using Admin.NET.Core;
using Admin.NET.Plugin.AiDOP.Const.S8;
using Admin.NET.Plugin.AiDOP.Entity.S8;

namespace Admin.NET.Plugin.AiDOP.Infrastructure.S8;

/// <summary>授权判定结果。拒绝时带原因码，便于前端与日志区分「没配」与「没权」。</summary>
public sealed record S8ActionAuthorizationResult(bool Allowed, string? ReasonCode, string? Message)
{
    public static S8ActionAuthorizationResult Pass() => new(true, null, null);
    public static S8ActionAuthorizationResult Deny(string reason, string message) => new(false, reason, message);
}

/// <summary>授权失败原因码。</summary>
public static class S8ActionDenyReason
{
    /// <summary>动作码不在目录里 —— 调用方拼错或用了已删除的动作。</summary>
    public const string UnknownAction = "action_unknown";

    /// <summary>该动作在本租户下一个角色都没配 —— 未配置即禁止，不是「未配置即放行」。</summary>
    public const string ActionNotConfigured = "action_not_configured";

    /// <summary>账号在本租户下的角色都不在该动作的授权名单里。</summary>
    public const string RoleNotGranted = "action_role_not_granted";
}

/// <summary>
/// S8-ACTION-PERMISSION-1：异常单动作授权的<b>唯一</b>判定入口。
///
/// <para><b>禁止各 Service 自己散落 HasRole 判断</b>。同一个问题一旦有两处实现，
/// 迟早出现「Controller 放行、Service 又拦一次且判据不同」或反之 ——
/// 本仓在 <c>S8OperatorBindingService</c> 上已经发生过一次同类事故
/// （List 用 ClearFilter + 可选谓词、Bind 用另一套口径，导致跨租户返回 500 行）。</para>
///
/// <para><b>判据三段，缺一不可</b>：
/// ① 动作在目录内；② 该动作在本租户配了至少一个角色；
/// ③ 账号在<b>本租户</b>持有其中任一角色。</para>
///
/// <para><b>fail closed 是硬要求</b>：配置表为空<b>不等于</b>所有人拥有全部权限。
/// 这类"空即放行"的默认值是权限系统最典型的事故来源 —— 上线时表还没灌数据，
/// 于是全员拥有全部动作，而且没有任何报错。</para>
///
/// <para><b>Factory 不参与</b>，且不得加回来。<b>Employee 不参与</b>：
/// S8 的人就是 <c>SysUser</c>，不存在「先查员工再查账号」。</para>
/// </summary>
public interface IS8ExceptionActionAuthorizer
{
    /// <summary>判定账号在租户内是否可执行该动作。不抛异常。</summary>
    Task<S8ActionAuthorizationResult> AuthorizeAsync(long tenantId, long userId, string actionCode);

    /// <summary>批量取该账号在本租户被允许的全部动作码（供前端按钮可见性使用）。</summary>
    Task<IReadOnlySet<string>> GetAllowedActionsAsync(long tenantId, long userId);
}

/// <summary>正式实现。生产代码里只有这一份；接口只为测试留 seam。</summary>
public sealed class S8ExceptionActionAuthorizer : IS8ExceptionActionAuthorizer, ITransient
{
    private readonly SqlSugarRepository<AdoS8ExceptionActionRole> _rep;
    private readonly IS8TenantRoleResolver _roleResolver;

    public S8ExceptionActionAuthorizer(
        SqlSugarRepository<AdoS8ExceptionActionRole> rep,
        IS8TenantRoleResolver roleResolver)
    {
        _rep = rep;
        _roleResolver = roleResolver;
    }

    public async Task<S8ActionAuthorizationResult> AuthorizeAsync(long tenantId, long userId, string actionCode)
    {
        // ① 未知动作：拒绝。绝不因为「没听说过这个动作」就放行。
        if (!S8ExceptionActionCatalog.IsKnown(actionCode))
            return S8ActionAuthorizationResult.Deny(S8ActionDenyReason.UnknownAction, "没有权限执行该操作");

        if (tenantId <= 0 || userId <= 0)
            return S8ActionAuthorizationResult.Deny(S8ActionDenyReason.RoleNotGranted, "没有权限执行该操作");

        var grantedRoleIds = await GrantedRoleIdsAsync(tenantId, actionCode);

        // ② 该动作在本租户一个角色都没配 —— fail closed。
        if (grantedRoleIds.Count == 0)
            return S8ActionAuthorizationResult.Deny(
                S8ActionDenyReason.ActionNotConfigured, "没有权限执行该操作");

        // ③ 账号在本租户持有的角色（跨租户角色在这里就已经被排除，见 S8TenantRoleResolver）。
        var userRoleIds = await _roleResolver.GetRoleIdsAsync(tenantId, userId);
        if (userRoleIds.Count == 0 || !userRoleIds.Any(grantedRoleIds.Contains))
            return S8ActionAuthorizationResult.Deny(
                S8ActionDenyReason.RoleNotGranted, "没有权限执行该操作");

        return S8ActionAuthorizationResult.Pass();
    }

    public async Task<IReadOnlySet<string>> GetAllowedActionsAsync(long tenantId, long userId)
    {
        var allowed = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
        if (tenantId <= 0 || userId <= 0) return allowed;

        var userRoleIds = await _roleResolver.GetRoleIdsAsync(tenantId, userId);
        if (userRoleIds.Count == 0) return allowed;

        var rows = await _rep.AsQueryable().ClearFilter()
            .Where(x => x.TenantId == tenantId && userRoleIds.Contains(x.RoleId))
            .Select(x => x.ActionCode)
            .ToListAsync();

        foreach (var code in rows.Where(S8ExceptionActionCatalog.IsKnown))
            allowed.Add(code);
        return allowed;
    }

    private async Task<HashSet<long>> GrantedRoleIdsAsync(long tenantId, string actionCode)
    {
        // ClearFilter：边界由本查询显式声明（tenant_id == 传入租户）。
        var ids = await _rep.AsQueryable().ClearFilter()
            .Where(x => x.TenantId == tenantId && x.ActionCode == actionCode)
            .Select(x => x.RoleId)
            .ToListAsync();
        return ids.ToHashSet();
    }
}