#define _CRT_SECURE_NO_WARNINGS 1 // for fopen

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <sys/time.h>
#include <unistd.h>
#include <pthread.h>

extern "C" {
#include "../src/libsm64.h"
#define SDL_MAIN_HANDLED
#include "level.h"
#include "context.h"
#include "renderer.h"
#include "gl33core/gl33core_renderer.h"
#include "gl20/gl20_renderer.h"
}

#include "audio.h"

int WINDOW_WIDTH = 1280;
int WINDOW_HEIGHT = 800;

uint8_t *utils_read_file_alloc( const char *path, size_t *fileLength )
{
    FILE *f = fopen( path, "rb" );

    if( !f ) return NULL;

    fseek( f, 0, SEEK_END );
    size_t length = (size_t)ftell( f );
    rewind( f );
    uint8_t *buffer = (uint8_t*)malloc( length + 1 );
    fread( buffer, 1, length, f );
    buffer[length] = 0;
    fclose( f );

    if( fileLength ) *fileLength = length;

    return buffer;
}

static float read_axis( int16_t val )
{
    float result = (float)val / 32767.0f;

    if( result < 0.2f && result > -0.2f )
        return 0.0f;

    return result > 0.0f ? (result - 0.2f) / 0.8f : (result + 0.2f) / 0.8f;
}

float lerp(float a, float b, float amount)
{
    return a + (b - a) * amount;
}

int main( void )
{
    size_t romSize;

    uint8_t *rom = utils_read_file_alloc( "baserom.us.z64", &romSize );

    if( rom == NULL )
    {
        printf("\nFailed to read ROM file \"baserom.us.z64\"\n\n");
        return 1;
    }

    uint8_t *texture = (uint8_t*)malloc( 4 * SM64_TEXTURE_WIDTH * SM64_TEXTURE_HEIGHT );

    sm64_global_terminate();
    sm64_global_init( rom, texture );
    sm64_audio_init(rom);
    sm64_static_surfaces_load( surfaces, surfaces_count );
    uint32_t marioId = sm64_mario_create( 0, 1000, 0 );

    free( rom );

    RenderState renderState;
    renderState.mario.index = NULL;
    vec3 cameraPos = { 0, 0, 0 };
    float cameraRot = 0.0f;

    struct Renderer *renderer;

    int major, minor, selection = 0;
    printf("Select OpenGL version\n1. OpenGL 3.3 Core\n2. OpenGL 2.0\n> ");
    scanf("%d", &selection);
    if (selection == 2)
    {
        printf("Launching with OpenGL 2.0\n\n");
        major = 2; minor = 0;
        renderer = &gl20_renderer;
    }
	else
    {
        printf("Launching with OpenGL 3.3 Core\n\n");
        major = 3; minor = 3;
        renderer = &gl33core_renderer;
    }

    printf("Select window resolution\n1. 1280x800\n2. 800x600\n> ");
    scanf("%d", &selection);
    if (selection == 2)
    {
        printf("Launching in 800x600\n");
		WINDOW_WIDTH = 800; WINDOW_HEIGHT = 600;
    }
	else
        printf("Launching in 1280x600\n");

    context_init( "libsm64", WINDOW_WIDTH, WINDOW_HEIGHT, major, minor );
    renderer->init( &renderState, texture );

    struct SM64MarioInputs marioInputs;
    struct SM64MarioState marioState;
    struct SM64MarioGeometryBuffers marioGeometry;

    // interpolation
    float lastPos[3], currPos[3];
    float lastGeoPos[9 * SM64_GEO_MAX_TRIANGLES], currGeoPos[9 * SM64_GEO_MAX_TRIANGLES];

    marioGeometry.position = (float*)malloc( sizeof(float) * 9 * SM64_GEO_MAX_TRIANGLES );
    marioGeometry.color    = (float*)malloc( sizeof(float) * 9 * SM64_GEO_MAX_TRIANGLES );
    marioGeometry.normal   = (float*)malloc( sizeof(float) * 9 * SM64_GEO_MAX_TRIANGLES );
    marioGeometry.uv       = (float*)malloc( sizeof(float) * 6 * SM64_GEO_MAX_TRIANGLES );
    marioGeometry.numTrianglesUsed = 0;

    float tick = 0, dt = 0;

    audio_init();

    do
    {
        uint64_t start = SDL_GetPerformanceCounter();

        SDL_GameController *controller = context_get_controller();
		float x_axis, y_axis, x0_axis;

        if (!controller) // keyboard
        {
            const Uint8* state = SDL_GetKeyboardState(NULL);

            float dir;
            float spd = 0;
			if (state[SDL_SCANCODE_UP] && state[SDL_SCANCODE_RIGHT])
			{
				dir = -M_PI * 0.25f;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_UP] && state[SDL_SCANCODE_LEFT])
			{
				dir = -M_PI * 0.75f;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_DOWN] && state[SDL_SCANCODE_RIGHT])
			{
				dir = M_PI * 0.25f;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_DOWN] && state[SDL_SCANCODE_LEFT])
			{
				dir = M_PI * 0.75f;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_UP])
			{
				dir = -M_PI * 0.5f;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_DOWN])
			{
				dir = M_PI * 0.5f;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_LEFT])
			{
				dir = M_PI;
				spd = 1;
			}
			else if (state[SDL_SCANCODE_RIGHT])
			{
				dir = 0;
				spd = 1;
			}

			x_axis = cosf(dir) * spd;
			y_axis = sinf(dir) * spd;
            x0_axis = state[SDL_SCANCODE_LSHIFT] ? 1 : state[SDL_SCANCODE_RSHIFT] ? -1 : 0;

            marioInputs.buttonA = state[SDL_SCANCODE_X];
            marioInputs.buttonB = state[SDL_SCANCODE_C];
            marioInputs.buttonZ = state[SDL_SCANCODE_Z];
        }
		else
		{
            x_axis = read_axis( SDL_GameControllerGetAxis( controller, SDL_CONTROLLER_AXIS_LEFTX ));
            y_axis = read_axis( SDL_GameControllerGetAxis( controller, SDL_CONTROLLER_AXIS_LEFTY ));
            x0_axis = read_axis( SDL_GameControllerGetAxis( controller, SDL_CONTROLLER_AXIS_RIGHTX ));

            marioInputs.buttonA = SDL_GameControllerGetButton( controller, (SDL_GameControllerButton)0 );
            marioInputs.buttonB = SDL_GameControllerGetButton( controller, (SDL_GameControllerButton)2 );
            marioInputs.buttonZ = SDL_GameControllerGetButton( controller, (SDL_GameControllerButton)9 );
		}

        cameraRot += x0_axis * dt * 2;
        cameraPos[0] = marioState.position[0] + 1000.0f * cosf( cameraRot );
        cameraPos[1] = marioState.position[1] + 200.0f;
        cameraPos[2] = marioState.position[2] + 1000.0f * sinf( cameraRot );

        marioInputs.camLookX = marioState.position[0] - cameraPos[0];
        marioInputs.camLookZ = marioState.position[2] - cameraPos[2];
        marioInputs.stickX = x_axis;
        marioInputs.stickY = y_axis;

        while (tick >= 1.f/30)
        {
            memcpy(lastPos, currPos, sizeof(currPos));
            memcpy(lastGeoPos, currGeoPos, sizeof(currGeoPos));

            tick -= 1.f/30;
            sm64_mario_tick( marioId, &marioInputs, &marioState, &marioGeometry );

            memcpy(currPos, marioState.position, sizeof(currPos));
            memcpy(currGeoPos, marioGeometry.position, sizeof(currGeoPos));
        }

        for (int i=0; i<3; i++) marioState.position[i] = lerp(lastPos[i], currPos[i], tick / (1.f/30));
        for (int i=0; i<marioGeometry.numTrianglesUsed*9; i++) marioGeometry.position[i] = lerp(lastGeoPos[i], currGeoPos[i], tick / (1.f/30));

        renderer->draw( &renderState, cameraPos, &marioState, &marioGeometry );

        uint64_t end = SDL_GetPerformanceCounter();
		dt = (float)(end-start) / (float)SDL_GetPerformanceFrequency();
		tick += dt;
    }
    while( context_flip_frame_poll_events() );

    sm64_global_terminate();
    context_terminate();

    return 0;
}