// ui_core.c - Clay wrapper implementation
// CLAY_IMPLEMENTATION must be defined exactly once before including clay.h.
// In the unity build, ui_core.h (which includes clay.h) has #pragma once,
// so we include clay.h directly here first to get the implementation compiled.

#include <stdlib.h>

// MSVC: stub out Clay's debug view (uses CLAY() macros MSVC can't compile in C)
#ifdef _MSC_VER
#define CLAY_DISABLE_DEBUG_VIEW
#endif

#define CLAY_IMPLEMENTATION
#include "clay.h"

// MSVC C mode: bypass Clay's wrapper struct pattern for designated initializers.
// Must come after clay.h so CLAY__CONFIG_WRAPPER is defined, then we override it.
#ifdef _MSC_VER
#undef CLAY__CONFIG_WRAPPER
#define CLAY__CONFIG_WRAPPER(type, ...) ((type) { __VA_ARGS__ })
#endif

#include "ui/ui_core.h"

////////////////////////////////
// UI scale global

F32 g_ui_scale = 1.0f;

////////////////////////////////
// Theme global

UI_Theme g_theme = {0};
S32 g_theme_id = 0;

void ui_set_theme(S32 theme_id) {
    g_theme_id = theme_id;

    switch (theme_id) {
    default:
    case 0: // Dark
        g_theme.bg_dark          = (Clay_Color){ 26,  26,  26, 255};
        g_theme.bg_medium        = (Clay_Color){ 36,  36,  36, 255};
        g_theme.bg_light         = (Clay_Color){ 46,  46,  46, 255};
        g_theme.bg_lighter       = (Clay_Color){ 54,  54,  54, 255};
        g_theme.border           = (Clay_Color){ 52,  52,  52, 255};
        g_theme.text             = (Clay_Color){220, 220, 220, 255};
        g_theme.text_dim         = (Clay_Color){105, 105, 105, 255};
        g_theme.accent           = (Clay_Color){ 87, 138, 176, 255};
        g_theme.accent_hover     = (Clay_Color){102, 153, 191, 255};
        g_theme.button_text      = (Clay_Color){224, 224, 224, 255};
        g_theme.disabled_bg      = (Clay_Color){ 44,  44,  44, 255};
        g_theme.disabled_text    = (Clay_Color){ 90,  90,  90, 255};
        g_theme.header_bg        = (Clay_Color){ 46,  46,  46, 255};
        g_theme.title_bar        = (Clay_Color){ 22,  22,  22, 255};
        g_theme.scrollbar_bg     = (Clay_Color){ 22,  22,  22, 255};
        g_theme.scrollbar_grab   = (Clay_Color){ 58,  58,  58, 255};
        g_theme.shadow           = (Clay_Color){  0,   0,   0,  30};
        g_theme.tab_active_top   = (Clay_Color){ 70, 120, 160, 255};
        g_theme.tab_active_bottom= (Clay_Color){ 30,  55,  80, 255};
        g_theme.tab_inactive     = (Clay_Color){ 40,  40,  40, 255};
        g_theme.tab_inactive_hover= (Clay_Color){ 50,  50,  50, 255};
        g_theme.tab_text         = (Clay_Color){240, 240, 240, 255};
        g_theme.corner_radius    = 4.0f;
        break;

    case 1: // Light
        g_theme.bg_dark          = (Clay_Color){195, 193, 190, 255};
        g_theme.bg_medium        = (Clay_Color){212, 210, 207, 255};
        g_theme.bg_light         = (Clay_Color){225, 223, 220, 255};
        g_theme.bg_lighter       = (Clay_Color){232, 230, 227, 255};
        g_theme.border           = (Clay_Color){178, 176, 173, 255};
        g_theme.text             = (Clay_Color){ 35,  33,  30, 255};
        g_theme.text_dim         = (Clay_Color){115, 113, 108, 255};
        g_theme.accent           = (Clay_Color){ 50, 110, 170, 255};
        g_theme.accent_hover     = (Clay_Color){ 65, 125, 185, 255};
        g_theme.button_text      = (Clay_Color){255, 255, 255, 255};
        g_theme.disabled_bg      = (Clay_Color){185, 183, 180, 255};
        g_theme.disabled_text    = (Clay_Color){145, 143, 140, 255};
        g_theme.header_bg        = (Clay_Color){202, 200, 197, 255};
        g_theme.title_bar        = (Clay_Color){202, 200, 197, 255};
        g_theme.scrollbar_bg     = (Clay_Color){202, 200, 197, 255};
        g_theme.scrollbar_grab   = (Clay_Color){168, 166, 163, 255};
        g_theme.shadow           = (Clay_Color){  0,   0,   0,  18};
        g_theme.tab_active_top   = (Clay_Color){ 70, 130, 180, 255};
        g_theme.tab_active_bottom= (Clay_Color){ 50, 100, 150, 255};
        g_theme.tab_inactive     = (Clay_Color){205, 203, 200, 255};
        g_theme.tab_inactive_hover= (Clay_Color){195, 193, 190, 255};
        g_theme.tab_text         = (Clay_Color){255, 255, 255, 255};
        g_theme.corner_radius    = 4.0f;
        break;
    }
}

////////////////////////////////
// Accent palette

S32 g_accent_id = 0;

void ui_set_accent(S32 accent_id) {
    g_accent_id = accent_id;
    B32 dark = (g_theme_id == 0);

    // Each palette: accent, accent_hover, tab_top, tab_bottom, button_text, tab_text
    typedef struct AccentColors {
        Clay_Color accent, accent_hover, tab_top, tab_bottom, button_text, tab_text;
    } AccentColors;

    // Dark-mode palettes
    static const AccentColors dark_palettes[] = {
        // 0: Blue
        { {87,138,176,255}, {102,153,191,255}, {70,120,160,255}, {30,55,80,255}, {224,224,224,255}, {240,240,240,255} },
        // 1: Turquoise
        { {60,160,155,255}, {75,175,170,255}, {50,140,135,255}, {25,70,68,255}, {224,224,224,255}, {240,240,240,255} },
        // 2: Orange
        { {200,130,50,255}, {215,145,65,255}, {190,120,40,255}, {100,60,20,255}, {240,240,240,255}, {240,240,240,255} },
        // 3: Purple
        { {130,100,180,255}, {145,115,195,255}, {120,90,170,255}, {60,45,85,255}, {224,224,224,255}, {240,240,240,255} },
        // 4: Pink
        { {185,95,140,255}, {200,110,155,255}, {175,85,130,255}, {88,42,65,255}, {240,240,240,255}, {240,240,240,255} },
        // 5: Red
        { {190,75,75,255}, {205,90,90,255}, {180,65,65,255}, {90,32,32,255}, {240,240,240,255}, {240,240,240,255} },
        // 6: Green
        { {80,155,80,255}, {95,170,95,255}, {70,140,70,255}, {35,70,35,255}, {240,240,240,255}, {240,240,240,255} },
    };

    // Light-mode palettes (slightly more saturated for contrast on light bg)
    static const AccentColors light_palettes[] = {
        // 0: Blue
        { {50,110,170,255}, {65,125,185,255}, {70,130,180,255}, {50,100,150,255}, {255,255,255,255}, {255,255,255,255} },
        // 1: Turquoise
        { {30,140,135,255}, {45,155,150,255}, {40,150,145,255}, {25,115,110,255}, {255,255,255,255}, {255,255,255,255} },
        // 2: Orange
        { {190,115,25,255}, {205,130,40,255}, {195,120,30,255}, {155,90,15,255}, {255,255,255,255}, {255,255,255,255} },
        // 3: Purple
        { {110,75,170,255}, {125,90,185,255}, {115,80,175,255}, {85,55,140,255}, {255,255,255,255}, {255,255,255,255} },
        // 4: Pink
        { {175,70,125,255}, {190,85,140,255}, {180,75,130,255}, {140,50,100,255}, {255,255,255,255}, {255,255,255,255} },
        // 5: Red
        { {185,55,55,255}, {200,70,70,255}, {190,60,60,255}, {150,40,40,255}, {255,255,255,255}, {255,255,255,255} },
        // 6: Green
        { {55,140,55,255}, {70,155,70,255}, {60,145,60,255}, {40,110,40,255}, {255,255,255,255}, {255,255,255,255} },
    };

    S32 idx = accent_id;
    if (idx < 0) idx = 0;
    if (idx > 6) idx = 6;

    const AccentColors *c = dark ? &dark_palettes[idx] : &light_palettes[idx];
    g_theme.accent            = c->accent;
    g_theme.accent_hover      = c->accent_hover;
    g_theme.tab_active_top    = c->tab_top;
    g_theme.tab_active_bottom = c->tab_bottom;
    g_theme.button_text       = c->button_text;
    g_theme.tab_text          = c->tab_text;
}

////////////////////////////////
// Clay error handler

static void clay_error_handler(Clay_ErrorData error) {
    char buf[512];
    S32 len = error.errorText.length < 511 ? error.errorText.length : 511;
    memcpy(buf, error.errorText.chars, len);
    buf[len] = '\0';
    fprintf(stderr, "[Clay Error] %s\n", buf);
}

////////////////////////////////
// Clay text measurement bridge
// Clay calls this; we forward to the app's UI_MeasureTextFn

static UI_Context *g_measure_ctx = NULL;

static Clay_Dimensions clay_measure_text(Clay_StringSlice text, Clay_TextElementConfig *config, void *user_data) {
    UI_Context *ctx = (UI_Context *)user_data;
    if (!ctx || !ctx->measure_text_fn || text.length == 0) {
        return (Clay_Dimensions){0, (F32)config->fontSize};
    }
    Vec2F32 result = ctx->measure_text_fn(text.chars, text.length, (F32)config->fontSize, ctx->measure_text_user_data);
    return (Clay_Dimensions){result.x, result.y};
}

////////////////////////////////
// Lifecycle

UI_Context *ui_create(F32 viewport_w, F32 viewport_h) {
    UI_Context *ctx = (UI_Context *)calloc(1, sizeof(UI_Context));

    U32 min_memory = Clay_MinMemorySize();
    ctx->clay_memory = malloc(min_memory);
    Clay_Arena clay_arena = Clay_CreateArenaWithCapacityAndMemory(min_memory, ctx->clay_memory);

    Clay_ErrorHandler err_handler = {0};
    err_handler.errorHandlerFunction = clay_error_handler;
    err_handler.userData = ctx;

    ctx->clay_ctx = Clay_Initialize(clay_arena,
        (Clay_Dimensions){viewport_w, viewport_h},
        err_handler);

    Clay_SetMeasureTextFunction(clay_measure_text, ctx);

    return ctx;
}

void ui_destroy(UI_Context *ctx) {
    if (!ctx) return;
    free(ctx->clay_memory);
    free(ctx);
}

void ui_begin_frame(UI_Context *ctx, F32 viewport_w, F32 viewport_h,
                    Vec2F32 mouse_pos, B32 mouse_down,
                    Vec2F32 scroll_delta, F32 dt)
{
    g_measure_ctx = ctx;
    Clay_SetCurrentContext(ctx->clay_ctx);
    Clay_SetLayoutDimensions((Clay_Dimensions){viewport_w, viewport_h});
    Clay_SetPointerState((Clay_Vector2){mouse_pos.x, mouse_pos.y}, mouse_down != 0);
    Clay_UpdateScrollContainers(false, (Clay_Vector2){scroll_delta.x, scroll_delta.y}, dt);
    Clay_BeginLayout();
}

Clay_RenderCommandArray ui_end_frame(UI_Context *ctx) {
    (void)ctx;
    return Clay_EndLayout();
}

void ui_set_measure_text_fn(UI_Context *ctx, UI_MeasureTextFn fn, void *user_data) {
    ctx->measure_text_fn = fn;
    ctx->measure_text_user_data = user_data;
}

Vec2F32 ui_measure_text(const char *text, S32 length, F32 font_size) {
    if (!g_measure_ctx || !g_measure_ctx->measure_text_fn || length == 0)
        return v2f32(0, font_size);
    return g_measure_ctx->measure_text_fn(text, length, font_size, g_measure_ctx->measure_text_user_data);
}