using System.Security.Claims;
using Fake.Application;
using Fake.Users;
using Oms.Domain.CustomersAggregate.Entities;
using Oms.Domain.CustomersAggregate.Repositories;

namespace Oms.Application.Shared;

/// <summary>
/// 从 JWT Claims 解析当前会话类型（管理员 / 客户）。
/// </summary>
public static class OmsSessionHelper
{
    /// <summary>
    /// JWT 中标识登录类型的 Claim 名称。
    /// </summary>
    public const string LoginTypeClaim = "loginType";

    /// <summary>
    /// JWT 中 RBAC mapId Claim 名称（与 FakeClaimTypes.UserId 对齐）。
    /// </summary>
    public const string MapIdClaim = "mapId";

    private const string CustomerLoginType = "1";
    private const string CustomerRoleName = "Customer";

    /// <summary>
    /// 当前会话是否为客户门户登录。
    /// </summary>
    public static bool IsCustomerLogin(ICurrentUser currentUser)
    {
        if (string.Equals(
                currentUser.FindClaimOrNull(LoginTypeClaim)?.Value,
                CustomerLoginType,
                StringComparison.Ordinal))
        {
            return true;
        }

        // 兼容 loginType 丢失但 role=Customer 仍在的令牌
        var role = currentUser.FindClaimOrNull(ClaimTypes.Role)?.Value
                   ?? currentUser.FindClaimOrNull("role")?.Value;
        return string.Equals(role, CustomerRoleName, StringComparison.OrdinalIgnoreCase);
    }

    /// <summary>
    /// 客户登录时返回 mapId（对应 t_customer.UserId / 订单 CreateUserId）；管理员返回 null。
    /// </summary>
    public static int? TryGetCustomerMapId(ICurrentUser currentUser)
    {
        if (!IsCustomerLogin(currentUser))
        {
            return null;
        }

        var userId = currentUser.GetId<int>();
        if (userId > 0)
        {
            return userId;
        }

        // GetId 未绑到 mapId 时，直接读 claim，避免客户会话被当成管理员（不过滤）
        var mapIdRaw = currentUser.FindClaimOrNull(MapIdClaim)?.Value;
        if (int.TryParse(mapIdRaw, out var mapId) && mapId > 0)
        {
            return mapId;
        }

        return null;
    }

    /// <summary>
    /// 客户登录时返回 mapId（对应订单 CreateUserId）；管理员返回 null（不过滤）。
    /// </summary>
    public static int? TryGetCustomerCreateUserId(ICurrentUser currentUser) =>
        TryGetCustomerMapId(currentUser);

    /// <summary>
    /// 解析当前会话对应的 t_customer 记录（客户按 UserId=mapId；管理员可按 CustomerId 代提交）。
    /// </summary>
    public static async Task<Customer> ResolveSessionCustomerAsync(
        ICustomerRepository customerRepository,
        ICurrentUser currentUser,
        int? requestedCustomerId = null)
    {
        var mapId = TryGetCustomerMapId(currentUser);
        if (mapId.HasValue)
        {
            var sessionCustomer = await customerRepository.FirstOrDefaultAsync(x => x.UserId == mapId.Value);
            if (sessionCustomer == null)
            {
                throw new BusinessException("未找到客户信息");
            }

            if (requestedCustomerId is > 0 && requestedCustomerId.Value != sessionCustomer.Id)
            {
                throw new BusinessException("客户ID非法");
            }

            return sessionCustomer;
        }

        var customerId = requestedCustomerId ?? currentUser.GetId<int>();
        if (customerId <= 0)
        {
            throw new BusinessException("客户ID不能为空");
        }

        var customer = await customerRepository.FirstOrDefaultAsync(x => x.Id == customerId);
        if (customer == null)
        {
            throw new BusinessException("客户不存在");
        }

        return customer;
    }

    /// <summary>
    /// 客户登录时强制返回 t_customer.Id；管理员返回入参 customerId。
    /// </summary>
    public static async Task<int?> ResolveListCustomerIdAsync(
        ICustomerRepository customerRepository,
        ICurrentUser currentUser,
        int? requestedCustomerId)
    {
        var mapId = TryGetCustomerMapId(currentUser);
        if (!mapId.HasValue)
        {
            return requestedCustomerId;
        }

        var customer = await customerRepository.FirstOrDefaultAsync(x => x.UserId == mapId.Value);
        if (customer == null)
        {
            throw new BusinessException("未找到客户信息");
        }

        return customer.Id;
    }

    /// <summary>
    /// 小红书模块客户上下文：客户登录返回 t_customer.Id；管理员无客户上下文时返回 0（系统级）。
    /// </summary>
    public static async Task<int> ResolveXhsCustomerIdAsync(
        ICustomerRepository customerRepository,
        ICurrentUser currentUser,
        int? requestedCustomerId = null)
    {
        var customerId = await ResolveListCustomerIdAsync(customerRepository, currentUser, requestedCustomerId);
        return customerId ?? 0;
    }
}