/*
 * This file is part of the Colobot: Gold Edition source code
 * Copyright (C) 2001-2014, Daniel Roux, EPSITEC SA & TerranovaTeam
 * http://epsiteс.ch; http://colobot.info; http://github.com/colobot
 *
 * 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 3 of the License, or
 * (at your option) 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://gnu.org/licenses
 */
#include "app/system.h"

#include "common/config.h"
#include "common/logger.h"
#include "common/image.h"
#include "common/iman.h"

#include "graphics/opengl/gldevice.h"

#include "math/geometry.h"

#include <SDL.h>
#include <SDL_image.h>
#include <unistd.h>

#include <iostream>
#include <map>

enum KeySlots
{
    K_Forward,
    K_Back,
    K_Left,
    K_Right,
    K_Up,
    K_Down,
    K_Count
};
bool KEYMAP[K_Count] = { false };

Math::Point MOUSE_POS_BASE;

Math::Vector TRANSLATION(0.0f, 2.0f, 0.0f);
Math::Vector ROTATION, ROTATION_BASE;

const int FRAME_DELAY = 5000;

SystemTimeStamp *PREV_TIME = NULL, *CURR_TIME = NULL;

void Init(Gfx::CGLDevice *device)
{
    device->SetRenderState(Gfx::RENDER_STATE_DEPTH_TEST, true);
    device->SetShadeModel(Gfx::SHADE_SMOOTH);
}

void Render(Gfx::CGLDevice *device)
{
    device->BeginScene();

    Math::Matrix persp;
    Math::LoadProjectionMatrix(persp, Math::PI / 4.0f, (800.0f) / (600.0f), 0.1f, 100.0f);
    device->SetTransform(Gfx::TRANSFORM_PROJECTION, persp);


    Math::Matrix viewMat;
    Math::Matrix mat;

    viewMat.LoadIdentity();

    Math::LoadRotationXMatrix(mat, -ROTATION.x);
    viewMat = Math::MultiplyMatrices(viewMat, mat);

    Math::LoadRotationYMatrix(mat, -ROTATION.y);
    viewMat = Math::MultiplyMatrices(viewMat, mat);

    Math::LoadTranslationMatrix(mat, -TRANSLATION);
    viewMat = Math::MultiplyMatrices(viewMat, mat);

    device->SetTransform(Gfx::TRANSFORM_VIEW, viewMat);


    Math::Matrix worldMat;
    worldMat.LoadIdentity();
    device->SetTransform(Gfx::TRANSFORM_WORLD, worldMat);

    Gfx::VertexCol line[2] = {};

    for (int x = -40; x <= 40; ++x)
    {
        line[0].color = Gfx::Color(0.7f + x / 120.0f, 0.0f, 0.0f);
        line[0].coord.z = -40;
        line[0].coord.x = x;
        line[1].color = Gfx::Color(0.7f + x / 120.0f, 0.0f, 0.0f);
        line[1].coord.z =  40;
        line[1].coord.x = x;
        device->DrawPrimitive(Gfx::PRIMITIVE_LINES, line, 2);
    }

    for (int z = -40; z <= 40; ++z)
    {
        line[0].color = Gfx::Color(0.0f, 0.7f + z / 120.0f, 0.0f);
        line[0].coord.z = z;
        line[0].coord.x = -40;
        line[1].color = Gfx::Color(0.0f, 0.7f + z / 120.0f, 0.0f);
        line[1].coord.z = z;
        line[1].coord.x =  40;
        device->DrawPrimitive(Gfx::PRIMITIVE_LINES, line, 2);
    }


    Gfx::VertexCol quad[6] = {};

    for (int i = 0; i < 6; ++i)
        quad[i].color = Gfx::Color(1.0f, 1.0f, 0.0f);

    quad[0].coord = Math::Vector(-1.0f, -1.0f, 0.0f);
    quad[1].coord = Math::Vector( 1.0f, -1.0f, 0.0f);
    quad[2].coord = Math::Vector( 1.0f,  1.0f, 0.0f);
    quad[3].coord = Math::Vector( 1.0f,  1.0f, 0.0f);
    quad[4].coord = Math::Vector(-1.0f,  1.0f, 0.0f);
    quad[5].coord = Math::Vector(-1.0f, -1.0f, 0.0f);

    Math::LoadTranslationMatrix(worldMat, Math::Vector(40.0f, 2.0f, 40.0f));
    device->SetTransform(Gfx::TRANSFORM_WORLD, worldMat);

    device->DrawPrimitive(Gfx::PRIMITIVE_TRIANGLES, quad, 6);

    for (int i = 0; i < 6; ++i)
        quad[i].color = Gfx::Color(0.0f, 1.0f, 1.0f);

    Math::LoadTranslationMatrix(worldMat, Math::Vector(-40.0f, 2.0f, -40.0f));
    device->SetTransform(Gfx::TRANSFORM_WORLD, worldMat);

    device->DrawPrimitive(Gfx::PRIMITIVE_TRIANGLES, quad, 6);

    for (int i = 0; i < 6; ++i)
        quad[i].color = Gfx::Color(1.0f, 0.0f, 1.0f);

    Math::LoadTranslationMatrix(worldMat, Math::Vector(0.0f, 10.0f, 0.0f));
    device->SetTransform(Gfx::TRANSFORM_WORLD, worldMat);

    device->DrawPrimitive(Gfx::PRIMITIVE_TRIANGLES, quad, 6);

    device->EndScene();
}

void Update()
{
    const float TRANS_SPEED =  6.0f; // units / sec

    GetSystemUtils()->GetCurrentTimeStamp(CURR_TIME);
    float timeDiff = GetSystemUtils()->TimeStampDiff(PREV_TIME, CURR_TIME, STU_SEC);
    GetSystemUtils()->CopyTimeStamp(PREV_TIME, CURR_TIME);

    Math::Vector incTrans;

    if (KEYMAP[K_Forward])
        incTrans.z = +TRANS_SPEED * timeDiff;
    if (KEYMAP[K_Back])
        incTrans.z = -TRANS_SPEED * timeDiff;
    if (KEYMAP[K_Right])
        incTrans.x = +TRANS_SPEED * timeDiff;
    if (KEYMAP[K_Left])
        incTrans.x = -TRANS_SPEED * timeDiff;
    if (KEYMAP[K_Up])
        incTrans.y = +TRANS_SPEED * timeDiff;
    if (KEYMAP[K_Down])
        incTrans.y = -TRANS_SPEED * timeDiff;

    Math::Point rotTrans = Math::RotatePoint(-ROTATION.y, Math::Point(incTrans.x, incTrans.z));
    incTrans.x = rotTrans.x;
    incTrans.z = rotTrans.y;
    TRANSLATION += incTrans;
}

void KeyboardDown(SDLKey key)
{
    switch (key)
    {
        case SDLK_w:
            KEYMAP[K_Forward] = true;
            break;
        case SDLK_s:
            KEYMAP[K_Back] = true;
            break;
        case SDLK_d:
            KEYMAP[K_Right] = true;
            break;
        case SDLK_a:
            KEYMAP[K_Left] = true;
            break;
        case SDLK_z:
            KEYMAP[K_Down] = true;
            break;
        case SDLK_x:
            KEYMAP[K_Up] = true;
            break;
        default:
            break;
    }
}

void KeyboardUp(SDLKey key)
{
    switch (key)
    {
        case SDLK_w:
            KEYMAP[K_Forward] = false;
            break;
        case SDLK_s:
            KEYMAP[K_Back] = false;
            break;
        case SDLK_d:
            KEYMAP[K_Right] = false;
            break;
        case SDLK_a:
            KEYMAP[K_Left] = false;
            break;
        case SDLK_z:
            KEYMAP[K_Down] = false;
            break;
        case SDLK_x:
            KEYMAP[K_Up] = false;
            break;
        default:
            break;
    }
}

void MouseMove(int x, int y)
{
    Math::Point currentPos(static_cast<float>(x), static_cast<float>(y));

    static bool first = true;
    if (first || (x < 10) || (y < 10) || (x > 790) || (y > 590))
    {
        SDL_WarpMouse(400, 300);
        MOUSE_POS_BASE.x = 400;
        MOUSE_POS_BASE.y = 300;
        ROTATION_BASE = ROTATION;
        first = false;
        return;
    }

    ROTATION.y = ROTATION_BASE.y + (static_cast<float> (x - MOUSE_POS_BASE.x) / 800.0f) * Math::PI;
    ROTATION.x = ROTATION_BASE.x + (static_cast<float> (y - MOUSE_POS_BASE.y) / 600.0f) * Math::PI;
}

extern "C"
{

int SDL_MAIN_FUNC(int argc, char *argv[])
{
    CLogger logger;

    CSystemUtils* systemUtils = CSystemUtils::Create(); // platform-specific utils
    systemUtils->Init();

    PREV_TIME = GetSystemUtils()->CreateTimeStamp();
    CURR_TIME = GetSystemUtils()->CreateTimeStamp();

    GetSystemUtils()->GetCurrentTimeStamp(PREV_TIME);
    GetSystemUtils()->GetCurrentTimeStamp(CURR_TIME);

    // Without any error checking, for simplicity

    SDL_Init(SDL_INIT_VIDEO);

    IMG_Init(IMG_INIT_PNG);

    const SDL_VideoInfo *videoInfo = SDL_GetVideoInfo();

    Uint32 videoFlags = SDL_OPENGL | SDL_GL_DOUBLEBUFFER | SDL_HWPALETTE;

    if (videoInfo->hw_available)
        videoFlags |= SDL_HWSURFACE;
    else
        videoFlags |= SDL_SWSURFACE;

    if (videoInfo->blit_hw)
        videoFlags |= SDL_HWACCEL;


    SDL_GL_SetAttribute(SDL_GL_RED_SIZE,   8);
    SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE,  8);
    SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);

    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 8);

    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    SDL_Surface *surface = SDL_SetVideoMode(800, 600, 32, videoFlags);


    SDL_WM_SetCaption("Transform Test", "Transform Test");

    //SDL_WM_GrabInput(SDL_GRAB_ON);
    SDL_ShowCursor(SDL_DISABLE);

    Gfx::CGLDevice *device = new Gfx::CGLDevice(Gfx::GLDeviceConfig());
    device->Create();

    Init(device);

    bool done = false;
    while (! done)
    {
        Render(device);
        Update();

        SDL_GL_SwapBuffers();

        SDL_Event event;
        while (SDL_PollEvent(&event))
        {
            if (event.type == SDL_QUIT)
            {
                break;
                done = true;
            }
            else if (event.type == SDL_KEYDOWN)
            {
                if (event.key.keysym.sym == SDLK_q)
                {
                    done = true;
                    break;
                }
                else
                    KeyboardDown(event.key.keysym.sym);
            }
            else if (event.type == SDL_KEYUP)
                KeyboardUp(event.key.keysym.sym);
            else if (event.type == SDL_MOUSEMOTION)
                MouseMove(event.motion.x, event.motion.y);
        }

        usleep(FRAME_DELAY);
    }

    //SDL_WM_GrabInput(SDL_GRAB_OFF);
    SDL_ShowCursor(SDL_ENABLE);

    device->Destroy();
    delete device;

    SDL_FreeSurface(surface);

    IMG_Quit();

    SDL_Quit();

    GetSystemUtils()->DestroyTimeStamp(PREV_TIME);
    GetSystemUtils()->DestroyTimeStamp(CURR_TIME);

    return 0;
}

} // extern "C"