form->frmLeft > 0 || form->frmTop > 0) {
            form->window->x = form->frmLeft;
            form->window->y = form->frmTop;
        }
        // Re-wire widget->userData pointers now that the controls array
        // is finalized. arrput may have reallocated during loading, so
        // any userData set during parsing could be stale.
        for (int32_t i = 0; i < form->controlCount; i++) {
            if (form->controls[i].widget) {
                form->controls[i].widget->userData = &form->controls[i];
            }
        }
    }

    // Cache the .frm source for reload after unload
    if (form) {
        bool cached = false;

        for (int32_t i = 0; i < rt->frmCacheCount; i++) {
            if (strcasecmp(rt->frmCache[i].formName, form->name) == 0) {
                cached = true;
                break;
            }
        }

        if (!cached) {
            BasFrmCacheT entry;
            memset(&entry, 0, sizeof(entry));
            snprintf(entry.formName, BAS_MAX_CTRL_NAME, "%s", form->name);
            entry.frmSource    = (char *)malloc(sourceLen + 1);
            entry.frmSourceLen = sourceLen;

            if (entry.frmSource) {
                memcpy(entry.frmSource, source, sourceLen);
                entry.frmSource[sourceLen] = '\0';
            }

            arrput(rt->frmCache, entry);
            rt->frmCacheCount = (int32_t)arrlen(rt->frmCache);
        }
    }

    // Fire the Load event now that the form and controls are ready
    if (form) {
        basFormRtFireEvent(rt, form, form->name, "Load");
    }

    return form;
}


// ============================================================
// basFormRtMsgBox
// ============================================================

int32_t basFormRtMsgBox(void *ctx, const char *message, int32_t flags) {
    BasFormRtT *rt = (BasFormRtT *)ctx;

    return dvxMessageBox(rt->ctx, "DVX BASIC", message, flags);
}


// ============================================================
// basFormRtSetProp
// ============================================================

void basFormRtSetProp(void *ctx, void *ctrlRef, const char *propName, BasValueT value) {
    (void)ctx;
    BasControlT *ctrl = (BasControlT *)ctrlRef;

    if (!ctrl || !ctrl->widget) {
        return;
    }

    // Common properties
    if (setCommonProp(ctrl, propName, value)) {
        return;
    }

    // "Caption" and "Text" map to wgtSetText for all widgets.
    // Copy to persistent buffer since some widgets (Button, Label)
    // store the text pointer without copying.
    if (strcasecmp(propName, "Caption") == 0 || strcasecmp(propName, "Text") == 0) {
        BasStringT *s = basValFormatString(value);
        snprintf(ctrl->textBuf, BAS_MAX_TEXT_BUF, "%s", s->data);
        basStringUnref(s);
        wgtSetText(ctrl->widget, ctrl->textBuf);
        return;
    }

    // Interface descriptor properties
    if (ctrl->iface) {
        if (setIfaceProp(ctrl->iface, ctrl->widget, propName, value)) {
            return;
        }
    }
}


// ============================================================
// basFormRtShowForm
// ============================================================

void basFormRtShowForm(void *ctx, void *formRef, bool modal) {
    BasFormRtT *rt   = (BasFormRtT *)ctx;
    BasFormT   *form = (BasFormT *)formRef;

    if (!form || !form->window) {
        return;
    }

    dvxShowWindow(rt->ctx, form->window);
    dvxRaiseWindow(rt->ctx, form->window);

    if (form->frmAutoSize) {
        dvxFitWindow(rt->ctx, form->window);
    }

    if (modal) {
        rt->ctx->modalWindow = form->window;
    }
}


// ============================================================
// basFormRtUnloadForm
// ============================================================

void basFormRtUnloadForm(void *ctx, void *formRef) {
    BasFormRtT *rt   = (BasFormRtT *)ctx;
    BasFormT   *form = (BasFormT *)formRef;

    if (!form) {
        return;
    }

    basFormRtFireEvent(rt, form, form->name, "Unload");

    // Release per-form variables
    if (form->formVars) {
        for (int32_t i = 0; i < form->formVarCount; i++) {
            basValRelease(&form->formVars[i]);
        }

        free(form->formVars);
        form->formVars     = NULL;
        form->formVarCount = 0;
    }

    for (int32_t i = 0; i < form->controlCount; i++) {
        freeListBoxItems(&form->controls[i]);
    }

    if (form->window) {
        if (rt->ctx->modalWindow == form->window) {
            rt->ctx->modalWindow = NULL;
        }

        dvxDestroyWindow(rt->ctx, form->window);
        form->window     = NULL;
        form->root       = NULL;
        form->contentBox = NULL;
    }

    int32_t idx = (int32_t)(form - rt->forms);

    if (idx >= 0 && idx < rt->formCount) {
        rt->formCount--;

        if (idx < rt->formCount) {
            rt->forms[idx] = rt->forms[rt->formCount];
        }

        memset(&rt->forms[rt->formCount], 0, sizeof(BasFormT));
    }
}


// ============================================================
// callCommonMethod
// ============================================================

static BasValueT callCommonMethod(BasControlT *ctrl, const char *methodName, BasValueT *args, int32_t argc) {
    (void)args;
    (void)argc;

    if (strcasecmp(methodName, "SetFocus") == 0) {
        wgtSetFocused(ctrl->widget);
        return zeroValue();
    }

    if (strcasecmp(methodName, "Refresh") == 0) {
        wgtInvalidatePaint(ctrl->widget);
        return zeroValue();
    }

    return zeroValue();
}


// ============================================================
// callListBoxMethod
// ============================================================
//
// Handles AddItem/RemoveItem/Clear/List for any widget that
// supports item lists (listbox, combobox, dropdown).

static BasValueT callListBoxMethod(BasControlT *ctrl, const char *methodName, BasValueT *args, int32_t argc) {
    if (strcasecmp(methodName, "AddItem") == 0) {
        if (argc >= 1 && args[0].type == BAS_TYPE_STRING && args[0].strVal) {
            ListBoxItemsT *lb = getListBoxItems(ctrl);

            if (lb && lb->count < MAX_LISTBOX_ITEMS) {
                lb->items[lb->count] = strdup(args[0].strVal->data);
                lb->count++;
                rebuildListBoxItems(ctrl);
            }
        }

        return zeroValue();
    }

    if (strcasecmp(methodName, "RemoveItem") == 0) {
        if (argc >= 1) {
            int32_t idx = (int32_t)basValToNumber(args[0]);
            ListBoxItemsT *lb = getListBoxItems(ctrl);

            if (lb && idx >= 0 && idx < lb->count) {
                free(lb->items[idx]);

                for (int32_t i = idx; i < lb->count - 1; i++) {
                    lb->items[i] = lb->items[i + 1];
                }

                lb->count--;
                rebuildListBoxItems(ctrl);
            }
        }

        return zeroValue();
    }

    if (strcasecmp(methodName, "Clear") == 0) {
        ListBoxItemsT *lb = getListBoxItems(ctrl);

        if (lb) {
            for (int32_t i = 0; i < lb->count; i++) {
                free(lb->items[i]);
            }

            lb->count = 0;
            rebuildListBoxItems(ctrl);
        }

        return zeroValue();
    }

    if (strcasecmp(methodName, "List") == 0) {
        if (argc >= 1) {
            int32_t idx = (int32_t)basValToNumber(args[0]);
            ListBoxItemsT *lb = getListBoxItems(ctrl);

            if (lb && idx >= 0 && idx < lb->count) {
                return basValStringFromC(lb->items[idx]);
            }
        }

        return basValStringFromC("");
    }

    return zeroValue();
}


// ============================================================
// createWidget
// ============================================================
//
// Create a DVX widget by type name using its registered API.
// The API's create function signature varies by widget type, so
// we call with sensible defaults for each creation pattern.

static WidgetT *createWidget(const char *wgtTypeName, WidgetT *parent) {
    const void *api = wgtGetApi(wgtTypeName);

    if (!api) {
        return NULL;
    }

    // Determine creation signature from the widget interface descriptor.
    const WgtIfaceT *iface = wgtGetIface(wgtTypeName);
    uint8_t sig = iface ? iface->createSig : WGT_CREATE_PARENT;

    typedef WidgetT *(*CreateParentFnT)(WidgetT *);
    typedef WidgetT *(*CreateParentTextFnT)(WidgetT *, const char *);
    typedef WidgetT *(*CreateParentIntFnT)(WidgetT *, int32_t);
    typedef WidgetT *(*CreateParentIntIntFnT)(WidgetT *, int32_t, int32_t);
    typedef WidgetT *(*CreateParentIntIntIntFnT)(WidgetT *, int32_t, int32_t, int32_t);
    typedef WidgetT *(*CreateParentIntBoolFnT)(WidgetT *, int32_t, bool);
    typedef WidgetT *(*CreateParentBoolFnT)(WidgetT *, bool);

    switch (sig) {
        case WGT_CREATE_PARENT_TEXT: {
            CreateParentTextFnT fn = *(CreateParentTextFnT *)api;
            return fn(parent, "");
        }
        case WGT_CREATE_PARENT_INT: {
            CreateParentIntFnT fn = *(CreateParentIntFnT *)api;
            return fn(parent, iface->createArgs[0]);
        }
        case WGT_CREATE_PARENT_INT_INT: {
            CreateParentIntIntFnT fn = *(CreateParentIntIntFnT *)api;
            return fn(parent, iface->createArgs[0], iface->createArgs[1]);
        }
        case WGT_CREATE_PARENT_INT_INT_INT: {
            CreateParentIntIntIntFnT fn = *(CreateParentIntIntIntFnT *)api;
            return fn(parent, iface->createArgs[0], iface->createArgs[1], iface->createArgs[2]);
        }
        case WGT_CREATE_PARENT_INT_BOOL: {
            CreateParentIntBoolFnT fn = *(CreateParentIntBoolFnT *)api;
            return fn(parent, iface->createArgs[0], (bool)iface->createArgs[1]);
        }
        case WGT_CREATE_PARENT_BOOL: {
            CreateParentBoolFnT fn = *(CreateParentBoolFnT *)api;
            return fn(parent, (bool)iface->createArgs[0]);
        }
        case WGT_CREATE_PARENT_DATA:
            return NULL;
        default: {
            CreateParentFnT fn = *(CreateParentFnT *)api;
            return fn(parent);
        }
    }
}


// ============================================================
// freeListBoxItems
// ============================================================

static void freeListBoxItems(BasControlT *ctrl) {
    for (int32_t i = 0; i < sAuxDataCount; i++) {
        if (sAuxData[i].ctrl == ctrl) {
            ListBoxItemsT *lb = sAuxData[i].items;

            if (lb) {
                for (int32_t j = 0; j < lb->count; j++) {
                    free(lb->items[j]);
                }

                free(lb);
            }

            sAuxDataCount--;

            if (i < sAuxDataCount) {
                sAuxData[i] = sAuxData[sAuxDataCount];
            }

            memset(&sAuxData[sAuxDataCount], 0, sizeof(AuxDataEntryT));
            return;
        }
    }
}


// ============================================================
// getCommonProp
// ============================================================

static BasValueT getCommonProp(BasControlT *ctrl, const char *propName, bool *handled) {
    *handled = true;

    if (strcasecmp(propName, "Name") == 0) {
        return basValStringFromC(ctrl->name);
    }

    if (strcasecmp(propName, "Left") == 0) {
        return basValLong(ctrl->widget->x);
    }

    if (strcasecmp(propName, "Top") == 0) {
        return basValLong(ctrl->widget->y);
    }

    if (strcasecmp(propName, "Width") == 0 || strcasecmp(propName, "MinWidth") == 0) {
        return basValLong(ctrl->widget->w);
    }

    if (strcasecmp(propName, "Height") == 0 || strcasecmp(propName, "MinHeight") == 0) {
        return basValLong(ctrl->widget->h);
    }

    if (strcasecmp(propName, "MaxWidth") == 0) {
        return basValLong(ctrl->widget->maxW ? (ctrl->widget->maxW & WGT_SIZE_VAL_MASK) : 0);
    }

    if (strcasecmp(propName, "MaxHeight") == 0) {
        return basValLong(ctrl->widget->maxH ? (ctrl->widget->maxH & WGT_SIZE_VAL_MASK) : 0);
    }

    if (strcasecmp(propName, "Weight") == 0) {
        return basValLong(ctrl->widget->weight);
    }

    if (strcasecmp(propName, "Visible") == 0) {
        return basValBool(ctrl->widget->visible);
    }

    if (strcasecmp(propName, "Enabled") == 0) {
        return basValBool(ctrl->widget->enabled);
    }

    if (strcasecmp(propName, "TabIndex") == 0) {
        return basValLong(0);
    }

    if (strcasecmp(propName, "BackColor") == 0) {
        return basValLong((int32_t)ctrl->widget->bgColor);
    }

    if (strcasecmp(propName, "ForeColor") == 0) {
        return basValLong((int32_t)ctrl->widget->fgColor);
    }

    *handled = false;
    return zeroValue();
}


// ============================================================
// getIfaceProp
// ============================================================
//
// Look up a property in the interface descriptor and call its
// getter, marshaling the return value to BasValueT.

static BasValueT getIfaceProp(const WgtIfaceT *iface, WidgetT *w, const char *propName, bool *handled) {
    *handled = false;

    for (int32_t i = 0; i < iface->propCount; i++) {
        if (strcasecmp(iface->props[i].name, propName) != 0) {
            continue;
        }

        *handled = true;
        const WgtPropDescT *p = &iface->props[i];

        if (!p->getFn) {
            return zeroValue();
        }

        switch (p->type) {
            case WGT_IFACE_STRING: {
                const char *s = ((const char *(*)(WidgetT *))p->getFn)(w);
                return basValStringFromC(s ? s : "");
            }

            case WGT_IFACE_INT: {
                int32_t v = ((int32_t (*)(const WidgetT *))p->getFn)(w);
                return basValLong(v);
            }

            case WGT_IFACE_BOOL: {
                bool v = ((bool (*)(const WidgetT *))p->getFn)(w);
                return basValBool(v);
            }

            case WGT_IFACE_FLOAT: {
                float v = ((float (*)(const WidgetT *))p->getFn)(w);
                return basValSingle(v);
            }
        }

        return zeroValue();
    }

    return zeroValue();
}


// ============================================================
// getListBoxItems
// ============================================================

static ListBoxItemsT *getListBoxItems(BasControlT *ctrl) {
    for (int32_t i = 0; i < sAuxDataCount; i++) {
        if (sAuxData[i].ctrl == ctrl) {
            return sAuxData[i].items;
        }
    }

    if (sAuxDataCount >= MAX_AUX_DATA) {
        return NULL;
    }

    ListBoxItemsT *lb = (ListBoxItemsT *)calloc(1, sizeof(ListBoxItemsT));

    if (!lb) {
        return NULL;
    }

    sAuxData[sAuxDataCount].ctrl  = ctrl;
    sAuxData[sAuxDataCount].items = lb;
    sAuxDataCount++;

    return lb;
}


// ============================================================
// onFormClose
// ============================================================
//
// Called when the user closes a BASIC form's window. Fires the
// Form_Unload event and stops the VM so the program exits.

static void onFormClose(WindowT *win) {
    if (!sFormRt) {
        return;
    }

    for (int32_t i = 0; i < sFormRt->formCount; i++) {
        BasFormT *form = &sFormRt->forms[i];

        if (form->window == win) {
            // QueryUnload: if Cancel is set, abort the close
            if (basFormRtFireEventWithCancel(sFormRt, form, form->name, "QueryUnload")) {
                return;
            }

            basFormRtFireEvent(sFormRt, form, form->name, "Unload");

            // Release per-form variables
            if (form->formVars) {
                for (int32_t j = 0; j < form->formVarCount; j++) {
                    basValRelease(&form->formVars[j]);
                }

                free(form->formVars);
                form->formVars     = NULL;
                form->formVarCount = 0;
            }

            // Free control resources
            for (int32_t j = 0; j < form->controlCount; j++) {
                freeListBoxItems(&form->controls[j]);
            }

            // Destroy the window
            if (sFormRt->ctx->modalWindow == win) {
                sFormRt->ctx->modalWindow = NULL;
            }

            dvxDestroyWindow(sFormRt->ctx, win);
            form->window     = NULL;
            form->root       = NULL;
            form->contentBox = NULL;

            // Remove from form list
            sFormRt->formCount--;

            if (i < sFormRt->formCount) {
                sFormRt->forms[i] = sFormRt->forms[sFormRt->formCount];
            }

            memset(&sFormRt->forms[sFormRt->formCount], 0, sizeof(BasFormT));

            // If no forms left, stop the VM
            if (sFormRt->formCount == 0 && sFormRt->vm) {
                sFormRt->vm->running = false;
            }

            return;
        }
    }
}


// ============================================================
// onFormResize
// ============================================================

static void onFormResize(WindowT *win, int32_t newW, int32_t newH) {
    (void)newW;
    (void)newH;

    if (!sFormRt) {
        return;
    }

    for (int32_t i = 0; i < sFormRt->formCount; i++) {
        BasFormT *form = &sFormRt->forms[i];

        if (form->window == win) {
            basFormRtFireEvent(sFormRt, form, form->name, "Resize");
            return;
        }
    }
}


// ============================================================
// onFormActivate / onFormDeactivate
// ============================================================

static void onFormActivate(WindowT *win) {
    if (!sFormRt) {
        return;
    }

    for (int32_t i = 0; i < sFormRt->formCount; i++) {
        BasFormT *form = &sFormRt->forms[i];

        if (form->window == win) {
            basFormRtFireEvent(sFormRt, form, form->name, "Activate");
            return;
        }
    }
}


static void onFormDeactivate(WindowT *win) {
    if (!sFormRt) {
        return;
    }

    for (int32_t i = 0; i < sFormRt->formCount; i++) {
        BasFormT *form = &sFormRt->forms[i];

        if (form->window == win) {
            basFormRtFireEvent(sFormRt, form, form->name, "Deactivate");
            return;
        }
    }
}


// ============================================================
// fireCtrlEvent -- fire event, prepending Index for array members
// ============================================================

#define MAX_FIRE_ARGS 8

static void fireCtrlEvent(BasFormRtT *rt, BasControlT *ctrl, const char *eventName, const BasValueT *args, int32_t argCount) {
    if (ctrl->index >= 0) {
        // Control array element: prepend Index as first argument
        BasValueT allArgs[MAX_FIRE_ARGS];
        allArgs[0] = basValLong(ctrl->index);

        for (int32_t i = 0; i < argCount && i < MAX_FIRE_ARGS - 1; i++) {
            allArgs[i + 1] = args[i];
        }

        basFormRtFireEventArgs(rt, ctrl->form, ctrl->name, eventName, allArgs, argCount + 1);
    } else if (argCount > 0 && args) {
        basFormRtFireEventArgs(rt, ctrl->form, ctrl->name, eventName, args, argCount);
    } else {
        basFormRtFireEvent(rt, ctrl->form, ctrl->name, eventName);
    }
}


// ============================================================
// Widget event callbacks
// ============================================================

static void onWidgetBlur(WidgetT *w) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        fireCtrlEvent(rt, ctrl, "LostFocus", NULL, 0);
    }
}


static void onWidgetChange(WidgetT *w) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        // Timer widgets fire "Timer" event, everything else fires "Change"
        const char *evtName = (strcasecmp(ctrl->typeName, "Timer") == 0) ? "Timer" : "Change";
        fireCtrlEvent(rt, ctrl, evtName, NULL, 0);
    }
}


static void onWidgetClick(WidgetT *w) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        fireCtrlEvent(rt, ctrl, "Click", NULL, 0);
    }
}


static void onWidgetDblClick(WidgetT *w) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        fireCtrlEvent(rt, ctrl, "DblClick", NULL, 0);
    }
}


static void onWidgetFocus(WidgetT *w) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        fireCtrlEvent(rt, ctrl, "GotFocus", NULL, 0);
    }
}


static void onWidgetKeyPress(WidgetT *w, int32_t keyAscii) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[1];
        args[0] = basValLong(keyAscii);
        fireCtrlEvent(rt, ctrl, "KeyPress", args, 1);
    }
}


static void onWidgetKeyDown(WidgetT *w, int32_t keyCode, int32_t shift) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[2];
        args[0] = basValLong(keyCode);
        args[1] = basValLong(shift);
        fireCtrlEvent(rt, ctrl, "KeyDown", args, 2);
    }
}


static void onWidgetKeyUp(WidgetT *w, int32_t keyCode, int32_t shift) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[2];
        args[0] = basValLong(keyCode);
        args[1] = basValLong(shift);
        fireCtrlEvent(rt, ctrl, "KeyUp", args, 2);
    }
}


static void onWidgetMouseDown(WidgetT *w, int32_t button, int32_t x, int32_t y) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[3];
        args[0] = basValLong(button);
        args[1] = basValLong(x);
        args[2] = basValLong(y);
        fireCtrlEvent(rt, ctrl, "MouseDown", args, 3);
    }
}


static void onWidgetMouseUp(WidgetT *w, int32_t button, int32_t x, int32_t y) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[3];
        args[0] = basValLong(button);
        args[1] = basValLong(x);
        args[2] = basValLong(y);
        fireCtrlEvent(rt, ctrl, "MouseUp", args, 3);
    }
}


static void onWidgetMouseMove(WidgetT *w, int32_t button, int32_t x, int32_t y) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[3];
        args[0] = basValLong(button);
        args[1] = basValLong(x);
        args[2] = basValLong(y);
        fireCtrlEvent(rt, ctrl, "MouseMove", args, 3);
    }
}


static void onWidgetScroll(WidgetT *w, int32_t delta) {
    BasControlT *ctrl = (BasControlT *)w->userData;

    if (!ctrl || !ctrl->form || !ctrl->form->vm) {
        return;
    }

    BasFormRtT *rt = (BasFormRtT *)ctrl->form->vm->ui.ctx;

    if (rt) {
        BasValueT args[1];
        args[0] = basValLong(delta);
        fireCtrlEvent(rt, ctrl, "Scroll", args, 1);
    }
}


// ============================================================
// parseFrmLine
// ============================================================

static void parseFrmLine(const char *line, char *key, char *value) {
    key[0]   = '\0';
    value[0] = '\0';

    while (*line == ' ' || *line == '\t') {
        line++;
    }

    int32_t ki = 0;

    while (*line && *line != '=' && *line != ' ' && *line != '\t' && ki < BAS_MAX_CTRL_NAME - 1) {
        key[ki++] = *line++;
    }

    key[ki] = '\0';

    while (*line == ' ' || *line == '\t') {
        line++;
    }

    if (*line == '=') {
        line++;
    }

    while (*line == ' ' || *line == '\t') {
        line++;
    }

    int32_t vi = 0;

    while (*line && *line != '\r' && *line != '\n' && vi < MAX_FRM_LINE_LEN - 1) {
        value[vi++] = *line++;
    }

    value[vi] = '\0';

    while (vi > 0 && (value[vi - 1] == ' ' || value[vi - 1] == '\t')) {
        value[--vi] = '\0';
    }
}


// ============================================================
// rebuildListBoxItems
// ============================================================

static void rebuildListBoxItems(BasControlT *ctrl) {
    ListBoxItemsT *lb = getListBoxItems(ctrl);

    if (!lb) {
        return;
    }

    // Use the widget's setItems API if available
    const WgtIfaceT *iface = ctrl->iface;

    if (!iface) {
        return;
    }

    // Look for a setItems-like method by checking the widget API directly
    const void *api = wgtGetApi("listbox");

    if (api) {
        // ListBoxApiT has setItems as the second function pointer
        typedef struct {
            void *create;
            void (*setItems)(WidgetT *, const char **, int32_t);
        } SetItemsPatternT;
        const SetItemsPatternT *p = (const SetItemsPatternT *)api;
        p->setItems(ctrl->widget, (const char **)lb->items, lb->count);
        return;
    }

    // Fallback: try combobox or dropdown API
    api = wgtGetApi("combobox");

    if (api) {
        typedef struct {
            void *create;
            void (*setItems)(WidgetT *, const char **, int32_t);
        } SetItemsPatternT;
        const SetItemsPatternT *p = (const SetItemsPatternT *)api;
        p->setItems(ctrl->widget, (const char **)lb->items, lb->count);
        return;
    }

    api = wgtGetApi("dropdown");

    if (api) {
        typedef struct {
            void *create;
            void (*setItems)(WidgetT *, const char **, int32_t);
        } SetItemsPatternT;
        const SetItemsPatternT *p = (const SetItemsPatternT *)api;
        p->setItems(ctrl->widget, (const char **)lb->items, lb->count);
    }
}


// ============================================================
// resolveTypeName
// ============================================================
//
// Resolve a type name (VB-style or DVX widget name) to a DVX
// widget type name. First tries wgtFindByBasName for VB names
// like "CommandButton", then falls back to direct widget name.

static const char *resolveTypeName(const char *typeName) {
    // Try VB name first (e.g. "CommandButton" -> "button")
    const char *wgtName = wgtFindByBasName(typeName);

    if (wgtName) {
        return wgtName;
    }

    // Try as direct widget type name (e.g. "button", "slider")
    if (wgtGetApi(typeName)) {
        return typeName;
    }

    return NULL;
}


// ============================================================
// setCommonProp
// ============================================================

static bool setCommonProp(BasControlT *ctrl, const char *propName, BasValueT value) {
    if (strcasecmp(propName, "Left") == 0) {
        ctrl->widget->x = (int32_t)basValToNumber(value);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "Top") == 0) {
        ctrl->widget->y = (int32_t)basValToNumber(value);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "Width") == 0 || strcasecmp(propName, "MinWidth") == 0) {
        int32_t w = (int32_t)basValToNumber(value);
        ctrl->widget->minW = wgtPixels(w);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "Height") == 0 || strcasecmp(propName, "MinHeight") == 0) {
        int32_t h = (int32_t)basValToNumber(value);
        ctrl->widget->minH = wgtPixels(h);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "MaxWidth") == 0) {
        int32_t mw = (int32_t)basValToNumber(value);
        ctrl->widget->maxW = mw > 0 ? wgtPixels(mw) : 0;
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "MaxHeight") == 0) {
        int32_t mh = (int32_t)basValToNumber(value);
        ctrl->widget->maxH = mh > 0 ? wgtPixels(mh) : 0;
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "Weight") == 0) {
        ctrl->widget->weight = (int32_t)basValToNumber(value);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "Visible") == 0) {
        wgtSetVisible(ctrl->widget, basValIsTruthy(value));
        return true;
    }

    if (strcasecmp(propName, "Enabled") == 0) {
        wgtSetEnabled(ctrl->widget, basValIsTruthy(value));
        return true;
    }

    if (strcasecmp(propName, "TabIndex") == 0) {
        return true;
    }

    if (strcasecmp(propName, "BackColor") == 0) {
        ctrl->widget->bgColor = (uint32_t)(int32_t)basValToNumber(value);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    if (strcasecmp(propName, "ForeColor") == 0) {
        ctrl->widget->fgColor = (uint32_t)(int32_t)basValToNumber(value);
        wgtInvalidate(ctrl->widget);
        return true;
    }

    return false;
}


// ============================================================
// setIfaceProp
// ============================================================
//
// Look up a property in the interface descriptor and call its
// setter, marshaling the BasValueT to the native type.

static bool setIfaceProp(const WgtIfaceT *iface, WidgetT *w, const char *propName, BasValueT value) {
    for (int32_t i = 0; i < iface->propCount; i++) {
        if (strcasecmp(iface->props[i].name, propName) != 0) {
            continue;
        }

        const WgtPropDescT *p = &iface->props[i];

        if (!p->setFn) {
            return true; // read-only, but recognized
        }

        switch (p->type) {
            case WGT_IFACE_STRING: {
                BasStringT *s = basValFormatString(value);
                ((void (*)(WidgetT *, const char *))p->setFn)(w, s->data);
                basStringUnref(s);
                break;
            }

            case WGT_IFACE_ENUM:
                if (p->enumNames && value.type == BAS_TYPE_STRING && value.strVal) {
                    // Map name to index
                    int32_t enumVal = 0;

                    for (int32_t en = 0; p->enumNames[en]; en++) {
                        if (strcasecmp(p->enumNames[en], value.strVal->data) == 0) {
                            enumVal = en;
                            break;
                        }
                    }

                    ((void (*)(WidgetT *, int32_t))p->setFn)(w, enumVal);
                } else {
                    ((void (*)(WidgetT *, int32_t))p->setFn)(w, (int32_t)basValToNumber(value));
                }
                break;

            case WGT_IFACE_INT:
                ((void (*)(WidgetT *, int32_t))p->setFn)(w, (int32_t)basValToNumber(value));
                break;

            case WGT_IFACE_BOOL:
                ((void (*)(WidgetT *, bool))p->setFn)(w, basValIsTruthy(value));
                break;

            case WGT_IFACE_FLOAT:
                ((void (*)(WidgetT *, float))p->setFn)(w, (float)basValToNumber(value));
                break;
        }

        return true;
    }

    return false;
}


// ============================================================
// zeroValue
// ============================================================

static BasValueT zeroValue(void) {
    BasValueT v;
    memset(&v, 0, sizeof(v));
    return v;
}