#include <stdio.h>
#include <stdlib.h>
#include "raylib.h"

const float gravity = 0.25;
const int bird_pos_x = 400;
const float bird_radius = 10.0;
const int pipe_vel = 3;
const int pipe_width = 50;
const int pipe_gap = 50;
const int pipe_height = 900;

struct Birdie {
  float velocityY;
  int positionY;
  bool is_colliding;
  int score;
};

struct Pipe {
  int positionX;
  int positionY;
};

struct DoublePipe {
  struct Pipe pipe1;
  struct Pipe pipe2;
};

void Jump(float* vel) {
  if (IsKeyPressed(KEY_UP) || GetTouchPointCount() != 0) {
    *vel = -7;
  }
}

void VelocityControl(float* vel) {
  if (*vel < -12) {
    *vel = -12;
  }
}

void FlappyBird(struct Birdie* bird) {
  Jump(&bird->velocityY);
  VelocityControl(&bird->velocityY);
  
  bird->velocityY += gravity;
  bird->positionY += (int)bird->velocityY;

  if (bird->positionY > GetScreenHeight()) {
    bird->positionY = GetScreenHeight();
    bird->velocityY = 0;
  }

  else if (bird->positionY < 0) {
    bird->positionY = 0;
    bird->velocityY = 0;
  }

  DrawCircle(bird_pos_x, bird->positionY, bird_radius, YELLOW);
}

struct DoublePipe CreateDoublePipe(int gap, int posY, int height) {
  struct DoublePipe double_pipe = {{GetScreenWidth(), posY - height - gap}, {GetScreenWidth(), posY + gap}};

  return double_pipe;
}

void DrawDoublePipe(struct DoublePipe* double_pipe) {
  DrawRectangle(double_pipe->pipe1.positionX, double_pipe->pipe1.positionY, pipe_width, pipe_height, GREEN);
  DrawRectangle(double_pipe->pipe2.positionX, double_pipe->pipe2.positionY, pipe_width, pipe_height, GREEN);
}

void MoveDoublePipe(struct DoublePipe* double_pipe, int height, int gap) {
  if (double_pipe->pipe1.positionX + pipe_width < 0 && double_pipe->pipe2.positionX < 0) {
    double_pipe->pipe1.positionX = GetScreenWidth();
    double_pipe->pipe2.positionX = GetScreenWidth();

    int randint = rand() % (GetScreenHeight() + 1);

    double_pipe->pipe1.positionY = randint - height - gap;
    double_pipe->pipe2.positionY = randint + gap;

  }

  double_pipe->pipe1.positionX -= 6;
  double_pipe->pipe2.positionX -= 6;
}

bool IsPlayerColliding(struct DoublePipe* double_pipe, struct Birdie* bird) {
  Rectangle rec1 = {double_pipe->pipe1.positionX, double_pipe->pipe1.positionY, pipe_width, pipe_height};
  Rectangle rec2 = {double_pipe->pipe2.positionX, double_pipe->pipe2.positionY, pipe_width, pipe_height};
  Vector2 center = {bird_pos_x, bird->positionY};
 
  return CheckCollisionCircleRec(center, bird_radius, rec1) || CheckCollisionCircleRec(center, bird_radius, rec2);
}

void Score(struct DoublePipe* double_pipe, struct Birdie* bird) {
  Rectangle rec1 = {double_pipe->pipe1.positionX, double_pipe->pipe1.positionY, pipe_width, pipe_height*25};
  Vector2 center = {bird_pos_x, bird->positionY};

  if (bird->is_colliding && !CheckCollisionCircleRec(center, bird_radius, rec1)) {
    bird->score += 1;
  }

  bird->is_colliding = CheckCollisionCircleRec(center, bird_radius, rec1);

  char array[20];
  sprintf(array, "%d", bird->score);
  DrawText(array, 10, 10, 12, WHITE);
}

enum GameState {
  Start,
  Game,
  Restart
};

enum GameState MainGame(struct DoublePipe* double_pipe, struct Birdie* bird, int pipe_height, int pipe_gap) {
    if (!IsPlayerColliding(double_pipe, bird)) {
      ClearBackground(BLACK);
    } else {
      return Restart;
    }

    FlappyBird(bird);

    DrawDoublePipe(double_pipe);
    MoveDoublePipe(double_pipe, pipe_height, pipe_gap);

    Score(double_pipe, bird);

    return Game;
}

enum GameState StartGame() {
  ClearBackground(BLACK);
  DrawText("Flappy bird", (GetScreenWidth()/2-(MeasureText("Flappy bird", 26)/2)), (GetScreenHeight()/2-13), 26, WHITE);
  DrawText("Press up to start", (GetScreenWidth()/2-(MeasureText("Press up to start", 12)/2)), (GetScreenHeight()/2+38), 12, WHITE);

  if (IsKeyPressed(KEY_UP) || GetTouchPointCount() != 0) {
    return Game;
  }

  return Start;
}

enum GameState RestartGame(struct DoublePipe* double_pipe, struct Birdie* bird) {
  ClearBackground(BLACK);

  char array[200];
  sprintf(array, "Your final score was: %d", bird->score);
  DrawText(array, (GetScreenWidth()/2-(MeasureText(array, 26)/2)), (GetScreenHeight()/2-13), 26, WHITE);
  DrawText("Press 'r' to restart", (GetScreenWidth()/2-(MeasureText("Press 'r' to restart", 12)/2)), (GetScreenHeight()/2+38), 12, WHITE);

  if (IsKeyPressed(KEY_R) || GetTouchPointCount() != 0) {
    struct Birdie new_bird = {0.0, 300, false, 0};

    *bird = new_bird;
    *double_pipe = CreateDoublePipe(pipe_gap, 200, pipe_height);
    
    return Game;
  }

  return Restart;
}

int main(void) {
  InitWindow(800, 600, "HELLO RAYLRIN!!!");
  SetTargetFPS(60);
  
  enum GameState gs = Start;

  struct Birdie bird = {0.0, 300, false, 0};
  struct DoublePipe double_pipe = CreateDoublePipe(pipe_gap, 200, pipe_height);

  while (!WindowShouldClose()) {
    BeginDrawing();

    switch (gs) {
      case Game:
        gs = MainGame(&double_pipe, &bird, pipe_height, pipe_gap);
        break;
      case Restart:
        gs = RestartGame(&double_pipe, &bird);
        break;
      case Start:
        gs = StartGame();
        break;
    }

    EndDrawing();
  }

  CloseWindow();
  return 0;
}