using System.Diagnostics;
using ErsatzTV.Application.Libraries;
using ErsatzTV.Core.Api.Libraries;
using ErsatzTV.Core.Interfaces.Repositories;
using ErsatzTV.Extensions;
using MediatR;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace ErsatzTV.Controllers.Api;

[ApiController]
[EndpointGroupName("general")]
public class LibrariesController(ITelevisionRepository televisionRepository, IMediator mediator) : ControllerBase
{
    [HttpGet("/api/libraries/scan-status", Name = "GetLibraryScanStatus")]
    [Tags("Libraries")]
    [EndpointSummary("Get active library scan status")]
    [ProducesResponseType(typeof(List<LibraryScanStatusResponseModel>), StatusCodes.Status200OK)]
    public async Task<List<LibraryScanStatusResponseModel>> GetScanStatus(CancellationToken cancellationToken) =>
        await mediator.Send(new GetLibraryScanStatus(), cancellationToken);

    [HttpPost("/api/libraries/{id:int}/scan")]
    [Tags("Libraries")]
    [EndpointSummary("Scan library")]
    [EndpointDescription("Queues a scan of the whole library. Pass ?deep=true for a deep (metadata-refresh) scan.")]
    [ProducesResponseType(StatusCodes.Status202Accepted)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status409Conflict)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
    public async Task<IActionResult> ScanLibrary(
        int id,
        [FromQuery] bool deep = false,
        CancellationToken cancellationToken = default)
    {
        QueueLibraryScanResult result =
            await mediator.Send(new QueueLibraryScanByLibraryId(id, deep), cancellationToken);
        return result switch
        {
            QueueLibraryScanResult.Queued => new AcceptedResult(),
            QueueLibraryScanResult.AlreadyScanning => ApiResults.ConflictProblem(
                "Library scan in progress",
                $"A scan for library {id} is already in progress."),
            QueueLibraryScanResult.SyncDisabled => new UnprocessableEntityObjectResult(
                new ProblemDetails
                {
                    Status = StatusCodes.Status422UnprocessableEntity,
                    Title = "Library sync is disabled",
                    Detail = $"Item sync is disabled for library {id}."
                }),
            _ => ApiResults.NotFoundProblem($"Library {id} does not exist.")
        };
    }

    [HttpPost("/api/libraries/{id:int}/scan-show")]
    [Tags("Libraries")]
    [EndpointSummary("Scan show")]
    [ProducesResponseType(StatusCodes.Status202Accepted)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status409Conflict)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
    public async Task<IActionResult> ScanShow(int id, [FromBody] ScanShowRequest request)
    {
        Option<string> maybeTitle = await televisionRepository.GetShowTitle(id, request.ShowId);
        foreach (string title in maybeTitle)
        {
            QueueShowScanResult result =
                await mediator.Send(new QueueShowScanByLibraryId(id, request.ShowId, title, request.DeepScan));

            return result switch
            {
                QueueShowScanResult.Queued => new AcceptedResult(),
                QueueShowScanResult.AlreadyScanning => ApiResults.ConflictProblem(
                    "Library scan in progress",
                    $"A scan for library {id} is already in progress; cannot scan an individual show."),
                QueueShowScanResult.SyncDisabled => new UnprocessableEntityObjectResult(
                    new ProblemDetails
                    {
                        Status = StatusCodes.Status422UnprocessableEntity,
                        Title = "Library sync is disabled",
                        Detail = $"Item sync is disabled for library {id}."
                    }),
                QueueShowScanResult.Unsupported => new UnprocessableEntityObjectResult(
                    new ProblemDetails
                    {
                        Status = StatusCodes.Status422UnprocessableEntity,
                        Title = "Single show scanning is not supported",
                        Detail = $"Library {id} does not support scanning an individual show."
                    }),
                QueueShowScanResult.ScanFailed => new UnprocessableEntityObjectResult(
                    new ProblemDetails
                    {
                        Status = StatusCodes.Status422UnprocessableEntity,
                        Title = "Unable to scan show",
                        Detail = $"The scan for show {request.ShowId} in library {id} could not be completed."
                    }),
                QueueShowScanResult.NotFound => ApiResults.NotFoundProblem($"Library {id} does not exist."),
                _ => throw new UnreachableException($"Unmapped QueueShowScanResult: {result}")
            };
        }

        return ApiResults.NotFoundProblem($"Show {request.ShowId} does not exist in library {id}.");
    }
}

public record ScanShowRequest(int ShowId, bool DeepScan = false);