#include "draw.h"
#include <vector>
#include "gif.h"
#include <algorithm>

namespace draw
{
    SDL_Window *win = nullptr;
    SDL_Renderer *ren = nullptr;
    SDL_Texture *tex = nullptr;

    SDL_Texture *source = nullptr;
    SDL_Texture *dest = nullptr;

    std::vector<texture_t> textures;

    uint32_t palette[16];

    void init()
    {
        SDL_Init(SDL_INIT_VIDEO);
        win = SDL_CreateWindow("DILEMMAKER v0.1", 1280, 960, 0);
        ren = SDL_CreateRenderer(win, NULL);
        tex = SDL_CreateTexture(ren, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, 256, 192);
        SDL_SetTextureScaleMode(tex, SDL_SCALEMODE_NEAREST);
    }

    void fillRect(int x, int y, int w, int h, uint8_t r, uint8_t g, uint8_t b, uint8_t a)
    {
        SDL_SetRenderDrawColor(ren, r, g, b, a);
        SDL_FRect rect {float(x), float(y), float(w), float(h)};
        SDL_RenderFillRect(ren, &rect);
    }

    void setSource(SDL_Texture *texture)
    {
        source = texture;
    }

    void setDest(SDL_Texture *texture)
    {
        dest = texture;
        SDL_SetRenderTarget(ren, dest);
    }

    void regenerateTexture(texture_t &texture)
    {
        if (texture.target) return;
        uint32_t *argb;
        int pitch;
        SDL_LockTexture(texture.texture, NULL, (void**)&argb, &pitch);
        for (int i=0; i<texture.w*texture.h; ++i) argb[i] = palette[texture.pixels[i]];
        SDL_UnlockTexture(texture.texture);
    }

    int loadPalette(const char *filename)
    {
        FILE *fp = fopen(filename, "r");
        if (!fp) return -1;

        char header[32];
        int version, count;

        // Read and validate header
        if (!fgets(header, sizeof(header), fp) || strncmp(header, "JASC-PAL", 8) != 0) {
            fclose(fp);
            return -2;
        }

        if (fscanf(fp, "%d\n%d\n", &version, &count) != 2 || count != 16) {
            fclose(fp);
            return -3;
        }

        for (int i = 0; i < 16; ++i) {
            int r, g, b;
            if (fscanf(fp, "%d %d %d\n", &b, &g, &r) != 3) {
                fclose(fp);
                return -4;
            }
            palette[i] = (0xFF << 24) | (r << 16) | (g << 8) | b;
        }

        fclose(fp);
        regenerateTextures();
        return 0; // Success
    }

    void regenerateTextures()
    {
        for (auto &tex : textures)
        {
            regenerateTexture(tex);
        }
    }

    texture_t getTexture(const char *filename)
    {
        std::string name = filename;
        for (auto tex : textures) if (tex.name == name) return tex;

        FILE *f = fopen(filename, "rb");
        fseek(f, 0, SEEK_END);
        int file_size = ftell(f);
        fseek(f, 0, SEEK_SET);
        uint8_t *buffer = (uint8_t*)malloc(file_size);
        fread(buffer, file_size, 1, f);
        fclose(f);

        uint16_t w, h;
        uint8_t *pixels = gif::Load(buffer, &w, &h);
        free(buffer);

        SDL_Texture * tex = SDL_CreateTexture(ren, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, w, h);
        SDL_SetTextureScaleMode(tex, SDL_SCALEMODE_NEAREST);

        texture_t t;
        t.name = filename;
        t.texture = tex;
        t.pixels = pixels;
        t.w = w;
        t.h = h;
        regenerateTexture(t);
        textures.push_back(t);

        return t;
    }

    texture_t createTexture(const char* name, int w, int h, SDL_TextureAccess access)
    {
        SDL_Texture * tex = SDL_CreateTexture(ren, SDL_PIXELFORMAT_ARGB8888, access, w, h);
        SDL_SetTextureScaleMode(tex, SDL_SCALEMODE_NEAREST);

        texture_t t;
        t.name = name;
        t.texture = tex;
        if (access == SDL_TEXTUREACCESS_TARGET) {
            t.target = true;
        } else {
            t.pixels = (uint8_t*)malloc(w*h);
            for (int i=0; i<w*h; ++i) t.pixels[i] = 0x00000000;
        }
        t.w = w;
        t.h = h;
        regenerateTexture(t);
        textures.push_back(t);

        return t;
    }

    void deleteTexture(const char *name)
    {
        for (auto it = textures.begin(); it != textures.end(); ++it) {
            if ((*it).name == name)
            {
                SDL_DestroyTexture((*it).texture);
                free((*it).pixels);
                textures.erase(it);
                return;
            }
        }
    }


    void draw(int dx, int dy, int dw, int dh, int sx, int sy, int sw, int sh)
    {
        SDL_FRect src {float(sx), float(sy), float(sw), float(sh)};
        SDL_FRect dst {float(dx), float(dy), float(dw), float(dh)};
        SDL_RenderTexture(ren, source, &src, &dst);
    }

    void present()
    {
        SDL_RenderPresent(ren);
    }

}