#include "core/core.h"
#include "core/core.c"

#define STB_TRUETYPE_IMPLEMENTATION
#define STBTT_ifloor(x) ((i32)f64_floor(x))
#define STBTT_iceil(x) ((i32)f64_ceil(x))
#define STBTT_sqrt(x) (f64_sqrt(x))
#define STBTT_fmod(x,y) (f64_mod(x,y))
#define STBTT_pow(x,y) (f64_pow(x,y))
#define STBTT_cos(x) (f64_cos(x))
#define STBTT_acos(x) (f64_acos(x))
#define STBTT_fabs(x) (f64_abs(x))
#define STBTT_malloc(x,u) ((void)u,ma_push_size(&tcx->temp,x))
#define STBTT_free(x,u) ((void)x,(void)u)
#define STBTT_assert(x) assert(x)
#define STBTT_strlen(x) str_len(x)
#define STBTT_memcpy memory_copy
#define STBTT_memset memory_set

#include "vendor/stb/stb_truetype.h"
#include "fira_code.c"

typedef struct bitmap_t bitmap_t;
struct bitmap_t {
    u32 *data;
    i32 x, y;
};

typedef struct glyph_t glyph_t;
struct glyph_t {
    bitmap_t bitmap;
    i32 xoff, yoff;
    i32 left_side_bearing, xadvance;
    r2f32_t tex;
};

typedef struct font_t font_t;
struct font_t {
    glyph_t glyphs[256];
    bitmap_t atlas;
    i32 ascent, descent, line_gap, size;
    f32 scale;
    i32 height;
};

fn font_t create_font(i32 size) {
    font_t font = {0};
    font.size = size;
    stbtt_fontinfo stb_font;
    i32 rc = stbtt_InitFont(&stb_font, main_font_data, 0);
    assert_expr(rc != 0);

    font.scale = stbtt_ScaleForPixelHeight(&stb_font, (f32)font.size);
    stbtt_GetFontVMetrics(&stb_font, &font.ascent, &font.descent, &font.line_gap);
    font.height = f32_round((font.ascent - font.descent) + font.line_gap) * font.scale;
    for (i32 c = 0; c < 256; c += 1) {
        glyph_t *glyph = font.glyphs + c;
        u8 *temp_data = (u8 *)stbtt_GetCodepointBitmap(&stb_font, 0, font.scale, c, &glyph->bitmap.x, &glyph->bitmap.y, &glyph->xoff, &glyph->yoff);
        glyph->bitmap.data = ma_push_array(&tcx->temp, u32, glyph->bitmap.x * glyph->bitmap.y);
        for (i32 y = 0; y < glyph->bitmap.y; y += 1) {
            for (i32 x = 0; x < glyph->bitmap.x; x += 1) {
                glyph->bitmap.data[x + y * glyph->bitmap.x] = temp_data[x + y * glyph->bitmap.x] << 24;
            }
        }
        stbtt_GetCodepointHMetrics(&stb_font, c, &glyph->xadvance, &glyph->left_side_bearing);
    }

    return font;
}

fn font_t create_font_atlas(i32 size) {
    stbtt_fontinfo stb_font;
    i32 rc = stbtt_InitFont(&stb_font, main_font_data, 0);
    assert_expr(rc != 0);

    font_t font = { 0 };
    font.size = size;
    font.atlas.x = 512;
    font.atlas.y = 512;
    font.atlas.data = ma_push_array(&tcx->temp, u32, font.atlas.x * font.atlas.y);
    font.scale = stbtt_ScaleForPixelHeight(&stb_font, (f32)font.size);
    stbtt_GetFontVMetrics(&stb_font, &font.ascent, &font.descent, &font.line_gap);

    i32 xiter = 2;
    i32 yiter = 2;
    i32 max_yiter_for_row = 0;
    for (i32 c = ' '; c < '~'; c += 1) {
        glyph_t *glyph = font.glyphs + (c - ' ');
        u8 *temp_data = (u8 *)stbtt_GetCodepointBitmap(&stb_font, 0, font.scale, c, &glyph->bitmap.x, &glyph->bitmap.y, &glyph->xoff, &glyph->yoff);
        if (xiter + glyph->bitmap.x >= font.atlas.x) {
            xiter = 0;
            yiter += max_yiter_for_row + 2;
        }

        glyph->tex.min.x = (f32)xiter / (f32)font.atlas.x;
        glyph->tex.min.y = (f32)yiter / (f32)font.atlas.y;
        glyph->tex.max.x = (f32)(xiter + glyph->bitmap.x)/ (f32)font.atlas.x;
        glyph->tex.max.y = (f32)(yiter + glyph->bitmap.y)/ (f32)font.atlas.y;

        max_yiter_for_row = MAX(max_yiter_for_row, glyph->bitmap.y);
        for (i32 y = 0; y < glyph->bitmap.y; y += 1) {
            for (i32 x = 0; x < glyph->bitmap.x; x += 1) {
                font.atlas.data[(xiter + x) + (yiter + y)*font.atlas.x] = temp_data[x + y * glyph->bitmap.x] << 24;
            }
        }
        xiter += glyph->bitmap.x + 2;
    }
    return font;
}

fn_export void init(void) {
    os_core_init();
}

fn void draw_bitmap(bitmap_t *canvas, bitmap_t *bitmap, i32 x, i32 y) {
    i32 x0 = x;
    i32 y0 = y;
    i32 x1 = x + bitmap->x;
    i32 y1 = y + bitmap->y;

    i32 cx0 = CLAMP(x0, 0, canvas->x);
    i32 cy0 = CLAMP(y0, 0, canvas->y);
    i32 cx1 = CLAMP(x1, 0, canvas->x);
    i32 cy1 = CLAMP(y1, 0, canvas->y);


    if (cx0 >= cx1 || cy0 >= cy1) {
        return;
    }

    i32 sx_off = cx0 - x0;
    i32 sy_off = cy0 - y0;

    i32 sy = sy_off;
    for (i32 y = cy0; y < cy1; y += 1) {
        i32 sx = sx_off;
        for (i32 x = cx0; x < cx1; x += 1) {
            canvas->data[x + y * canvas->x] = bitmap->data[sx + sy * bitmap->x];
            //canvas->data[x + y * canvas->x] = blend_pixel_u32(canvas->data[x + y * canvas->x], bitmap->data[sx + sy * bitmap->x]);
            sx += 1;
        }
        sy += 1;
    }
}

fn void draw_rect(bitmap_t *canvas, i32 x, i32 y, i32 w, i32 h, u32 color) {
    i32 x0 = x;
    i32 y0 = y;
    i32 x1 = x + w;
    i32 y1 = y + h;

    i32 cx0 = CLAMP(x0, 0, canvas->x);
    i32 cy0 = CLAMP(y0, 0, canvas->y);
    i32 cx1 = CLAMP(x1, 0, canvas->x);
    i32 cy1 = CLAMP(y1, 0, canvas->y);


    if (cx0 >= cx1 || cy0 >= cy1) {
        return;
    }

    i32 sx_off = cx0 - x0;
    i32 sy_off = cy0 - y0;

    for (i32 y = cy0; y < cy1; y += 1) {
        for (i32 x = cx0; x < cx1; x += 1) {
            canvas->data[x + y * canvas->x] = color;
            //canvas->data[x + y * canvas->x] = blend_pixel_u32(canvas->data[x + y * canvas->x], color);
        }
    }
}

fn v2i32_t draw_string(bitmap_t *canvas, font_t *font, i32 ix, i32 iy, b32 draw, char *string) {
    i32 xiter = 0;
    v2i32_t R = {0};
    for (char *it = string; *it; it += 1) {
        glyph_t *g = font->glyphs + (*it);

        i32 curr_xiter = xiter;
        xiter += g->xadvance * font->scale;
        R.x = xiter;
        R.y = MAX(R.y, g->bitmap.y);

        if (!draw) {
            continue;
        }

        draw_bitmap(canvas, &g->bitmap, curr_xiter + g->xoff + ix, g->yoff + font->ascent*font->scale + iy);
    }
    return R;
}

fn_export u32 *update(i32 width, i32 height, f32 dpr) {
    ma_set0(&tcx->temp);
    u32 *pixels = ma_push_array(&tcx->temp, u32, width * height);
    bitmap_t canvas = {pixels, width, height};
    font_t font = create_font_atlas(60);
    draw_bitmap(&canvas, &font.atlas, 0, 0);
    for (i32 i = 0; i < lengthof(font.glyphs); i += 1) {
        glyph_t *g = &font.glyphs[i];
        i32 x = g->tex.min.x * font.atlas.x;
        i32 y = g->tex.min.y * font.atlas.y;
        i32 w = (g->tex.max.x - g->tex.min.x) * font.atlas.x;
        i32 h = (g->tex.max.y - g->tex.min.y) * font.atlas.y;
        //draw_rect(&canvas, x, y, w, h, 0xFF0000FF);
    }
    //bitmap_t canvas = {pixels, width, height};
    //font_t font = create_font(60);
    //v2i32_t size = draw_string(&canvas, &font, 200, 500, false, "Hello world (stb)");
    //draw_string(&canvas, &font, (width-size.x)/2, height - size.y*2, true, "Hello world (stb)");
    return pixels;
}