using System;
using System.Collections.Generic;
using System.Linq;
using Xabbo.Core;

public struct Point : IEquatable<Point>
{
    public int X { get; }
    public int Y { get; }
    public Point(int x, int y) { X = x; Y = y; }
    public bool Equals(Point other) => X == other.X && Y == other.Y;
    public override bool Equals(object obj) => obj is Point other && Equals(other);
    public override int GetHashCode() => HashCode.Combine(X, Y);
    public override string ToString() => $"({X}, {Y})";
}

// --- Configuration ---
string targetFurniName = "Number Tile Dark";
int minX = 16; int minY = 28;
int maxX = 54; int maxY = 62;
int stepDelayMilliseconds = 2500;
// --- End Configuration ---

Log("Dominosa Backtracking Solver v4 Initialized.");

Log("Phase 1: Analyzing board state...");

var numberTiles = new Dictionary<Point, IFloorItem>();
var connectionTiles = new Dictionary<Point, (Point, Point)>();
var floorMap = new Dictionary<Point, List<IFloorItem>>();

try
{
    if (FloorItems == null) { Log("ERROR: Cannot access FloorItems."); return; }
    foreach (IFloorItem item in FloorItems)
    {
        if (item == null) continue;
        var p = new Point(item.Location.X, item.Location.Y);
        if (!floorMap.ContainsKey(p)) floorMap[p] = new List<IFloorItem>();
        floorMap[p].Add(item);
    }

    var numberTileLocations = new HashSet<Point>();
    foreach (var item in floorMap.SelectMany(kvp => kvp.Value))
    {
        if (item.GetName() != targetFurniName) continue;
        int x = item.Location.X;
        int y = item.Location.Y;
        if (x >= minX && x <= maxX && y >= minY && y <= maxY)
        {
            var p = new Point(x, y);
            numberTiles[p] = item;
            numberTileLocations.Add(p);
        }
    }

    foreach (Point p1 in numberTileLocations)
    {
        Point p2_horiz = new Point(p1.X + 4, p1.Y);
        if (numberTileLocations.Contains(p2_horiz)) connectionTiles[new Point(p1.X + 2, p1.Y)] = (p1, p2_horiz);
        Point p2_vert = new Point(p1.X, p1.Y + 4);
        if (numberTileLocations.Contains(p2_vert)) connectionTiles[new Point(p1.X, p1.Y + 2)] = (p1, p2_vert);
    }
}
catch (Exception ex) { Log($"ERROR during analysis: {ex.Message}"); return; }

Log($"Analysis complete. Found {numberTiles.Count} numbers and {connectionTiles.Count} connections.");

Func<Point, bool> isGapTileConnected = (p) => {
    if (floorMap.TryGetValue(p, out var stack))
        return stack.Any(f => f.GetName() == "Dark Tile" && Math.Abs(f.Location.Z - 0.25) < 0.001);
    return false;
};

var activeConnections = new HashSet<Point>();
foreach (var c in connectionTiles)
{
    bool isHorizontal = numberTiles.ContainsKey(new Point(c.Key.X - 2, c.Key.Y));
    if (isHorizontal)
    {
        if (isGapTileConnected(new Point(c.Key.X - 1, c.Key.Y)) && isGapTileConnected(c.Key) && isGapTileConnected(new Point(c.Key.X + 1, c.Key.Y)))
            activeConnections.Add(c.Key);
    }
    else
    {
        if (isGapTileConnected(new Point(c.Key.X, c.Key.Y - 1)) && isGapTileConnected(c.Key) && isGapTileConnected(new Point(c.Key.X, c.Key.Y + 1)))
            activeConnections.Add(c.Key);
    }
}
Log($"Detected {activeConnections.Count} currently active connections on the board.");

Log("Phase 2: Calculating ideal solution with backtracking...");

var idealConnections = new HashSet<Point>();
var pairedTiles = new HashSet<Point>();
var usedDominoes = new HashSet<(int, int)>();
var precomputedNeighbors = numberTiles.Keys.ToDictionary(
    p => p,
    p => new Point[] { new Point(p.X - 4, p.Y), new Point(p.X + 4, p.Y), new Point(p.X, p.Y - 4), new Point(p.X, p.Y + 4) }
        .Where(n => numberTiles.ContainsKey(n)).ToList()
);

bool SolveRecursive()
{
    if (pairedTiles.Count == numberTiles.Count) return true; 

    var firstUnpaired = numberTiles.Keys.FirstOrDefault(p => !pairedTiles.Contains(p));
    if (firstUnpaired.Equals(default(Point))) return true; 

    foreach (var neighbor in precomputedNeighbors[firstUnpaired])
    {
        if (pairedTiles.Contains(neighbor)) continue;

        var domino = (Math.Min(numberTiles[firstUnpaired].State, numberTiles[neighbor].State), Math.Max(numberTiles[firstUnpaired].State, numberTiles[neighbor].State));
        if (usedDominoes.Contains(domino)) continue; 


        var connection = connectionTiles.First(kvp => (kvp.Value.Item1.Equals(firstUnpaired) && kvp.Value.Item2.Equals(neighbor)) || (kvp.Value.Item1.Equals(neighbor) && kvp.Value.Item2.Equals(firstUnpaired))).Key;
        pairedTiles.Add(firstUnpaired);
        pairedTiles.Add(neighbor);
        usedDominoes.Add(domino);
        idealConnections.Add(connection);

        if (SolveRecursive()) return true; 


        idealConnections.Remove(connection);
        usedDominoes.Remove(domino);
        pairedTiles.Remove(neighbor);
        pairedTiles.Remove(firstUnpaired);
    }

    return false;
}

bool success = SolveRecursive();

Log($"Calculation complete. Success: {success}. Ideal solution has {idealConnections.Count} steps.");

if (!success)
{
    Log("CRITICAL ERROR: The solver could not find any valid solution for the board.");
    return;
}

Log("Phase 3: Reconciling current state with ideal solution...");

var movesToDisconnect = activeConnections.Except(idealConnections).ToList();
var movesToConnect = idealConnections.Except(activeConnections).ToList();

Log($"Found {movesToDisconnect.Count} incorrect connections to UNDO.");
Log($"Found {movesToConnect.Count} missing connections to MAKE.");
Log($"Found {activeConnections.Intersect(idealConnections).Count()} connections that are already correct.");

if (movesToDisconnect.Count == 0 && movesToConnect.Count == 0)
{
    Log("\nBoard is already solved! No action needed.");
    return;
}

if (movesToDisconnect.Any())
{
    Log("\n--- [PLAN: UNDO MOVES] ---");
    movesToDisconnect.ForEach(p => Log($"  -> Click {p} to disconnect"));
    Log("------------------------\nExecuting... Please wait.");
    Delay(2000);
    for (int i = 0; i < movesToDisconnect.Count; i++)
    {
        var p = movesToDisconnect[i];
        Log($"Undoing {i + 1}/{movesToDisconnect.Count}: MoveTo {p}");
        Send(Out["MoveAvatar"], p.X, p.Y);
        Delay(stepDelayMilliseconds);
    }
    Log("Disconnections complete.");
}

if (movesToConnect.Any())
{
    Log("\n--- [PLAN: MAKE MOVES] ---");
    movesToConnect.ForEach(p => Log($"  -> Click {p} to connect"));
    Log("------------------------\nExecuting... Please wait.");
    Delay(2000);
    for (int i = 0; i < movesToConnect.Count; i++)
    {
        var p = movesToConnect[i];
        Log($"Connecting {i + 1}/{movesToConnect.Count}: MoveTo {p}");
        Send(Out["MoveAvatar"], p.X, p.Y);
        Delay(stepDelayMilliseconds);
    }
    Log("Connections complete.");
}

Log("\nReconciliation complete. Puzzle should be solved.");