using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class ObstacleManager : MonoBehaviour {
	
	public float minSpawnRate = 2.5f; //rate of obstacle spawn
	public float maxSpawnRate = 5.0f; //rate of obstacle spawn
	public float maxSpeed = 0.1f; //speed at which objects move to left
	public float secondsPerPoint = 5.0f;
	
	//hard coding each obstacle type in this one mega class because small game
	public GameObject foodstuffPrefab;			//0
	public GameObject flyingFoodstuffPrefab;	//0
	public GameObject ballPrefab;				//1
	public GameObject verticalCactiPrefab;		//2
	public GameObject loopPrefab;				//3
	public GameObject loopFlippedPrefab;		//4
	public GameObject curvyCavePrefab;			//5
	public GameObject curvyCaveFlippedPrefab;	//6
	
	public GameObject foregroundPrefab;
	public GameObject backgroundPrefab;
	public GameObject backgroundBGPrefab;
	
	private List<GameObject> obstacles = new List<GameObject>(); //all active obstacles
	private List<GameObject> foregrounds = new List<GameObject>(); //all active foregrounds
	private List<GameObject> backgrounds = new List<GameObject>(); //all active backgrounds
	private List<GameObject> backgroundBGs = new List<GameObject>(); //all active backgroundBGs
	private float timeTilObstacleSpawn = 0;
	private int nextObstacle; //corresponding to prefabs as shown above
	private System.Random rng;

	private GUIText scoreDisplay;
	private float timeTilNextPoint;
	private int points;

	private bool paused = false;

	void Start () {
		rng = new System.Random();
		scoreDisplay = GameObject.Find ("Score Display").GetComponent<GUIText>();
		scoreDisplay.text = "0";
		paused = true;

		PlanNextObstacle();
		timeTilObstacleSpawn = 0;
		
		//initialize non-obstacle-y scenery lists
		CreateSceneryAtPos(new Vector3(-8.0f, 0.0f));
		CreateSceneryAtPos(new Vector3(0.0f, 0.0f));
		CreateSceneryAtPos(new Vector3(8.0f, 0.0f));
	}

	void CreateSceneryAtPos(Vector3 spawnPosition) {
		GameObject newObject = Instantiate(foregroundPrefab, 
		                        spawnPosition, 
		                        Quaternion.identity) as GameObject;
		foregrounds.Add(newObject);
		newObject = Instantiate(backgroundPrefab, 
		                        spawnPosition, 
		                        Quaternion.identity) as GameObject;
		backgrounds.Add(newObject);
		newObject = Instantiate(backgroundBGPrefab, 
		                        spawnPosition, 
		                        Quaternion.identity) as GameObject;
		backgroundBGs.Add(newObject);
	}

	void FixedUpdate () {
		timeTilObstacleSpawn -= Time.fixedDeltaTime;
		timeTilNextPoint -= Time.fixedDeltaTime;

		//spawn obstacle if it's time
		if (!paused && timeTilObstacleSpawn <= 0) {
			switch (nextObstacle) {
			case 0:
				SpawnFoodstuffs();
				break;
			case 1:
				SpawnBalls();
				break;
			case 2:
				SpawnVerticalCacti();
				break;
			case 3:
				SpawnLoop(false);
				break;
			case 4:
				SpawnLoop(true);
				break;
			case 5:
				SpawnCurvyCave(false);
				break;
			case 6:
				SpawnCurvyCave(true);
				break;
			default:
				break;
			}

			PlanNextObstacle();
		}

		if (!paused && timeTilNextPoint <= 0) {
			GameObject.Find ("EarnPoint").audio.Play();
			++points;
			scoreDisplay.text = points.ToString();
			timeTilNextPoint = secondsPerPoint;
		}
		
		//check first obstacle in list, if offscreen to left, destroy
		//	technically, multiple objects could be off screen at the same time, 
		//	if rng dictates it as such, but who cares, this is good enough
		if (obstacles.Count > 0) {
			GameObject firstObstacle = obstacles[0] as GameObject;
			if (firstObstacle.transform.position.x < -10.0f) {
				Destroy(firstObstacle);
				obstacles.RemoveAt(0);
			}
		}
		
		//loop through all objects, moving them to left
		foreach (GameObject obstacle in obstacles) {
			Vector3 position = obstacle.transform.position;
			position.x -= maxSpeed;
			obstacle.transform.position = position;
		}
		
		//check first foreground in list, if offscreen to left, destroy
		if (foregrounds.Count > 0) {
			GameObject firstForeground = foregrounds[0] as GameObject;
			if (firstForeground.transform.position.x <= -8.0f) {
				Destroy(firstForeground);
				foregrounds.RemoveAt(0);
				
				Vector3 spawnPosition = foregrounds[0].transform.position;
				spawnPosition.x += 8.0f;
				GameObject newForeground = Instantiate(foregroundPrefab, 
				                                       spawnPosition, 
				                                       Quaternion.identity) as GameObject;
				foregrounds.Add(newForeground);
			}
		}
		
		//loop through all foregrounds, moving them to left
		foreach (GameObject foreground in foregrounds) {
			Vector3 position = foreground.transform.position;
			position.x -= maxSpeed;
			foreground.transform.position = position;
		}
		
		//check first background in list, if offscreen to left, destroy
		if (backgrounds.Count > 0) {
			GameObject firstBackground = backgrounds[0] as GameObject;
			if (firstBackground.transform.position.x <= -8.0f) {
				Destroy(firstBackground);
				backgrounds.RemoveAt(0);
				
				Vector3 spawnPosition = backgrounds[0].transform.position;
				spawnPosition.x += 8.0f;
				GameObject newBackground = Instantiate(backgroundPrefab, 
				                                       spawnPosition, 
				                                       Quaternion.identity) as GameObject;
				backgrounds.Add(newBackground);
			}
		}
		
		//loop through all backgrounds, moving them to left
		foreach (GameObject background in backgrounds) {
			Vector3 position = background.transform.position;
			position.x -= maxSpeed/2;
			background.transform.position = position;
		}
		
		//check first background in list, if offscreen to left, destroy
		if (backgroundBGs.Count > 0) {
			GameObject firstBackgroundBG = backgroundBGs[0] as GameObject;
			if (firstBackgroundBG.transform.position.x <= -8.0f) {
				Destroy(firstBackgroundBG);
				backgroundBGs.RemoveAt(0);
				
				Vector3 spawnPosition = backgroundBGs[0].transform.position;
				spawnPosition.x += 8.0f;
				GameObject newBackgroundBG = Instantiate(backgroundBGPrefab, 
				                                         spawnPosition, 
				                                         Quaternion.identity) as GameObject;
				backgroundBGs.Add(newBackgroundBG);
			}
		}
		
		//loop through all backgrounds, moving them to left
		foreach (GameObject backgroundBG in backgroundBGs) {
			Vector3 position = backgroundBG.transform.position;
			position.x -= maxSpeed/4;
			backgroundBG.transform.position = position;
		}
	}

	public void Pause() {
		paused = true;

		GameObject.Find ("Score Text").GetComponent<GUIText>().text = points.ToString();
	}

	public void Reset() {
		foreach (GameObject obj in obstacles) {
			GameObject.Destroy(obj);
		}
		obstacles.Clear();
		PlanNextObstacle();
		timeTilObstacleSpawn = 0;
		
		scoreDisplay.text = "0";
		timeTilNextPoint = secondsPerPoint;
		points = 0;
		paused = false;
	}

	void PlanNextObstacle() {
		double result = (rng.NextDouble()*100.0f);

		//hard code (again!) probabilities because small game
		if (result <= 35) {
			//ball course
			nextObstacle = 1;
		}
		else if (result <= 70) {
			//cacti course
			nextObstacle = 2;
		}
		else if (result <= 77.5) {
			//loop 1
			nextObstacle = 3;
		}
		else if (result <= 85) {
			//loop 2
			nextObstacle = 4;
		}
		else if (result <= 92.5) {
			//curvy cave 1
			nextObstacle = 5;
		}
		else {//if (result <= 100) {
			//curvy cave 2
			nextObstacle = 6;
		}

		//nextObstacle = 5;
	}
	
	void SpawnFoodstuffs() {
		//spawn at same x coordinate, but varied y coordinate
		Vector3 spawnPosition = new Vector3(4.5f, (float)rng.NextDouble()*(3.0f-2.22f) - 3.0f);
		GameObject newFoodstuff = Instantiate(foodstuffPrefab, 
		                                      spawnPosition, 
		                                      Quaternion.identity) as GameObject;
		obstacles.Add (newFoodstuff);

		timeTilObstacleSpawn = 3f;
	}

	//haha this function is a mess
	void SpawnBalls() {
		//randomize number of columns of balls, from 2 to 10
		int numBallColumns = rng.Next (5,11);
		bool lastColHadFood = false;
		for (int i=0; i<numBallColumns; ++i) {
			//spawn at varied x and y coordinates, in stacks of three
			//top ball
			Vector3 spawnPosition = new Vector3(4.5f+2.0f*i+((float)rng.NextDouble()/1.0f),
			                                    (float)rng.NextDouble() - 2.5f);
			bool resetFood = lastColHadFood;
			GameObject newObject;
			//sometimes spawn foodstuff instead of ball
			if (lastColHadFood || rng.NextDouble() <= 0.8) {
				newObject = Instantiate(ballPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastColHadFood |= false;
			}
			else {
				newObject = Instantiate(flyingFoodstuffPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastColHadFood |= true;
			}
			
			obstacles.Add (newObject);

			//middle ball
			spawnPosition = new Vector3(4.5f+2.0f*i+((float)rng.NextDouble()/1.0f),
			                            (float)rng.NextDouble() - 0.5f);
			//sometimes spawn foodstuff instead of ball
			if (lastColHadFood || rng.NextDouble() <= 0.8) {
				newObject = Instantiate(ballPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastColHadFood |= false;
			}
			else {
				newObject = Instantiate(flyingFoodstuffPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastColHadFood |= true;
			}
			
			obstacles.Add (newObject);

			//bottom ball
			spawnPosition = new Vector3(4.5f+2.0f*i+((float)rng.NextDouble()/1.0f),
			                            (float)rng.NextDouble() + 1.5f);
			//sometimes spawn foodstuff instead of ball
			if (lastColHadFood || rng.NextDouble() <= 0.8) {
				newObject = Instantiate(ballPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastColHadFood |= false;
			}
			else {
				newObject = Instantiate(flyingFoodstuffPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastColHadFood |= true;
			}
			obstacles.Add (newObject);

			if (resetFood)
				lastColHadFood = false;
		}
		
		timeTilObstacleSpawn = 2*(0.5f + 1.0f*(numBallColumns))/(maxSpeed*(1/Time.fixedDeltaTime));
	}
	
	void SpawnVerticalCacti() {
		//randomize number of cacti, from 3 to 6
		int numCacti = rng.Next (3,7);
		bool lastObjectWasFood = false;
		for (int i=0; i<numCacti; ++i) {
			//spawn at same x coordinate, but varied y coordinate
			GameObject newObject;
			//sometimes spawn foodstuff instead of cactus, but never more than one in a row in same set of cacti
			if (lastObjectWasFood || rng.NextDouble() <= 0.7) {
				Vector3 spawnPosition = new Vector3(4.5f+2.5f*i, (float)rng.NextDouble()*4.0f - 2.0f);
				newObject = Instantiate(verticalCactiPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastObjectWasFood = false;
			}
			else {
				Vector3 spawnPosition = new Vector3(4.5f+2.5f*i, (float)rng.NextDouble()*(3.0f-2.22f) - 3.0f);
				newObject = Instantiate(foodstuffPrefab, 
				                        spawnPosition, 
				                        Quaternion.identity) as GameObject;
				lastObjectWasFood = true;
			}
			obstacles.Add (newObject);
		}
		
		timeTilObstacleSpawn = 2*(1.25f*(numCacti))/(maxSpeed*(1/Time.fixedDeltaTime))+0.5f;
	}

    void SpawnLoop(bool flipped) {
        //spawn at same x and y coordinate
		Vector3 spawnPosition = new Vector3(8.0f, 0.0f);
		GameObject newLoop;
		if (flipped)
			newLoop = Instantiate(loopPrefab, 
			                      spawnPosition, 
			                      Quaternion.identity) as GameObject;
		else
			newLoop = Instantiate(loopFlippedPrefab, 
			                      spawnPosition, 
			                      Quaternion.identity) as GameObject;
		obstacles.Add (newLoop);
		
		timeTilObstacleSpawn = 6f;
	}
	
	void SpawnCurvyCave(bool flipped) {
		//spawn at same x and y coordinate
		Vector3 spawnPosition = new Vector3(8.0f, 0.0f);
		GameObject newCurvyCave;
		if (flipped)
			newCurvyCave = Instantiate(curvyCavePrefab, 
			                      	   spawnPosition, 
			                      	   Quaternion.identity) as GameObject;
		else
			newCurvyCave = Instantiate(curvyCaveFlippedPrefab, 
			                           spawnPosition, 
			                           Quaternion.identity) as GameObject;
		obstacles.Add (newCurvyCave);
		
		timeTilObstacleSpawn = 6f;
	}
}