using UnityEngine;
using UnityEngine.Serialization;
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace Fungus
{
	/**
	 * The FungusScript class has been renamed to Flowchart to be more descriptive.
	 */
	[Obsolete("Use Flowchart class instead")]
	[ExecuteInEditMode]
	public class FungusScript : Flowchart
	{}

	/**
	 * Visual scripting controller for the Flowchart programming language.
	 * Flowchart objects may be edited visually using the Flowchart editor window.
	 */
	[ExecuteInEditMode]
	public class Flowchart : MonoBehaviour 
	{
		/**
		 * Scroll position of Flowchart editor window.
		 */
		[HideInInspector]
		public Vector2 scrollPos;

		/**
		 * Scroll position of Flowchart variables window.
		 */
		[HideInInspector]
		public Vector2 variablesScrollPos;

		/**
		 * Show the variables pane.
		 */
		[HideInInspector]
		public bool variablesExpanded = true;

		/**
		 * Height of command block view in inspector.
		 */
		[HideInInspector]
		public float blockViewHeight = 400;

		/**
		 * Zoom level of Flowchart editor window
		 */
		[HideInInspector]
		public float zoom = 1f;

		/**
		 * Scrollable area for Flowchart editor window.
		 */
		[HideInInspector]
		public Rect scrollViewRect;

		/**
		 * Currently selected block in the Flowchart editor.
		 */
		[HideInInspector]
		[FormerlySerializedAs("selectedSequence")]
		public Block selectedBlock;
		
		/**
		 * Currently selected command in the Flowchart editor.
		 */
		[HideInInspector]
		public List<Command> selectedCommands = new List<Command>();

		/**
		 * The list of variables that can be accessed by the Flowchart.
		 */
		[HideInInspector]
		public List<Variable> variables = new List<Variable>();

		[TextArea(3, 5)]
		[Tooltip("Description text displayed in the Flowchart editor window")]
		public string description = "";

		/**
	 	 * Minimum time for each command to execute when runSlowInEditor is enabled.
	 	 */
		[Range(0f, 5f)]
		[Tooltip("Minimum time that each command will take to execute when Run Slow In Editor is enabled")]
		public float runSlowDuration = 0.25f;

		/**
		 * Use command color when displaying the command list in the inspector.
		 */
		[Tooltip("Use command color when displaying the command list in the Fungus Editor window")]
		public bool colorCommands = true;
		
		/**
		 * Hides the Flowchart block and command components in the inspector.
		 * Deselect to inspect the block and command components that make up the Flowchart.
		 */
		[Tooltip("Hides the Flowchart block and command components in the inspector")]
		public bool hideComponents = true;

		/**
		 * Saves the selected block and commands when saving the scene.
		 * Helps avoid version control conflicts if you've only changed the active selection.
		 */
		[Tooltip("Saves the selected block and commands when saving the scene.")]
		public bool saveSelection = true;

		/**
		 * Unique identifier for identifying this flowchart in localized string keys.
		 */
		[Tooltip("Unique identifier for this flowchart in localized string keys. This id must be provided for localization string export to work.")]
		public string localizationId = "";

		/**
		 * Unique id to assign to the next created item.
		 * Increases monotonically every time a new item is added to the Flowchart.
		 */
		[FormerlySerializedAs("nextCommandId")]
		[SerializeField]
		protected int nextItemId = 0;

		/**
		 * Returns the next id to assign to a new flowchart item.
		 * Item ids increase monotically so they are guaranteed to
		 * be unique within a Flowchart.
		 */
		public int NextItemId()
		{
			return nextItemId++;
		}

		public virtual void OnEnable()
		{
			// Assign an item id to any block or command that doesn't have one yet.
			// This should only happen after loading a legacy Flowchart
			Block[] blocks = GetComponentsInChildren<Block>();
			foreach (Block block in blocks)
			{
				if (block.itemId == -1)
				{
					block.itemId = NextItemId();
				}
			}

			Command[] commands = GetComponentsInChildren<Command>();
			foreach (Command command in commands)
			{
				if (command.itemId == -1)
				{
					command.itemId = NextItemId();
				}
			}
		}

		protected virtual Block CreateBlockComponent(GameObject parent)
		{
			Block block = parent.AddComponent<Block>();
			return block;
		}

		/**
		 * Create a new block node which you can then add commands to.
		 */
		public virtual Block CreateBlock(Vector2 position)
		{
			Block b = CreateBlockComponent(gameObject);
			b.nodeRect.x = position.x;
			b.nodeRect.y = position.y;
			b.blockName = GetUniqueBlockKey(b.blockName, b);
			b.itemId = NextItemId();

			return b;
		}

		/**
		 * Start running another Flowchart by executing a specific child block.
		 * The block must be in an idle state to be executed.
		 * Returns true if the Block started execution.
		 */
		public virtual bool ExecuteBlock(string blockName)
		{
			Block [] blocks = GetComponentsInChildren<Block>();
			foreach (Block block in blocks)
			{
				if (block.blockName == blockName)
				{
					return ExecuteBlock(block);
				}
			}

			return false;
		}

		/**
		 * Sends a message to this Flowchart only.
		 * Any block with a matching MessageReceived event handler will start executing.
		 */
		public virtual void SendFungusMessage(string messageName)
		{
			MessageReceived[] eventHandlers = GetComponentsInChildren<MessageReceived>();
			foreach (MessageReceived eventHandler in eventHandlers)
			{
				eventHandler.OnSendFungusMessage(messageName);
			}
		}

		/**
		 * Sends a message to all Flowchart objects in the current scene.
		 * Any block with a matching MessageReceived event handler will start executing.
		 */
		public static void BroadcastFungusMessage(string messageName)
		{
			MessageReceived[] eventHandlers = GameObject.FindObjectsOfType<MessageReceived>();
			foreach (MessageReceived eventHandler in eventHandlers)
			{
				eventHandler.OnSendFungusMessage(messageName);
			}
		}

		/**
		 * Start running another Flowchart by executing a specific child block.
		 * The block must be in an idle state to be executed.
		 * Returns true if the Block started execution.
		 */
		public virtual bool ExecuteBlock(Block block)
		{
			// Block must be a component of the Flowchart game object
			if (block == null ||
			    block.gameObject != gameObject) 
			{
				return false;
			}

			// Can't restart a running block, have to wait until it's idle again
			if (block.IsExecuting())
			{
				return false;
			}

			// Execute the first command in the command list
			block.ExecuteCommand(0);

			return true;
		}

		/**
		 * Returns a new variable key that is guaranteed not to clash with any existing variable in the list.
		 */
		public virtual string GetUniqueVariableKey(string originalKey, Variable ignoreVariable = null)
		{
			int suffix = 0;
			string baseKey = originalKey;

			// Only letters and digits allowed
			char[] arr = baseKey.Where(c => (char.IsLetterOrDigit(c) || c == '_')).ToArray(); 
			baseKey = new string(arr);

			// No leading digits allowed
			baseKey = baseKey.TrimStart('0','1','2','3','4','5','6','7','8','9');

			// No empty keys allowed
			if (baseKey.Length == 0)
			{
				baseKey = "Var";
			}

			string key = baseKey;
			while (true)
			{
				bool collision = false;
				foreach(Variable variable in variables)
				{
					if (variable == null ||
						variable == ignoreVariable ||
					    variable.key == null)
					{
						continue;
					}

					if (variable.key.Equals(key, StringComparison.CurrentCultureIgnoreCase))
					{
						collision = true;
						suffix++;
						key = baseKey + suffix;
					}
				}
				
				if (!collision)
				{
					return key;
				}
			}
		}

		/**
		 * Returns a new Block key that is guaranteed not to clash with any existing Block in the Flowchart.
		 */
		public virtual string GetUniqueBlockKey(string originalKey, Block ignoreBlock = null)
		{
			int suffix = 0;
			string baseKey = originalKey.Trim();
			
			// No empty keys allowed
			if (baseKey.Length == 0)
			{
				baseKey = "New Block";
			}

			Block[] blocks = GetComponentsInChildren<Block>();

			string key = baseKey;
			while (true)
			{
				bool collision = false;
				foreach(Block block in blocks)
				{
					if (block == ignoreBlock ||
					    block.blockName == null)
					{
						continue;
					}
					
					if (block.blockName.Equals(key, StringComparison.CurrentCultureIgnoreCase))
					{
						collision = true;
						suffix++;
						key = baseKey + suffix;
					}
				}
				
				if (!collision)
				{
					return key;
				}
			}
		}

		/**
		 * Returns a new Label key that is guaranteed not to clash with any existing Label in the Block.
		 */
		public virtual string GetUniqueLabelKey(string originalKey, Label ignoreLabel)
		{
			int suffix = 0;
			string baseKey = originalKey.Trim();
			
			// No empty keys allowed
			if (baseKey.Length == 0)
			{
				baseKey = "New Label";
			}
			
			Block block = ignoreLabel.parentBlock;
			
			string key = baseKey;
			while (true)
			{
				bool collision = false;
				foreach(Command command in block.commandList)
				{
					Label label = command as Label;
					if (label == null ||
						label == ignoreLabel)
					{
						continue;
					}
					
					if (label.key.Equals(key, StringComparison.CurrentCultureIgnoreCase))
					{
						collision = true;
						suffix++;
						key = baseKey + suffix;
					}
				}
				
				if (!collision)
				{
					return key;
				}
			}
		}

		/**
		 * Returns the variable with the specified key, or null if the key is not found.
		 * You can then access the variable's value using the Value property. e.g.
		 * 	BooleanVariable boolVar = flowchart.GetVariable<BooleanVariable>("MyBool");
		 * 	boolVar.Value = false;
		 */
		public T GetVariable<T>(string key) where T : Variable
		{
			foreach (Variable variable in variables)
			{
				if (variable.key == key)
				{
					return variable as T;
				}
			}

			return null;
		}

		/**
		 * Gets a list of all variables with public scope in this Flowchart.
		 */
		public virtual List<Variable> GetPublicVariables()
		{
			List<Variable> publicVariables = new List<Variable>();
			foreach (Variable v in variables)
			{
				if (v.scope == VariableScope.Public)
				{
					publicVariables.Add(v);
				}
			}

			return publicVariables;
		}

		/**
		 * Gets the value of a boolean variable.
		 * Returns false if the variable key does not exist.
		 */
		public virtual bool GetBooleanVariable(string key)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					BooleanVariable variable = v as BooleanVariable;
					if (variable != null)
					{
						return variable.value;
					}
				}
			}
			Debug.LogWarning("Boolean variable " + key + " not found.");
			return false;
		}
					
		/**
		 * Sets the value of a boolean variable.
		 * The variable must already be added to the list of variables for this Flowchart.
		 */
		public virtual void SetBooleanVariable(string key, bool value)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					BooleanVariable variable = v as BooleanVariable;
					if (variable != null)
					{
						variable.value = value;
						return;
					}
				}
			}
			Debug.LogWarning("Boolean variable " + key + " not found.");
		}

		/**
		 * Gets the value of an integer variable.
		 * Returns 0 if the variable key does not exist.
		 */
		public virtual int GetIntegerVariable(string key)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					IntegerVariable variable = v as IntegerVariable;
					if (variable != null)
					{
						return variable.value;
					}
				}
			}
			Debug.LogWarning("Integer variable " + key + " not found.");
			return 0;
		}

		/**
		 * Sets the value of an integer variable.
		 * The variable must already be added to the list of variables for this Flowchart.
		 */
		public virtual void SetIntegerVariable(string key, int value)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					IntegerVariable variable = v as IntegerVariable;
					if (variable != null)
					{
						variable.value = value;
						return;
					}
				}
			}
			Debug.LogWarning("Integer variable " + key + " not found.");
		}

		/**
		 * Gets the value of a float variable.
		 * Returns 0 if the variable key does not exist.
		 */
		public virtual float GetFloatVariable(string key)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					FloatVariable variable = v as FloatVariable;
					if (variable != null)
					{
						return variable.value;
					}
				}
			}
			Debug.LogWarning("Float variable " + key + " not found.");
			return 0f;
		}
				
		/**
		 * Sets the value of a float variable.
		 * The variable must already be added to the list of variables for this Flowchart.
		 */
		public virtual void SetFloatVariable(string key, float value)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					FloatVariable variable = v as FloatVariable;
					if (variable != null)
					{
						variable.value = value;
						return;
					}
				}
			}
			Debug.LogWarning("Float variable " + key + " not found.");
		}

		/**
		 * Gets the value of a string variable.
		 * Returns the empty string if the variable key does not exist.
		 */
		public virtual string GetStringVariable(string key)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					StringVariable variable = v as StringVariable;
					if (variable != null)
					{
						return variable.value;
					}
				}
			}
			Debug.LogWarning("String variable " + key + " not found.");
			return "";
		}

		/**
		 * Sets the value of a string variable.
		 * The variable must already be added to the list of variables for this Flowchart.
		 */
		public virtual void SetStringVariable(string key, string value)
		{
			foreach (Variable v in variables)
			{
				if (v.key == key)
				{
					StringVariable variable = v as StringVariable;
					if (variable != null)
					{
						variable.value = value;
						return;
					}
				}
			}
			Debug.LogWarning("String variable " + key + " not found.");
		}

		/**
		 * Set the block objects to be hidden or visible depending on the hideComponents property.
		 */
		public virtual void UpdateHideFlags()
		{
			if (hideComponents)
			{
				Block[] blocks = GetComponentsInChildren<Block>();
				foreach (Block block in blocks)
				{
					block.hideFlags = HideFlags.HideInInspector;
					if (block.gameObject != gameObject)
					{
						block.gameObject.hideFlags = HideFlags.HideInHierarchy;
					}
				}

				Command[] commands = GetComponentsInChildren<Command>();
				foreach (Command command in commands)
				{
					command.hideFlags = HideFlags.HideInInspector;
				}

				EventHandler[] eventHandlers = GetComponentsInChildren<EventHandler>();
				foreach (EventHandler eventHandler in eventHandlers)
				{
					eventHandler.hideFlags = HideFlags.HideInInspector;
				}
			}
			else
			{
				MonoBehaviour[] monoBehaviours = GetComponentsInChildren<MonoBehaviour>();
				foreach (MonoBehaviour monoBehaviour in monoBehaviours)
				{
					if (monoBehaviour == null)
					{
						continue;
					}

					monoBehaviour.hideFlags = HideFlags.None;
					monoBehaviour.gameObject.hideFlags = HideFlags.None;
				}
			}

		}

		public virtual void ClearSelectedCommands()
		{
			selectedCommands.Clear();
		}

		public virtual void AddSelectedCommand(Command command)
		{
			if (!selectedCommands.Contains(command))
			{
				selectedCommands.Add(command);
			}
		}

		public virtual void Reset(bool resetCommands, bool resetVariables)
		{
			if (resetCommands)
			{
				Command[] commands = GetComponentsInChildren<Command>();
				foreach (Command command in commands)
				{
					command.OnReset();
				}
			}

			if (resetVariables)
			{
			    foreach (Variable variable in variables)
				{
					variable.OnReset();
				}
			}
		}

		public virtual string SubstituteVariables(string text)
		{
			string subbedText = text;
			
			// Instantiate the regular expression object.
			Regex r = new Regex("{\\$.*?}");
			
			// Match the regular expression pattern against a text string.
			var results = r.Matches(text);
			foreach (Match match in results)
			{
				string key = match.Value.Substring(2, match.Value.Length - 3);

				// Look for matching variable first
				foreach (Variable variable in variables)
				{
					if (variable.key == key)
					{	
						string value = variable.ToString();
						subbedText = subbedText.Replace(match.Value, value);
						return subbedText;
					}
				}

				// Next look for matching localized string
				string localizedString = Localization.GetLocalizedString(key);
				if (localizedString != null)
				{
					subbedText = subbedText.Replace(match.Value, localizedString);
					return subbedText;
				}
			}
			
			return subbedText;
		}
	}

}