/*******************************************************************************************
*
*   raylib - sample game: space invaders
*
*   Based on Sample game developed by Ian Eito, Albert Martos and Ramon Santamaria
*   Modifed by Monster Brain (monsterbraininc.com) - 2018
*   
*   This game has been created using raylib v1.3 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Copyright (c) 2015 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include <math.h>
#include "raylib.h"

//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------

typedef struct Player
{
    Rectangle rect;
    Vector2 speed;
    Color color;
} Player;

typedef struct Enemy
{
    Rectangle rect;
    Vector2 speed;
    bool active;
    Color color;
} Enemy;

typedef struct Shoot
{
    Rectangle rect;
    Vector2 speed;
    bool active;
    Color color;
} Shoot;

//----------------------------------------------------------------------------------
// Some Defines
//----------------------------------------------------------------------------------
#define NUM_SHOOTS 50
#define NUM_MAX_ENEMIES 50
#define FIRST_WAVE 10
#define SECOND_WAVE 20
#define THIRD_WAVE 50

//------------------------------------------------------------------------------------
// Global Variables Declaration
//------------------------------------------------------------------------------------
static int screenWidth = 800;
static int screenHeight = 450;

static Player player;
static Enemy enemy[NUM_MAX_ENEMIES];
static Shoot shoot[NUM_SHOOTS];

static int shootRate;

static int activeEnemies;

static Sound sfxShoot;
static Sound sfxExplode;

//------------------------------------------------------------------------------------
// Module Functions Declaration (local)
//------------------------------------------------------------------------------------
static void InitGame(void);        // Initialize game
static void UpdateGame(void);      // Update game (one frame)
static void DrawGame(void);        // Draw game (one frame)
static void UnloadGame(void);      // Unload game
static void UpdateDrawFrame(void); // Update and Draw (one frame)

int main()
{

    InitWindow(screenWidth, screenHeight, "Space Invader - Sample");

    // Initialize audio device
    InitAudioDevice();

    InitGame();

    SetTargetFPS(60);

    // Main game loop
    while (!WindowShouldClose()) // Detect window close button or ESC key
    {
        // Update and Draw
        UpdateDrawFrame();
    }

    UnloadGame();

    CloseWindow();
    return 0;
}

// Module Functions Definitions (local)

// Initialize game variables
void InitGame(void)
{
    activeEnemies = 10;
    shootRate = 0;

    sfxShoot = LoadSound("shoot.ogg");
    sfxExplode = LoadSound("explode.ogg");

    // Initialize player
    player.rect.x = screenWidth / 2.0f;
    player.rect.y = screenHeight - 20;
    player.rect.width = 20;
    player.rect.height = 20;
    player.speed.x = 5;
    player.speed.y = 5;
    player.color = BLACK;

    // Initialize enemies
    for (int i = 0; i < NUM_MAX_ENEMIES; i++)
    {
        enemy[i].rect.width = 20;
        enemy[i].rect.height = 20;
        enemy[i].rect.x = GetRandomValue(0, screenWidth);
        enemy[i].rect.y = GetRandomValue(-screenHeight, -20);
        enemy[i].speed.x = 5;
        enemy[i].speed.y = 5;
        enemy[i].active = true;
        enemy[i].color = BLUE;
    }

    // Initialize shoots
    for (int i = 0; i < NUM_SHOOTS; i++)
    {
        shoot[i].rect.x = player.rect.x;
        shoot[i].rect.y = player.rect.y + player.rect.height / 4;
        shoot[i].rect.width = 5;
        shoot[i].rect.height = 10;
        shoot[i].speed.x = 0;
        shoot[i].speed.y = -10;
        shoot[i].active = false;
        shoot[i].color = MAROON;
    }
}

// Update game (one frame)
void UpdateGame(void)
{
    // Player movement
    if (IsKeyDown(KEY_RIGHT))
        player.rect.x += player.speed.x;
    if (IsKeyDown(KEY_LEFT))
        player.rect.x -= player.speed.x;

    // Enemy behaviour
    for (int i = 0; i < activeEnemies; i++)
    {
        if (enemy[i].active)
        {
            enemy[i].rect.y += enemy[i].speed.y;

            if (enemy[i].rect.y > screenHeight)
            {
                enemy[i].rect.x = GetRandomValue(0, screenWidth);
                enemy[i].rect.y = GetRandomValue(-screenHeight, -20);
            }
        }
    }

    // Wall behaviour
    if (player.rect.x <= 0)
        player.rect.x = 0;
    if (player.rect.x + player.rect.width >= screenWidth)
        player.rect.x = screenWidth - player.rect.width;

    //Shoot initialization
    if (IsKeyDown(KEY_SPACE))
    {

        shootRate += 5;

        for (int i = 0; i < NUM_SHOOTS; i++)
        {
            if (!shoot[i].active && shootRate % 40 == 0)
            {
                PlaySound(sfxShoot);
                shoot[i].rect.x = player.rect.x;
                shoot[i].rect.y = player.rect.y + player.rect.height / 4;
                shoot[i].active = true;
                break;
            }
        }
    }

    // Shoot logic
    for (int i = 0; i < NUM_SHOOTS; i++)
    {
        if (shoot[i].active)
        {
            // Movement
            shoot[i].rect.y += shoot[i].speed.y;

            // Collision with enemy
            for (int j = 0; j < activeEnemies; j++)
            {
                if (enemy[j].active)
                {
                    if (CheckCollisionRecs(shoot[i].rect, enemy[j].rect))
                    {
                        shoot[i].active = false;
                        enemy[j].rect.x = GetRandomValue(screenWidth, screenWidth + 1000);
                        enemy[j].rect.y = GetRandomValue(0, screenHeight - enemy[j].rect.height);
                        shootRate = 0;

                        PlaySound(sfxExplode);
                        // enemiesKill++;
                        // score += 100;
                    }

                    if (shoot[i].rect.y <= 0) //goes above the screen
                    {
                        shoot[i].active = false;
                        shootRate = 0;
                    }
                }
            }
        }
    }
}

// Draw game (one frame)
void DrawGame(void)
{
    BeginDrawing();

    ClearBackground(RAYWHITE);

    DrawRectangleRec(player.rect, player.color);

    for (int i = 0; i < activeEnemies; i++)
    {
        if (enemy[i].active)
            DrawRectangleRec(enemy[i].rect, enemy[i].color);
    }

    for (int i = 0; i < NUM_SHOOTS; i++)
    {
        if (shoot[i].active)
            DrawRectangleRec(shoot[i].rect, shoot[i].color);
    }

    EndDrawing();
}

// Update and Draw (one frame)
void UpdateDrawFrame(void)
{
    UpdateGame();
    DrawGame();
}

void UnloadGame(void){
    UnloadSound(sfxShoot);
    UnloadSound(sfxExplode);
}