using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;
using DorkNet.Models.GameSessions;
using DorkNet.Server.Auth;
using DorkNet.Server.Data;
using DorkNet.Server.Data.Entities;
using DorkNet.Server.Services;

namespace DorkNet.Server.Controllers.Match;

/// <summary>
/// match.rec.net — dedicated matchmaking service used by later 2020 builds.
/// Delegates to the Postgres-backed GameSessionService.
/// </summary>
[ApiController]
[Authorize]
public class MatchController(
    GameSessionService sessionService,
    PlayerPresenceService presence,
    PrivateInstanceService privateInstances,
    DorkNetDbContext db,
    ILogger<MatchController> logger) : ControllerBase
{
    /// <summary>POST <c>match.*/roominstance/{id}/reportjoinresult</c> —
    /// the watch fires this AFTER its Photon connect+join attempt,
    /// reporting how it went via <c>RecNet.Matchmaking+GameJoinResult</c>
    /// (Matchmaking.cs:121):
    ///   0 = Success, 1 = FailedToConnectToRegion,
    ///   2 = FailedToConnectToRoom, 3 = FailedToSpawnPlayer.
    /// Body is form-urlencoded <c>result=N</c>. Watch ignores the
    /// response body and just needs 2xx (Matchmaking.txt:6668-6699), so
    /// we mostly use this for visibility into Photon-side issues —
    /// without it, all we see in the catch-all is an opaque "200, empty
    /// reply" and no clue why a player crashed back to dorm.</summary>
    [HttpPost("/roominstance/{instanceId:long}/reportjoinresult")]
    public IActionResult ReportJoinResult(long instanceId, [FromForm(Name = "result")] int? result)
    {
        var code = result ?? -1;
        var label = code switch
        {
            0 => "Success",
            1 => "FailedToConnectToRegion",
            2 => "FailedToConnectToRoom",
            3 => "FailedToSpawnPlayer",
            _ => $"Unknown({code})",
        };
        var pid = this.RequireCurrentPlayerId();
        if (code == 0)
        {
            logger.LogInformation(
                "[joinresult] player={Player} instance={Instance} OK ({Label})",
                pid, instanceId, label);
        }
        else
        {
            logger.LogWarning(
                "[joinresult] player={Player} instance={Instance} FAILED code={Code} ({Label}) — Photon-side error, check Photon AppId/region/auth",
                pid, instanceId, code, label);
        }
        return Ok();
    }


    /// <summary>PUT <c>/roominstance/{id}/inprogress</c> — fired by
    /// <c>RecNet.Matchmaking.SetGameInProgress(bool inProgress)</c>
    /// (Matchmaking.cs:333). Body is form-urlencoded
    /// <c>inProgress=true|false</c>. The watch uses this to mark a
    /// match as "in progress" so newcomers are sent to a fresh instance
    /// instead of joining a game already underway (e.g. paintball
    /// during a round). Our matchmaker doesn't gate on this yet — log
    /// + 200 to take it off the catch-all.</summary>
    [HttpPut("/roominstance/{instanceId:long}/inprogress")]
    [Consumes("application/x-www-form-urlencoded", "multipart/form-data")]
    public IActionResult SetInProgress(
        long instanceId,
        [FromForm(Name = "inProgress")] bool? inProgress)
    {
        var pid = this.RequireCurrentPlayerId();
        logger.LogInformation(
            "[set-inprogress] player={Player} instance={Instance} inProgress={Flag}",
            pid, instanceId, inProgress);
        return Ok();
    }

    /// <summary>POST <c>/roominstance/{id}/markprivate</c> — promote
    /// the caller's current public instance to an invite-gated
    /// PrivateInstance row. The watch only needs a RecNet result
    /// wrapper, but the server persists the privacy state so later
    /// invite joins are enforced by <see cref="PrivateInstanceService"/>.</summary>
    [HttpPost("/roominstance/{instanceId:long}/markprivate")]
    public async Task<IActionResult> MarkPrivate(long instanceId)
    {
        var pid = this.RequireCurrentPlayerId();
        var existing = await db.PrivateInstances.FirstOrDefaultAsync(p => p.Id == instanceId);
        if (existing is not null)
        {
            if (existing.OwnerPlayerId != pid) return Forbid();
            return Ok(new { Success = true, Error = string.Empty });
        }

        var current = presence.GetRoom(pid);
        if (current is null || current.RoomInstanceId != instanceId)
            return NotFound(new { Success = false, Error = "room instance not found for current player" });

        db.PrivateInstances.Add(new PrivateInstanceEntity
        {
            Id = instanceId,
            RoomId = current.RoomId,
            SubRoomId = current.SubRoomId,
            OwnerPlayerId = pid,
            PhotonRoomId = current.PhotonRoomId,
            Location = current.Location,
            DataBlob = current.DataBlob,
            PhotonRegion = current.PhotonRegionId,
            MaxCapacity = current.MaxCapacity,
            Name = current.Name,
            CreatedAt = DateTime.UtcNow,
        });
        await db.SaveChangesAsync();
        logger.LogInformation("[mark-private] player={Player} instance={Instance}", pid, instanceId);
        return Ok(new { Success = true, Error = string.Empty });
    }

    /// <summary>GET/POST <c>/roominstance/{id}/roomcode</c> — raw
    /// JSON string room code shown by the watch. Codes are stable for
    /// an instance id and do not expose the numeric id directly.</summary>
    [HttpGet("/roominstance/{instanceId:long}/roomcode")]
    [HttpPost("/roominstance/{instanceId:long}/roomcode")]
    public IActionResult RoomCode(long instanceId)
    {
        var code = RoomCodeService.Generate(instanceId);
        return Content(JsonSerializer.Serialize(code), "application/json");
    }

    [HttpPost("/v1/find")]
    public async Task<ActionResult<JoinGameSessionResponse>> Find([FromBody] JoinRandomGameSessionRequest req)
    {
        var session = await sessionService.JoinOrCreateAsync(req.RoomId, req.ActivityLevelId, req.RegionId);
        return Ok(new JoinGameSessionResponse { Result = JoinGameErrorCode.Success, GameSession = session });
    }

    [HttpPost("/v1/join/{sessionId:long}")]
    public async Task<ActionResult<JoinGameSessionResponse>> Join(long sessionId)
    {
        var session = await sessionService.GetByIdAsync(sessionId);
        if (session is null) return Ok(new JoinGameSessionResponse { Result = JoinGameErrorCode.NotFound });
        if (session.IsFull) return Ok(new JoinGameSessionResponse { Result = JoinGameErrorCode.Full });
        return Ok(new JoinGameSessionResponse { Result = JoinGameErrorCode.Success, GameSession = session });
    }

    [HttpPost("/v1/leave/{sessionId:long}")]
    public async Task<IActionResult> Leave(long sessionId)
    {
        await sessionService.PlayerLeftAsync(sessionId);
        return Ok();
    }

    [HttpGet("/v1/session/{sessionId:long}")]
    public async Task<ActionResult<GameSession>> GetSession(long sessionId)
    {
        var session = await sessionService.GetByIdAsync(sessionId);
        if (session is null) return NotFound();
        return Ok(session);
    }

    /// <summary>GET <c>match.*/room/{id}/instances</c> — the
    /// "RoomInstanceBrowser" the watch shows when you tap a room tile.
    /// Returns the currently-active instances so the player can see
    /// which one their friends are in (and join it) instead of being
    /// matchmade into a fresh empty room. Verified URL at
    /// Matchmaking.txt:6286; response is a
    /// <c>List&lt;SimpleRoomInstance&gt;</c> per
    /// <c>SimpleRoomInstance.cs</c>: RoomInstanceId/RoomId/SubRoomId,
    /// IsFull, CreatedAt, PlayerIds, SubroomName, PlayerCount,
    /// HasModPresent, HashedInstanceId.
    ///
    /// We derive instances from PlayerPresenceService's per-player
    /// RoomInstanceDto: every distinct PhotonRoomId in the same RoomId
    /// is one instance, with the players currently presenced there.
    /// PrivateInstances are surfaced as well so the inviter and
    /// invitee see the same room in the browser.</summary>
    [HttpGet("/room/{roomId:long}/instances")]
    [AllowAnonymous]
    public async Task<IActionResult> RoomInstances(long roomId)
    {
        var presenced = presence.EnumerateActiveInstances(roomId).ToList();
        // Only surface the caller's OWN private instances — we never
        // leak someone else's PhotonRoomId into the browser. The Photon
        // join check still requires CanJoinAsync, but redacting at the
        // list level matches the existing RoomInstanceDto.Redact policy.
        var pid = this.CurrentPlayerId() ?? 0;
        var privates = pid == 0
            ? new List<Data.Entities.PrivateInstanceEntity>()
            : await db.PrivateInstances
                .Where(p => p.RoomId == roomId && p.OwnerPlayerId == pid)
                .ToListAsync();

        // Merge: presence rows are authoritative (player currently
        // there); add any owned private instance the inviter created
        // but nobody's joined yet so the inviter can still see it.
        var byKey = new Dictionary<string, SimpleInstance>(StringComparer.Ordinal);
        foreach (var (room, playerIds) in presenced)
        {
            if (string.IsNullOrEmpty(room.PhotonRoomId)) continue;
            byKey[room.PhotonRoomId] = new SimpleInstance(
                RoomInstanceId: room.RoomInstanceId,
                RoomId: room.RoomId,
                SubRoomId: room.SubRoomId,
                IsFull: false,
                CreatedAt: DateTime.UtcNow,
                PlayerIds: playerIds.Select(p => (int)p).ToList(),
                SubroomName: room.Name ?? string.Empty,
                PlayerCount: playerIds.Count,
                HasModPresent: false,
                HashedInstanceId: room.PhotonRoomId);
        }
        foreach (var p in privates)
        {
            if (string.IsNullOrEmpty(p.PhotonRoomId) || byKey.ContainsKey(p.PhotonRoomId)) continue;
            byKey[p.PhotonRoomId] = new SimpleInstance(
                RoomInstanceId: p.Id,
                RoomId: p.RoomId,
                SubRoomId: p.SubRoomId,
                IsFull: false,
                CreatedAt: DateTime.SpecifyKind(p.CreatedAt, DateTimeKind.Utc),
                PlayerIds: new List<int>(),
                SubroomName: p.Name,
                PlayerCount: 0,
                HasModPresent: false,
                HashedInstanceId: p.PhotonRoomId);
        }

        // Wire shape: SimpleRoomInstance.Deserialize reads CAMELCASE
        // keys — verified at Cpp2IL_ISIL/.../RecNet/SimpleRoomInstance.txt
        // lines 765-808 ({roomInstanceId, roomId, subRoomId, isFull,
        // createdAt, playerIds}). SubroomName / PlayerCount /
        // HasModPresent / HashedInstanceId are populated locally on the
        // watch (PlayerIds.Count, local hash, etc.) — not read from
        // JSON, so we don't send them. Earlier PascalCase response made
        // every field default to 0/null on the watch, breaking the
        // browser.
        return Ok(byKey.Values.Select(i => new
        {
            roomInstanceId = i.RoomInstanceId,
            roomId = i.RoomId,
            subRoomId = i.SubRoomId,
            isFull = i.IsFull,
            createdAt = i.CreatedAt,
            playerIds = i.PlayerIds.ToArray(),
        }));
    }

    private sealed record SimpleInstance(
        long RoomInstanceId, long RoomId, long SubRoomId, bool IsFull,
        DateTime CreatedAt, List<int> PlayerIds, string SubroomName,
        int PlayerCount, bool HasModPresent, string HashedInstanceId);

    /// <summary>DELETE <c>match.*/invite/{id}</c> — Matchmaking.cs
    /// DeclineRoomInvite. Verified URL at Matchmaking.txt:6505 (method
    /// enum 4 = DELETE). The id is a MessageEntity row id (V2 game and
    /// party invites are stored as Type 6/7 messages). Mark it read so the inviter's
    /// inbox stops nagging, and remove the invitee from the private
    /// instance's allow-list so they can't change their mind without
    /// a fresh invite.</summary>
    [HttpDelete("/invite/{messageId:long}")]
    public async Task<IActionResult> DeclineInvite(long messageId)
    {
        var pid = this.RequireCurrentPlayerId();
        var msg = await db.Messages
            .FirstOrDefaultAsync(m => m.Id == messageId && m.RecipientPlayerId == pid);
        if (msg is null) return NotFound();

        if (msg.ReadAt is null)
        {
            msg.ReadAt = DateTime.UtcNow;
        }

        // Current invite messages carry the bare roomInstanceId in
        // Data/Body. Older local DBs may still have the legacy
        // "Invite to private match (instance N)" text, so accept both.
        if (TryParseRoomInstanceId(msg.Body, out var instId))
        {
            await privateInstances.RevokeInviteAsync(instId, pid);
        }

        await db.SaveChangesAsync();
        logger.LogInformation("[invite] declined messageId={Id} by player={Player}", messageId, pid);
        return Ok();
    }

    // Same three-shape parser as GoToController.TryParseRoomInstanceId
    // (see that file for the rationale): JSON for current Type-6/7
    // invites, bare int for the pre-fix shape, "Invite to private match
    // (instance N)" text for ancient rows.
    private static bool TryParseRoomInstanceId(string body, out long instanceId)
    {
        instanceId = 0;
        if (string.IsNullOrWhiteSpace(body)) return false;
        if (body.TrimStart().StartsWith('{'))
        {
            try
            {
                using var doc = System.Text.Json.JsonDocument.Parse(body);
                if (doc.RootElement.TryGetProperty("roomInstanceId", out var v))
                {
                    // See GoToController.TryParseRoomInstanceId for the
                    // rationale on accepting both string and number forms.
                    if (v.ValueKind == System.Text.Json.JsonValueKind.String
                        && long.TryParse(v.GetString(), System.Globalization.NumberStyles.Integer,
                            System.Globalization.CultureInfo.InvariantCulture, out var strInst))
                    { instanceId = strInst; return true; }
                    if (v.ValueKind == System.Text.Json.JsonValueKind.Number
                        && v.TryGetInt64(out var numInst))
                    { instanceId = numInst; return true; }
                }
            }
            catch { /* fall through to legacy formats */ }
        }
        if (long.TryParse(body, out instanceId)) return true;
        var open = body.IndexOf("instance ", StringComparison.Ordinal);
        if (open < 0) return false;
        var tail = body[(open + "instance ".Length)..].TrimEnd(')', '.', ' ');
        return long.TryParse(tail, out instanceId);
    }

}