import crypto from 'node:crypto';
import Joi from 'joi';
import Boom from '@hapi/boom';
import bcrypt from 'bcryptjs';
import { signToken, credentials, authResponse } from '../plugins/auth.js';
import { env } from '../config/env.js';
import { User } from '../models/User.js';
import { sendPasswordResetEmail } from '../services/mail.js';
import { writeAudit, clientIp } from '../services/audit.js';
import { isMobileNumber } from '../services/cryptoPii.js';
import { hitRateLimit } from '../services/rateLimit.js';
import {
  applySessionCookies,
  clearSessionCookies,
  issueRefreshSession,
  REFRESH_COOKIE,
  rotateRefreshSession,
  revokeRefreshSession,
} from '../services/sessionCookies.js';

const GENERIC_RESET_MESSAGE = 'If that account exists, we sent a password reset link.';

function hashResetToken(token) {
  return crypto.createHash('sha256').update(token).digest('hex');
}

function assertAuthRate(request, email) {
  const ip = clientIp(request);
  if (hitRateLimit(`auth:${request.path}:${ip}`, 5) || (email && hitRateLimit(`auth:${request.path}:${email}`, 5))) {
    throw Boom.tooManyRequests('Too many attempts. Try again in a minute.');
  }
}

async function startSession(h, user) {
  const token = signToken(user);
  const refresh = await issueRefreshSession(user._id);
  return applySessionCookies(h.response(authResponse(user, token)), token, refresh);
}

export function authRoutes(server) {
  server.route({
    method: 'POST',
    path: '/api/auth/login',
    options: {
      auth: false,
      validate: {
        payload: Joi.object({
          email: Joi.string().email({ tlds: { allow: false } }).required(),
          password: Joi.string().required(),
        }),
      },
    },
    handler: async (request, h) => {
      const email = request.payload.email.toLowerCase().trim();
      assertAuthRate(request, email);
      const user = await User.findOne({ email }).populate('role');
      if (!user || !(await bcrypt.compare(request.payload.password, user.passwordHash))) {
        await writeAudit(request, { action: 'login.failure', resourceType: 'user' });
        throw Boom.unauthorized('Invalid email or password');
      }
      if (!user.isActive) throw Boom.forbidden('This account is disabled');
      user.lastLoginAt = new Date();
      await user.save();
      await writeAudit(request, { action: 'login.success', resourceType: 'user', resourceId: user._id, actor: user._id });
      return startSession(h, user);
    },
  });

  server.route({
    method: 'POST',
    path: '/api/auth/refresh',
    options: { auth: false },
    handler: async (request, h) => {
      const rotated = await rotateRefreshSession(request.state?.[REFRESH_COOKIE]);
      if (!rotated) {
        throw Boom.unauthorized();
      }
      const user = await User.findById(rotated.userId).populate('role');
      if (!user || !user.isActive) {
        throw Boom.unauthorized();
      }
      const token = signToken(user);
      return applySessionCookies(h.response(authResponse(user, token)), token, rotated.raw);
    },
  });

  server.route({
    method: 'GET',
    path: '/api/auth/me',
    handler: async (request) => {
      const { user } = credentials(request);
      const fresh = await User.findById(user._id).populate('role');
      if (!fresh || !fresh.isActive) throw Boom.unauthorized();
      const { token, ...rest } = authResponse(fresh, 'unused');
      return rest;
    },
  });

  server.route({
    method: 'PATCH',
    path: '/api/auth/profile',
    options: {
      validate: {
        payload: Joi.object({
          firstName: Joi.string().trim().min(1).required(),
          lastName: Joi.string().trim().min(1).required(),
          phone: Joi.string().allow('', null),
          specializations: Joi.array().items(Joi.string().trim().min(1)),
          availableSlots: Joi.array().items(Joi.string().trim().min(1)),
          availableStartWeekdays: Joi.array().items(Joi.number().integer().min(0).max(6)),
          maxCohorts: Joi.number().integer().min(1).max(20).allow(null),
        }),
      },
    },
    handler: async (request) => {
      const { user } = credentials(request);
      const fresh = await User.findById(user._id).populate('role');
      if (!fresh || !fresh.isActive) throw Boom.unauthorized();
      fresh.firstName = request.payload.firstName;
      fresh.lastName = request.payload.lastName;
      if (request.payload.phone != null && String(request.payload.phone).trim() && !isMobileNumber(request.payload.phone)) {
        throw Boom.badRequest('Mobile must be 10 digits.');
      }
      if (request.payload.phone != null) fresh.phone = request.payload.phone;
      if (request.payload.specializations) fresh.specializations = request.payload.specializations;
      if (request.payload.availableSlots) fresh.availableSlots = request.payload.availableSlots;
      if (request.payload.availableStartWeekdays) fresh.availableStartWeekdays = request.payload.availableStartWeekdays;
      if (request.payload.maxCohorts !== undefined) fresh.maxCohorts = request.payload.maxCohorts;
      await fresh.save();
      await fresh.populate('role');
      const { token, ...rest } = authResponse(fresh, 'unused');
      return rest;
    },
  });

  server.route({
    method: 'POST',
    path: '/api/auth/change-password',
    options: {
      validate: {
        payload: Joi.object({
          currentPassword: Joi.string().required(),
          newPassword: Joi.string().min(6).required(),
        }),
      },
    },
    handler: async (request, h) => {
      const { user } = credentials(request);
      const fresh = await User.findById(user._id);
      if (!fresh || !fresh.isActive) throw Boom.unauthorized();
      if (!(await bcrypt.compare(request.payload.currentPassword, fresh.passwordHash))) {
        throw Boom.badRequest('Current password is incorrect');
      }
      if (request.payload.currentPassword === request.payload.newPassword) {
        throw Boom.badRequest('New password must be different from the current password');
      }
      fresh.passwordHash = await bcrypt.hash(request.payload.newPassword, 10);
      await fresh.save();
      const token = signToken(fresh);
      const refresh = await issueRefreshSession(fresh._id);
      return applySessionCookies(h.response({ ok: true }), token, refresh);
    },
  });

  server.route({
    method: 'POST',
    path: '/api/auth/forgot-password',
    options: {
      auth: false,
      validate: {
        payload: Joi.object({
          email: Joi.string().email({ tlds: { allow: false } }).required(),
        }),
      },
    },
    handler: async (request) => {
      const email = request.payload.email.toLowerCase().trim();
      assertAuthRate(request, email);
      const user = await User.findOne({ email, isActive: true });
      if (user) {
        const rawToken = crypto.randomBytes(32).toString('hex');
        user.passwordResetToken = hashResetToken(rawToken);
        user.passwordResetExpires = new Date(Date.now() + 60 * 60 * 1000);
        await user.save();
        const resetUrl = `${env.APP_URL}/reset-password?token=${rawToken}`;
        try {
          await sendPasswordResetEmail({
            to: user.email,
            name: user.firstName,
            resetUrl,
          });
        } catch (err) {
          request.log(['error', 'mail'], err);
          throw Boom.badImplementation('Could not send the reset email. Try again later.');
        }
      }
      return { ok: true, message: GENERIC_RESET_MESSAGE };
    },
  });

  server.route({
    method: 'POST',
    path: '/api/auth/reset-password',
    options: {
      auth: false,
      validate: {
        payload: Joi.object({
          token: Joi.string().hex().min(32).required(),
          newPassword: Joi.string().min(6).required(),
        }),
      },
    },
    handler: async (request) => {
      const hashed = hashResetToken(request.payload.token);
      const user = await User.findOne({
        passwordResetToken: hashed,
        passwordResetExpires: { $gt: new Date() },
        isActive: true,
      });
      if (!user) throw Boom.badRequest('This reset link is invalid or has expired.');
      user.passwordHash = await bcrypt.hash(request.payload.newPassword, 10);
      user.passwordResetToken = null;
      user.passwordResetExpires = null;
      await user.save();
      return { ok: true };
    },
  });

  server.route({
    method: 'POST',
    path: '/api/auth/logout',
    options: { auth: false },
    handler: async (request, h) => {
      await revokeRefreshSession(request.state?.[REFRESH_COOKIE]);
      return clearSessionCookies(h.response({ ok: true }));
    },
  });
}