#include "font.h"
#include "arena.h"
#include "ttf.h"
#include "asset_cache.h"
#include "resource.h"
#include "log.h"
#include "string.h"
#include "gp.h"

#define LOOKUP_TABLE_SIZE (256)
GLOBAL u32 g_font_codes[] = {
    0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F,0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
};

struct font_task_params {
    struct font_task_params *next_free;

    struct asset *asset;
    f32 point_size;
    u64 path_len;
    char path_cstr[1024];
};

struct font_task_params_store {
    struct font_task_params *head_free;
    struct arena *arena;
    struct sys_mutex *mutex;
};

/* ========================== *
 * Global state
 * ========================== */

GLOBAL struct {
    struct font_task_params_store params;
} G = ZI, DEBUG_ALIAS(G, L_font);

/* ========================== *
 * Startup
 * ========================== */

struct font_startup_receipt font_startup(struct gp_startup_receipt *gp_sr,
                                         struct asset_cache_startup_receipt *asset_cache_sr,
                                         struct ttf_startup_receipt *ttf_sr,
                                         struct resource_startup_receipt *resource_sr)
{
    (UNUSED)gp_sr;
    (UNUSED)asset_cache_sr;
    (UNUSED)ttf_sr;
    (UNUSED)resource_sr;

    G.params.arena = arena_alloc(GIGABYTE(64));
    G.params.mutex = sys_mutex_alloc();

    return (struct font_startup_receipt) { 0 };
}

/* ========================== *
 * Load task param store
 * ========================== */

INTERNAL struct font_task_params *font_task_params_alloc(void)
{
    struct font_task_params *p = NULL;
    {
        struct sys_lock lock = sys_mutex_lock_e(G.params.mutex);
        if (G.params.head_free) {
            p = G.params.head_free;
            G.params.head_free = p->next_free;
        } else {
            p = arena_push(G.params.arena, struct font_task_params);
        }
        sys_mutex_unlock(&lock);
    }
    return p;
}

INTERNAL void font_task_params_release(struct font_task_params *p)
{
    struct sys_lock lock = sys_mutex_lock_e(G.params.mutex);
    p->next_free = G.params.head_free;
    G.params.head_free = p;
    sys_mutex_unlock(&lock);
}

/* ========================== *
 * Load
 * ========================== */

INTERNAL SYS_JOB_DEF(font_load_asset_job, job)
{
    __prof;
    struct arena_temp scratch = scratch_begin_no_conflict();

    struct font_task_params *params = job.sig;
    struct string path = STRING(params->path_len, (u8 *)params->path_cstr);
    f32 point_size = params->point_size;
    struct asset *asset = params->asset;

    logf_info("Loading font \"%F\" (point size %F)", FMT_STR(path), FMT_FLOAT((f64)point_size));
    i64 start_ns = sys_time_ns();

    ASSERT(string_ends_with(path, LIT(".ttf")));
    ASSERT(countof(g_font_codes) < LOOKUP_TABLE_SIZE);

    /* Decode */
    struct resource res = resource_open(path);
    if (!resource_exists(&res)) {
        /* FIME: Load baked font instead of panicking */
        sys_panic(string_format(scratch.arena,
                                LIT("Font \"%F\" not found"),
                                FMT_STR(path)));
    }
    struct ttf_decode_result result = ttf_decode(scratch.arena, resource_get_data(&res), point_size, g_font_codes, countof(g_font_codes));
    resource_close(&res);

    /* Send texture to GPU */
    struct gp_resource *texture = gp_texture_alloc(GP_TEXTURE_FORMAT_R8G8B8A8_UNORM, 0, V2I32(result.image_data.width, result.image_data.height), result.image_data.pixels);

    /* Allocate store memory */
    struct font *font = NULL;
    {
        struct asset_cache_store store = asset_cache_store_open();
        font = arena_push(store.arena, struct font);
        font->glyphs = arena_push_array_no_zero(store.arena, struct font_glyph, result.glyphs_count);
        font->lookup = arena_push_array(store.arena, u16, LOOKUP_TABLE_SIZE);
        asset_cache_store_close(&store);
    }

    /* Set font data */
    font->texture = texture;
    font->image_width = result.image_data.width;
    font->image_height = result.image_data.height;
    font->glyphs_count = result.glyphs_count;
    font->point_size = point_size;

    /* FIXME: Load baked font instead of panicking */
    if (font->glyphs_count <= 0) {
        sys_panic(string_format(scratch.arena,
                                LIT("Parsed 0 glyphs from font \"%F\"!"),
                                FMT_STR(path)));
    }

    /* Copy glyphs from decode result */
    MEMCPY(font->glyphs, result.glyphs, sizeof(*font->glyphs) * result.glyphs_count);

    /* Build lookup table */
    for (u64 i = 0; i < countof(g_font_codes); ++i) {
        u32 codepoint = g_font_codes[i];
        font->lookup[codepoint] = result.cache_indices[i];
    }

    font_task_params_release(params);

    logf_success("Loaded font \"%F\" (point size %F) in %F seconds", FMT_STR(path), FMT_FLOAT((f64)point_size), FMT_FLOAT(SECONDS_FROM_NS(sys_time_ns() - start_ns)));
    asset_cache_mark_ready(asset, font);

    scratch_end(scratch);
}

/* Returns the asset from the asset cache */
struct asset *font_load_asset(struct string path, f32 point_size, b32 wait)
{
    __prof;
    struct arena_temp scratch = scratch_begin_no_conflict();

    /* Concatenate point_size to path for key */
    struct string key = string_format(scratch.arena,
                                      LIT("%F%F_font"),
                                      FMT_STR(path),
                                      FMT_FLOAT_P((f64)point_size, 1));
    u64 hash = asset_cache_hash(key);
    b32 is_first_touch;
    struct asset *asset = asset_cache_touch(key, hash, &is_first_touch);

    if (is_first_touch) {
        /* Assemble task params */
        struct font_task_params *params = font_task_params_alloc();
        if (path.len > (sizeof(params->path_cstr) - 1)) {
            sys_panic(string_format(scratch.arena,
                                    LIT("Font path \"%F\" too long!"),
                                    FMT_STR(path)));
        }
        cstr_buff_from_string(STRING_FROM_ARRAY(params->path_cstr), path);
        params->path_len = path.len;
        params->asset = asset;
        params->point_size = point_size;

        /* Push task */
        asset_cache_mark_loading(asset);
        sys_run(1, font_load_asset_job, params, SYS_JOB_PRIORITY_BACKGROUND, &asset->counter);
        if (wait) {
            asset_cache_wait(asset);
        }
    }

    scratch_end(scratch);
    return asset;
}

struct font *font_load_async(struct string path, f32 point_size)
{
    __prof;
    struct asset *asset = font_load_asset(path, point_size, false);
    struct font *f = (struct font *)asset_cache_get_store_data(asset);
    return f;
}

struct font *font_load(struct string path, f32 point_size)
{
    __prof;
    struct asset *asset = font_load_asset(path, point_size, true);
    asset_cache_wait(asset);
    struct font *f = (struct font *)asset_cache_get_store_data(asset);
    return f;
}

/* ========================== *
 * Other
 * ========================== */

struct font_glyph *font_get_glyph(struct font *font, u32 codepoint)
{
    if (codepoint < LOOKUP_TABLE_SIZE) {
        u16 index = font->lookup[codepoint];
        if (index < font->glyphs_count) {
            return &font->glyphs[index];
        }
    }
    if (codepoint == '?') {
        return &font->glyphs[font->lookup[0]];
    } else {
        return &font->glyphs[font->lookup['?']];
    }
}