using System;
using System.Threading;
using System.Threading.Tasks;
using AutoMapper;
using LaDOSE.Business.Interface;
using LaDOSE.DTO;
using LaDOSE.Entity;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

namespace LaDOSE.Api.Controllers
{
    /// <summary>
    /// Pushes ranking tables into the club's Google Spreadsheet.
    ///
    /// The tables arrive already built: the browser reuses the same buildRanking() that produces
    /// the CSV export, so the sheet and the CSV cannot drift. This controller resolves the target
    /// from configuration, validates, and relays — see SheetsExportService.
    ///
    /// Returns IActionResult with explicit ProducesResponseType, like UsersController: the API has
    /// no exception middleware, so an escaping throw reaches the browser as an HTML developer page
    /// that the client can only report as a bare status.
    /// </summary>
    [Authorize]
    [Produces("application/json")]
    [Route("api/[controller]")]
    public class SheetsController : ControllerBase
    {
        private readonly ISheetsExportService _service;
        private readonly IMapper _mapper;
        private readonly ILogger<SheetsController> _logger;

        public SheetsController(IMapper mapper, ISheetsExportService service, ILogger<SheetsController> logger)
        {
            _mapper = mapper;
            _service = service;
            _logger = logger;
        }

        /// <summary>
        /// Whether the export is usable and where it points, so the panel can render itself and
        /// disable the button when the server is not set up. Carries no secret and no key path.
        /// </summary>
        [HttpGet("Config")]
        [ProducesResponseType(typeof(SheetsConfigDTO), StatusCodes.Status200OK)]
        public IActionResult GetConfig()
        {
            return Ok(_mapper.Map<SheetsConfigDTO>(_service.GetConfig()));
        }

        /// <summary>
        /// Writes one tab per table, in the order given — oldest event first, each tab holding the
        /// cumulative result up to and including its own event.
        ///
        /// Existing tabs of the same name are cleared and rewritten in place, keeping their
        /// formatting; anything typed into them by hand is lost. Tabs not named in the request are
        /// never touched or deleted.
        /// </summary>
        [HttpPost("Export")]
        [ProducesResponseType(typeof(SheetExportResultDTO), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status502BadGateway)]
        [ProducesResponseType(StatusCodes.Status503ServiceUnavailable)]
        public async Task<IActionResult> Export([FromBody] SheetExportRequestDTO dto, CancellationToken ct)
        {
            if (dto?.Tabs == null || dto.Tabs.Count == 0)
                return BadRequest(new { message = "No table to write." });

            var request = _mapper.Map<SheetExportRequest>(dto);

            try
            {
                var result = await _service.ExportAsync(request, ct);

                _logger.LogInformation(
                    "Sheets export by user {User}: {TabCount} tabs to spreadsheet {SpreadsheetId} via {Writer}",
                    User?.Identity?.Name, result.Tabs?.Count ?? 0, result.SpreadsheetId, result.Writer);

                return Ok(_mapper.Map<SheetExportResultDTO>(result));
            }
            catch (SheetsExportException ex)
            {
                _logger.LogWarning(ex, "Sheets export refused ({StatusCode})", ex.StatusCode);
                return StatusCode(ex.StatusCode, new { message = ex.Message });
            }
            catch (OperationCanceledException)
            {
                // The caller navigated away or hit cancel; nothing to report to them.
                throw;
            }
            catch (Exception ex)
            {
                // Anything unforeseen still has to arrive as JSON with a message.
                _logger.LogError(ex, "Sheets export failed");
                return StatusCode(StatusCodes.Status502BadGateway, new { message = ex.Message });
            }
        }
    }
}