using Asp.Versioning;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using TarninaHub.Application.Abstractions;
using TarninaHub.Application.Dtos;
using TarninaHub.Application.Mappings;
using TarninaHub.Application.Security;
using TarninaHub.Domain.Rules;

namespace TarninaHub.Controllers;

[ApiController]
[ApiVersion("1.0")]
[Route("api/submissions")]
[Authorize]
public class SubmissionsController : ControllerBase
{
    private readonly ISubmissionService _submissionService;
    private readonly IMatchmakingService _matchmakingService;
    private readonly INotificationService _notifications;

    public SubmissionsController(
        ISubmissionService submissionService,
        IMatchmakingService matchmakingService,
        INotificationService notifications)
    {
        _submissionService = submissionService;
        _matchmakingService = matchmakingService;
        _notifications = notifications;
    }

    [HttpPost]
    public async Task<ActionResult<SubmissionResponse>> Create(
        CreateSubmissionRequest request,
        CancellationToken cancellationToken)
    {
        var userId = User.GetUserId();

        if (string.IsNullOrWhiteSpace(userId))
        {
            return Unauthorized();
        }

        var created = await _submissionService.CreateAsync(userId, request, cancellationToken);

        await _matchmakingService.IndexSubmissionAsync(created.Id, cancellationToken);

        await _notifications.NotifyStaffAsync(
            "submission.created",
            new Dictionary<string, string?>
            {
                ["submissionId"] = created.Id,
                ["title"] = created.Title,
                ["authorId"] = created.AuthorId,
            },
            cancellationToken);

        return CreatedAtAction(nameof(GetById), new { submissionId = created.Id }, created);
    }

    [HttpGet]
    public async Task<ActionResult<PagedResponse<SubmissionResponse>>> List(
        [FromQuery] string? status,
        [FromQuery] int page = 1,
        [FromQuery] int pageSize = 20,
        CancellationToken cancellationToken = default)
    {
        var userId = User.GetUserId();

        if (string.IsNullOrWhiteSpace(userId))
        {
            return Unauthorized();
        }

        page = page < 1 ? 1 : page;
        pageSize = pageSize is < 1 or > 100 ? 20 : pageSize;

        var result = await _submissionService.ListAsync(
            userId,
            IsStaff(),
            status,
            page,
            pageSize,
            cancellationToken);

        return Ok(result);
    }

    [HttpGet("{submissionId}")]
    public async Task<ActionResult<SubmissionResponse>> GetById(
        string submissionId,
        CancellationToken cancellationToken)
    {
        var userId = User.GetUserId();

        if (string.IsNullOrWhiteSpace(userId))
        {
            return Unauthorized();
        }

        var submission = await _submissionService.GetAsync(submissionId, cancellationToken);

        if (submission is null)
        {
            return NotFound();
        }

        if (!IsStaff() && !string.Equals(submission.AuthorId, userId, StringComparison.Ordinal))
        {
            return Forbid();
        }

        return Ok(submission);
    }

    [HttpPut("{submissionId}/status")]
    [Authorize(Policy = Policies.OperatorOrAdmin)]
    public async Task<ActionResult<SubmissionResponse>> UpdateStatus(
        string submissionId,
        UpdateSubmissionStatusRequest request,
        CancellationToken cancellationToken)
    {
        var current = await _submissionService.GetAsync(submissionId, cancellationToken);

        if (current is null)
        {
            return NotFound();
        }

        var from = SubmissionStatusWire.Parse(current.Status);
        var to = SubmissionStatusWire.Parse(request.Status);

        if (to is null)
        {
            ModelState.AddModelError(nameof(request.Status), "Unknown status value.");

            return ValidationProblem(ModelState);
        }

        if (from is null || !SubmissionWorkflow.CanTransition(from.Value, to.Value))
        {
            ModelState.AddModelError(
                nameof(request.Status),
                $"Transition from '{current.Status}' to '{request.Status}' is not allowed.");

            return ValidationProblem(ModelState);
        }

        var updated = await _submissionService.UpdateStatusAsync(submissionId, to.Value.ToWire(), cancellationToken);

        return updated is null ? NotFound() : Ok(updated);
    }

    [HttpPost("{submissionId}/match")]
    public async Task<ActionResult<MatchResponse>> Match(
        string submissionId,
        [FromBody] MatchRequest? request,
        CancellationToken cancellationToken)
    {
        var access = await AuthorizeSubmissionAccessAsync(submissionId, cancellationToken);

        if (access is not null)
        {
            return access;
        }

        var result = await _matchmakingService.MatchAsync(
            submissionId,
            request ?? new MatchRequest(null, null),
            cancellationToken);

        return result is null ? NotFound() : Ok(result);
    }

    [HttpGet("{submissionId}/matches")]
    public async Task<ActionResult<MatchResponse>> Matches(
        string submissionId,
        [FromQuery] string? challengeId,
        [FromQuery] int? maxResults,
        CancellationToken cancellationToken)
    {
        var access = await AuthorizeSubmissionAccessAsync(submissionId, cancellationToken);

        if (access is not null)
        {
            return access;
        }

        var result = await _matchmakingService.MatchAsync(
            submissionId,
            new MatchRequest(maxResults, challengeId),
            cancellationToken);

        return result is null ? NotFound() : Ok(result);
    }

    private async Task<ActionResult?> AuthorizeSubmissionAccessAsync(
        string submissionId,
        CancellationToken cancellationToken)
    {
        var userId = User.GetUserId();

        if (string.IsNullOrWhiteSpace(userId))
        {
            return Unauthorized();
        }

        var submission = await _submissionService.GetAsync(submissionId, cancellationToken);

        if (submission is null)
        {
            return NotFound();
        }

        if (!IsStaff() && !string.Equals(submission.AuthorId, userId, StringComparison.Ordinal))
        {
            return Forbid();
        }

        return null;
    }

    private bool IsStaff() =>
        User.IsInRole(RoleNames.Operator) || User.IsInRole(RoleNames.Manager) || User.IsInRole(RoleNames.Admin);
}