using MediatR;
using TakeoutSaaS.Application.Identity.Contracts;
using TakeoutSaaS.Application.Identity.Queries;
using TakeoutSaaS.Domain.Identity.Repositories;
using TakeoutSaaS.Shared.Abstractions.Tenancy;

namespace TakeoutSaaS.Application.Identity.Handlers;

/// <summary>
/// 按用户 ID 获取权限概览处理器。
/// </summary>
public sealed class GetUserPermissionsQueryHandler(
    IIdentityUserRepository identityUserRepository,
    ITenantProvider tenantProvider)
    : IRequestHandler<GetUserPermissionsQuery, UserPermissionDto?>
{
    private readonly IIdentityUserRepository _identityUserRepository = identityUserRepository;
    private readonly ITenantProvider _tenantProvider = tenantProvider;

    /// <inheritdoc />
    public async Task<UserPermissionDto?> Handle(GetUserPermissionsQuery request, CancellationToken cancellationToken)
    {
        var tenantId = _tenantProvider.GetCurrentTenantId();
        var user = await _identityUserRepository.FindByIdAsync(request.UserId, cancellationToken);
        if (user == null || user.TenantId != tenantId)
        {
            return null;
        }

        return new UserPermissionDto
        {
            UserId = user.Id,
            TenantId = user.TenantId,
            MerchantId = user.MerchantId,
            Account = user.Account,
            DisplayName = user.DisplayName,
            Roles = user.Roles,
            Permissions = user.Permissions,
            CreatedAt = user.CreatedAt
        };
    }
}