using Fake.DependencyInjection;
using Fake.Rbac.Infrastructure;
using Microsoft.EntityFrameworkCore;

namespace Oms.Application.Shared;

/// <summary>
/// 将 OMS 审计字段中的 RBAC mapId（user.userid）解析为展示名称。
/// </summary>
public class OmsRbacUserDisplayNameResolver : IScopedDependency
{
    private readonly FakeRbacDbContext _rbacDbContext;

    public OmsRbacUserDisplayNameResolver(FakeRbacDbContext rbacDbContext)
    {
        _rbacDbContext = rbacDbContext;
    }

    public async Task<string?> ResolveAsync(int userId, CancellationToken cancellationToken = default)
    {
        if (userId <= 0)
        {
            return null;
        }

        var map = await ResolveManyAsync([userId], cancellationToken);
        return FormatUserId(userId, map);
    }

    public async Task<IReadOnlyDictionary<int, string>> ResolveManyAsync(
        IEnumerable<int> userIds,
        CancellationToken cancellationToken = default)
    {
        var ids = userIds.Where(x => x > 0).Distinct().ToList();
        if (ids.Count == 0)
        {
            return new Dictionary<int, string>();
        }

        try
        {
            var sql =
                $"SELECT `userid` AS `{nameof(RbacUserNameRow.UserId)}`, `Name` AS `{nameof(RbacUserNameRow.DisplayName)}` FROM `user` WHERE `IsDeleted` = 0 AND `userid` IN ({string.Join(",", ids)})";
            var rows = await _rbacDbContext.Database
                .SqlQueryRaw<RbacUserNameRow>(sql)
                .ToListAsync(cancellationToken);

            return rows.ToDictionary(
                x => x.UserId,
                x => NormalizeDisplayName(x.DisplayName, x.UserId));
        }
        catch
        {
            return ids.ToDictionary(x => x, x => x.ToString());
        }
    }

    public static string? FormatUserId(int userId, IReadOnlyDictionary<int, string>? nameMap)
    {
        if (userId <= 0)
        {
            return null;
        }

        if (nameMap != null &&
            nameMap.TryGetValue(userId, out var name) &&
            !string.IsNullOrWhiteSpace(name))
        {
            return name;
        }

        return userId.ToString();
    }

    private static string NormalizeDisplayName(string? name, int userId)
    {
        var trimmed = name?.Trim();
        return string.IsNullOrWhiteSpace(trimmed) ? userId.ToString() : trimmed;
    }

    private sealed class RbacUserNameRow
    {
        public int UserId { get; set; }

        public string? DisplayName { get; set; }
    }
}