using System.Net;

using collAnon.Client.Services;

using decePubClient.Extensions;
using decePubClient.Models;

using PrivaPub.ClientModels;
using PrivaPub.ClientModels.Group;

namespace decePubClient.Services
{
	/// <summary>The persona's communities and circles (/clientapi/group): made, joined by invitation, edited and left;
	/// for their owners and moderators, who is in them and who asks to join.</summary>
	public class GroupService(IHttpService httpService, ILoggingService logger, CoalescingStringLocalizer localizer)
	{
		/// <summary>The persona's groups, communities first; empty on failure.</summary>
		public async Task<List<ViewGroup>> List(string personaId, CancellationToken cancellationToken = default)
		{
			if (personaId is null)
				return [];

			using var response = await httpService.Get(APIs.ClientApi.GET_Groups, [$"avatarId={Uri.EscapeDataString(personaId)}"],
				cancellationToken: cancellationToken);
			if (!response.IsSuccessStatusCode)
			{
				var result = await response.Content.ReadWebResult(response.StatusCode, localizer, cancellationToken);
				if (result.StatusCode is not (int)HttpStatusCode.Gone)
					await logger.ProcessWarning(result.ToString(localizer), $"{nameof(GroupService)}.{nameof(List)}", cancellationToken);
				return [];
			}

			var groups = await response.DefaultReadFromJsonAsync<List<ViewGroup>>(cancellationToken) ?? [];
			return [.. groups.OrderByDescending(g => g.IsCommunity).ThenBy(g => g.Name ?? g.UserName)];
		}

		/// <summary>Makes a community or a circle owned by the persona; Data is the ViewGroup.</summary>
		public Task<WebResult> Insert(InsertGroupForm form, CancellationToken cancellationToken = default) =>
			GroupResult(APIs.ClientApi.POST_InsertGroup, form, cancellationToken);

		/// <summary>Changes a group the persona runs; Data is the ViewGroup.</summary>
		public Task<WebResult> Update(UpdateGroupForm form, CancellationToken cancellationToken = default) =>
			GroupResult(APIs.ClientApi.POST_UpdateGroup, form, cancellationToken);

		/// <summary>Joins a group by its invitation (and its password, when it has one); Data is the ViewGroup.</summary>
		public Task<WebResult> Join(JoinGroupForm form, CancellationToken cancellationToken = default) =>
			GroupResult(APIs.ClientApi.POST_JoinGroup, form, cancellationToken);

		public Task<WebResult> Leave(string personaId, string groupId, CancellationToken cancellationToken = default) =>
			Membership(APIs.ClientApi.POST_LeaveGroup, personaId, groupId, null, cancellationToken);

		/// <summary>Lets in someone who asked to join a group the persona runs.</summary>
		public Task<WebResult> Approve(string personaId, string groupId, string actorUri, CancellationToken cancellationToken = default) =>
			Membership(APIs.ClientApi.POST_ApproveGroupMember, personaId, groupId, actorUri, cancellationToken);

		/// <summary>Declines a request to join; the asker's server is told.</summary>
		public Task<WebResult> Reject(string personaId, string groupId, string actorUri, CancellationToken cancellationToken = default) =>
			Membership(APIs.ClientApi.POST_RejectGroupMember, personaId, groupId, actorUri, cancellationToken);

		/// <summary>Takes a member out of a group the persona runs.</summary>
		public Task<WebResult> Remove(string personaId, string groupId, string actorUri, CancellationToken cancellationToken = default) =>
			Membership(APIs.ClientApi.POST_RemoveGroupMember, personaId, groupId, actorUri, cancellationToken);

		/// <summary>Who is in a group the persona runs, and who asks to join; empty on failure.</summary>
		public async Task<List<ViewGroupMember>> Members(string personaId, string groupId, CancellationToken cancellationToken = default)
		{
			using var response = await httpService.Get(APIs.ClientApi.GET_GroupMembers,
				[$"avatarId={Uri.EscapeDataString(personaId)}", $"groupId={Uri.EscapeDataString(groupId)}"], cancellationToken: cancellationToken);
			if (!response.IsSuccessStatusCode)
			{
				var result = await response.Content.ReadWebResult(response.StatusCode, localizer, cancellationToken);
				await logger.ProcessWarning(result.ToString(localizer), $"{nameof(GroupService)}.{nameof(Members)}", cancellationToken);
				return [];
			}

			return await response.DefaultReadFromJsonAsync<List<ViewGroupMember>>(cancellationToken) ?? [];
		}

		async Task<WebResult> GroupResult(string route, object form, CancellationToken cancellationToken)
		{
			using var response = await httpService.Post(route, form, cancellationToken: cancellationToken);
			if (!response.IsSuccessStatusCode)
				return await response.Content.ReadWebResult(response.StatusCode, localizer, cancellationToken);

			return new WebResult { Data = await response.DefaultReadFromJsonAsync<ViewGroup>(cancellationToken) };
		}

		async Task<WebResult> Membership(string route, string personaId, string groupId, string actorUri, CancellationToken cancellationToken)
		{
			using var response = await httpService.Post(route, new GroupMembershipForm { AvatarId = personaId, GroupId = groupId, MemberActorURI = actorUri },
				cancellationToken: cancellationToken);
			if (!response.IsSuccessStatusCode)
				return await response.Content.ReadWebResult(response.StatusCode, localizer, cancellationToken);

			return new WebResult();
		}
	}
}