''' Config reader '''

import json
import utils

def read_config(path: str) -> dict | None:
    ''' Read config '''
    default = {
        'management_token': 'TELEGRAM_BOT_TOKEN_HERE',
        'tg_api_id': 12345,
        'tg_api_hash': '0123456789abcdef0123456789abcdef',
        'accounts': {
            'account1': {
                'login': '+71234567890',
                'mod_basic': True,
                'mod_eternal_online': False,
                'mod_video_downloader': True
            }
        }
    }
    # root fields
    root_required_fields = {
        'management_token': [str],
        'tg_api_id': [int],
        'tg_api_hash': [str],
        'tg_admin_uid': [int],
        'accounts': [dict]
    }

    # account fields
    required_fields = {
        'login': [str]
    }
    optional_fields = {}
    for mod_name in utils.get_all_mods():
        optional_fields[mod_name] = ([bool], False)
    optional_fields['mod_basic'] = ([bool], True)
    try:
        j = None
        with open(path, 'r') as f:
            j = json.loads(f.read())
        # root fields check
        for key in root_required_fields:
            if key not in j:
                print('[!] Config misses key \'%s\'' % key)
                return None
            if type(j[key]) not in root_required_fields[key]:
                print('[!] Config has key \'%s\' of invalid type: must be one of %s' % (key, root_required_fields[key]))
                return None
        # check all accounts
        for account_name in dict(j['accounts']):
            # to remove the account?
            to_remove = False

            # save the account with short name
            acc = j['accounts'][account_name]
            # check if all required fields are present
            for key in required_fields:
                # missing field
                if key not in acc:
                    to_remove = True
                    print('[!] Account \'%s\' misses required field \'%s\'' % (account_name, key))
                    break
                # invalid type
                t = type(acc[key])
                if t not in required_fields[key]:
                    to_remove = True
                    print('[!] Account \'%s\' has required field of invalid type: \'%s\' must be one of %s' % (account_name, key, required_fields[key]))
                    break
            # remove the account
            if to_remove:
                print('[!] Account \'%s\' will not be served until errors are fixed' % account_name)
                del j[account_name]
                continue
            # check all optional fields
            for key in optional_fields:
                # get allowed types and default value
                allowed_types, default_value = optional_fields[key]
                # missing - add default value
                if key not in acc:
                    print(
                        '[W] Account \'%s\' misses optional field \'%s\', using default value \'%s\'' % \
                        (account_name, key, default_value)
                    )
                    acc[key] = default_value
                    continue
                # invalid type
                t = type(acc[key])
                if t not in allowed_types:
                    print(
                        '[W] Account \'%s\' has optional field of invalid type: \'%s\' must be one of %s. Using default value %s' % \
                        (account_name, key, types, default_value)
                    )
                    acc[key] = default_value
                    continue
            # log
            print('[I] Added account \'%s\' (login \'%s\')' % (account_name, acc['login']))
        # return
        return j
    except:
        try:
            with open(path, 'w') as f:
                f.write(json.dumps(default, indent=4))
            print('[!] Saved default config to %s' % path)
        except:
            print('[!] Failed to save default config to %s' % path)
        return None