using JdeScoping.Api.Contracts.ManualSync;
using JdeScoping.DataAccess.Services;
using JdeScoping.DataSync.Services;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace JdeScoping.Api.Controllers;

/// <summary>
/// API endpoints for manual data sync request management.
/// </summary>
[Route("api/manual-sync")]
[ApiController]
[Authorize]
public class ManualSyncController : ApiControllerBase
{
    private readonly IManualSyncRequestService _manualSyncRequestService;
    private readonly IPipelineRegistry _pipelineRegistry;

    /// <summary>
    /// Initializes a new instance of the <see cref="ManualSyncController"/> class.
    /// </summary>
    /// <param name="manualSyncRequestService">The service for managing manual sync requests.</param>
    /// <param name="pipelineRegistry">The pipeline registry for querying pipeline information.</param>
    public ManualSyncController(
        IManualSyncRequestService manualSyncRequestService,
        IPipelineRegistry pipelineRegistry)
    {
        _manualSyncRequestService = manualSyncRequestService;
        _pipelineRegistry = pipelineRegistry;
    }

    /// <summary>
    /// Gets all manual sync requests, optionally filtered to pending only.
    /// </summary>
    /// <param name="pendingOnly">If true, returns only pending requests. Default is false.</param>
    /// <param name="ct">Cancellation token.</param>
    /// <returns>A list of manual sync request view models.</returns>
    [HttpGet]
    [ProducesResponseType(typeof(List<ManualSyncRequestViewModel>), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    public async Task<ActionResult<List<ManualSyncRequestViewModel>>> GetRequests(
        [FromQuery] bool pendingOnly = false,
        CancellationToken ct = default)
    {
        var requests = await _manualSyncRequestService.GetRequestsAsync(pendingOnly, ct);

        var viewModels = requests.Select(r => new ManualSyncRequestViewModel
        {
            Id = r.Id,
            PipelineName = r.PipelineName,
            SyncType = r.SyncType,
            RequestDT = r.RequestDT,
            RequestedBy = r.RequestedBy,
            CompletedDT = r.CompletedDT,
            CancelDT = r.CancelDT,
            CancelledBy = r.CancelledBy,
            Status = r.Status,
            RowVersionBase64 = Convert.ToBase64String(r.RowVersion)
        }).ToList();

        return Ok(viewModels);
    }

    /// <summary>
    /// Gets all available pipelines with their supported sync types.
    /// </summary>
    /// <returns>A list of pipeline information view models.</returns>
    [HttpGet("pipelines")]
    [ProducesResponseType(typeof(List<PipelineInfoViewModel>), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    public ActionResult<List<PipelineInfoViewModel>> GetPipelines()
    {
        var pipelines = _pipelineRegistry.GetEnabledPipelines()
            .Select(p => new PipelineInfoViewModel
            {
                Name = p.Name,
                SupportedSyncTypes = GetSupportedSyncTypes(p)
            })
            .ToList();

        return Ok(pipelines);
    }

    /// <summary>
    /// Creates a new manual sync request.
    /// </summary>
    /// <param name="dto">The create request containing pipeline name and sync type.</param>
    /// <param name="ct">Cancellation token.</param>
    /// <returns>The created manual sync request view model.</returns>
    [HttpPost]
    [ProducesResponseType(typeof(ManualSyncRequestViewModel), StatusCodes.Status201Created)]
    [ProducesResponseType(StatusCodes.Status400BadRequest)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    public async Task<ActionResult<ManualSyncRequestViewModel>> CreateRequest(
        [FromBody] CreateManualSyncRequestDto dto,
        CancellationToken ct = default)
    {
        var username = User.Identity?.Name;
        if (string.IsNullOrEmpty(username))
        {
            return Unauthorized();
        }

        // Validate pipeline and sync type combination using the registry
        if (!_pipelineRegistry.IsValidPipelineAndSyncType(dto.PipelineName, dto.SyncType))
        {
            return BadRequest($"Invalid pipeline/sync type combination. Pipeline '{dto.PipelineName}' does not support sync type '{dto.SyncType}'.");
        }

        var request = await _manualSyncRequestService.CreateRequestAsync(
            dto.PipelineName,
            dto.SyncType,
            username,
            ct);

        var viewModel = new ManualSyncRequestViewModel
        {
            Id = request.Id,
            PipelineName = request.PipelineName,
            SyncType = request.SyncType,
            RequestDT = request.RequestDT,
            RequestedBy = request.RequestedBy,
            CompletedDT = request.CompletedDT,
            CancelDT = request.CancelDT,
            CancelledBy = request.CancelledBy,
            Status = request.Status,
            RowVersionBase64 = Convert.ToBase64String(request.RowVersion)
        };

        return CreatedAtAction(nameof(GetRequests), viewModel);
    }

    /// <summary>
    /// Cancels a pending manual sync request.
    /// </summary>
    /// <param name="id">The ID of the request to cancel.</param>
    /// <param name="dto">The cancel request containing the row version for concurrency.</param>
    /// <param name="ct">Cancellation token.</param>
    /// <returns>A success message if cancelled, or a conflict error if already processed.</returns>
    [HttpPost("{id:int}/cancel")]
    [ProducesResponseType(typeof(object), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    [ProducesResponseType(StatusCodes.Status409Conflict)]
    public async Task<IActionResult> CancelRequest(
        int id,
        [FromBody] CancelManualSyncRequestDto dto,
        CancellationToken ct = default)
    {
        var username = User.Identity?.Name;
        if (string.IsNullOrEmpty(username))
        {
            return Unauthorized();
        }

        byte[] rowVersion;
        try
        {
            rowVersion = Convert.FromBase64String(dto.RowVersionBase64);
        }
        catch (FormatException)
        {
            return BadRequest("Invalid RowVersionBase64 format.");
        }

        var cancelled = await _manualSyncRequestService.CancelRequestAsync(
            id,
            username,
            rowVersion,
            ct);

        if (!cancelled)
        {
            return Conflict(new { message = "The request has already been completed or cancelled, or the data has been modified by another user." });
        }

        return Ok(new { message = "Request cancelled successfully." });
    }

    private static List<string> GetSupportedSyncTypes(DataSync.Configuration.EtlPipelineConfig pipeline)
    {
        var types = new List<string>();
        if (pipeline.SupportsMassSync) types.Add("mass");
        if (pipeline.SupportsDailySync) types.Add("daily");
        if (pipeline.SupportsHourlySync) types.Add("hourly");
        return types;
    }
}