using MiaoJiZhang.Api.Contracts;
using MiaoJiZhang.Api.Services;
using MiaoJiZhang.Domain.Entities;
using MiaoJiZhang.Infrastructure.Persistence;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace MiaoJiZhang.Api.Controllers;

[ApiController]
[AdminAuth(AdminRoles.SuperAdmin)]
[Route("api/admin/security")]
public sealed class AdminAccountsController(AppDbContext db) : ControllerBase
{
    [HttpGet("accounts")]
    public async Task<IActionResult> Accounts(CancellationToken ct)
    {
        var users = await db.AdminUsers.AsNoTracking()
            .OrderBy(item => item.Username)
            .Select(item => new
            {
                item.Id,
                item.Username,
                item.Role,
                item.IsActive,
                item.MustChangePassword,
                item.LastLoginAt,
                item.CreatedAt,
                activeSessions = item.Sessions.Count(session =>
                    !session.RevokedAt.HasValue && session.ExpiresAt > DateTime.UtcNow),
            })
            .ToListAsync(ct);
        return Ok(users);
    }

    [HttpPost("accounts")]
    public async Task<IActionResult> Create(CreateAdminUserRequest request, CancellationToken ct)
    {
        var username = request.Username.Trim();
        if (username.Length is < 3 or > 64 || request.Password.Length is < 12 or > 128 ||
            !AdminRoles.All.Contains(request.Role))
            return BadRequest(new ApiError("ADMIN_ACCOUNT_INVALID", "管理员账号、密码或角色无效"));
        if (await db.AdminUsers.AnyAsync(item => item.Username == username, ct))
            return Conflict(new ApiError("ADMIN_ACCOUNT_EXISTS", "管理员用户名已存在"));
        var now = DateTime.UtcNow;
        var user = new AdminUser
        {
            Username = username,
            PasswordHash = AdminSessionService.HashPassword(request.Password),
            Role = request.Role,
            IsActive = true,
            MustChangePassword = true,
            CreatedAt = now,
            UpdatedAt = now,
        };
        db.AdminUsers.Add(user);
        await db.SaveChangesAsync(ct);
        return Ok(new { user.Id, user.Username, user.Role, user.IsActive, user.MustChangePassword });
    }

    [HttpPut("accounts/{id:long}")]
    public async Task<IActionResult> Update(
        long id,
        UpdateAdminUserRequest request,
        CancellationToken ct)
    {
        if (!AdminRoles.All.Contains(request.Role))
            return BadRequest(new ApiError("ADMIN_ROLE_INVALID", "管理员角色无效"));
        var user = await db.AdminUsers.FindAsync([id], ct);
        if (user is null) return NotFound();
        if (user.Role == AdminRoles.SuperAdmin &&
            (!request.IsActive || request.Role != AdminRoles.SuperAdmin) &&
            await ActiveSuperAdminCount(ct) <= 1)
        {
            return Conflict(new ApiError("LAST_SUPER_ADMIN", "不能停用或降级最后一个超级管理员"));
        }
        user.Role = request.Role;
        user.IsActive = request.IsActive;
        user.MustChangePassword = request.MustChangePassword;
        user.AuthVersion++;
        user.UpdatedAt = DateTime.UtcNow;
        await RevokeSessions(id, ct);
        await db.SaveChangesAsync(ct);
        return Ok(new { user.Id, user.Username, user.Role, user.IsActive, user.MustChangePassword });
    }

    [HttpPut("accounts/{id:long}/password")]
    public async Task<IActionResult> ResetPassword(
        long id,
        ResetAdminPasswordRequest request,
        CancellationToken ct)
    {
        if (request.Password.Length is < 12 or > 128)
            return BadRequest(new ApiError("ADMIN_PASSWORD_INVALID", "密码长度必须为 12 到 128 位"));
        var user = await db.AdminUsers.FindAsync([id], ct);
        if (user is null) return NotFound();
        user.PasswordHash = AdminSessionService.HashPassword(request.Password);
        user.MustChangePassword = true;
        user.AuthVersion++;
        user.UpdatedAt = DateTime.UtcNow;
        await RevokeSessions(id, ct);
        await db.SaveChangesAsync(ct);
        return NoContent();
    }

    [HttpPost("accounts/{id:long}/revoke-sessions")]
    public async Task<IActionResult> Revoke(long id, CancellationToken ct)
    {
        if (!await db.AdminUsers.AnyAsync(item => item.Id == id, ct)) return NotFound();
        await RevokeSessions(id, ct);
        return NoContent();
    }

    [HttpGet("audit")]
    public async Task<IActionResult> Audit(
        [FromQuery] string? username,
        [FromQuery] int page = 1,
        [FromQuery] int limit = 50,
        CancellationToken ct = default)
    {
        page = Math.Max(1, page);
        limit = Math.Clamp(limit, 1, 100);
        var query = db.AdminAuditLogs.AsNoTracking();
        if (!string.IsNullOrWhiteSpace(username))
        {
            var term = username.Trim();
            query = query.Where(item => item.Username != null && item.Username.Contains(term));
        }
        var total = await query.CountAsync(ct);
        var list = await query.OrderByDescending(item => item.CreatedAt)
            .Skip((page - 1) * limit).Take(limit).ToListAsync(ct);
        return Ok(new { total, page, list });
    }

    private Task<int> ActiveSuperAdminCount(CancellationToken ct) => db.AdminUsers.CountAsync(
        item => item.IsActive && item.Role == AdminRoles.SuperAdmin,
        ct);

    private Task<int> RevokeSessions(long userId, CancellationToken ct)
    {
        var now = DateTime.UtcNow;
        return db.AdminSessions.Where(item => item.AdminUserId == userId && !item.RevokedAt.HasValue)
            .ExecuteUpdateAsync(setters => setters.SetProperty(item => item.RevokedAt, now), ct);
    }
}