import { Injectable, ForbiddenException, UnauthorizedException } from '@nestjs/common';
import { PrismaService } from '../../infrastructure/database/prisma.service';
import { AppleAuthService } from './apple-auth.service';
import { TokenService } from './token.service';
import type { AppleLoginDto, DevLoginDto } from './dto';

@Injectable()
export class AuthService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly appleAuthService: AppleAuthService,
    private readonly tokenService: TokenService,
  ) {}

  async devLogin(dto: DevLoginDto) {
    if (process.env.NODE_ENV === 'production') {
      throw new ForbiddenException('dev-login is disabled in production');
    }

    const devSecret = process.env.DEV_SECRET;
    if (!devSecret || dto.devSecret !== devSecret) {
      throw new UnauthorizedException('devSecret 无效');
    }

    const providerUserId = dto.email;

    let account = await this.prisma.authAccount.findUnique({
      where: {
        provider_providerUserId: {
          provider: 'DEV',
          providerUserId,
        },
      },
      include: { user: true },
    });

    if (!account) {
      account = await this.prisma.authAccount.create({
        data: {
          provider: 'DEV',
          providerUserId,
          email: dto.email,
          user: {
            create: {
              email: dto.email,
              nickname: dto.nickname || '测试用户',
              status: 'active',
            },
          },
        },
        include: { user: true },
      });
    }

    return this.buildLoginResponse(account.user);
  }

  async appleLogin(dto: AppleLoginDto) {
    const { appleUserId, email: appleEmail } =
      await this.appleAuthService.verifyIdentityToken(dto.identityToken);

    let account = await this.prisma.authAccount.findUnique({
      where: {
        provider_providerUserId: {
          provider: 'APPLE',
          providerUserId: appleUserId,
        },
      },
      include: { user: true },
    });

    if (!account) {
      const displayName =
        dto.fullName?.givenName
          ? `${dto.fullName.familyName || ''}${dto.fullName.givenName}`
          : undefined;

      account = await this.prisma.authAccount.create({
        data: {
          provider: 'APPLE',
          providerUserId: appleUserId,
          email: appleEmail || dto.email || null,
          user: {
            create: {
              email: appleEmail || dto.email || null,
              nickname: displayName || undefined,
              status: 'active',
            },
          },
        },
        include: { user: true },
      });
    }

    return this.buildLoginResponse(account.user);
  }

  async refresh(refreshToken: string) {
    const hash = this.tokenService.hashToken(refreshToken);
    const stored = await this.prisma.refreshToken.findFirst({
      where: { tokenHash: hash, revokedAt: null },
      include: { user: true },
    });

    if (!stored || stored.expiresAt < new Date()) {
      throw new UnauthorizedException('刷新令牌无效或已过期');
    }

    await this.prisma.refreshToken.update({
      where: { id: stored.id },
      data: { revokedAt: new Date() },
    });

    const { token: newRefreshToken, hash: newHash } =
      this.tokenService.generateRefreshToken();

    await this.prisma.refreshToken.create({
      data: {
        userId: stored.userId,
        tokenHash: newHash,
        expiresAt: new Date(Date.now() + 7 * 86400000),
      },
    });

    const accessToken = await this.tokenService.generateAccessToken(
      stored.user,
    );

    return {
      accessToken,
      refreshToken: newRefreshToken,
      user: this.serializeUser(stored.user),
    };
  }

  async logout(userId: bigint | string, refreshToken: string) {
    const hash = this.tokenService.hashToken(refreshToken);
    const stored = await this.prisma.refreshToken.findFirst({
      where: {
        tokenHash: hash,
        userId: BigInt(userId),
        revokedAt: null,
      },
    });

    if (stored) {
      await this.prisma.refreshToken.update({
        where: { id: stored.id },
        data: { revokedAt: new Date() },
      });
    }
  }

  private async buildLoginResponse(user: {
    id: bigint;
    email: string | null;
    nickname: string | null;
    avatarUrl: string | null;
    role: string;
    status: string;
    onboardingCompleted: boolean;
  }) {
    const accessToken = await this.tokenService.generateAccessToken(user);

    const { token: refreshToken, hash } =
      this.tokenService.generateRefreshToken();

    await this.prisma.refreshToken.create({
      data: {
        userId: user.id,
        tokenHash: hash,
        expiresAt: new Date(Date.now() + 7 * 86400000),
      },
    });

    return {
      accessToken,
      refreshToken,
      user: this.serializeUser(user),
    };
  }

  private serializeUser(user: {
    id: bigint;
    email: string | null;
    nickname: string | null;
    avatarUrl: string | null;
    role: string;
    status: string;
    onboardingCompleted: boolean;
  }) {
    return {
      id: String(user.id),
      email: user.email,
      nickname: user.nickname,
      avatarUrl: user.avatarUrl,
      role: user.role,
      status: user.status,
      onboardingCompleted: user.onboardingCompleted,
    };
  }
}