using System;
using UnityEngine;

public class Player : BasePlayer, IGamePlayer
{
    public event Action<int, int> OnChipDropped;
    public event Action OnMoveCommitted;
    public event Action OnThinkingStarted;

    [Header("Movement Settings")]
    [SerializeField] private float chipYOffset = 5f;
    [SerializeField] private float prepareSpeed;
    [SerializeField] private float moveSpeed;

    // State
    private PlayerState state = PlayerState.Sleep;
    private Chip currentChip;
    private int[] availableColumns;
    private int selectedColumnIndex;

    // Movement targets
    private Vector2 stickedTargetPosition;
    private Vector2 dropTargetPosition;

    private int droppedRow, droppedColumn;

    private int SelectedColumn => availableColumns[selectedColumnIndex];

    public JoystickSide ControlSide { get; set; } = JoystickSide.Left;
    public bool ControlsEnabled { get; set; } = true;

    #region Public Methods

    public void PrepareChip()
    {
        SetState(PlayerState.Preparing);

        CacheAvailableColumns();
        CreateChip();
        SetInitialChipPosition();
    }

    public void Sleep()
    {
        SetState(PlayerState.Sleep);
        currentChip = null;
        availableColumns = null;
    }

    public void CancelTurn()
    {
        if (currentChip != null)
        {
            if (state == PlayerState.Dropping)
                currentChip.transform.position = dropTargetPosition;
            else
                ChipPool.Instance.Release(currentChip);
        }

        currentChip = null;
        availableColumns = null;
        SetState(PlayerState.Sleep);
    }

    public void ReturnPreparedChipToPool()
    {
        if (currentChip == null || state == PlayerState.Sleep || state == PlayerState.Dropping)
            return;

        ChipPool.Instance.Release(currentChip);
        currentChip = null;
        availableColumns = null;
        SetState(PlayerState.Sleep);
    }

    public bool ForceDrop()
    {
        if (currentChip == null
            || availableColumns == null
            || state == PlayerState.Sleep
            || state == PlayerState.Dropping)
            return false;

        BeginDrop();
        return true;
    }

    public void UpdateControls()
    {
        // Always update state machine regardless of ControlsEnabled
        switch (state)
        {
            case PlayerState.Preparing:
                UpdatePreparing();
                break;

            case PlayerState.Idle:
                UpdateIdle();
                break;

            case PlayerState.Moving:
                UpdateMoving();
                break;

            case PlayerState.Dropping:
                UpdateDropping();
                break;

            case PlayerState.Sleep:
                // Nothing to do
                break;
        }
    }

    #endregion

    #region State Updates

    private void UpdatePreparing()
    {
        if (currentChip.MoveToLinear(stickedTargetPosition, prepareSpeed))
        {
            SetState(PlayerState.Idle);
            OnThinkingStarted?.Invoke();
        }
    }

    private void UpdateIdle()
    {
        // Only process input if controls are enabled
        if (!ControlsEnabled) return;

        // Try horizontal movement first
        if (TryHorizontalMovement()) return;

        // Then try drop
        TryDrop();
    }

    private void UpdateMoving()
    {
        // Process horizontal input even while moving
        if (ControlsEnabled)
        {
            TryHorizontalMovement();
        }

        // Wait for chip to reach target
        if (currentChip.MoveToLinear(stickedTargetPosition, moveSpeed))
        {
            SetState(PlayerState.Idle);
        }
    }

    private void UpdateDropping()
    {
        if (currentChip.MoveToAccelerated(dropTargetPosition))
        {
            if (currentChip.MoveToAccelerated(dropTargetPosition))
            {
                SetState(PlayerState.Sleep);
                OnChipDropped?.Invoke(droppedColumn, droppedRow);
            }
        }
    }

    #endregion

    #region Actions

    private bool TryHorizontalMovement()
    {
        int direction = GetHorizontalInput();
        if (direction == 0) return false;

        int newIndex = Mathf.Clamp(selectedColumnIndex + direction, 0, availableColumns.Length - 1);
        if (newIndex == selectedColumnIndex) return false;

        selectedColumnIndex = newIndex;
        SoundManager.instance?.PlayColumnSelectionSound();
        stickedTargetPosition = board.GetStickedPosition(SelectedColumn);
        SetState(PlayerState.Moving);

        return true;
    }

    private void TryDrop()
    {
        if (!IsActionPressed())
            return;

        BeginDrop();
    }

    private void BeginDrop()
    {

        dropTargetPosition = board.GetTargetPosition(SelectedColumn);

        droppedColumn = SelectedColumn;
        droppedRow = board.GetLowestEmptyRow(SelectedColumn);

        board.DropChip(currentChip, SelectedColumn);
        OnMoveCommitted?.Invoke();
        SetState(PlayerState.Dropping);
    }

    #endregion

    #region Helpers

    private void CacheAvailableColumns()
    {
        availableColumns = board.GetNonFullColumns();
        selectedColumnIndex = availableColumns.Length / 2;
    }

    private void CreateChip()
    {
        currentChip = ChipPool.Instance.GetConfigured(chipSprite, team);
    }

    private void SetInitialChipPosition()
    {
        stickedTargetPosition = board.GetStickedPosition(SelectedColumn);
        currentChip.transform.position = stickedTargetPosition + Vector2.up * chipYOffset;
    }

    private int GetHorizontalInput()
    {
        return In.GetHorizontalAxis(ControlSide, InteractMode.Discrete);
    }

    private bool IsActionPressed()
    {
        return In.GetAction(ControlSide, InteractMode.Discrete);
    }

    private void SetState(PlayerState newState)
    {
        state = newState;
    }

    #endregion

    #region Nested Types

    private enum PlayerState
    {
        Sleep,      // No input, chip placed on board
        Preparing,  // No input, chip moving to sticked position
        Idle,       // Input enabled, waiting for action
        Moving,     // Input enabled (horizontal only), chip moving horizontally
        Dropping    // No input, chip falling down
    }

    #endregion
}