using System;
using System.Collections;
using System.Collections.Generic;
using Core;
using Interactions;
using UnityEngine;
using PuzzleS;

namespace Dialogue
{
    [AddComponentMenu("Apple Hills/Dialogue/Dialogue Component")]
    public class DialogueComponent : MonoBehaviour
    {
        [SerializeField] private RuntimeDialogueGraph dialogueGraph;
        
        private RuntimeDialogueNode currentNode;
        private int currentLineIndex;
        private bool initialized = false;
        
        // Properties
        public bool IsActive { get; private set; }
        public bool IsCompleted { get; private set; }
        public string CurrentSpeakerName => dialogueGraph?.speakerName;
        
        // Event for UI updates if needed
        public event Action<string> OnDialogueChanged;
        
        private void Start()
        {
            // Register for global events
            if (PuzzleManager.Instance != null)
                PuzzleManager.Instance.OnStepCompleted += OnAnyPuzzleStepCompleted;
                
            if (ItemManager.Instance != null)
            {
                ItemManager.Instance.OnItemPickedUp += OnAnyItemPickedUp;
                ItemManager.Instance.OnCorrectItemSlotted += OnAnyItemSlotted;
            }
            
            // Auto-start the dialogue
            StartDialogue();
        }
        
        private void OnDestroy()
        {
            // Unregister from events
            if (PuzzleManager.Instance != null)
                PuzzleManager.Instance.OnStepCompleted -= OnAnyPuzzleStepCompleted;
                
            if (ItemManager.Instance != null)
            {
                ItemManager.Instance.OnItemPickedUp -= OnAnyItemPickedUp;
                ItemManager.Instance.OnCorrectItemSlotted -= OnAnyItemSlotted;
            }
        }
        
        /// <summary>
        /// Start the dialogue from the beginning
        /// </summary>
        public void StartDialogue()
        {
            if (dialogueGraph == null)
            {
                Debug.LogError("DialogueComponent: No dialogue graph assigned!");
                return;
            }
            
            // Reset state
            IsActive = true;
            IsCompleted = false;
            currentLineIndex = 0;
            initialized = true;
            
            // Set to entry node
            currentNode = dialogueGraph.GetNodeByID(dialogueGraph.entryNodeID);
            
            // Process the node
            ProcessCurrentNode();
        }
        
        /// <summary>
        /// Get the current dialogue line and advance to the next line or node if appropriate
        /// Each call represents one interaction with the NPC
        /// </summary>
        public string GetCurrentDialogueLine()
        {
            // Initialize if needed
            if (!initialized)
            {
                StartDialogue();
            }
            
            if (!IsActive || IsCompleted || currentNode == null || currentNode.dialogueLines.Count == 0)
                return string.Empty;
            
            // Get current line
            string currentLine = string.Empty;
            if (currentLineIndex >= 0 && currentLineIndex < currentNode.dialogueLines.Count)
            {
                currentLine = currentNode.dialogueLines[currentLineIndex];
            }
            
            // Advance dialogue state for next interaction
            AdvanceDialogueState();
            
            // Return the current line
            return currentLine;
        }
        
        /// <summary>
        /// Advance dialogue state for the next interaction
        /// </summary>
        private void AdvanceDialogueState()
        {
            if (!IsActive || IsCompleted || currentNode == null)
                return;
                
            // If we're on a conditional node, we can't advance past it until condition is met
            if (IsWaitingForCondition())
                return;
                
            // If we have more lines in the current node, advance to the next line
            if (currentLineIndex < currentNode.dialogueLines.Count - 1)
            {
                currentLineIndex++;
                return;
            }
            
            // If we should loop through lines, reset the index
            if (currentNode.loopThroughLines && currentNode.dialogueLines.Count > 0)
            {
                currentLineIndex = 0;
                return;
            }
            
            // Otherwise, move to the next node
            MoveToNextNode();
        }
        
        private void MoveToNextNode()
        {
            // If there's no next node, complete the dialogue
            if (string.IsNullOrEmpty(currentNode.nextNodeID))
            {
                IsActive = false;
                IsCompleted = true;
                return;
            }
            
            // Move to the next node
            currentNode = dialogueGraph.GetNodeByID(currentNode.nextNodeID);
            currentLineIndex = 0;
            
            // Process the new node
            ProcessCurrentNode();
        }
        
        private void ProcessCurrentNode()
        {
            if (currentNode == null)
            {
                Debug.LogError("DialogueComponent: Current node is null!");
                return;
            }
            
            // Handle different node types
            switch (currentNode.nodeType)
            {
                case RuntimeDialogueNodeType.Dialogue:
                    // Regular dialogue node, nothing special to do
                    break;
                    
                case RuntimeDialogueNodeType.WaitOnPuzzleStep:
                    // Check if the puzzle step is already completed
                    if (IsPuzzleStepComplete(currentNode.puzzleStepID))
                    {
                        // If it's already complete, move past this node automatically
                        MoveToNextNode();
                    }
                    break;
                    
                case RuntimeDialogueNodeType.WaitOnPickup:
                    // Check if the item is already picked up
                    if (IsItemPickedUp(currentNode.pickupItemID))
                    {
                        // If it's already picked up, move past this node automatically
                        MoveToNextNode();
                    }
                    break;
                    
                case RuntimeDialogueNodeType.WaitOnSlot:
                    // Check if the item is already slotted
                    if (IsItemSlotted(currentNode.slotItemID))
                    {
                        // If it's already slotted, move past this node automatically
                        MoveToNextNode();
                    }
                    break;
                    
                case RuntimeDialogueNodeType.End:
                    // End node, complete the dialogue
                    IsActive = false;
                    IsCompleted = true;
                    break;
                    
                default:
                    Debug.LogError($"DialogueComponent: Unknown node type {currentNode.nodeType}");
                    break;
            }
        }
        
        // Global event handlers
        private void OnAnyPuzzleStepCompleted(PuzzleStepSO step)
        {
            // Only react if we're active and waiting on a puzzle step
            if (!IsActive || IsCompleted || currentNode == null || 
                currentNode.nodeType != RuntimeDialogueNodeType.WaitOnPuzzleStep)
                return;
                
            // Check if this is the step we're waiting for
            if (step.stepId == currentNode.puzzleStepID)
            {
                // Move to next node automatically when condition is met
                MoveToNextNode();
                OnDialogueChanged?.Invoke(GetCurrentDialogueLine());
            }
        }
        
        private void OnAnyItemPickedUp(PickupItemData item)
        {
            // Only react if we're active and waiting on an item pickup
            if (!IsActive || IsCompleted || currentNode == null || 
                currentNode.nodeType != RuntimeDialogueNodeType.WaitOnPickup)
                return;
                
            // Check if this is the item we're waiting for
            if (item.itemId == currentNode.pickupItemID)
            {
                // Move to next node automatically when condition is met
                MoveToNextNode();
                OnDialogueChanged?.Invoke(GetCurrentDialogueLine());
            }
        }
        
        private void OnAnyItemSlotted(PickupItemData slotDefinition, PickupItemData slottedItem)
        {
            // Only react if we're active and waiting on a slot
            if (!IsActive || IsCompleted || currentNode == null || 
                currentNode.nodeType != RuntimeDialogueNodeType.WaitOnSlot)
                return;
                
            // Check if this is the slot we're waiting for
            if (slotDefinition.itemId == currentNode.slotItemID)
            {
                // Move to next node automatically when condition is met
                MoveToNextNode();
                OnDialogueChanged?.Invoke(GetCurrentDialogueLine());
            }
        }
        
        // Helper methods
        private bool IsWaitingForCondition()
        {
            if (currentNode == null) return false;
            
            switch (currentNode.nodeType)
            {
                case RuntimeDialogueNodeType.WaitOnPuzzleStep:
                    return !IsPuzzleStepComplete(currentNode.puzzleStepID);
                case RuntimeDialogueNodeType.WaitOnPickup:
                    return !IsItemPickedUp(currentNode.pickupItemID);
                case RuntimeDialogueNodeType.WaitOnSlot:
                    return !IsItemSlotted(currentNode.slotItemID);
                default:
                    return false;
            }
        }
        
        private bool IsPuzzleStepComplete(string stepID)
        {
            return PuzzleManager.Instance != null && 
                   PuzzleManager.Instance.IsPuzzleStepCompleted(stepID);
        }
        
        private bool IsItemPickedUp(string itemID)
        {
            if (ItemManager.Instance == null) return false;
            
            // Check all pickups for the given ID
            foreach (var pickup in ItemManager.Instance.Pickups)
            {
                if (pickup.isPickedUp && pickup.itemData != null && 
                    pickup.itemData.itemId == itemID)
                {
                    return true;
                }
            }
            return false;
        }
        
        private bool IsItemSlotted(string slotID)
        {
            if (ItemManager.Instance == null) return false;
            
            // Check if any slot with this ID has the correct item
            foreach (var slot in ItemManager.Instance.ItemSlots)
            {
                if (slot.itemData != null && slot.itemData.itemId == slotID && 
                    slot.CurrentSlottedState == ItemSlotState.Correct)
                {
                    return true;
                }
            }
            return false;
        }
        
        // Editor functionality
        public void SetDialogueGraph(RuntimeDialogueGraph graph)
        {
            dialogueGraph = graph;
        }
    }
}