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

namespace MiaoJiZhang.Api.Controllers;

[ApiController]
[Route("api/admin/auth")]
public sealed class AdminAuthController(
    AppDbContext db,
    AdminSessionService sessions) : ControllerBase
{
    [HttpPost("login")]
    [EnableRateLimiting("admin-auth")]
    public async Task<IActionResult> Login(AdminLoginRequest request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Username) || string.IsNullOrEmpty(request.Password))
            return BadRequest(new ApiError("ADMIN_LOGIN_INVALID", "请输入用户名和密码"));
        var result = await sessions.LoginAsync(
            HttpContext,
            request.Username,
            request.Password,
            ct);
        return result is null
            ? Unauthorized(new ApiError("ADMIN_LOGIN_FAILED", "用户名或密码错误，账号也可能已锁定"))
            : Ok(ToResponse(result.Principal, result.CsrfToken));
    }

    [HttpGet("me")]
    [AdminAuth]
    public async Task<IActionResult> Me(CancellationToken ct)
    {
        var principal = AdminRequestContext.Principal(HttpContext)!;
        var csrfToken = await sessions.RotateCsrfAsync(principal.SessionId, ct);
        return Ok(ToResponse(principal, csrfToken));
    }

    [HttpPost("logout")]
    [AdminAuth]
    public async Task<IActionResult> Logout(CancellationToken ct)
    {
        var principal = AdminRequestContext.Principal(HttpContext)!;
        await sessions.LogoutAsync(HttpContext, principal.SessionId, ct);
        return NoContent();
    }

    [HttpPut("password")]
    [AdminAuth]
    public async Task<IActionResult> ChangePassword(
        AdminChangePasswordRequest request,
        CancellationToken ct)
    {
        if (request.NewPassword.Length < AdminPasswordPolicy.MinLength ||
            request.NewPassword.Length > AdminPasswordPolicy.MaxLength)
            return BadRequest(new ApiError("ADMIN_PASSWORD_INVALID", "新密码长度必须为 6 到 128 位"));
        var principal = AdminRequestContext.Principal(HttpContext)!;
        var user = await db.AdminUsers.FirstAsync(item => item.Id == principal.UserId, ct);
        if (!BCrypt.Net.BCrypt.Verify(request.CurrentPassword, user.PasswordHash))
            return BadRequest(new ApiError("ADMIN_PASSWORD_INCORRECT", "当前密码不正确"));
        if (BCrypt.Net.BCrypt.Verify(request.NewPassword, user.PasswordHash))
            return BadRequest(new ApiError("ADMIN_PASSWORD_UNCHANGED", "新密码不能与当前密码相同"));

        user.PasswordHash = AdminSessionService.HashPassword(request.NewPassword);
        user.MustChangePassword = false;
        user.AuthVersion++;
        user.UpdatedAt = DateTime.UtcNow;
        await sessions.RevokeOtherSessionsAsync(user.Id, principal.SessionId, user.AuthVersion, ct);
        await db.SaveChangesAsync(ct);
        var csrfToken = await sessions.RotateCsrfAsync(principal.SessionId, ct);
        var updated = principal with { MustChangePassword = false };
        HttpContext.Items[AdminRequestContext.PrincipalKey] = updated;
        return Ok(ToResponse(updated, csrfToken));
    }

    private static object ToResponse(AdminPrincipal principal, string csrfToken) => new
    {
        id = principal.UserId,
        principal.Username,
        principal.Role,
        principal.MustChangePassword,
        csrfToken,
    };
}