import {
  Body,
  Controller,
  Get,
  Post,
  Query,
  Render,
  Req,
  Res,
  Session,
  UseGuards,
} from '@nestjs/common';
import { Throttle } from '@nestjs/throttler';
import { Request, Response } from 'express';
import { SessionData } from 'express-session';
import { LoginAntispamGuard } from 'src/guards/login-antispam.guard';
import { AuditAction } from 'src/modules/objects/audit/audit.enum';
import { AuditService } from 'src/modules/objects/audit/audit.service';
import {
  UserToken,
  UserTokenType,
} from 'src/modules/objects/user-token/user-token.entity';
import { UserTokenService } from 'src/modules/objects/user-token/user-token.service';
import { UserTOTPService } from 'src/modules/objects/user-token/user-totp-token.service';
import { User } from 'src/modules/objects/user/user.entity';
import { UserService } from 'src/modules/objects/user/user.service';
import { FormUtilityService } from 'src/modules/utility/services/form-utility.service';
import { TokenService } from 'src/modules/utility/services/token.service';

interface VerifyChallenge {
  type: 'verify';
  id: string;
  user: string;
  remember: boolean;
}

@Controller('/login')
@UseGuards(LoginAntispamGuard)
export class LoginController {
  constructor(
    private readonly userService: UserService,
    private readonly totpService: UserTOTPService,
    private readonly userTokenService: UserTokenService,
    private readonly formUtil: FormUtilityService,
    private readonly token: TokenService,
    private readonly audit: AuditService,
  ) {}

  @Get()
  @Render('login/login')
  public loginView(
    @Req() req: Request,
    @Query('redirectTo') redirectTo?: string,
  ): Record<string, unknown> {
    return this.formUtil.populateTemplate(req, {
      query: redirectTo
        ? new URLSearchParams({ redirectTo }).toString()
        : undefined,
    });
  }

  @Post()
  public async loginRequest(
    @Req() req: Request,
    @Res() res: Response,
    @Body() body: { username: string; password: string; remember: boolean },
    @Query('redirectTo') redirectTo?: string,
  ) {
    const { username, password, remember } = this.formUtil.trimmed(body, [
      'username',
    ]);
    const user = await this.userService.getByUsername(username);

    // User exists and password matches
    if (
      !user ||
      !user.activated ||
      !(await this.userService.comparePasswords(user.password, password))
    ) {
      req.flash('form', { username });
      req.flash('message', {
        error: true,
        text: 'Invalid username or password',
      });

      res.redirect(req.originalUrl);
      return;
    }

    await this.audit.auditRequest(req, AuditAction.LOGIN, req.session.id, user);

    if (await this.totpService.userHasTOTP(user)) {
      const challenge: VerifyChallenge = {
        type: 'verify',
        id: req.session.id,
        user: user.uuid,
        remember,
      };
      const encrypted = await this.token.encryptChallenge(challenge);
      res.redirect(
        `login/verify?challenge=${encrypted}${
          redirectTo ? '&redirectTo=' + encodeURIComponent(redirectTo) : ''
        }`,
      );
      return;
    }

    // Extend session cookie to a month
    if (remember) {
      const month = 30 * 24 * 60 * 60 * 1000;
      req.session.cookie.maxAge = month;
      req.session.cookie.expires = new Date(Date.now() + month);
    }

    req.session.user = user.uuid;
    res.redirect(redirectTo ? decodeURIComponent(redirectTo) : '/');
  }

  @Get('verify')
  public verifyUserTokenView(
    @Req() req: Request,
    @Res() res: Response,
    @Query() query: { redirectTo: string; challenge: string },
  ) {
    if (!query.challenge) {
      req.flash('message', {
        error: true,
        text: 'An unexpected error occured, please log in again.',
      });

      res.redirect(
        '/login' +
          (query.redirectTo
            ? '?redirectTo=' + encodeURIComponent(query.redirectTo)
            : ''),
      );
      return;
    }

    res.render('login/totp-verify', this.formUtil.populateTemplate(req));
  }

  @Post('verify')
  public async verifyUserToken(
    @Session() session: SessionData,
    @Body() body: { totp: string },
    @Req() req: Request,
    @Res() res: Response,
    @Query() query: { redirectTo: string; challenge: string },
  ) {
    let user: User;
    let remember = false;

    try {
      if (!query.challenge) {
        throw new Error('No challenge');
      }

      const decrypted = await this.token.decryptChallenge<VerifyChallenge>(
        query.challenge,
      );
      if (
        !decrypted ||
        decrypted.type !== 'verify' ||
        decrypted.id !== req.session.id ||
        !decrypted.user
      ) {
        throw new Error('Bad challenge');
      }

      user = await this.userService.getByUUID(decrypted.user);
      if (!user) {
        throw new Error('Bad challenge');
      }

      remember = decrypted.remember;
    } catch (e: unknown) {
      req.flash('message', {
        error: true,
        text: 'An unexpected error occured, please log in again.',
      });

      res.redirect(
        '/login' +
          (query.redirectTo
            ? '?redirectTo=' + encodeURIComponent(query.redirectTo)
            : ''),
      );
      return;
    }

    try {
      const totp = await this.totpService.getUserTOTP(user);

      if (!this.totpService.validateTOTP(totp.token, body.totp)) {
        throw new Error('Invalid code!');
      }
    } catch (e: unknown) {
      req.flash('message', {
        error: true,
        text: (e as Error).message,
      });
      res.redirect(req.originalUrl);
      return;
    }

    // Extend session cookie to a month
    if (remember) {
      const month = 30 * 24 * 60 * 60 * 1000;
      req.session.cookie.maxAge = month;
    }

    session.user = user.uuid;
    res.redirect(query.redirectTo ? decodeURIComponent(query.redirectTo) : '/');
  }

  @Get('activate')
  public async activateUser(
    @Req() req: Request,
    @Res() res: Response,
    @Query() query: { token: string },
    @Query('redirectTo') redirectTo?: string,
  ) {
    const loginPath = `/login${
      redirectTo ? `?redirectTo=${encodeURIComponent(redirectTo)}` : ''
    }`;
    let user: User;
    let token: UserToken;

    try {
      if (!query || !query.token) {
        throw new Error();
      }

      token = await this.userTokenService.get(
        query.token,
        UserTokenType.ACTIVATION,
      );

      if (!token) {
        throw new Error();
      }

      user = token.user;
    } catch (e: unknown) {
      req.flash('message', {
        error: true,
        text: 'Invalid or expired activation link.',
      });

      res.redirect(loginPath);
      return;
    }

    user.activated = true;
    await this.userService.updateUser(user);
    await this.userTokenService.delete(token);

    req.flash('message', {
      error: false,
      text: 'Account has been activated successfully. You may now log in.',
    });

    res.redirect(loginPath);
  }

  @Get('password')
  public async recoverView(
    @Req() req: Request,
    @Res() res: Response,
    @Query() query: { token: string },
  ) {
    if (query.token) {
      const token = await this.userTokenService.get(
        query.token,
        UserTokenType.PASSWORD,
      );

      if (!token) {
        req.flash('message', {
          error: true,
          text: 'Invalid or expired reset link.',
        });

        res.redirect('/login');
        return;
      }

      res.render('login/password', {
        ...this.formUtil.populateTemplate(req),
        token: true,
      });
      return;
    }

    res.render('login/password', {
      ...this.formUtil.populateTemplate(req),
      token: false,
    });
  }

  @Post('password')
  @Throttle(3, 60)
  public async setNewPassword(
    @Req() req: Request,
    @Res() res: Response,
    @Body()
    body: { email?: string; password?: string; password_repeat?: string },
    @Query() query: { token: string },
  ) {
    // Email send fragment
    if (!query.token) {
      if (!body.email || !body.email.match(this.formUtil.emailRegex)) {
        req.flash('message', {
          error: true,
          text: 'A valid email address is mandatory.',
        });

        res.redirect(req.originalUrl);
        return;
      }

      await this.userService.userPassword(body.email);

      req.flash('message', {
        error: false,
        text: 'If there is an account registered with this email, instructions to reset the password will be sent shortly!',
      });

      res.redirect('/login');
      return;
    }

    // Change password fragment
    const token = await this.userTokenService.get(
      query.token,
      UserTokenType.PASSWORD,
    );

    if (!token) {
      req.flash('message', {
        error: true,
        text: 'Invalid or expired reset link.',
      });

      res.redirect('/login');
      return;
    }

    const { password, password_repeat } = body;

    try {
      if (!password || !password_repeat) {
        throw new Error('Please fill out all of the fields.');
      }

      if (!password.match(this.formUtil.passwordRegex)) {
        throw new Error(
          'Password must be at least 8 characters long, contain a capital and lowercase letter and a number',
        );
      }

      if (password !== password_repeat) {
        throw new Error('The passwords do not match!');
      }

      const hashword = await this.userService.hashPassword(password);
      token.user.password = hashword;

      await this.userService.updateUser(token.user);
      await this.userTokenService.delete(token);
      await this.audit.auditRequest(req, AuditAction.PASSWORD_CHANGE, 'token');

      req.flash('message', {
        error: false,
        text: 'Your password has been reset successfully. You may now log in with your new password!',
      });

      res.redirect('/login');
    } catch (e: unknown) {
      req.flash('message', { error: true, text: (e as Error).message });
      res.redirect(req.originalUrl);
    }
  }
}