using Dalamud.Plugin.Services;

namespace PlayerNotes;

/// <summary>
/// Watches the party/alliance list on every framework update and prints a chat notification
/// whenever a player from the friend list or blacklist joins a party we are in (including
/// when we join a party that already contains one of them). Notifications fire once per
/// membership transition, so they do not repeat while the player stays in the party.
/// </summary>
public class PartyWatcher
{
    // FFXIV uiColors palette keys (the game's role colors), used for the colored
    // "[Blacklist]"/"[Friends]" message tag via IChatGui.Print(message, tag, color).
    private static readonly ushort BlacklistColor = 0x221; // DPS red   (uiColors key 545)
    private static readonly ushort FriendColor = 0x1F8;    // Healer green (uiColors key 504)

    private readonly IPartyList partyList;
    private readonly IPlayerState playerState;
    private readonly Storage storage;
    private readonly IChatGui chatGui;

    /// <summary>Content IDs that were in the party on the previous frame.</summary>
    private HashSet<ulong> previousMembers = new();

    public PartyWatcher(IPartyList partyList, IPlayerState playerState, Storage storage, IChatGui chatGui)
    {
        this.partyList = partyList;
        this.playerState = playerState;
        this.storage = storage;
        this.chatGui = chatGui;
    }

    public void OnFrameworkUpdate(IFramework _)
    {
        if (playerState.ContentId == 0)
            return; // not logged in / transitioning

        var currentMembers = new HashSet<ulong>();
        foreach (var member in partyList)
        {
            if (member is not null && member.ContentId != 0)
                currentMembers.Add(member.ContentId);
        }

        // Solo (or no readable party data): treat as "not in a party" so that the next
        // time we group up, joins are detected again from scratch.
        if (currentMembers.Count <= 1)
        {
            previousMembers.Clear();
            return;
        }

        foreach (var member in partyList)
        {
            if (member is null || member.ContentId == 0)
                continue;
            if (previousMembers.Contains(member.ContentId))
                continue; // already notified / already present last frame
            if (member.ContentId == playerState.ContentId)
                continue; // ignore our own join

            NotifyIfListed(member);
        }

        previousMembers = currentMembers;
    }

    private void NotifyIfListed(Dalamud.Game.ClientState.Party.IPartyMember member)
    {
        var data = storage.Data;
        var name = member.Name.TextValue;
        var world = MemberWorld(member);

        // Blacklist takes priority: it is the more important warning.
        if (Match(data.Blacklist, member.ContentId, name, world) is { } blacklisted)
        {
            chatGui.Print(BuildAlert(blacklisted, world), "Blacklist", BlacklistColor);
            return;
        }

        if (Match(data.Friends, member.ContentId, name, world) is { } friend)
            chatGui.Print(BuildAlert(friend, world), "Friends", FriendColor);
    }

    /// <summary>The party member's home world, or "" when it cannot be determined.</summary>
    private static string MemberWorld(Dalamud.Game.ClientState.Party.IPartyMember member)
    {
        var world = member.World;
        return world.IsValid ? world.Value.Name.ExtractText() : ""; // Lumina sheet rows are structs
    }

    /// <summary>
    /// Matches by content ID first, then by name. When several entries share a name,
    /// the party member's world disambiguates between them (entries with an unknown
    /// world still match by name alone).
    /// </summary>
    private static PlayerEntry? Match(List<PlayerEntry> pool, ulong contentId, string name, string world)
    {
        if (contentId != 0)
        {
            var byId = pool.FirstOrDefault(e => e.ContentId == contentId);
            if (byId is not null)
                return byId;
        }

        var candidates = pool.Where(e => string.Equals(e.Name, name, StringComparison.OrdinalIgnoreCase)).ToList();
        if (candidates.Count > 1 && world.Length > 0)
            candidates = candidates.Where(e => e.World.Length == 0 ||
                                               string.Equals(e.World, world, StringComparison.OrdinalIgnoreCase)).ToList();

        return candidates.FirstOrDefault();
    }

    /// <summary>
    /// Builds the alert text. The colored "[Blacklist]"/"[Friends]" tag comes from
    /// IChatGui.Print's messageTag + tagColor parameters (this Dalamud build has no
    /// ARGB text-color SeString payload, only palette-keyed UI colors).
    /// </summary>
    private static string BuildAlert(PlayerEntry entry, string world)
    {
        var tags = entry.Tags.Count > 0 ? $" [{string.Join(", ", entry.Tags)}]" : "";
        var worldSuffix = world.Length > 0 ? $" ({world})" : "";
        return $"\"{entry.Name}\"{worldSuffix}{tags} just joined your party!";
    }
}