using FastEndpoints;
using Microsoft.EntityFrameworkCore;
using Socialize.Api.Data;
using Socialize.Api.Modules.Comments.Data;
using Socialize.Api.Modules.ContentItems.Data;
using Socialize.Api.Infrastructure.Security;

namespace Socialize.Api.Modules.Comments.Handlers;

public record GetCommentsRequest(Guid ContentItemId);

public record CommentDto(
    Guid Id,
    Guid WorkspaceId,
    Guid ContentItemId,
    Guid? ParentCommentId,
    Guid AuthorUserId,
    string AuthorDisplayName,
    string AuthorEmail,
    string? AuthorPortraitUrl,
    string Body,
    DateTimeOffset CreatedAt);

public class GetCommentsHandler(
    AppDbContext dbContext,
    AccessScopeService accessScopeService)
    : Endpoint<GetCommentsRequest, IReadOnlyCollection<CommentDto>>
{
    public override void Configure()
    {
        Get("/api/comments");
        Options(o => o.WithTags("Comments"));
    }

    public override async Task HandleAsync(GetCommentsRequest request, CancellationToken ct)
    {
        ContentItem? item = await dbContext.ContentItems
            .SingleOrDefaultAsync(candidate => candidate.Id == request.ContentItemId, ct);
        if (item is null)
        {
            await SendNotFoundAsync(ct);
            return;
        }

        if (!await accessScopeService.CanReviewContentAsync(User, item.WorkspaceId, item.ClientId, item.CampaignId, ct))
        {
            await SendForbiddenAsync(ct);
            return;
        }

        List<Comment> comments = await dbContext.Comments
            .Where(comment => comment.ContentItemId == request.ContentItemId)
            .OrderBy(comment => comment.CreatedAt)
            .ToListAsync(ct);

        List<Guid> authorIds = comments
            .Select(comment => comment.AuthorUserId)
            .Distinct()
            .ToList();

        Dictionary<Guid, string?> authorPortraits = await dbContext.Users
            .Where(user => authorIds.Contains(user.Id))
            .ToDictionaryAsync(user => user.Id, user => user.PortraitUrl, ct);

        List<CommentDto> dtos = comments
            .Select(comment => new CommentDto(
                comment.Id,
                comment.WorkspaceId,
                comment.ContentItemId,
                comment.ParentCommentId,
                comment.AuthorUserId,
                comment.AuthorDisplayName,
                comment.AuthorEmail,
                authorPortraits.GetValueOrDefault(comment.AuthorUserId),
                comment.Body,
                comment.CreatedAt))
            .ToList();

        await SendOkAsync(dtos, ct);
    }
}