// dvxWidget.h — Widget system for DV/X GUI
#ifndef DVX_WIDGET_H
#define DVX_WIDGET_H

#include "dvxTypes.h"

// Forward declaration
struct AppContextT;

// ============================================================
// Size specifications
// ============================================================
//
// Tagged size values encode both a unit type and a numeric value.
// Use wgtPixels(), wgtChars(), or wgtPercent() to create them.
// A raw 0 means "auto" (use the widget's natural size).

#define WGT_SIZE_TYPE_MASK  0xC0000000
#define WGT_SIZE_VAL_MASK   0x3FFFFFFF
#define WGT_SIZE_PIXELS     0x00000000
#define WGT_SIZE_CHARS      0x40000000
#define WGT_SIZE_PERCENT    0x80000000

static inline int32_t wgtPixels(int32_t v) {
    return (int32_t)(WGT_SIZE_PIXELS | ((uint32_t)v & WGT_SIZE_VAL_MASK));
}

static inline int32_t wgtChars(int32_t v) {
    return (int32_t)(WGT_SIZE_CHARS | ((uint32_t)v & WGT_SIZE_VAL_MASK));
}

static inline int32_t wgtPercent(int32_t v) {
    return (int32_t)(WGT_SIZE_PERCENT | ((uint32_t)v & WGT_SIZE_VAL_MASK));
}

// ============================================================
// Widget type enum
// ============================================================

typedef enum {
    WidgetVBoxE,
    WidgetHBoxE,
    WidgetLabelE,
    WidgetButtonE,
    WidgetCheckboxE,
    WidgetRadioGroupE,
    WidgetRadioE,
    WidgetTextInputE,
    WidgetTextAreaE,
    WidgetListBoxE,
    WidgetSpacerE,
    WidgetSeparatorE,
    WidgetFrameE
} WidgetTypeE;

// ============================================================
// Alignment enum
// ============================================================
//
// Controls main-axis alignment of children within a container.
// HBox: AlignStartE=left, AlignCenterE=center, AlignEndE=right
// VBox: AlignStartE=top,  AlignCenterE=center, AlignEndE=bottom

typedef enum {
    AlignStartE,
    AlignCenterE,
    AlignEndE
} WidgetAlignE;

// ============================================================
// Widget structure
// ============================================================

#define MAX_WIDGET_NAME 32

typedef struct WidgetT {
    WidgetTypeE      type;
    char             name[MAX_WIDGET_NAME];

    // Tree linkage
    struct WidgetT  *parent;
    struct WidgetT  *firstChild;
    struct WidgetT  *lastChild;
    struct WidgetT  *nextSibling;
    WindowT         *window;

    // Computed geometry (relative to window content area)
    int32_t          x;
    int32_t          y;
    int32_t          w;
    int32_t          h;

    // Computed minimum size (set by layout engine)
    int32_t          calcMinW;
    int32_t          calcMinH;

    // Size hints (tagged: wgtPixels/wgtChars/wgtPercent, 0 = auto)
    int32_t          minW;
    int32_t          minH;
    int32_t          maxW;       // 0 = no limit
    int32_t          maxH;
    int32_t          prefW;      // preferred size, 0 = auto
    int32_t          prefH;
    int32_t          weight;     // extra-space distribution (0 = fixed, 100 = normal)

    // Container properties
    WidgetAlignE     align;      // main-axis alignment for children
    int32_t          spacing;    // tagged size for spacing between children (0 = default)
    int32_t          padding;    // tagged size for internal padding (0 = default)

    // State
    bool             visible;
    bool             enabled;
    bool             focused;

    // User data and callbacks
    void            *userData;
    void           (*onClick)(struct WidgetT *w);
    void           (*onChange)(struct WidgetT *w);

    // Type-specific data
    union {
        struct {
            const char *text;
        } label;

        struct {
            const char *text;
            bool        pressed;
        } button;

        struct {
            const char *text;
            bool        checked;
        } checkbox;

        struct {
            int32_t selectedIdx;
        } radioGroup;

        struct {
            const char *text;
            int32_t     index;
        } radio;

        struct {
            char    *buf;
            int32_t  bufSize;
            int32_t  len;
            int32_t  cursorPos;
            int32_t  scrollOff;
        } textInput;

        struct {
            char    *buf;
            int32_t  bufSize;
            int32_t  len;
            int32_t  cursorRow;
            int32_t  cursorCol;
            int32_t  scrollRow;
        } textArea;

        struct {
            const char **items;
            int32_t      itemCount;
            int32_t      selectedIdx;
            int32_t      scrollPos;
        } listBox;

        struct {
            bool vertical;
        } separator;

        struct {
            const char *title;
        } frame;
    } as;
} WidgetT;

// ============================================================
// Window integration
// ============================================================

// Set up a window for widgets. Returns the root container (VBox).
// Automatically installs onPaint, onMouse, onKey, and onResize handlers.
WidgetT *wgtInitWindow(struct AppContextT *ctx, WindowT *win);

// ============================================================
// Container creation
// ============================================================

WidgetT *wgtVBox(WidgetT *parent);
WidgetT *wgtHBox(WidgetT *parent);
WidgetT *wgtFrame(WidgetT *parent, const char *title);

// ============================================================
// Basic widgets
// ============================================================

WidgetT *wgtLabel(WidgetT *parent, const char *text);
WidgetT *wgtButton(WidgetT *parent, const char *text);
WidgetT *wgtCheckbox(WidgetT *parent, const char *text);
WidgetT *wgtTextInput(WidgetT *parent, int32_t maxLen);

// ============================================================
// Radio buttons
// ============================================================

WidgetT *wgtRadioGroup(WidgetT *parent);
WidgetT *wgtRadio(WidgetT *parent, const char *text);

// ============================================================
// Spacing and visual dividers
// ============================================================

WidgetT *wgtSpacer(WidgetT *parent);
WidgetT *wgtHSeparator(WidgetT *parent);
WidgetT *wgtVSeparator(WidgetT *parent);

// ============================================================
// Complex widgets
// ============================================================

WidgetT *wgtListBox(WidgetT *parent);
WidgetT *wgtTextArea(WidgetT *parent, int32_t maxLen);

// ============================================================
// Operations
// ============================================================

// Mark a widget (and ancestors) for relayout and repaint
void wgtInvalidate(WidgetT *w);

// Set/get widget text (label, button, textInput, etc.)
void wgtSetText(WidgetT *w, const char *text);
const char *wgtGetText(const WidgetT *w);

// Enable/disable a widget
void wgtSetEnabled(WidgetT *w, bool enabled);

// Show/hide a widget
void wgtSetVisible(WidgetT *w, bool visible);

// Find a widget by name (searches the subtree rooted at root)
WidgetT *wgtFind(WidgetT *root, const char *name);

// Destroy a widget and all its children (removes from parent)
void wgtDestroy(WidgetT *w);

// ============================================================
// List box operations
// ============================================================

void wgtListBoxSetItems(WidgetT *w, const char **items, int32_t count);
int32_t wgtListBoxGetSelected(const WidgetT *w);
void wgtListBoxSetSelected(WidgetT *w, int32_t idx);

// ============================================================
// Layout (called internally; available for manual trigger)
// ============================================================

// Resolve a tagged size to pixels
int32_t wgtResolveSize(int32_t taggedSize, int32_t parentSize, int32_t charWidth);

// Run layout on the entire widget tree
void wgtLayout(WidgetT *root, int32_t availW, int32_t availH,
               const BitmapFontT *font);

// Paint the entire widget tree
void wgtPaint(WidgetT *root, DisplayT *d, const BlitOpsT *ops,
              const BitmapFontT *font, const ColorSchemeT *colors);

#endif // DVX_WIDGET_H