// Copyright (C) 2021-present sam (starshines.gay)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

using System.Net;
using Catalogger.Backend.Api.Middleware;
using Catalogger.Backend.Extensions;
using Microsoft.AspNetCore.Mvc;
using Remora.Discord.API;
using Remora.Discord.API.Abstractions.Objects;

namespace Catalogger.Backend.Api;

public partial class GuildsController
{
    [HttpGet("ignored-users")]
    public async Task<IActionResult> GetIgnoredUsersAsync(string id, CancellationToken ct = default)
    {
        var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
        // not actually sure how long fetching members might take. timing it out after 10 seconds just in case
        // the underlying redis library doesn't support CancellationTokens so we don't pass it down
        // we just end the loop early if it expires
        cts.CancelAfter(TimeSpan.FromSeconds(10));

        var (guildId, _) = await ParseGuildAsync(id);
        var guildConfig = await guildRepository.GetAsync(guildId);

        var output = new List<IgnoredUser>();
        foreach (var userId in guildConfig.Messages.IgnoredUsers)
        {
            if (cts.Token.IsCancellationRequested)
                break;

            var member = await memberCache.TryGetAsync(guildId, DiscordSnowflake.New(userId));
            output.Add(
                new IgnoredUser(
                    Id: userId,
                    Tag: member != null ? member.User.Value.Tag() : "unknown user"
                )
            );
        }

        return Ok(output.OrderBy(i => i.Id));
    }

    private record IgnoredUser(ulong Id, string Tag);

    [HttpPut("ignored-users/{userId}")]
    public async Task<IActionResult> AddIgnoredUserAsync(string id, ulong userId)
    {
        var (guildId, _) = await ParseGuildAsync(id);
        var guildConfig = await guildRepository.GetAsync(guildId);

        IUser? user;
        var member = await memberCache.TryGetAsync(guildId, DiscordSnowflake.New(userId));
        if (member != null)
            user = member.User.Value;
        else
            user = await userCache.GetUserAsync(DiscordSnowflake.New(userId));

        if (user == null)
            throw new ApiError(HttpStatusCode.NotFound, ErrorCode.BadRequest, "User not found");

        if (guildConfig.Messages.IgnoredUsers.Contains(user.ID.Value))
            return Ok(new IgnoredUser(user.ID.Value, user.Tag()));

        guildConfig.Messages.IgnoredUsers.Add(user.ID.Value);
        await guildRepository.UpdateConfigAsync(guildId, guildConfig);

        return Ok(new IgnoredUser(user.ID.Value, user.Tag()));
    }

    [HttpDelete("ignored-users/{userId}")]
    public async Task<IActionResult> RemoveIgnoredUserAsync(string id, ulong userId)
    {
        var (guildId, _) = await ParseGuildAsync(id);
        var guildConfig = await guildRepository.GetAsync(guildId);

        guildConfig.Messages.IgnoredUsers.Remove(userId);
        await guildRepository.UpdateConfigAsync(guildId, guildConfig);

        return NoContent();
    }

    [HttpGet("users")]
    public async Task<IActionResult> ListUsersAsync(string id, [FromQuery] string query)
    {
        var (guildId, _) = await ParseGuildAsync(id);
        var members = await memberCache.GetMemberNamesAsync(guildId, query);

        return Ok(members.OrderBy(m => m.Name).Select(m => new UserQueryResponse(m.Name, m.Id)));
    }

    private record UserQueryResponse(string Name, string Id);
}