// widgetRadio.c — RadioGroup and Radio button widgets
//
// Two-level architecture: RadioGroupE is an invisible container that
// holds the selection state (selectedIdx), while RadioE children are
// the visible buttons. This separation means the group tracks which
// index is selected while each radio button only knows its own index,
// keeping the per-button state minimal.
//
// Selection state is stored as an integer index on the parent group
// rather than a pointer, because indices survive widget reordering
// and are trivially serializable. The index is auto-assigned at
// construction time based on sibling order.
//
// Rendering: diamond-shaped indicator (Motif-style) using scanline
// horizontal lines rather than a circle algorithm. This avoids any
// need for anti-aliasing or trigonometry -- purely integer H/V lines.
// The selection dot inside uses a hardcoded width table for a 6-row
// filled diamond, sized to look crisp at the fixed 12px box size.
//
// Keyboard: Space/Enter select the current radio. Arrow keys move
// focus AND selection together (standard radio group behavior --
// focus and selection are coupled, unlike checkboxes).

#include "widgetInternal.h"


// ============================================================
// wgtRadio
// ============================================================

// Auto-index is computed by counting RadioE siblings before this one.
// This means radio buttons must be added in order and not reordered
// after construction -- which is the normal pattern for radio groups.
WidgetT *wgtRadio(WidgetT *parent, const char *text) {
    WidgetT *w = widgetAlloc(parent, WidgetRadioE);

    if (w) {
        w->as.radio.text = text;
        w->accelKey      = accelParse(text);

        // Auto-assign index based on position in parent
        int32_t idx = 0;

        for (WidgetT *c = parent->firstChild; c != w; c = c->nextSibling) {
            if (c->type == WidgetRadioE) {
                idx++;
            }
        }

        w->as.radio.index = idx;
    }

    return w;
}


// ============================================================
// wgtRadioGroup
// ============================================================

WidgetT *wgtRadioGroup(WidgetT *parent) {
    WidgetT *w = widgetAlloc(parent, WidgetRadioGroupE);

    if (w) {
        w->as.radioGroup.selectedIdx = 0;
    }

    return w;
}


// ============================================================
// widgetRadioGetText
// ============================================================

const char *widgetRadioGetText(const WidgetT *w) {
    return w->as.radio.text;
}


// ============================================================
// widgetRadioSetText
// ============================================================

void widgetRadioSetText(WidgetT *w, const char *text) {
    w->as.radio.text = text;
    w->accelKey = accelParse(text);
}


// ============================================================
// widgetRadioCalcMinSize
// ============================================================

// Shares CHECKBOX_BOX_SIZE/GAP constants with the checkbox widget
// so radio buttons and checkboxes align when placed in the same
// column, and the indicator + label layout is visually consistent.
void widgetRadioCalcMinSize(WidgetT *w, const BitmapFontT *font) {
    w->calcMinW = CHECKBOX_BOX_SIZE + CHECKBOX_GAP +
                   textWidthAccel(font, w->as.radio.text);
    w->calcMinH = DVX_MAX(CHECKBOX_BOX_SIZE, font->charHeight);
}


// ============================================================
// widgetRadioOnKey
// ============================================================

// Arrow keys move focus AND selection simultaneously -- this is the
// standard radio group behavior where navigating with arrows also
// commits the selection. This differs from checkboxes where arrows
// just move focus and Space toggles. The coupling is deliberate:
// radio groups represent a single mutually-exclusive choice, so
// "looking at" an option means "choosing" it.
//
// Key codes use DOS BIOS scancode convention: high byte 0x01 flag
// ORed with the scancode. 0x50=Down, 0x4D=Right, 0x48=Up, 0x4B=Left.
void widgetRadioOnKey(WidgetT *w, int32_t key, int32_t mod) {
    (void)mod;

    if (key == ' ' || key == 0x0D) {
        // Select this radio
        if (w->parent && w->parent->type == WidgetRadioGroupE) {
            w->parent->as.radioGroup.selectedIdx = w->as.radio.index;

            if (w->parent->onChange) {
                w->parent->onChange(w->parent);
            }
        }

        wgtInvalidatePaint(w);
    } else if (key == (0x50 | 0x100) || key == (0x4D | 0x100)) {
        // Down or Right — next radio in group
        if (w->parent && w->parent->type == WidgetRadioGroupE) {
            WidgetT *next = NULL;

            for (WidgetT *s = w->nextSibling; s; s = s->nextSibling) {
                if (s->type == WidgetRadioE && s->visible && s->enabled) {
                    next = s;
                    break;
                }
            }

            if (next) {
                w->focused = false;
                next->focused  = true;
                sFocusedWidget = next;
                next->parent->as.radioGroup.selectedIdx = next->as.radio.index;

                if (next->parent->onChange) {
                    next->parent->onChange(next->parent);
                }

                wgtInvalidatePaint(next);
            }
        }
    } else if (key == (0x48 | 0x100) || key == (0x4B | 0x100)) {
        // Up or Left — previous radio in group
        if (w->parent && w->parent->type == WidgetRadioGroupE) {
            WidgetT *prev = NULL;

            for (WidgetT *s = w->parent->firstChild; s && s != w; s = s->nextSibling) {
                if (s->type == WidgetRadioE && s->visible && s->enabled) {
                    prev = s;
                }
            }

            if (prev) {
                w->focused = false;
                prev->focused  = true;
                sFocusedWidget = prev;
                prev->parent->as.radioGroup.selectedIdx = prev->as.radio.index;

                if (prev->parent->onChange) {
                    prev->parent->onChange(prev->parent);
                }

                wgtInvalidatePaint(prev);
            }
        }
    }
}


// ============================================================
// widgetRadioOnMouse
// ============================================================

void widgetRadioOnMouse(WidgetT *w, WidgetT *root, int32_t vx, int32_t vy) {
    (void)root;
    (void)vx;
    (void)vy;
    w->focused = true;

    if (w->parent && w->parent->type == WidgetRadioGroupE) {
        w->parent->as.radioGroup.selectedIdx = w->as.radio.index;

        if (w->parent->onChange) {
            w->parent->onChange(w->parent);
        }
    }
}


// ============================================================
// widgetRadioPaint
// ============================================================

// The diamond radio indicator is rendered in three passes:
// 1. Interior fill -- scanline-based diamond fill for the background
// 2. Border -- upper-left edges in shadow, lower-right in highlight
//    (sunken appearance, same lighting model as bevels)
// 3. Selection dot -- smaller filled diamond from a hardcoded 6-row
//    width table. The static const avoids recomputation per paint.
//
// This approach avoids floating point entirely. Each scanline's
// left/right extent is computed with simple integer distance from
// the midpoint, making the diamond perfectly symmetric at any size.
void widgetRadioPaint(WidgetT *w, DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, const ColorSchemeT *colors) {
    uint32_t fg  = w->fgColor ? w->fgColor : colors->contentFg;
    uint32_t bg  = w->bgColor ? w->bgColor : colors->contentBg;
    int32_t boxY = w->y + (w->h - CHECKBOX_BOX_SIZE) / 2;

    // Draw diamond-shaped radio box
    int32_t bx  = w->x;
    int32_t mid = CHECKBOX_BOX_SIZE / 2;
    uint32_t hi = colors->windowShadow;
    uint32_t sh = colors->windowHighlight;

    // Fill interior
    for (int32_t i = 0; i < CHECKBOX_BOX_SIZE; i++) {
        int32_t dist  = i < mid ? i : CHECKBOX_BOX_SIZE - 1 - i;
        int32_t left  = mid - dist;
        int32_t right = mid + dist;

        if (right > left) {
            drawHLine(d, ops, bx + left + 1, boxY + i, right - left - 1, bg);
        }
    }

    // Diamond border — upper-left edges get highlight, lower-right get shadow
    for (int32_t i = 0; i < mid; i++) {
        int32_t left  = mid - i;
        int32_t right = mid + i;
        drawHLine(d, ops, bx + left, boxY + i, 1, hi);
        drawHLine(d, ops, bx + right, boxY + i, 1, sh);
    }

    for (int32_t i = mid; i < CHECKBOX_BOX_SIZE; i++) {
        int32_t left  = mid - (CHECKBOX_BOX_SIZE - 1 - i);
        int32_t right = mid + (CHECKBOX_BOX_SIZE - 1 - i);
        drawHLine(d, ops, bx + left, boxY + i, 1, hi);
        drawHLine(d, ops, bx + right, boxY + i, 1, sh);
    }

    // Draw filled diamond if selected
    if (w->parent && w->parent->type == WidgetRadioGroupE &&
        w->parent->as.radioGroup.selectedIdx == w->as.radio.index) {
        uint32_t dotFg = w->enabled ? fg : colors->windowShadow;

        static const int32_t dotW[] = {2, 4, 6, 6, 4, 2};

        for (int32_t i = 0; i < 6; i++) {
            int32_t dw = dotW[i];
            drawHLine(d, ops, bx + mid - dw / 2, boxY + mid - 3 + i, dw, dotFg);
        }
    }

    int32_t labelX = w->x + CHECKBOX_BOX_SIZE + CHECKBOX_GAP;
    int32_t labelY = w->y + (w->h - font->charHeight) / 2;
    int32_t labelW = textWidthAccel(font, w->as.radio.text);

    if (!w->enabled) {
        drawTextAccelEmbossed(d, ops, font, labelX, labelY, w->as.radio.text, colors);
    } else {
        drawTextAccel(d, ops, font, labelX, labelY, w->as.radio.text, fg, bg, false);
    }

    if (w->focused) {
        drawFocusRect(d, ops, labelX - 1, labelY - 1, labelW + 2, font->charHeight + 2, fg);
    }
}