using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using SVSim.Database;
using SVSim.Database.Entities.Guild;
using SVSim.Database.Models;
using SVSim.Database.Models.Config;
using SVSim.Database.Services;
using SVSim.Database.Services.Guild;
using SVSim.EmulatedEntrypoint.Models.Dtos.Common;
using SVSim.EmulatedEntrypoint.Models.Dtos.Common.Guild;
using SVSim.EmulatedEntrypoint.Models.Dtos.Guild;
using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;

namespace SVSim.EmulatedEntrypoint.Controllers;

/// <summary>/guild/* — 22 endpoints. See docs/api-spec/endpoints/post-login/guild-*.md.</summary>
[Route("guild")]
public sealed class GuildController : SVSimController
{
    private readonly IGuildService _guild;
    private readonly IGameConfigService _configs;
    private readonly SVSimDbContext _db;

    // Wire error code returned when guild operations fail (non-1 result_code).
    private const int GuildErrorResultCode = 2;

    public GuildController(IGuildService guild, IGameConfigService configs, SVSimDbContext db)
    {
        _guild = guild;
        _configs = configs;
        _db = db;
    }

    [HttpPost("info")]
    public async Task<ActionResult<GuildInfoResponse>> Info([FromBody] BaseRequest _, CancellationToken ct)
    {
        if (!TryGetViewerId(out var viewerId)) return Unauthorized();
        var cfg = _configs.Get<GuildConfig>();
        var view = await _guild.GetMyGuildAsync(viewerId, ct);
        var resp = new GuildInfoResponse
        {
            MaxMemberNum = cfg.MaxMemberNum,
            MaxSubLeaderNum = cfg.MaxSubLeaderNum,
            UsableStampList = cfg.UsableStampList.ConvertAll(i => i.ToString()),
        };
        if (view is null)
        {
            resp.GuildStatus = 0;                         // NOT_JOINING
        }
        else
        {
            resp.GuildStatus = 2;                         // JOINING
            resp.JoinRequestCount = view.JoinRequestCount;
            resp.InviteCount = view.InviteCount;
            var memberDtos = await ToMemberDtoListAsync(view.Members, viewerId, ct);
            var leaderName = memberDtos.FirstOrDefault(m => m.ViewerId == view.Guild.LeaderViewerId)?.Name ?? "";
            resp.Guild = new GuildBundle
            {
                Detail = ToDetailDto(view.Guild, view.Members.Count, leaderName),
                Members = memberDtos,
            };
        }
        return resp;
    }

    // ===== 21 remaining stubs — each returns the response DTO with defaults =====

    [HttpPost("create")]
    public async Task<ActionResult<EmptyResponse>> Create([FromBody] GuildCreateRequest req, CancellationToken ct)
    {
        if (!TryGetViewerId(out var viewerId)) return Unauthorized();
        var res = await _guild.CreateAsync(viewerId, new(req.GuildName, req.Activity, req.JoinCondition), ct);
        if (res.IsOk) return new EmptyResponse();
        return MapErrorToWire(res);
    }

    [HttpPost("breakup")]
    public async Task<ActionResult<EmptyResponse>> Breakup([FromBody] BaseRequest _, CancellationToken ct)
    {
        if (!TryGetViewerId(out var v)) return Unauthorized();
        var r = await _guild.BreakupAsync(v, ct);
        return r.IsOk ? new EmptyResponse() : MapErrorToWire(r);
    }

    [HttpPost("update")]
    public async Task<ActionResult<GuildUpdateResponse>> Update([FromBody] GuildUpdateRequest req, CancellationToken ct)
    {
        if (!TryGetViewerId(out var viewerId)) return Unauthorized();
        int? activity = req.Activity != 0 ? req.Activity : null;
        int? joinCondition = req.JoinCondition != 0 ? req.JoinCondition : null;
        var r = await _guild.UpdateAsync(viewerId, new(activity, joinCondition), ct);
        if (!r.IsOk) return WireError();

        var m = await _db.GuildMembers.FirstOrDefaultAsync(m => m.ViewerId == viewerId, ct);
        if (m is null) return WireError();
        var guild = await _guild.GetActiveAsync(m.GuildId, ct);
        if (guild is null) return WireError();
        var memberCount = await _db.GuildMembers.CountAsync(x => x.GuildId == guild.GuildId, ct);
        var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
        return new GuildUpdateResponse
        {
            Guild = new GuildDetailSubTree { Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") }
        };
    }

    [HttpPost("update_description")]
    public async Task<ActionResult<EmptyResponse>> UpdateDescription([FromBody] GuildUpdateDescriptionRequest req, CancellationToken ct)
    {
        if (!TryGetViewerId(out var viewerId)) return Unauthorized();
        var r = await _guild.UpdateDescriptionAsync(viewerId, req.Description, ct);
        return r.IsOk ? new EmptyResponse() : MapErrorToWire(r);
    }

    [HttpPost("update_emblem")]
    public async Task<ActionResult<GuildUpdateResponse>> UpdateEmblem([FromBody] GuildUpdateEmblemRequest req, CancellationToken ct)
    {
        if (!TryGetViewerId(out var viewerId)) return Unauthorized();
        var r = await _guild.UpdateEmblemAsync(viewerId, req.EmblemId, ct);
        if (!r.IsOk) return WireError();

        var m = await _db.GuildMembers.FirstOrDefaultAsync(m => m.ViewerId == viewerId, ct);
        if (m is null) return WireError();
        var guild = await _guild.GetActiveAsync(m.GuildId, ct);
        if (guild is null) return WireError();
        var memberCount = await _db.GuildMembers.CountAsync(x => x.GuildId == guild.GuildId, ct);
        var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
        return new GuildUpdateResponse
        {
            Guild = new GuildDetailSubTree { Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") }
        };
    }

    [HttpPost("search_guild")]
    public Task<ActionResult<GuildSearchGuildResponse>> SearchGuild([FromBody] GuildSearchGuildRequest req, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildSearchGuildResponse>>(new GuildSearchGuildResponse { List = new() });

    [HttpPost("emblem_list")]
    public async Task<ActionResult<GuildEmblemListResponse>> EmblemList([FromBody] BaseRequest _, CancellationToken ct)
    {
        if (!TryGetViewerId(out var viewerId)) return Unauthorized();
        var viewer = await _db.Viewers
            .AsNoTracking()
            .Include(v => v.Emblems)
            .FirstOrDefaultAsync(v => v.Id == viewerId, ct);
        var emblems = viewer?.Emblems ?? new();
        return new GuildEmblemListResponse
        {
            EmblemList = emblems.Select(e => new GuildEmblemEntry { EmblemId = e.Id }).ToList()
        };
    }

    [HttpPost("others_info")]
    public async Task<ActionResult<GuildOthersInfoResponse>> OthersInfo([FromBody] GuildOthersInfoRequest req, CancellationToken ct)
    {
        if (!TryGetViewerId(out _)) return Unauthorized();
        var guild = await _guild.GetActiveAsync(req.GuildId, ct);
        if (guild is null) return new GuildOthersInfoResponse();
        var memberCount = await _db.GuildMembers.CountAsync(m => m.GuildId == guild.GuildId, ct);
        var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
        return new GuildOthersInfoResponse
        {
            Guild = new GuildDetailSubTree
            {
                Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "")
            }
        };
    }

    [HttpPost("friend_list")]
    public Task<ActionResult<GuildFriendListResponse>> FriendList([FromBody] BaseRequest _, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildFriendListResponse>>(new GuildFriendListResponse { Friends = new() });

    [HttpPost("invite_user_list")]
    public Task<ActionResult<GuildInviteUserListResponse>> InviteUserList([FromBody] BaseRequest _, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildInviteUserListResponse>>(new GuildInviteUserListResponse { Users = new() });

    [HttpPost("invited_guild_list")]
    public Task<ActionResult<GuildInvitedGuildListResponse>> InvitedGuildList([FromBody] GuildInvitedGuildListRequest req, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildInvitedGuildListResponse>>(new GuildInvitedGuildListResponse { List = new() });

    [HttpPost("invite")]
    public Task<ActionResult<EmptyResponse>> Invite([FromBody] GuildInviteRequest req, CancellationToken ct) => Stub();

    [HttpPost("cancel_invite")]
    public Task<ActionResult<EmptyResponse>> CancelInvite([FromBody] GuildCancelInviteRequest req, CancellationToken ct) => Stub();

    [HttpPost("reject_invite")]
    public Task<ActionResult<EmptyResponse>> RejectInvite([FromBody] GuildRejectInviteRequest req, CancellationToken ct) => Stub();

    [HttpPost("join")]
    public Task<ActionResult<GuildJoinResponse>> Join([FromBody] GuildJoinEndpointRequest req, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildJoinResponse>>(new GuildJoinResponse { GuildStatus = 0 });

    [HttpPost("cancel_join_request")]
    public Task<ActionResult<EmptyResponse>> CancelJoinRequest([FromBody] GuildCancelJoinRequestRequest req, CancellationToken ct) => Stub();

    [HttpPost("join_request_list")]
    public Task<ActionResult<GuildJoinRequestListResponse>> JoinRequestList([FromBody] GuildJoinRequestListRequest req, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildJoinRequestListResponse>>(new GuildJoinRequestListResponse { Users = new() });

    [HttpPost("join_request_accept")]
    public Task<ActionResult<EmptyResponse>> JoinRequestAccept([FromBody] GuildJoinRequestAcceptRequest req, CancellationToken ct) => Stub();

    [HttpPost("reject_join_request")]
    public Task<ActionResult<EmptyResponse>> RejectJoinRequest([FromBody] GuildRejectJoinRequestRequest req, CancellationToken ct) => Stub();

    [HttpPost("leave")]
    public Task<ActionResult<EmptyResponse>> Leave([FromBody] BaseRequest _, CancellationToken ct) => Stub();

    [HttpPost("remove")]
    public Task<ActionResult<EmptyResponse>> Remove([FromBody] GuildRemoveRequest req, CancellationToken ct) => Stub();

    [HttpPost("change_role")]
    public Task<ActionResult<GuildChangeRoleResponse>> ChangeRole([FromBody] GuildChangeRoleRequest req, CancellationToken ct)
        => Task.FromResult<ActionResult<GuildChangeRoleResponse>>(new GuildChangeRoleResponse { Members = new() });

    // ===== Private helpers =====

    private static GuildDetailDto ToDetailDto(SVSim.Database.Entities.Guild.Guild guild, int memberCount, string leaderName = "") => new()
    {
        GuildId = guild.GuildId,
        GuildName = guild.Name,
        Description = guild.Description,
        GuildEmblemId = guild.EmblemId,
        JoinCondition = (int)guild.JoinCondition,
        Activity = (int)guild.Activity,
        MemberNum = memberCount,
        LeaderViewerId = guild.LeaderViewerId,
        LeaderName = leaderName,
    };

    private async Task<List<GuildMemberInfoDto>> ToMemberDtoListAsync(
        IReadOnlyList<GuildMember> members,
        long callerViewerId,
        CancellationToken ct)
    {
        if (members.Count == 0) return new();

        var viewerIds = members.Select(m => m.ViewerId).ToList();

        // Batch-load viewer rows with Info + SelectedEmblem + SelectedDegree.
        var viewers = await _db.Viewers
            .AsNoTracking()
            .Include(v => v.Info.SelectedEmblem)
            .Include(v => v.Info.SelectedDegree)
            .Where(v => viewerIds.Contains(v.Id))
            .ToDictionaryAsync(v => v.Id, ct);

        var result = new List<GuildMemberInfoDto>(members.Count);
        foreach (var m in members)
        {
            viewers.TryGetValue(m.ViewerId, out var v);
            result.Add(ToMemberDto(m, v));
        }
        return result;
    }

    private static GuildMemberInfoDto ToMemberDto(GuildMember member, Viewer? viewer) => new()
    {
        ViewerId = member.ViewerId,
        Name = viewer?.DisplayName ?? "",
        EmblemId = viewer?.Info?.SelectedEmblem?.Id is > 0 ? viewer.Info.SelectedEmblem.Id : 100_000_000L,
        CountryCode = viewer?.Info?.CountryCode ?? "",
        Rank = 1,            // TODO: populate from actual rank data when rank tracking lands
        DegreeId = viewer?.Info?.SelectedDegree?.Id ?? 0,
        IsOfficialMarkDisplayed = viewer?.Info?.IsOfficialMarkDisplayed == true ? 1 : 0,
        Role = (int)member.Role,
    };

    /// <summary>
    /// Maps a failed GuildOpResult to the wire error envelope convention used throughout the
    /// codebase (see CampaignController.Fail(), AchievementController, MissionController).
    /// Returns HTTP 200 with a JSON body carrying <c>result_code: 2</c>.
    /// </summary>
    private ActionResult<EmptyResponse> MapErrorToWire(GuildOpResult res)
        => Ok(new { result_code = GuildErrorResultCode });

    /// <summary>
    /// Returns a wire-error for endpoints that return a non-EmptyResponse type.
    /// Identical result_code=2 body, but typed as ObjectResult so it fits any TResult.
    /// </summary>
    private ObjectResult WireError() => Ok(new { result_code = GuildErrorResultCode });

    private static Task<ActionResult<EmptyResponse>> Stub() =>
        Task.FromResult<ActionResult<EmptyResponse>>(new EmptyResponse());
}