/*
 *  The Mana Client
 *  Copyright (C) 2004-2009  The Mana World Development Team
 *  Copyright (C) 2009-2012  The Mana Developers
 *
 *  This file is part of The Mana Client.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <cassert>

#include "graphics.h"
#include "log.h"

#include "resources/image.h"

#include "utils/gettext.h"

#include <SDL_gfxBlitFunc.h>
#include <SDL/SDL_rotozoom.h>

Graphics::Graphics():
    mWidth(0),
    mHeight(0),
    mScale(1),
    mBpp(0),
    mFullscreen(false),
    mHWAccel(false),
    mBlitMode(BLIT_NORMAL),
    mScreenSurface(0)
{
    mTarget = 0;
}

Graphics::~Graphics()
{
    _endDraw();
}

bool Graphics::setVideoMode(int w, int h, int bpp, bool fs, bool hwaccel)
{
    logger->log("Setting video mode %dx%d %s",
            w, h, fs ? "fullscreen" : "windowed");

    logger->log("Bits per pixel: %d", bpp);

    int displayFlags = SDL_ANYFORMAT;

    if (fs)
        displayFlags |= SDL_FULLSCREEN;
    else
        displayFlags |= SDL_RESIZABLE;

    if (hwaccel)
        displayFlags |= SDL_HWSURFACE | SDL_DOUBLEBUF;
    else
        displayFlags |= SDL_SWSURFACE;

    SDL_FreeSurface(mTarget);
    mTarget = 0;

    // Calculate scaling factor
    mScale = std::max(w / 640, h / 360);

    mScreenSurface = SDL_SetVideoMode(w, h, bpp, displayFlags);
    const SDL_PixelFormat& fmt = *(mScreenSurface->format);
    setTarget(SDL_CreateRGBSurface(SDL_SWSURFACE,
                                   w / mScale, h / mScale,
                                   fmt.BitsPerPixel,
                                   fmt.Rmask, fmt.Gmask, fmt.Bmask, 0));

    if (!mTarget)
        return false;

    mWidth = mTarget->w;
    mHeight = mTarget->h;
    mBpp = bpp;
    mFullscreen = fs;
    mHWAccel = hwaccel;

    char videoDriverName[64];

    if (SDL_VideoDriverName(videoDriverName, 64))
        logger->log("Using video driver: %s", videoDriverName);
    else
        logger->log("Using video driver: unknown");

    const SDL_VideoInfo *vi = SDL_GetVideoInfo();

    logger->log("Possible to create hardware surfaces: %s",
                vi->hw_available ? "yes" : "no");
    logger->log("Window manager available: %s",
                vi->wm_available ? "yes" : "no");
    logger->log("Accelerated hardware to hardware blits: %s",
                vi->blit_hw ? "yes" : "no");
    logger->log("Accelerated hardware to hardware colorkey blits: %s",
                vi->blit_hw_CC ? "yes" : "no");
    logger->log("Accelerated hardware to hardware alpha blits: %s",
                vi->blit_hw_A ? "yes" : "no");
    logger->log("Accelerated software to hardware blits: %s",
                vi->blit_sw ? "yes" : "no");
    logger->log("Accelerated software to hardware colorkey blits: %s",
                vi->blit_sw_CC ? "yes" : "no");
    logger->log("Accelerated software to hardware alpha blits: %s",
                vi->blit_sw_A ? "yes" : "no");
    logger->log("Accelerated color fills: %s",
                vi->blit_fill ? "yes" : "no");
    logger->log("Available video memory: %d", vi->video_mem);

    return true;
}

bool Graphics::changeVideoMode(int w, int h, int bpp, bool fs, bool hwaccel)
{
    // Just return success if we're already in this mode
    if (mScreenSurface && mScreenSurface->w == w &&
            mScreenSurface->h == h &&
            mBpp == bpp &&
            mFullscreen == fs &&
            mHWAccel == hwaccel)
        return true;

    _endDraw();

    bool success = setVideoMode(w, h, bpp, fs, hwaccel);

    // If it didn't work, try to restore fallback resolution. If that doesn't
    // work either, we're in big trouble and bail out.
    if (!success)
    {
        if (!setVideoMode(640, 360, mBpp, mFullscreen, mHWAccel))
        {
            logger->error(_("Failed to change video mode and couldn't "
                            "switch back to the fallback mode!"));
        }
    }

    _beginDraw();

    return success;
}

bool Graphics::drawImage(Image *image, int x, int y)
{
    if (image)
        return drawImage(image, 0, 0, x, y, image->mBounds.w, image->mBounds.h);
    else
        return false;
}

bool Graphics::drawRescaledImage(Image *image, int srcX, int srcY,
                               int dstX, int dstY,
                               int width, int height,
                               int desiredWidth, int desiredHeight,
                               bool useColor)
{
    // Check that preconditions for blitting are met.
    if (!mTarget || !image)
        return false;
    if (!image->mSDLSurface)
        return false;

    Image *tmpImage = image->SDLgetScaledImage(desiredWidth, desiredHeight);
    bool returnValue = false;

    if (!tmpImage)
        return false;

    dstX += mClipStack.top().xOffset;
    dstY += mClipStack.top().yOffset;

    srcX += image->mBounds.x;
    srcY += image->mBounds.y;

    SDL_Rect dstRect;
    SDL_Rect srcRect;
    dstRect.x = dstX; dstRect.y = dstY;
    srcRect.x = srcX; srcRect.y = srcY;
    srcRect.w = tmpImage->getWidth();
    srcRect.h = tmpImage->getHeight();

    returnValue = !(SDL_BlitSurface(tmpImage->mSDLSurface, &srcRect,
                                    mTarget, &dstRect) < 0);

    tmpImage->decRef(Resource::DeleteImmediately);

    return returnValue;
}

bool Graphics::drawImage(Image *image, int srcX, int srcY, int dstX, int dstY,
                         int width, int height, bool)
{
    // Check that preconditions for blitting are met.
    if (!mTarget || !image || !image->mSDLSurface)
        return false;

    dstX += mClipStack.top().xOffset;
    dstY += mClipStack.top().yOffset;

    srcX += image->mBounds.x;
    srcY += image->mBounds.y;

    SDL_Rect dstRect;
    SDL_Rect srcRect;
    dstRect.x = dstX; dstRect.y = dstY;
    srcRect.x = srcX; srcRect.y = srcY;
    srcRect.w = width;
    srcRect.h = height;

    if (mBlitMode == BLIT_NORMAL)
        return !(SDL_BlitSurface(image->mSDLSurface, &srcRect, mTarget, &dstRect) < 0);
    else
        return !(SDL_gfxBlitRGBA(image->mSDLSurface, &srcRect, mTarget, &dstRect) < 0);
}

void Graphics::drawImagePattern(Image *image, int x, int y, int w, int h)
{
    // Check that preconditions for blitting are met.
    if (!mTarget || !image)
        return;
    if (!image->mSDLSurface)
        return;

    const int iw = image->getWidth();
    const int ih = image->getHeight();

    if (iw == 0 || ih == 0)
        return;

    for (int py = 0; py < h; py += ih)     // Y position on pattern plane
    {
        int dh = (py + ih >= h) ? h - py : ih;
        int srcY = image->mBounds.y;
        int dstY = y + py + mClipStack.top().yOffset;

        for (int px = 0; px < w; px += iw) // X position on pattern plane
        {
            int dw = (px + iw >= w) ? w - px : iw;
            int srcX = image->mBounds.x;
            int dstX = x + px + mClipStack.top().xOffset;

            SDL_Rect dstRect;
            SDL_Rect srcRect;
            dstRect.x = dstX; dstRect.y = dstY;
            srcRect.x = srcX; srcRect.y = srcY;
            srcRect.w = dw;   srcRect.h = dh;

            SDL_BlitSurface(image->mSDLSurface, &srcRect, mTarget, &dstRect);
        }
    }
}

void Graphics::drawRescaledImagePattern(Image *image,
                                        int x, int y,
                                        int w, int h,
                                        int scaledWidth, int scaledHeight)
{
    // Check that preconditions for blitting are met.
    if (!mTarget || !image)
        return;
    if (!image->mSDLSurface)
        return;

    if (scaledHeight == 0 || scaledWidth == 0)
        return;

    Image *tmpImage = image->SDLgetScaledImage(scaledWidth, scaledHeight);
    if (!tmpImage)
        return;

    const int iw = tmpImage->getWidth();
    const int ih = tmpImage->getHeight();

    if (iw == 0 || ih == 0)
    {
        tmpImage->decRef(Resource::DeleteImmediately);
        return;
    }

    for (int py = 0; py < h; py += ih)     // Y position on pattern plane
    {
        int dh = (py + ih >= h) ? h - py : ih;
        int srcY = tmpImage->mBounds.y;
        int dstY = y + py + mClipStack.top().yOffset;

        for (int px = 0; px < w; px += iw) // X position on pattern plane
        {
            int dw = (px + iw >= w) ? w - px : iw;
            int srcX = tmpImage->mBounds.x;
            int dstX = x + px + mClipStack.top().xOffset;

            SDL_Rect dstRect;
            SDL_Rect srcRect;
            dstRect.x = dstX; dstRect.y = dstY;
            srcRect.x = srcX; srcRect.y = srcY;
            srcRect.w = dw;   srcRect.h = dh;

            SDL_BlitSurface(tmpImage->mSDLSurface, &srcRect, mTarget, &dstRect);
        }
    }

    tmpImage->decRef(Resource::DeleteImmediately);
}

void Graphics::drawImageRect(int x, int y, int w, int h,
                             Image *topLeft, Image *topRight,
                             Image *bottomLeft, Image *bottomRight,
                             Image *top, Image *right,
                             Image *bottom, Image *left,
                             Image *center)
{
    pushClipArea(gcn::Rectangle(x, y, w, h));

    // Draw the center area
    drawImagePattern(center,
            topLeft->getWidth(), topLeft->getHeight(),
            w - topLeft->getWidth() - topRight->getWidth(),
            h - topLeft->getHeight() - bottomLeft->getHeight());

    // Draw the sides
    drawImagePattern(top,
            left->getWidth(), 0,
            w - left->getWidth() - right->getWidth(), top->getHeight());
    drawImagePattern(bottom,
            left->getWidth(), h - bottom->getHeight(),
            w - left->getWidth() - right->getWidth(),
            bottom->getHeight());
    drawImagePattern(left,
            0, top->getHeight(),
            left->getWidth(),
            h - top->getHeight() - bottom->getHeight());
    drawImagePattern(right,
            w - right->getWidth(), top->getHeight(),
            right->getWidth(),
            h - top->getHeight() - bottom->getHeight());

    // Draw the corners
    drawImage(topLeft, 0, 0);
    drawImage(topRight, w - topRight->getWidth(), 0);
    drawImage(bottomLeft, 0, h - bottomLeft->getHeight());
    drawImage(bottomRight,
            w - bottomRight->getWidth(),
            h - bottomRight->getHeight());

    popClipArea();
}

void Graphics::drawImageRect(int x, int y, int w, int h,
                             const ImageRect &imgRect)
{
    drawImageRect(x, y, w, h,
            imgRect.grid[0], imgRect.grid[2], imgRect.grid[6], imgRect.grid[8],
            imgRect.grid[1], imgRect.grid[5], imgRect.grid[7], imgRect.grid[3],
            imgRect.grid[4]);
}

void Graphics::updateScreen()
{
    // Center viewport
    SDL_Rect dstRect;
    dstRect.x = (mScreenSurface->w-getWidth() * mScale) / 2;
    dstRect.y = (mScreenSurface->h-getHeight() * mScale) / 2;

    // Zoom in if necessary
    if (mScale > 1)
    {
        SDL_Surface *tmp = zoomSurface(mTarget, mScale, mScale, 0);

        // Copy temporary surface to screen
        SDL_BlitSurface(tmp, NULL, mScreenSurface, &dstRect);
        SDL_FreeSurface(tmp);
    }
    else
    {
        // Copy mTarget directly to screen
        SDL_BlitSurface(mTarget, NULL, mScreenSurface, &dstRect);
    }

    SDL_Flip(mScreenSurface);
}

SDL_Surface *Graphics::getScreenshot()
{
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
    int rmask = 0xff000000;
    int gmask = 0x00ff0000;
    int bmask = 0x0000ff00;
#else
    int rmask = 0x000000ff;
    int gmask = 0x0000ff00;
    int bmask = 0x00ff0000;
#endif
    int amask = 0x00000000;

    SDL_Surface *screenshot = SDL_CreateRGBSurface(SDL_SWSURFACE, mTarget->w,
            mTarget->h, 24, rmask, gmask, bmask, amask);

    SDL_BlitSurface(mTarget, NULL, screenshot, NULL);

    return screenshot;
}