using MailSharp.MailClient.Services;
using MailSharp.MailClient.Services.Logging;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

namespace MailSharp.MailClient.Controllers.Api;

[ApiController]
[Route("api/maintenance")]
[Authorize(Policy = "AdminOnly")]
public class MaintenanceApiController(
	ILogStore logStore,
	IAccountStore accountStore,
	IMessageIndexStore indexStore,
	IFolderSettingsStore folderSettingsStore,
	IMailCacheStore mailCacheStore,
	IBackgroundIndexingStatus indexingStatus) : ControllerBase
{
	[HttpGet("logs")]
	public IActionResult Logs(
		LogLevel? level = null,
		string? category = null,
		int? accountId = null,
		DateTime? from = null,
		DateTime? to = null,
		string? search = null,
		int page = 1,
		int pageSize = 50)
	{
		var result = logStore.Query(new LogQuery
		{
			Level = level,
			Category = category,
			AccountId = accountId,
			From = from,
			To = to,
			Search = search,
			Page = page,
			PageSize = pageSize
		});

		return Ok(new { items = result.Items, totalCount = result.TotalCount, page, pageSize });
	}

	[HttpPost("logs/clear")]
	public IActionResult ClearLogs()
	{
		logStore.Clear();
		return Ok();
	}

	[HttpGet("status")]
	public IActionResult Status()
	{
		// Per-account/folder index summary (accounts, indexed folders, total messages) - the same
		// underlying data as the Metrics tab, but rolled up to totals here rather than shown
		// per-folder, since this panel is about "is the background work healthy", not the folder
		// browser the Metrics tab already is.
		var accounts = accountStore.GetAll();
		var indexSummaries = accounts.Select(account =>
		{
			var folders = indexStore.GetIndexedFolders(account.Id);
			return new
			{
				accountId = account.Id,
				emailAddress = account.EmailAddress,
				indexedFolderCount = folders.Count,
				indexedMessageCount = folders.Sum(f => indexStore.GetMessageCount(account.Id, f)),
				indexedSizeBytes = folders.Sum(f => indexStore.GetTotalSize(account.Id, f))
			};
		}).ToList();

		var cache = mailCacheStore.GetStats();

		return Ok(new
		{
			indexing = new
			{
				maxConcurrentIndexing = indexingStatus.MaxConcurrentIndexing,
				currentlyAvailableSlots = indexingStatus.CurrentlyAvailableSlots,
				inProgress = indexingStatus.InProgressKeys.Select(key =>
				{
					indexingStatus.TryGetProgress(key, out var processed, out var total);
					return new { key, processed, total };
				})
			},
			index = new
			{
				accounts = indexSummaries,
				totalIndexedFolders = indexSummaries.Sum(a => a.indexedFolderCount),
				totalIndexedMessages = indexSummaries.Sum(a => a.indexedMessageCount),
				totalIndexedSizeBytes = indexSummaries.Sum(a => a.indexedSizeBytes)
			},
			cache = new
			{
				messageListCacheEntries = cache.MessageListCacheEntries,
				contactMailSearchEntries = cache.ContactMailSearchEntries,
				senderImagePreferences = cache.SenderImagePreferences,
				imageUrlMappings = cache.ImageUrlMappings,
				messageIdMappings = cache.MessageIdMappings,
				cachedMessages = new { fileCount = cache.CachedMessages.FileCount, totalBytes = cache.CachedMessages.TotalBytes },
				cachedAttachments = new { fileCount = cache.CachedAttachments.FileCount, totalBytes = cache.CachedAttachments.TotalBytes },
				cachedImages = new { fileCount = cache.CachedImages.FileCount, totalBytes = cache.CachedImages.TotalBytes }
			}
		});
	}

	[HttpGet("metrics")]
	public IActionResult Metrics(int? accountId = null)
	{
		var accounts = accountStore.GetAll()
			.Where(a => accountId == null || a.Id == accountId.Value)
			.Select(account =>
			{
				// Same display order the user set up in Settings > Mappen beheren (see
				// IImapService.GetFoldersAsync/ApplyDisplayOrder) - folders the user dragged to the
				// top there should show in that order here too, not in whatever order LiteDB happens
				// to return them.
				var savedOrder = folderSettingsStore.GetOrder(account.Id);
				var position = savedOrder.Select((name, i) => (name, i)).ToDictionary(x => x.name, x => x.i, StringComparer.Ordinal);

				var folders = indexStore.GetIndexedFolders(account.Id)
					.Select((folder, naturalIndex) => (folder, naturalIndex))
					.OrderBy(x => position.TryGetValue(x.folder, out var idx) ? idx : int.MaxValue)
					.ThenBy(x => x.naturalIndex)
					.Select(x => new
					{
						folder = x.folder,
						messageCount = indexStore.GetMessageCount(account.Id, x.folder),
						sizeBytes = indexStore.GetTotalSize(account.Id, x.folder)
					}).ToList();

				return new
				{
					accountId = account.Id,
					emailAddress = account.EmailAddress,
					folders,
					totalMessages = folders.Sum(f => f.messageCount),
					totalSizeBytes = folders.Sum(f => f.sizeBytes)
				};
			}).ToList();

		return Ok(new
		{
			accounts,
			totalMessages = accounts.Sum(a => a.totalMessages),
			totalSizeBytes = accounts.Sum(a => a.totalSizeBytes)
		});
	}
}