using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.Json;
using Pal.Client.Extensions;
using Pal.Common;

namespace Pal.Client.Configuration.Legacy;

/// <summary>
/// Legacy JSON file for marker locations.
/// </summary>
[Obsolete]
public sealed class JsonFloorState
{
    private static readonly JsonSerializerOptions JsonSerializerOptions = new() { IncludeFields = true };
    private const int CurrentVersion = 4;

    private static string _pluginConfigDirectory = null!;

    internal static void SetContextProperties(string pluginConfigDirectory)
    {
        _pluginConfigDirectory = pluginConfigDirectory;
    }

    public ushort TerritoryType { get; set; }
    public ConcurrentBag<JsonMarker> Markers { get; set; } = new();

    public JsonFloorState(ushort territoryType)
    {
        TerritoryType = territoryType;
    }

    private void ApplyFilters()
    {
        Markers = new ConcurrentBag<JsonMarker>(Markers.Where(x => x.Seen || !x.WasImported || x.Imports.Count > 0));
    }

    public static JsonFloorState? Load(ushort territoryType)
    {
        string path = GetSaveLocation(territoryType);
        if (!File.Exists(path))
            return null;

        string content = File.ReadAllText(path);
        if (content.Length == 0)
            return null;

        JsonFloorState localState;
        int version = 1;
        if (content[0] == '[')
        {
            // v1 only had a list of markers, not a JSON object as root
            localState = new JsonFloorState(territoryType)
            {
                Markers = new ConcurrentBag<JsonMarker>(JsonSerializer.Deserialize<HashSet<JsonMarker>>(content, JsonSerializerOptions) ?? new()),
            };
        }
        else
        {
            var save = JsonSerializer.Deserialize<SaveFile>(content, JsonSerializerOptions);
            if (save == null)
                return null;

            localState = new JsonFloorState(territoryType)
            {
                Markers = new ConcurrentBag<JsonMarker>(save.Markers.Where(o => o.Type == JsonMarker.EType.Trap || o.Type == JsonMarker.EType.Hoard)),
            };
            version = save.Version;
        }

        localState.ApplyFilters();

        if (version <= 3)
        {
            foreach (var marker in localState.Markers)
                marker.RemoteSeenOn = marker.RemoteSeenOn.Select(x => x.ToPartialId()).ToList();
        }

        if (version < CurrentVersion)
            localState.Save();

        return localState;
    }

    public void Save()
    {
        string path = GetSaveLocation(TerritoryType);

        ApplyFilters();
        SaveImpl(path);
    }

    public void Backup(string suffix)
    {
        string path = $"{GetSaveLocation(TerritoryType)}.{suffix}";
        if (!File.Exists(path))
        {
            SaveImpl(path);
        }
    }

    private void SaveImpl(string path)
    {
        foreach (var marker in Markers)
        {
            if (string.IsNullOrEmpty(marker.SinceVersion))
                marker.SinceVersion = typeof(Plugin).Assembly.GetName().Version!.ToString(2);
        }

        if (Markers.Count == 0)
            File.Delete(path);
        else
        {
            File.WriteAllText(path, JsonSerializer.Serialize(new SaveFile
            {
                Version = CurrentVersion,
                Markers = new HashSet<JsonMarker>(Markers)
            }, JsonSerializerOptions));
        }
    }

    public string GetSaveLocation() => GetSaveLocation(TerritoryType);

    private static string GetSaveLocation(uint territoryType) => Path.Join(_pluginConfigDirectory, $"{territoryType}.json");

    public static void ForEach(Action<JsonFloorState> action)
    {
        foreach (ETerritoryType territory in typeof(ETerritoryType).GetEnumValues())
        {
            // we never had markers for eureka orthos, so don't bother
            if (territory > ETerritoryType.HeavenOnHigh_91_100)
                break;

            JsonFloorState? localState = Load((ushort)territory);
            if (localState != null)
                action(localState);
        }
    }

    public static void UpdateAll()
    {
        ForEach(s => s.Save());
    }

    public void UndoImport(List<Guid> importIds)
    {
        // When saving a floor state, any markers not seen, not remote seen, and not having an import id are removed;
        // so it is possible to remove "wrong" markers by not having them be in the current import.
        foreach (var marker in Markers)
            marker.Imports.RemoveAll(importIds.Contains);
    }

    public sealed class SaveFile
    {
        public int Version { get; set; }
        public HashSet<JsonMarker> Markers { get; set; } = new();
    }
}