#include "DrawUtils.h"

#include <cmath>
#include <coreinit/cache.h>
#include <coreinit/memory.h>
#include <coreinit/screen.h>
#include <ft2build.h>
#include <png.h>
#include FT_FREETYPE_H

// buffer width
#define TV_WIDTH 0x500
#define DRC_WIDTH 0x380

bool DrawUtils::isBackBuffer;

uint8_t *DrawUtils::tvBuffer = nullptr;
uint32_t DrawUtils::tvSize = 0;
uint8_t *DrawUtils::drcBuffer = nullptr;
uint32_t DrawUtils::drcSize = 0;

// Don't put those into the class or we have to include ft everywhere
static FT_Library ft_lib = nullptr;
static FT_Face ft_face = nullptr;
static Color font_col = {0xFFFFFFFF};

void DrawUtils::initBuffers(void *tvBuffer, uint32_t tvSize, void *drcBuffer, uint32_t drcSize) {
    DrawUtils::tvBuffer = (uint8_t *) tvBuffer;
    DrawUtils::tvSize = tvSize;
    DrawUtils::drcBuffer = (uint8_t *) drcBuffer;
    DrawUtils::drcSize = drcSize;
}

void DrawUtils::beginDraw() {
    uint32_t pixel = *(uint32_t *) tvBuffer;

    // check which buffer is currently used
    OSScreenPutPixelEx(SCREEN_TV, 0, 0, 0xABCDEF90);
    if (*(uint32_t *) tvBuffer == 0xABCDEF90) {
        isBackBuffer = false;
    } else {
        isBackBuffer = true;
    }

    // restore the pixel we used for checking
    *(uint32_t *) tvBuffer = pixel;
}

void DrawUtils::endDraw() {
    // OSScreenFlipBuffersEx already flushes the cache?
    // DCFlushRange(tvBuffer, tvSize);
    // DCFlushRange(drcBuffer, drcSize);

    OSScreenFlipBuffersEx(SCREEN_DRC);
    OSScreenFlipBuffersEx(SCREEN_TV);
}

void DrawUtils::clear(Color col) {
    OSScreenClearBufferEx(SCREEN_TV, col.color);
    OSScreenClearBufferEx(SCREEN_DRC, col.color);
}

void DrawUtils::drawPixel(uint32_t x, uint32_t y, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
    float opacity = a / 255.0f;

    // put pixel in the drc buffer
    uint32_t i = (x + y * DRC_WIDTH) * 4;
    if (i + 3 < drcSize / 2) {
        if (isBackBuffer) {
            i += drcSize / 2;
        }
        if (a == 0xFF) {
            drcBuffer[i] = r;
            drcBuffer[i + 1] = g;
            drcBuffer[i + 2] = b;
        } else {
            drcBuffer[i] = r * opacity + drcBuffer[i] * (1 - opacity);
            drcBuffer[i + 1] = g * opacity + drcBuffer[i + 1] * (1 - opacity);
            drcBuffer[i + 2] = b * opacity + drcBuffer[i + 2] * (1 - opacity);
        }
    }

    // scale and put pixel in the tv buffer
    for (uint32_t yy = (y * 1.5); yy < ((y * 1.5) + 1); yy++) {
        for (uint32_t xx = (x * 1.5); xx < ((x * 1.5) + 1); xx++) {
            uint32_t i = (xx + yy * TV_WIDTH) * 4;
            if (i + 3 < tvSize / 2) {
                if (isBackBuffer) {
                    i += tvSize / 2;
                }
                if (a == 0xFF) {
                    tvBuffer[i] = r;
                    tvBuffer[i + 1] = g;
                    tvBuffer[i + 2] = b;
                } else {
                    tvBuffer[i] = r * opacity + tvBuffer[i] * (1 - opacity);
                    tvBuffer[i + 1] = g * opacity + tvBuffer[i + 1] * (1 - opacity);
                    tvBuffer[i + 2] = b * opacity + tvBuffer[i + 2] * (1 - opacity);
                }
            }
        }
    }
}

void DrawUtils::drawRectFilled(uint32_t x, uint32_t y, uint32_t w, uint32_t h, Color col) {
    for (uint32_t yy = y; yy < y + h; yy++) {
        for (uint32_t xx = x; xx < x + w; xx++) {
            drawPixel(xx, yy, col);
        }
    }
}

void DrawUtils::drawRect(uint32_t x, uint32_t y, uint32_t w, uint32_t h, uint32_t borderSize, Color col) {
    drawRectFilled(x, y, w, borderSize, col);
    drawRectFilled(x, y + h - borderSize, w, borderSize, col);
    drawRectFilled(x, y, borderSize, h, col);
    drawRectFilled(x + w - borderSize, y, borderSize, h, col);
}

void DrawUtils::drawBitmap(uint32_t x, uint32_t y, uint32_t target_width, uint32_t target_height, const uint8_t *data) {
    if (data[0] != 'B' || data[1] != 'M') {
        // invalid header
        return;
    }

    uint32_t dataPos = __builtin_bswap32(*(uint32_t *) &(data[0x0A]));
    uint32_t width = __builtin_bswap32(*(uint32_t *) &(data[0x12]));
    uint32_t height = __builtin_bswap32(*(uint32_t *) &(data[0x16]));

    if (dataPos == 0) {
        dataPos = 54;
    }

    data += dataPos;

    // TODO flip image since bitmaps are stored upside down

    for (uint32_t yy = y; yy < y + target_height; yy++) {
        for (uint32_t xx = x; xx < x + target_width; xx++) {
            uint32_t i = (((xx - x) * width / target_width) + ((yy - y) * height / target_height) * width) * 3;
            drawPixel(xx, yy, data[i + 2], data[i + 1], data[i], 0xFF);
        }
    }
}

static void png_read_data(png_structp png_ptr, png_bytep outBytes, png_size_t byteCountToRead) {
    void **data = (void **) png_get_io_ptr(png_ptr);

    memcpy(outBytes, *data, byteCountToRead);
    *((uint8_t **) data) += byteCountToRead;
}

void DrawUtils::drawPNG(uint32_t x, uint32_t y, const uint8_t *data) {
    png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    if (png_ptr == NULL) {
        return;
    }

    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (info_ptr == NULL) {
        png_destroy_read_struct(&png_ptr, NULL, NULL);
        return;
    }

    png_set_read_fn(png_ptr, (void *) &data, png_read_data);

    png_read_info(png_ptr, info_ptr);

    uint32_t width = 0;
    uint32_t height = 0;
    int bitDepth = 0;
    int colorType = -1;
    uint32_t retval = png_get_IHDR(png_ptr, info_ptr, &width, &height, &bitDepth, &colorType, NULL, NULL, NULL);
    if (retval != 1) {
        return;
    }

    uint32_t bytesPerRow = png_get_rowbytes(png_ptr, info_ptr);
    uint8_t *rowData = new uint8_t[bytesPerRow];

    for (uint32_t yy = y; yy < y + height; yy++) {
        png_read_row(png_ptr, (png_bytep) rowData, NULL);

        for (uint32_t xx = x; xx < x + width; xx++) {
            if (colorType == PNG_COLOR_TYPE_RGB_ALPHA) {
                uint32_t i = (xx - x) * 4;
                drawPixel(xx, yy, rowData[i], rowData[i + 1], rowData[i + 2], rowData[i + 3]);
            } else if (colorType == PNG_COLOR_TYPE_RGB) {
                uint32_t i = (xx - x) * 3;
                drawPixel(xx, yy, rowData[i], rowData[i + 1], rowData[i + 2], 0xFF);
            }
        }
    }

    delete[] rowData;
    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
}

void DrawUtils::initFont() {
    void *font = NULL;
    uint32_t size = 0;
    OSGetSharedData(OS_SHAREDDATATYPE_FONT_STANDARD, 0, &font, &size);

    if (font && size) {
        FT_Init_FreeType(&ft_lib);
        FT_New_Memory_Face(ft_lib, (FT_Byte *) font, size, 0, &ft_face);
    }
}

void DrawUtils::deinitFont() {
    FT_Done_Face(ft_face);
    FT_Done_FreeType(ft_lib);
}

void DrawUtils::setFontSize(uint32_t size) {
    FT_Set_Pixel_Sizes(ft_face, 0, size);
}

void DrawUtils::setFontColor(Color col) {
    font_col = col;
}

static void draw_freetype_bitmap(FT_Bitmap *bitmap, FT_Int x, FT_Int y) {
    FT_Int i, j, p, q;
    FT_Int x_max = x + bitmap->width;
    FT_Int y_max = y + bitmap->rows;

    for (i = x, p = 0; i < x_max; i++, p++) {
        for (j = y, q = 0; j < y_max; j++, q++) {
            if (i < 0 || j < 0 || i >= SCREEN_WIDTH || j >= SCREEN_HEIGHT) {
                continue;
            }

            float opacity = bitmap->buffer[q * bitmap->pitch + p] / 255.0f;
            DrawUtils::drawPixel(i, j, font_col.r, font_col.g, font_col.b, font_col.a * opacity);
        }
    }
}

void DrawUtils::print(uint32_t x, uint32_t y, const char *string, bool alignRight) {
    wchar_t *buffer = new wchar_t[strlen(string) + 1];

    size_t num = mbstowcs(buffer, string, strlen(string));
    if (num > 0) {
        buffer[num] = 0;
    } else {
        wchar_t *tmp = buffer;
        while ((*tmp++ = *string++))
            ;
    }

    print(x, y, buffer, alignRight);
    delete[] buffer;
}

void DrawUtils::print(uint32_t x, uint32_t y, const wchar_t *string, bool alignRight) {
    FT_GlyphSlot slot = ft_face->glyph;
    FT_Vector pen = {(int) x, (int) y};

    if (alignRight) {
        pen.x -= getTextWidth(string);
    }

    for (; *string; string++) {
        uint32_t charcode = *string;

        if (charcode == '\n') {
            pen.y += ft_face->size->metrics.height >> 6;
            pen.x = x;
            continue;
        }

        FT_Load_Glyph(ft_face, FT_Get_Char_Index(ft_face, charcode), FT_LOAD_DEFAULT);
        FT_Render_Glyph(slot, FT_RENDER_MODE_NORMAL);

        draw_freetype_bitmap(&slot->bitmap, pen.x + slot->bitmap_left, pen.y - slot->bitmap_top);
        pen.x += slot->advance.x >> 6;
    }
}

uint32_t DrawUtils::getTextWidth(const char *string) {
    wchar_t *buffer = new wchar_t[strlen(string) + 1];

    size_t num = mbstowcs(buffer, string, strlen(string));
    if (num > 0) {
        buffer[num] = 0;
    } else {
        wchar_t *tmp = buffer;
        while ((*tmp++ = *string++))
            ;
    }

    uint32_t width = getTextWidth(buffer);
    delete[] buffer;

    return width;
}

uint32_t DrawUtils::getTextWidth(const wchar_t *string) {
    FT_GlyphSlot slot = ft_face->glyph;
    uint32_t width = 0;

    for (; *string; string++) {
        FT_Load_Glyph(ft_face, FT_Get_Char_Index(ft_face, *string), FT_LOAD_BITMAP_METRICS_ONLY);

        width += slot->advance.x >> 6;
    }

    return width;
}