using Microsoft.AspNetCore.Mvc;

using MongoDB.Entities;

using PrivaPub.Api.Mastodon.Entities;
using PrivaPub.Api.Mastodon.Infrastructure;
using PrivaPub.Api.Mastodon.Mappers;
using PrivaPub.Domain.Media;
using PrivaPub.Domain.Privacy;
using PrivaPub.Domain.Relationships;
using PrivaPub.Domain.Social;
using PrivaPub.Federation.Actors;
using PrivaPub.Federation.Outbox;
using PrivaPub.Models.Federation;
using PrivaPub.Models.Post;
using PrivaPub.Models.Social;
using PrivaPub.Models.User;
using PrivaPub.StaticServices;

using PostEntity = PrivaPub.Models.Post.Post;

namespace PrivaPub.Api.Mastodon.Controllers
{
	public class AccountsController : MastodonController
	{
		readonly MastodonMapper _mapper;
		readonly DbEntities _dbEntities;
		readonly ILocalActorService _localActors;
		readonly IRemoteActorService _remoteActors;
		readonly IFollowService _follows;
		readonly IOutboxPublisher _outbox;
		readonly IRelationshipService _relationships;

		public AccountsController(MastodonMapper mapper, DbEntities dbEntities, ILocalActorService localActors, IRemoteActorService remoteActors,
			IFollowService follows, IOutboxPublisher outbox, IRelationshipService relationships)
		{
			_relationships = relationships;
			_mapper = mapper;
			_dbEntities = dbEntities;
			_localActors = localActors;
			_remoteActors = remoteActors;
			_follows = follows;
			_outbox = outbox;
		}

		[HttpGet("/api/v1/accounts/verify_credentials"), Scope("read:accounts")]
		public async Task<IActionResult> VerifyCredentials(CancellationToken token) => Json(await _mapper.Local(Me, withSource: true, token));

		[HttpPatch("/api/v1/accounts/update_credentials"), Scope("write:accounts"), RequestSizeLimit(20 * 1024 * 1024),
			RequestFormLimits(MultipartBodyLengthLimit = 20 * 1024 * 1024)]
		public async Task<IActionResult> UpdateCredentials([FromServices] IMediaService media, CancellationToken token)
		{
			var avatar = await _dbEntities.Avatars.MatchID(Me.Id).ExecuteFirstAsync(token);
			if (Request.HasFormContentType)
			{
				var form = await Request.ReadFormAsync(token);
				if (form.Files["avatar"] is { } picture && await media.ProfileImage(picture, 400, 400, token) is { } pictureUrl)
					avatar.PictureURL = pictureUrl;
				if (form.Files["header"] is { } header && await media.ProfileImage(header, 1500, 500, token) is { } headerUrl)
					avatar.ThumbnailURL = headerUrl;
			}
			if (Params.Has("display_name"))
				avatar.Name = Params.Get("display_name")?.Trim();
			if (Params.Has("note"))
				avatar.Biography = Params.Get("note");
			if (Params.Bool("locked") is { } locked)
				avatar.Settings.IsLocked = locked;
			if (Params.Bool("bot") is { } bot)
				avatar.Settings.IsBot = bot;
			if (Params.Bool("discoverable") is { } discoverable)
				avatar.Settings.IsDiscoverable = discoverable;
			if (Params.Bool("indexable") is { } indexable)
				avatar.Settings.IsIndexable = indexable;
			if (Params.Bool("hide_collections") is { } hide)
				avatar.Settings.HideCollections = hide;
			if (Params.Get("source[privacy]") is { } privacy && privacy is "public" or "unlisted" or "private")
				avatar.Settings.DefaultVisibility = privacy;
			if (Params.Bool("source[sensitive]") is { } sensitive)
				avatar.Settings.DefaultSensitive = sensitive;
			if (Params.Has("source[language]"))
				avatar.Settings.DefaultLanguage = Params.Get("source[language]");
			if (Params.Get("source[quote_policy]") is { } quotePolicy && QuotePolicies.IsKnown(quotePolicy))
				avatar.Settings.QuotePolicy = quotePolicy;
			var fields = new Dictionary<string, string>();
			for (var i = 0; i < 4; i++)
			{
				var name = Params.Get($"fields_attributes[{i}][name]") ?? Params.Get($"fields_attributes[][name]");
				if (!string.IsNullOrWhiteSpace(name))
					fields[name.Trim()] = Params.Get($"fields_attributes[{i}][value]")?.Trim() ?? string.Empty;
			}
			if (Params.List("fields_attributes[][name]").Count > 0)
			{
				var names = Params.List("fields_attributes[][name]");
				var values = Params.List("fields_attributes[][value]");
				fields = names.Select((n, i) => (n, v: i < values.Count ? values[i] : string.Empty)).Where(f => !string.IsNullOrWhiteSpace(f.n))
					.Take(4).ToDictionary(f => f.n.Trim(), f => f.v.Trim());
			}
			if (fields.Count > 0 || Params.Has("fields_attributes[0][name]"))
				avatar.Fields = fields;
			avatar.UpdatedAt = DateTime.UtcNow;
			await DB.Default.SaveAsync(avatar, token);

			var actor = _localActors.FromAvatar(avatar);
			await _outbox.PublishProfile(actor, token);
			return Json(await _mapper.Local(actor, withSource: true, token));
		}

		[HttpGet("/api/v1/accounts/lookup"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
		public async Task<IActionResult> Lookup(CancellationToken token)
		{
			var acct = Params.Get("acct")?.Trim().TrimStart('@');
			var parts = acct?.Split('@');
			if (parts is not { Length: 1 or 2 } || string.IsNullOrEmpty(parts[0]))
				return NotFoundError();
			var localDomain = new Uri(_localActors.BaseAddress).Authority;
			if (parts.Length == 1 || parts[1].Equals(localDomain, StringComparison.OrdinalIgnoreCase))
			{
				var local = await _localActors.FindByUserName(parts[0], token);
				return local is { IsFederated: true, IsCircle: false, Kind: not LocalActorKind.Application } ? Json(await _mapper.Local(local, false, token)) : NotFoundError();
			}
			var userName = parts[0];
			var domain = parts[1].ToLowerInvariant();
			var foreign = await _dbEntities.ForeignAvatars.Match(f => f.UserName == userName && f.Domain == domain).ExecuteFirstAsync(token);
			return foreign == default ? NotFoundError() : Json(_mapper.Foreign(foreign));
		}

		[HttpGet("/api/v1/accounts/relationships"), Scope("read:follows")]
		public async Task<IActionResult> Relationships(CancellationToken token)
		{
			var relationships = new List<Relationship>();
			foreach (var id in Params.List("id").Distinct().Take(40))
				relationships.Add(await Relationship(id, token));
			return Json(relationships);
		}

		[HttpGet("/api/v1/accounts/search"), Scope("read:accounts")]
		public async Task<IActionResult> Search([FromServices] AccountSearch search, CancellationToken token) =>
			Json(await search.Find(Params.Get("q"), Params.Bool("resolve") == true && MyId != default, Limit(), token));

		[HttpGet("/api/v1/accounts/{id}"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
		public async Task<IActionResult> Get(string id, CancellationToken token)
		{
			var account = await _mapper.Account(id, token);
			return account == default ? NotFoundError() : Json(account);
		}

		[HttpGet("/api/v1/accounts/{id}/statuses"), Scope("read:statuses", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
		public async Task<IActionResult> Statuses(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default)
				return NotFoundError();
			if (Params.Bool("pinned") == true)
			{
				if (local == default)
					return Json(Array.Empty<Status>());
				var pinIds = (await DB.Default.Find<Pin>().Match(p => p.AvatarId == local.Id).Sort(p => p.ID, Order.Descending).ExecuteAsync(token)).Select(p => p.PostId).ToList();
				var pinnedPosts = await _dbEntities.Posts.Match(p => pinIds.Contains(p.ID)).Match(VisibilityPolicy.IsPublic).ExecuteAsync(token);
				return Json(await _mapper.Statuses(pinIds.Select(id => pinnedPosts.FirstOrDefault(p => p.ID == id)).Where(p => p != default).ToList(), MyId, token));
			}

			var query = local != default
				? _dbEntities.Posts.Match(p => p.GroupUserId == local.Id && !p.IsFederatedCopy).Match(VisibilityPolicy.IsShown)
				: _dbEntities.Posts.Match(p => p.ActorURI == remote.ActorURI && p.IsFederatedCopy).Match(VisibilityPolicy.IsShown);
			var viewerFollows = MyId != default && local != default
				&& await _dbEntities.Followings.Match(f => f.AvatarId == MyId && f.TargetAccountId == local.Id && f.State == FollowState.Accepted).ExecuteAnyAsync(token);
			if (MyId != id)
				query.Match(viewerFollows
					? p => p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted || p.Visibility == PostVisibility.FollowersOnly
					: p => p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted);
			else
				query.Match(p => p.Visibility != PostVisibility.LocalGeo);
			if (Params.Bool("exclude_replies") == true)
				query.Match(p => p.InReplyToURI == null);
			if (Params.Bool("exclude_reblogs") == true)
				query.Match(p => p.ReblogOfPostId == null);
			if (Params.Bool("only_media") == true)
				query.Match(p => p.Media.Count > 0);
			if (Params.Get("tagged") is { } tag)
				query.Match(p => p.Tags.Contains(tag.ToLowerInvariant()));

			var posts = await Page.From(Params, Limit()).Fetch(query, p => p.ID, token);
			var statuses = await _mapper.Statuses(posts, MyId, token);
			Link($"/api/v1/accounts/{id}/statuses", posts.LastOrDefault()?.ID, posts.FirstOrDefault()?.ID);
			return Json(statuses);
		}

		[HttpGet("/api/v1/accounts/{id}/followers"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
		public async Task<IActionResult> Followers(string id, CancellationToken token)
		{
			var (local, _) = await Find(id, token);
			if (local == default || local.Id != MyId)
				return Json(Array.Empty<Account>());
			var followers = await _dbEntities.Followers.Match(f => f.LocalActorId == local.Id && f.LocalActorKind == local.Kind && f.IsAccepted)
				.Sort(f => f.ID, Order.Descending).Limit(Limit(40, 80)).ExecuteAsync(token);
			return Json(await AccountsFor(followers.Select(f => f.ActorURI), token));
		}

		[HttpGet("/api/v1/accounts/{id}/following"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
		public async Task<IActionResult> Following(string id, CancellationToken token)
		{
			var (local, _) = await Find(id, token);
			if (local == default || local.Id != MyId)
				return Json(Array.Empty<Account>());
			var following = await _dbEntities.Followings.Match(f => f.AvatarId == local.Id && f.State == FollowState.Accepted)
				.Sort(f => f.ID, Order.Descending).Limit(Limit(40, 80)).ExecuteAsync(token);
			var accounts = await _mapper.Accounts(following.Select(f => f.TargetAccountId), token);
			return Json(following.Select(f => accounts.GetValueOrDefault(f.TargetAccountId)).Where(a => a != default).ToList());
		}

		[HttpPost("/api/v1/accounts/{id}/follow"), Scope("write:follows")]
		public async Task<IActionResult> Follow(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default)
				return NotFoundError();
			var following = await _follows.FollowAs(Me, local?.Uri ?? remote.ActorURI, Params.Bool("reblogs") != false, token);
			return following == default ? Error(StatusCodes.Status403Forbidden, "This action is not allowed") : Json(await Relationship(id, token));
		}

		[HttpPost("/api/v1/accounts/{id}/unfollow"), Scope("write:follows")]
		public async Task<IActionResult> Unfollow(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default)
				return NotFoundError();
			await _follows.UnfollowAs(Me, local?.Uri ?? remote.ActorURI, token);
			return Json(await Relationship(id, token));
		}

		[HttpPost("/api/v1/accounts/{id}/remove_from_followers"), Scope("write:follows")]
		public async Task<IActionResult> RemoveFromFollowers(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			var uri = local?.Uri ?? remote?.ActorURI;
			if (uri == default)
				return NotFoundError();
			await DB.Default.DeleteAsync<Follower>(f => f.LocalActorId == Me.Id && f.ActorURI == uri);
			if (local != default)
				await DB.Default.DeleteAsync<Following>(f => f.AvatarId == local.Id && f.TargetActorURI == Me.Uri);
			return Json(await Relationship(id, token));
		}

		[HttpPost("/api/v1/accounts/{id}/block"), Scope("write:blocks")]
		public async Task<IActionResult> Block(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default || local?.Id == MyId)
				return NotFoundError();
			await _relationships.Block(Me, local?.Uri ?? remote.ActorURI, id, token);
			return Json(await Relationship(id, token));
		}

		[HttpPost("/api/v1/accounts/{id}/unblock"), Scope("write:blocks")]
		public async Task<IActionResult> Unblock(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default)
				return NotFoundError();
			await _relationships.Unblock(Me, local?.Uri ?? remote.ActorURI, token);
			return Json(await Relationship(id, token));
		}

		[HttpPost("/api/v1/accounts/{id}/mute"), Scope("write:mutes")]
		public async Task<IActionResult> Mute(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default || local?.Id == MyId)
				return NotFoundError();
			var duration = Params.Int("duration") is { } seconds and > 0 ? TimeSpan.FromSeconds(seconds) : (TimeSpan?)null;
			await _relationships.Mute(Me, local?.Uri ?? remote.ActorURI, id, Params.Bool("notifications") != false, duration, token);
			return Json(await Relationship(id, token));
		}

		[HttpPost("/api/v1/accounts/{id}/unmute"), Scope("write:mutes")]
		public async Task<IActionResult> Unmute(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			if (local == default && remote == default)
				return NotFoundError();
			await _relationships.Unmute(Me, local?.Uri ?? remote.ActorURI, token);
			return Json(await Relationship(id, token));
		}

		[HttpGet("/api/v1/blocks"), Scope("read:blocks")]
		public async Task<IActionResult> Blocks(CancellationToken token)
		{
			var blocks = await Page.From(Params, Limit(40, 80)).Fetch(DB.Default.Find<Block>().Match(b => b.AvatarId == MyId), b => b.ID, token);
			var accounts = await _mapper.Accounts(blocks.Select(b => b.TargetAccountId), token);
			Link("/api/v1/blocks", blocks.LastOrDefault()?.ID, blocks.FirstOrDefault()?.ID);
			return Json(blocks.Select(b => accounts.GetValueOrDefault(b.TargetAccountId)).Where(a => a != default).ToList());
		}

		[HttpGet("/api/v1/mutes"), Scope("read:mutes")]
		public async Task<IActionResult> Mutes(CancellationToken token)
		{
			var mutes = await Page.From(Params, Limit(40, 80)).Fetch(DB.Default.Find<Mute>().Match(m => m.AvatarId == MyId), m => m.ID, token);
			var accounts = await _mapper.Accounts(mutes.Select(m => m.TargetAccountId), token);
			Link("/api/v1/mutes", mutes.LastOrDefault()?.ID, mutes.FirstOrDefault()?.ID);
			return Json(mutes.Select(m => accounts.GetValueOrDefault(m.TargetAccountId)).Where(a => a != default).ToList());
		}

		[HttpGet("/api/v1/domain_blocks"), Scope("read:blocks")]
		public async Task<IActionResult> DomainBlocks(CancellationToken token) =>
			Json((await DB.Default.Find<AccountDomainBlock>().Match(b => b.AvatarId == MyId).Sort(b => b.Domain, Order.Ascending).ExecuteAsync(token)).Select(b => b.Domain).ToList());

		[HttpPost("/api/v1/domain_blocks"), Scope("write:blocks")]
		public async Task<IActionResult> BlockDomain(CancellationToken token)
		{
			await _relationships.BlockDomain(Me, Params.Get("domain"), token);
			return Json(new { });
		}

		[HttpDelete("/api/v1/domain_blocks"), Scope("write:blocks")]
		public async Task<IActionResult> UnblockDomain(CancellationToken token)
		{
			await _relationships.UnblockDomain(Me, Params.Get("domain"), token);
			return Json(new { });
		}

		[HttpGet("/api/v1/follow_requests"), Scope("read:follows")]
		public async Task<IActionResult> FollowRequests(CancellationToken token)
		{
			var requests = await _dbEntities.Followers.Match(f => f.LocalActorId == Me.Id && f.LocalActorKind == LocalActorKind.Person && !f.IsAccepted)
				.Sort(f => f.ID, Order.Descending).Limit(Limit(40, 80)).ExecuteAsync(token);
			return Json(await AccountsFor(requests.Select(r => r.ActorURI), token));
		}

		[HttpPost("/api/v1/follow_requests/{id}/authorize"), Scope("write:follows")]
		public async Task<IActionResult> Authorize(string id, CancellationToken token) =>
			await _follows.Decide(Me, id, accept: true, token) ? Json(await Relationship(id, token)) : NotFoundError();

		[HttpPost("/api/v1/follow_requests/{id}/reject"), Scope("write:follows")]
		public async Task<IActionResult> Reject(string id, CancellationToken token) =>
			await _follows.Decide(Me, id, accept: false, token) ? Json(await Relationship(id, token)) : NotFoundError();

		[HttpGet("/api/v1/accounts/{id}/featured_tags"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
		public IActionResult FeaturedTags(string id) => Json(Array.Empty<object>());

		[HttpGet("/api/v1/accounts/{id}/lists"), Scope("read:lists")]
		public IActionResult Lists(string id) => Json(Array.Empty<object>());

		[HttpGet("/api/v1/accounts/familiar_followers"), Scope("read:follows")]
		public IActionResult FamiliarFollowers() => Json(Params.List("id").Select(id => new { id, accounts = Array.Empty<Account>() }).ToList());

		async Task<List<Account>> AccountsFor(IEnumerable<string> actorUris, CancellationToken token)
		{
			var accounts = new List<Account>();
			foreach (var uri in actorUris)
			{
				var local = await _localActors.FindByUri(uri, token);
				if (local != default)
				{
					accounts.Add(await _mapper.Local(local, false, token));
					continue;
				}
				var foreign = await _dbEntities.ForeignAvatars.Match(f => f.ActorURI == uri).ExecuteFirstAsync(token);
				if (foreign != default)
					accounts.Add(_mapper.Foreign(foreign));
			}
			return accounts;
		}

		async Task<(LocalActor Local, ForeignAvatar Remote)> Find(string id, CancellationToken token)
		{
			var avatar = await _dbEntities.Avatars.MatchID(id).ExecuteFirstAsync(token);
			if (avatar is { DeletionAt: null })
				return (_localActors.FromAvatar(avatar), default);
			var group = await _dbEntities.Groups.MatchID(id).ExecuteFirstAsync(token);
			if (group is { DeletionAt: null } && _localActors.FromGroup(group) is { IsFederated: true, IsCircle: false } community)
				return (community, default);
			return (default, await _dbEntities.ForeignAvatars.MatchID(id).ExecuteFirstAsync(token));
		}

		async Task<Relationship> Relationship(string id, CancellationToken token)
		{
			var (local, remote) = await Find(id, token);
			var uri = local?.Uri ?? remote?.ActorURI;
			var following = uri == default ? default : await _dbEntities.Followings.Match(f => f.AvatarId == MyId && f.TargetActorURI == uri).ExecuteFirstAsync(token);
			var followedBy = uri == default ? default : await _dbEntities.Followers.Match(f => f.LocalActorId == MyId && f.ActorURI == uri).ExecuteFirstAsync(token);
			var blocking = uri != default && await DB.Default.Find<Block>().Match(b => b.AvatarId == MyId && b.TargetActorURI == uri).ExecuteAnyAsync(token);
			var mute = uri == default ? default : await DB.Default.Find<Mute>().Match(m => m.AvatarId == MyId && m.TargetActorURI == uri).ExecuteFirstAsync(token);
			var blockedBy = local != default && await DB.Default.Find<Block>().Match(b => b.AvatarId == local.Id && b.TargetActorURI == Me.Uri).ExecuteAnyAsync(token);
			var domainBlocked = remote != default && await DB.Default.Find<AccountDomainBlock>().Match(b => b.AvatarId == MyId && b.Domain == remote.Domain).ExecuteAnyAsync(token);
			return new Relationship
			{
				Id = id,
				Blocking = blocking,
				BlockedBy = blockedBy,
				Muting = mute != default && (mute.ExpiresAt == default || mute.ExpiresAt > DateTime.UtcNow),
				MutingNotifications = mute?.HideNotifications == true,
				DomainBlocking = domainBlocked,
				Following = following?.State == FollowState.Accepted,
				Requested = following?.State == FollowState.Requested,
				ShowingReblogs = following?.ShowReblogs ?? false,
				FollowedBy = followedBy?.IsAccepted == true,
				RequestedBy = followedBy is { IsAccepted: false }
			};
		}
	}
}