#!/usr/bin/env python3
"""Create permanent-password Cognito grading users and seed the local EC2 database."""
from __future__ import annotations

import argparse
import json
import os
import secrets
import subprocess
from pathlib import Path

import boto3


def private_json(path: Path, value: dict):
    fd = os.open(path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
    os.fchmod(fd, 0o600)
    with os.fdopen(fd, 'w') as stream:
        json.dump(value, stream, indent=2)
        stream.write('\n')


def account(client, pool: str, username: str, group: str):
    try:
        client.admin_create_user(UserPoolId=pool, Username=username,
            UserAttributes=[{'Name': 'email', 'Value': username},
                            {'Name': 'email_verified', 'Value': 'true'}],
            MessageAction='SUPPRESS')
    except client.exceptions.UsernameExistsException:
        pass
    password = 'Aa1!' + secrets.token_urlsafe(24)
    client.admin_set_user_password(UserPoolId=pool, Username=username,
                                   Password=password, Permanent=True)
    other = 'patient' if group == 'doctor' else 'doctor'
    try:
        client.admin_remove_user_from_group(UserPoolId=pool, Username=username, GroupName=other)
    except client.exceptions.ResourceNotFoundException:
        pass
    client.admin_add_user_to_group(UserPoolId=pool, Username=username, GroupName=group)
    user = client.admin_get_user(UserPoolId=pool, Username=username)
    sub = next(x['Value'] for x in user['UserAttributes'] if x['Name'] == 'sub')
    return password, sub


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--region', required=True)
    parser.add_argument('--user-pool-id', required=True)
    parser.add_argument('--app-client-id', required=True)
    parser.add_argument('--base-url', required=True, help='Public site origin, e.g. http://EC2_PUBLIC_IP')
    parser.add_argument('--doctor-email', required=True)
    parser.add_argument('--alice-email', required=True)
    parser.add_argument('--bob-email', required=True)
    parser.add_argument('--student-id', default='')
    args = parser.parse_args()
    emails = [args.doctor_email, args.alice_email, args.bob_email]
    if len(set(emails)) != 3:
        parser.error('Doctor, Alice, and Bob must have distinct emails')
    client = boto3.client('cognito-idp', region_name=args.region)
    app_client = client.describe_user_pool_client(UserPoolId=args.user_pool_id,
        ClientId=args.app_client_id)['UserPoolClient']
    if app_client.get('ClientSecret'):
        parser.error('App client must be public, without a secret')
    if 'ALLOW_USER_PASSWORD_AUTH' not in app_client.get('ExplicitAuthFlows', []):
        parser.error('App client must support ALLOW_USER_PASSWORD_AUTH')
    for group in ('doctor', 'patient'):
        try:
            client.create_group(UserPoolId=args.user_pool_id, GroupName=group)
        except client.exceptions.GroupExistsException:
            pass
    specs = [('doctor', args.doctor_email, 'doctor', None, None),
             ('alice', args.alice_email, 'patient', 'P1001', 'Alice'),
             ('bob', args.bob_email, 'patient', 'P1002', 'Bob')]
    accounts, seed = {}, []
    for label, email, role, patient_id, name in specs:
        password, sub = account(client, args.user_pool_id, email, role)
        accounts[label] = {'username': email, 'password': password}
        if patient_id:
            accounts[label]['patient_id'] = patient_id
        seed.append({'sub': sub, 'role': role, 'patient_id': patient_id, 'name': name})
    subprocess.run(['docker', 'compose', 'exec', '-T', 'api', 'python',
                    '/app/scripts/seed_accounts.py'], input=json.dumps(seed),
                   text=True, check=True)
    origin = args.base_url.rstrip('/')
    submission = {'base_url': origin + '/api', 'web_url': origin + '/',
                  'student_id': args.student_id, 'region': args.region,
                  'user_pool_id': args.user_pool_id, 'app_client_id': args.app_client_id,
                  'accounts': {label: {'username': value['username'],
                                      **({'patient_id': value['patient_id']} if 'patient_id' in value else {})}
                               for label, value in accounts.items()}}
    Path('submission.json').write_text(json.dumps(submission, indent=2) + '\n')
    private_json(Path('private_accounts.json'), accounts)
    print('Wrote submission.json (non-secret) and private_accounts.json (mode 0600).')
    print('Each run resets all three passwords. Send the private file only via Canvas private submission.')


if __name__ == '__main__':
    main()