using System;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using Dalamud.Game.ClientState.Objects.Enums;
using Dalamud.Game.ClientState.Objects.Types;
using Newtonsoft.Json.Linq;
using Penumbra.String;

namespace Penumbra.GameData.Actors;

public partial class ActorManager
{
    /// <summary>
    /// Try to create an ActorIdentifier from a already parsed JObject <paramref name="data"/>.
    /// </summary>
    /// <param name="data">A parsed JObject</param>
    /// <returns>ActorIdentifier.Invalid if the JObject can not be converted, a valid ActorIdentifier otherwise.</returns>
    public ActorIdentifier FromJson(JObject data)
    {
        var type = data[nameof(ActorIdentifier.Type)]?.Value<IdentifierType>() ?? IdentifierType.Invalid;
        switch (type)
        {
            case IdentifierType.Player:
            {
                var name      = ByteString.FromStringUnsafe(data[nameof(ActorIdentifier.PlayerName)]?.Value<string>(), false);
                var homeWorld = data[nameof(ActorIdentifier.HomeWorld)]?.Value<ushort>() ?? 0;
                return CreatePlayer(name, homeWorld);
            }
            case IdentifierType.Owned:
            {
                var name      = ByteString.FromStringUnsafe(data[nameof(ActorIdentifier.PlayerName)]?.Value<string>(), false);
                var homeWorld = data[nameof(ActorIdentifier.HomeWorld)]?.Value<ushort>() ?? 0;
                var kind      = data[nameof(ActorIdentifier.Kind)]?.Value<ObjectKind>() ?? ObjectKind.CardStand;
                var dataId    = data[nameof(ActorIdentifier.DataId)]?.Value<uint>() ?? 0;
                return CreateOwned(name, homeWorld, kind, dataId);
            }
            case IdentifierType.Special:
            {
                var special = data[nameof(ActorIdentifier.Special)]?.Value<SpecialActor>() ?? 0;
                return CreateSpecial(special);
            }
            case IdentifierType.Npc:
            {
                var index  = data[nameof(ActorIdentifier.Index)]?.Value<ushort>() ?? ushort.MaxValue;
                var kind   = data[nameof(ActorIdentifier.Kind)]?.Value<ObjectKind>() ?? ObjectKind.CardStand;
                var dataId = data[nameof(ActorIdentifier.DataId)]?.Value<uint>() ?? 0;
                return CreateNpc(kind, dataId, index);
            }
            case IdentifierType.Invalid:
            default:
                return ActorIdentifier.Invalid;
        }
    }

    /// <summary>
    /// Use stored data to convert an ActorIdentifier to a string.
    /// </summary>
    public string ToString(ActorIdentifier id)
    {
        return id.Type switch
        {
            IdentifierType.Player => id.HomeWorld != _clientState.LocalPlayer?.HomeWorld.Id
                ? $"{id.PlayerName} ({Worlds[id.HomeWorld]})"
                : id.PlayerName.ToString(),
            IdentifierType.Owned => id.HomeWorld != _clientState.LocalPlayer?.HomeWorld.Id
                ? $"{id.PlayerName} ({Worlds[id.HomeWorld]})'s {ToName(id.Kind, id.DataId)}"
                : $"{id.PlayerName}s {ToName(id.Kind,                           id.DataId)}",
            IdentifierType.Special => ToName(id.Special),
            IdentifierType.Npc =>
                id.Index == ushort.MaxValue
                    ? ToName(id.Kind, id.DataId)
                    : $"{ToName(id.Kind, id.DataId)} at {id.Index}",
            _ => "Invalid",
        };
    }


    /// <summary>
    /// Fixed names for special actors.
    /// </summary>
    public static string ToName(SpecialActor actor)
        => actor switch
        {
            SpecialActor.CharacterScreen => "Character Screen Actor",
            SpecialActor.ExamineScreen   => "Examine Screen Actor",
            SpecialActor.FittingRoom     => "Fitting Room Actor",
            SpecialActor.DyePreview      => "Dye Preview Actor",
            SpecialActor.Portrait        => "Portrait Actor",
            _                            => "Invalid",
        };

    /// <summary>
    /// Convert a given ID for a certain ObjectKind to a name.
    /// </summary>
    /// <returns>Invalid or a valid name.</returns>
    public string ToName(ObjectKind kind, uint dataId)
        => TryGetName(kind, dataId, out var ret) ? ret : "Invalid";


    /// <summary>
    /// Convert a given ID for a certain ObjectKind to a name.
    /// </summary>
    public bool TryGetName(ObjectKind kind, uint dataId, [NotNullWhen(true)] out string? name)
    {
        name = null;
        return kind switch
        {
            ObjectKind.MountType => Mounts.TryGetValue(dataId, out name),
            ObjectKind.Companion => Companions.TryGetValue(dataId, out name),
            ObjectKind.BattleNpc => BNpcs.TryGetValue(dataId, out name),
            ObjectKind.EventNpc  => ENpcs.TryGetValue(dataId, out name),
            _                    => false,
        };
    }

    /// <summary>
    /// Compute an ActorIdentifier from a GameObject.
    /// </summary>
    public unsafe ActorIdentifier FromObject(FFXIVClientStructs.FFXIV.Client.Game.Object.GameObject* actor)
    {
        if (actor == null)
            return ActorIdentifier.Invalid;

        var idx = actor->ObjectIndex;
        if (idx is >= (ushort)SpecialActor.CutsceneStart and < (ushort)SpecialActor.CutsceneEnd)
        {
            var parentIdx = _toParentIdx(idx);
            if (parentIdx >= 0)
                return FromObject((FFXIVClientStructs.FFXIV.Client.Game.Object.GameObject*)_objects.GetObjectAddress(parentIdx));
        }
        else if (idx is >= (ushort)SpecialActor.CharacterScreen and <= (ushort)SpecialActor.Portrait)
        {
            return CreateSpecial((SpecialActor)idx);
        }

        switch ((ObjectKind)actor->ObjectKind)
        {
            case ObjectKind.Player:
            {
                var name      = new ByteString(actor->Name);
                var homeWorld = ((FFXIVClientStructs.FFXIV.Client.Game.Character.Character*)actor)->HomeWorld;
                return CreatePlayer(name, homeWorld);
            }
            case ObjectKind.BattleNpc:
            {
                var ownerId = actor->OwnerID;
                if (ownerId != 0xE0000000)
                {
                    var owner =
                        (FFXIVClientStructs.FFXIV.Client.Game.Character.Character*)(_objects.SearchById(ownerId)?.Address ?? IntPtr.Zero);
                    if (owner == null)
                        return ActorIdentifier.Invalid;

                    var name      = new ByteString(owner->GameObject.Name);
                    var homeWorld = owner->HomeWorld;
                    return CreateOwned(name, homeWorld, ObjectKind.BattleNpc,
                        ((FFXIVClientStructs.FFXIV.Client.Game.Character.Character*)actor)->NameID);
                }

                return CreateNpc(ObjectKind.BattleNpc, ((FFXIVClientStructs.FFXIV.Client.Game.Character.Character*)actor)->NameID, actor->ObjectIndex);
            }
            case ObjectKind.EventNpc: return CreateNpc(ObjectKind.EventNpc, actor->DataID, actor->ObjectIndex);
            case ObjectKind.MountType:
            case ObjectKind.Companion:
            {
                if (actor->ObjectIndex % 2 == 0)
                    return ActorIdentifier.Invalid;

                var owner = (FFXIVClientStructs.FFXIV.Client.Game.Character.Character*)_objects.GetObjectAddress(actor->ObjectIndex - 1);
                if (owner == null)
                    return ActorIdentifier.Invalid;

                var dataId = GetCompanionId(actor, &owner->GameObject);
                return CreateOwned(new ByteString(owner->GameObject.Name), owner->HomeWorld, (ObjectKind)actor->ObjectKind, dataId);
            }
            default: return ActorIdentifier.Invalid;
        }
    }

    /// <summary>
    /// Obtain the current companion ID for an object by its actor and owner.
    /// </summary>
    private unsafe uint GetCompanionId(FFXIVClientStructs.FFXIV.Client.Game.Object.GameObject* actor,
        FFXIVClientStructs.FFXIV.Client.Game.Object.GameObject* owner)
    {
        return (ObjectKind)actor->ObjectKind switch
        {
            ObjectKind.MountType => *(ushort*)((byte*)owner + 0x668),
            ObjectKind.Companion => *(ushort*)((byte*)actor + 0x1AAC),
            _                    => actor->DataID,
        };
    }

    public unsafe ActorIdentifier FromObject(GameObject? actor)
        => FromObject((FFXIVClientStructs.FFXIV.Client.Game.Object.GameObject*)(actor?.Address ?? IntPtr.Zero));

    public ActorIdentifier CreatePlayer(ByteString name, ushort homeWorld)
    {
        if (!VerifyWorld(homeWorld) || !VerifyPlayerName(name))
            return ActorIdentifier.Invalid;

        return new ActorIdentifier(IdentifierType.Player, ObjectKind.Player, homeWorld, 0, name);
    }

    public ActorIdentifier CreateSpecial(SpecialActor actor)
    {
        if (!VerifySpecial(actor))
            return ActorIdentifier.Invalid;

        return new ActorIdentifier(IdentifierType.Special, ObjectKind.Player, (ushort)actor, 0, ByteString.Empty);
    }

    public ActorIdentifier CreateNpc(ObjectKind kind, uint data, ushort index = ushort.MaxValue)
    {
        if (!VerifyIndex(index) || !VerifyNpcData(kind, data))
            return ActorIdentifier.Invalid;

        return new ActorIdentifier(IdentifierType.Npc, kind, index, data, ByteString.Empty);
    }

    public ActorIdentifier CreateOwned(ByteString ownerName, ushort homeWorld, ObjectKind kind, uint dataId)
    {
        if (!VerifyWorld(homeWorld) || !VerifyPlayerName(ownerName) || !VerifyOwnedData(kind, dataId))
            return ActorIdentifier.Invalid;

        return new ActorIdentifier(IdentifierType.Owned, kind, homeWorld, dataId, ownerName);
    }

    /// <summary> Checks SE naming rules. </summary>
    private static bool VerifyPlayerName(ByteString name)
    {
        // Total no more than 20 characters + space.
        if (name.Length is < 5 or > 21)
            return false;

        var split = name.Split((byte)' ');

        // Forename and surname, no more spaces.
        if (split.Count != 2)
            return false;

        static bool CheckNamePart(ByteString part)
        {
            // Each name part at least 2 and at most 15 characters.
            if (part.Length is < 2 or > 15)
                return false;

            // Each part starting with capitalized letter.
            if (part[0] is < (byte)'A' or > (byte)'Z')
                return false;

            // Every other symbol needs to be lowercase letter, hyphen or apostrophe.
            if (part.Skip(1).Any(c => c != (byte)'\'' && c != (byte)'-' && c is < (byte)'a' or > (byte)'z'))
                return false;

            var hyphens = part.Split((byte)'-');
            // Apostrophes can not be used in succession, after or before apostrophes.
            return !hyphens.Any(p => p.Length == 0 || p[0] == (byte)'\'' || p.Last() == (byte)'\'');
        }

        return CheckNamePart(split[0]) && CheckNamePart(split[1]);
    }

    /// <summary> Checks if the world is a valid public world or ushort.MaxValue (any world). </summary>
    private bool VerifyWorld(ushort worldId)
        => Worlds.ContainsKey(worldId);

    /// <summary> Verify that the enum value is a specific actor and return the name if it is. </summary>
    private static bool VerifySpecial(SpecialActor actor)
        => actor is >= SpecialActor.CharacterScreen and <= SpecialActor.Portrait;

    /// <summary> Verify that the object index is a valid index for an NPC. </summary>
    private static bool VerifyIndex(ushort index)
    {
        return index switch
        {
            < 200                           => index % 2 == 0,
            > (ushort)SpecialActor.Portrait => index < 426,
            _                               => false,
        };
    }

    /// <summary> Verify that the object kind is a valid owned object, and the corresponding data Id. </summary>
    private bool VerifyOwnedData(ObjectKind kind, uint dataId)
    {
        return kind switch
        {
            ObjectKind.MountType => Mounts.ContainsKey(dataId),
            ObjectKind.Companion => Companions.ContainsKey(dataId),
            ObjectKind.BattleNpc => BNpcs.ContainsKey(dataId),
            _                    => false,
        };
    }

    private bool VerifyNpcData(ObjectKind kind, uint dataId)
        => kind switch
        {
            ObjectKind.BattleNpc => BNpcs.ContainsKey(dataId),
            ObjectKind.EventNpc  => ENpcs.ContainsKey(dataId),
            _                    => false,
        };
}