#include <graphics.h>
#include <stdio.h>

#define WINDOW_WIDTH 1536
#define WINDOW_HEIGHT 896

static void copyScreenTexture(uint8_t *dst, const uint8_t *src, int pitch) {
    int x, y, i;
    uint8_t color;
    int delta = pitch / 384;
    for (y = 0; y < 224; ++y) {
        for (x = 0; x < 384; x += 1) {
            color = src[(y * 384) + x];
            for (i = 0; i < delta; ++i) {
                dst[(y * pitch) + (x * delta) + i] = color;
            }
        }
    }
}

int gfxInit(GraphicsContext *gfx) {
    float fontScale = 1;

    gfx->window = SDL_CreateWindow("Shrooms VB",
        SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
        WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI);
    if (!gfx->window) {
        fprintf(stderr, "Error creating window: %s\n", SDL_GetError());
        return 1;
    }

    gfx->renderer = SDL_CreateRenderer(gfx->window, -1, 0);
    if (!gfx->renderer) {
        fprintf(stderr, "Error creating renderer: %s\n", SDL_GetError());
        goto cleanup_window;
    }

    /* scale the renderer output for High-DPI displays */
    {
        int renderW, renderH;
        int windowW, windowH;
        float scaleX, scaleY;
        SDL_GetRendererOutputSize(gfx->renderer, &renderW, &renderH);
        SDL_GetWindowSize(gfx->window, &windowW, &windowH);
        scaleX = (float)(renderW) / (float)(windowW);
        scaleY = (float)(renderH) / (float)(windowH);
        SDL_RenderSetScale(gfx->renderer, scaleX, scaleY);
    }

    gfx->nk = nk_sdl_init(gfx->window, gfx->renderer);

    {
        struct nk_font_atlas *atlas;
        struct nk_font *font;
        struct nk_font_config config = nk_font_config(0);
        
        nk_sdl_font_stash_begin(&atlas);
        font = nk_font_atlas_add_default(atlas, 13 * fontScale, &config);
        nk_sdl_font_stash_end();

        font->handle.height /= fontScale;
        nk_style_set_font(gfx->nk, &font->handle);
    }

    gfx->bg.r = 0.10f;
    gfx->bg.g = 0.18f;
    gfx->bg.b = 0.24f;
    gfx->bg.a = 1.0f;

    gfx->leftEye = SDL_CreateTexture(gfx->renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, 384, 224);
    if (!gfx->leftEye) {
        fprintf(stderr, "Error creating left eye texture: %s\n", SDL_GetError());
        goto cleanup_window;
    }
    SDL_SetTextureColorMod(gfx->leftEye, 0xff, 0, 0);

    gfx->rightEye = SDL_CreateTexture(gfx->renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, 384, 224);
    if (!gfx->rightEye) {
        fprintf(stderr, "Error creating left eye texture: %s\n", SDL_GetError());
        goto cleanup_left_eye;
    }
    SDL_SetTextureColorMod(gfx->rightEye, 0, 0xc6, 0xf0);
    SDL_SetTextureBlendMode(gfx->rightEye, SDL_BLENDMODE_ADD);

    return 0;

cleanup_left_eye:
    SDL_DestroyTexture(gfx->leftEye);
cleanup_window:
    SDL_DestroyWindow(gfx->window);
    return 1;
}

void gfxDestroy(GraphicsContext *gfx) {
    SDL_DestroyTexture(gfx->rightEye);
    SDL_DestroyTexture(gfx->leftEye);
    SDL_DestroyWindow(gfx->window);
}

static void gfxUpdateEye(SDL_Texture *eye, const uint8_t *bytes) {
    void *target;
    int pitch;
    if (SDL_LockTexture(eye, NULL, &target, &pitch)) {
        fprintf(stderr, "Error locking buffer for eye: %s\n", SDL_GetError());
        return;
    }
    copyScreenTexture(target, bytes, pitch);
    SDL_UnlockTexture(eye);
}

void gfxUpdateLeftEye(GraphicsContext *gfx, const uint8_t *bytes) {
    gfxUpdateEye(gfx->leftEye, bytes);
}
void gfxUpdateRightEye(GraphicsContext *gfx, const uint8_t *bytes) {
    gfxUpdateEye(gfx->rightEye, bytes);
}

void gfxMenuInputBegin(GraphicsContext *gfx) {
    nk_input_begin(gfx->nk);
}

void gfxMenuHandleEvent(GraphicsContext *gfx, SDL_Event *event) {
    (void) gfx;
    nk_sdl_handle_event(event);
}

void gfxMenuInputEnd(GraphicsContext *gfx) {
    nk_sdl_handle_grab();
    nk_input_end(gfx->nk);
}

void gfxRender(GraphicsContext *gfx) {
    /* GUI */
    if (nk_begin(gfx->nk, "Demo", nk_rect(50, 50, 230, 250),
        NK_WINDOW_BORDER|NK_WINDOW_MOVABLE|NK_WINDOW_SCALABLE|
        NK_WINDOW_MINIMIZABLE|NK_WINDOW_TITLE))
    {
        enum {EASY, HARD};
        static int op = EASY;
        static int property = 20;

        nk_layout_row_static(gfx->nk, 30, 80, 1);
        if (nk_button_label(gfx->nk, "button"))
            fprintf(stdout, "button pressed\n");
        nk_layout_row_dynamic(gfx->nk, 30, 2);
        if (nk_option_label(gfx->nk, "easy", op == EASY)) op = EASY;
        if (nk_option_label(gfx->nk, "hard", op == HARD)) op = HARD;
        nk_layout_row_dynamic(gfx->nk, 25, 1);
        nk_property_int(gfx->nk, "Compression:", 0, &property, 100, 10, 1);

        nk_layout_row_dynamic(gfx->nk, 20, 1);
        nk_label(gfx->nk, "background:", NK_TEXT_LEFT);
        nk_layout_row_dynamic(gfx->nk, 25, 1);
        if (nk_combo_begin_color(gfx->nk, nk_rgb_cf(gfx->bg), nk_vec2(nk_widget_width(gfx->nk),400))) {
            nk_layout_row_dynamic(gfx->nk, 120, 1);
            gfx->bg = nk_color_picker(gfx->nk, gfx->bg, NK_RGBA);
            nk_layout_row_dynamic(gfx->nk, 25, 1);
            gfx->bg.r = nk_propertyf(gfx->nk, "#R:", 0, gfx->bg.r, 1.0f, 0.01f,0.005f);
            gfx->bg.g = nk_propertyf(gfx->nk, "#G:", 0, gfx->bg.g, 1.0f, 0.01f,0.005f);
            gfx->bg.b = nk_propertyf(gfx->nk, "#B:", 0, gfx->bg.b, 1.0f, 0.01f,0.005f);
            gfx->bg.a = nk_propertyf(gfx->nk, "#A:", 0, gfx->bg.a, 1.0f, 0.01f,0.005f);
            nk_combo_end(gfx->nk);
        }
    }
    nk_end(gfx->nk);

    SDL_SetRenderDrawColor(gfx->renderer, gfx->bg.r * 255, gfx->bg.g * 255, gfx->bg.b * 255, gfx->bg.a * 255);
    SDL_RenderClear(gfx->renderer);

    nk_sdl_render(NK_ANTI_ALIASING_ON);

    SDL_RenderPresent(gfx->renderer);
}