using System.Collections.Generic;
using System.Linq;
using EHR.Modules;
using Hazel;
using UnityEngine;

namespace EHR;

internal static class TargetArrow
{
    private static readonly Dictionary<ArrowInfo, string> TargetArrows = [];

    private static readonly string[] Arrows =
    [
        "↑",
        "↗",
        "→",
        "↘",
        "↓",
        "↙",
        "←",
        "↖",
        "・"
    ];

    public static void Init()
    {
        TargetArrows.Clear();
    }

    public static void ReceiveRPC(MessageReader reader)
    {
        switch (reader.ReadPackedInt32())
        {
            case 1:
                Add(reader.ReadByte(), reader.ReadByte());
                break;
            case 2:
                Remove(reader.ReadByte(), reader.ReadByte());
                break;
            case 3:
                RemoveAllTarget(reader.ReadByte());
                break;
        }
    }

    /// <summary>
    ///     Register a new target arrow object
    /// </summary>
    /// <param name="seer"></param>
    /// <param name="target"></param>
    public static void Add(byte seer, byte target)
    {
        if (Main.PlayerStates.TryGetValue(seer, out var state) && state.SubRoles.Contains(CustomRoles.Blind)) return;
        
        ArrowInfo arrowInfo = new(seer, target);

        if (!TargetArrows.Any(a => a.Key.Equals(arrowInfo)))
        {
            TargetArrows[arrowInfo] = "・";
            Utils.SendRPC(CustomRPC.Arrow, true, 1, seer, target);
            Logger.Info($"New target arrow: {seer} ({seer.GetPlayer()?.GetRealName()}) => {target} ({target.GetPlayer()?.GetRealName()})", "TargetArrow");
        }
    }

    /// <summary>
    ///     Delete target
    /// </summary>
    /// <param name="seer"></param>
    /// <param name="target"></param>
    public static void Remove(byte seer, byte target)
    {
        ArrowInfo arrowInfo = new(seer, target);
        List<ArrowInfo> removeList = new(TargetArrows.Keys.Where(k => k.Equals(arrowInfo)));
        if (removeList.Count == 0) return;
        removeList.ForEach(a => TargetArrows.Remove(a));

        Utils.SendRPC(CustomRPC.Arrow, true, 2, seer, target);
        Logger.Info($"Removed target arrow: {seer} ({seer.GetPlayer()?.GetRealName()}) => {target} ({target.GetPlayer()?.GetRealName()})", "TargetArrow");
    }

    /// <summary>
    ///     Delete all targets for the specified seer
    /// </summary>
    /// <param name="seer"></param>
    public static void RemoveAllTarget(byte seer)
    {
        List<ArrowInfo> removeList = new(TargetArrows.Keys.Where(k => k.From == seer));
        if (removeList.Count == 0) return;
        removeList.ForEach(a => TargetArrows.Remove(a));

        Utils.SendRPC(CustomRPC.Arrow, true, 3, seer);
        Logger.Info($"Removed all target arrows for {seer} ({seer.GetPlayer()?.GetRealName()})", "TargetArrow");
    }

    /// <summary>
    ///     Get all visible target arrows for the specified seer to the specified target(s)
    /// </summary>
    /// <param name="seer"></param>
    /// <param name="targets"></param>
    /// <returns></returns>
    public static string GetArrows(PlayerControl seer, params byte[] targets)
    {
        return TargetArrows.Keys.Where(ai => ai.From == seer.PlayerId && targets.Contains(ai.To)).Aggregate(string.Empty, (current, arrowInfo) => current + TargetArrows[arrowInfo]);
    }

    /// <summary>
    ///     Get all visible target arrows for the specified seer
    /// </summary>
    /// <param name="seer"></param>
    /// <returns></returns>
    public static string GetAllArrows(byte seer)
    {
        return TargetArrows.Keys.Where(ai => ai.From == seer).Aggregate(string.Empty, (current, arrowInfo) => current + TargetArrows[arrowInfo]);
    }

    private static readonly List<ArrowInfo> ArrowList = [];
    /// <summary>
    ///     Check target arrow every FixedUpdate
    ///     Issue NotifyRoles when there are updates
    /// </summary>
    /// <param name="seer"></param>
    public static void OnFixedUpdate(PlayerControl seer)
    {
        if (!GameStates.IsInTask) return;

        bool seerIsDead = !seer.IsAlive();

        ArrowList.Clear();
        foreach (var arrowInfo in TargetArrows.Keys)
        {
            if (arrowInfo.From == seer.PlayerId)
                ArrowList.Add(arrowInfo);
        }
        int arrowCount = ArrowList.Count;
        if (arrowCount == 0) return;

        var update = false;

        for (int arrowId = 0; arrowId < arrowCount; arrowId++)
        {
            ArrowInfo arrowInfo = ArrowList[arrowId];
            byte targetId = arrowInfo.To;
            PlayerControl target = Utils.GetPlayerById(targetId);

            if (seerIsDead || !target.IsAlive() && !seer.Is(CustomRoles.Spiritualist))
            {
                TargetArrows.Remove(arrowInfo);
                update = true;
                continue;
            }

            // Take the direction vector of the target
            Vector3 dir = target.Pos3() - seer.Pos3();
            int index;

            if (dir.magnitude < 2)
            {
                // Display a dot when close
                index = 8;
            }
            else
            {
                // Convert to index with -22.5 to 22.5 degrees as 0
                // Bottom is 0 degrees, left side is +180, right side is -180
                // Adding 180 degrees clockwise with top being 0 degrees
                // Add 45/2 to make index in 45 degree units
                double angle = Vector3.SignedAngle(Vector3.down, dir, Vector3.back) + 180 + 22.5;
                index = (int)(angle / 45) % 8;
            }

            string arrow = Arrows[index];

            if (TargetArrows[arrowInfo] != arrow)
            {
                TargetArrows[arrowInfo] = arrow;
                update = true;
            }
        }

        if (update) Utils.NotifyRoles(SpecifySeer: seer, ForceLoop: false, SpecifyTarget: seer);
    }

    private class ArrowInfo(byte from, byte to)
    {
        public readonly byte From = from;
        public readonly byte To = to;

        public bool Equals(ArrowInfo obj)
        {
            return From == obj.From && To == obj.To;
        }

        public override string ToString()
        {
            return $"(From:{From} To:{To})";
        }
    }
}