#include "jUnit.h"
#include "gif.c"
#include <stdio.h>

struct jSurface_s
{
    Uint8 *data;
    Uint16 w, h;
};

static SDL_Window *jWin = NULL;
static SDL_Renderer *jRen = NULL;
static SDL_Texture *jTex = NULL;
static jSurface jScreen;
static jSurface jDestSurf;
static jSurface jSourceSurf = NULL;
static Uint32 paleta[256];
static int jWidth = 320;
static int jHeight = 240;
static int jZoom = 2;
static int transparentColor = 0;

jSurface jNewSurface(int w, int h)
{
    jSurface surf = (jSurface)malloc(sizeof(jSurface_s));
    surf->w = w;
    surf->h = h;
    surf->data = (Uint8 *)malloc(w * h);
    return surf;
}

void jDeleteSurface(jSurface surf)
{
    if (surf == NULL)
        return;
    if (surf->data != NULL)
        free(surf->data);
    free(surf);
}

void jSetDest(jSurface surf)
{
    if (surf == NULL)
        jDestSurf = jScreen;
    else
        jDestSurf = surf;
}

void jSetSource(jSurface surf)
{
    jSourceSurf = surf;
}

void jBlit(int dx, int dy, int sx, int sy, int w, int h)
{
    if (jSourceSurf == NULL)
        return;
    
    for (int iy = 0; iy < h; ++iy)
    {
        for (int ix = 0; ix < w; ++ix)
            jPutPixel(dx + ix, dy + iy, jGetPixel(sx + ix, sy + iy));
    }
}

jSurface jLoadSurface(const char *filename)
{
    FILE *f = fopen(filename, "rb");
    if (!f)
        return NULL;

    fseek(f, 0, SEEK_END);
    long size = ftell(f);
    fseek(f, 0, SEEK_SET);
    Uint8 *buffer = (Uint8 *)malloc(size);
    fread(buffer, size, 1, f);
    fclose(f);

    Uint16 w, h;
    Uint8 *pixels = LoadGif(buffer, &w, &h);
    if (pixels == NULL)
    {
        return NULL;
    }
    jSurface surf = (jSurface)malloc(sizeof(jSurface_s));
    surf->w = w;
    surf->h = h;
    surf->data = pixels;
    free(buffer);
    return surf;
}

void jLoadPal(const char *filename)
{
    FILE *f = fopen(filename, "rb");
    if (!f)
        return;

    fseek(f, 0, SEEK_END);
    long size = ftell(f);
    fseek(f, 0, SEEK_SET);
    Uint8 *buffer = (Uint8 *)malloc(size);
    fread(buffer, size, 1, f);
    fclose(f);

    Uint32 *pal = LoadPalette(buffer);
    if (pal == NULL)
    {
        return;
    }
    free(buffer);
    for (int i = 0; i < 256; ++i)
    {
        paleta[i] = pal[i];
    }
}

void jInit(const char *titol, int w, int h, int z)
{
    SDL_Init(SDL_INIT_EVERYTHING);
    jWidth = w;
    jHeight = h;
    jZoom = z;
    jWin = SDL_CreateWindow(titol, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, w * z, h * z, SDL_WINDOW_SHOWN);
    jRen = SDL_CreateRenderer(jWin, -1, 0);
    SDL_RenderSetLogicalSize(jRen, w, h);
    jTex = SDL_CreateTexture(jRen, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, w, h);
    jScreen = jNewSurface(w, h);
    jDestSurf = jScreen;
}

void jSetPal(int index, Uint32 color)
{
    paleta[index] = color;
}

void jCls(Uint8 color)
{
    for (int i = 0; i < jDestSurf->w * jDestSurf->h; ++i)
        jDestSurf->data[i] = color;
}

void jFlip()
{
    Uint32 *pixels;
    int pitch;
    SDL_LockTexture(jTex, NULL, (void **)&pixels, &pitch);
    for (int i = 0; i < jWidth * jHeight; ++i)
        pixels[i] = paleta[jScreen->data[i]];
    SDL_UnlockTexture(jTex);
    SDL_RenderCopy(jRen, jTex, NULL, NULL);
    SDL_RenderPresent(jRen);
}

void jPutPixel(int x, int y, Uint8 color)
{
    if (x < 0 || y < 0 || x >= jDestSurf->w || y >= jDestSurf->h || color == transparentColor)
        return;
    jDestSurf->data[x + y * jDestSurf->w] = color;
}

Uint8 jGetPixel(int x, int y)
{
    return jSourceSurf->data[x + y * jSourceSurf->w];
}