import json
import logging
import os
import pkg_resources
import re
import requests
import urllib3

from typing import Optional

import pandas as pd

import seeq
from seeq.base import system
from seeq.sdk import *
from seeq.sdk.rest import ApiException
from seeq import spy

from . import _common, _config, _url
from ._common import Status

from urllib3.connectionpool import MaxRetryError, SSLError

client: Optional[ApiClient] = None
user: Optional[UserOutputV1] = None
server_version: Optional[str] = None
supported_units: Optional[set] = None
corporate_folder: Optional[FolderOutputV1] = None

https_verify_ssl = True
https_key_file = None
https_cert_file = None

AUTOMATIC_PROXY_DETECTION = '__auto__'


def login(username=None, password=None, *, access_key=None, url=None, directory='Seeq', ignore_ssl_errors=False,
          proxy=AUTOMATIC_PROXY_DETECTION, credentials_file=None, auth_token=None, force=True, quiet=False,
          status=None, auth_provider=None):
    """
    Establishes a connection with Seeq Server and logs in with a set of
    credentials. At least one set of credentials must be provided.
    Applicable credential sets are:
        - username + password (where username is in "Seeq" user directory)
        - username + password + directory
        - access_key + password
        - credentials_file (where username is in "Seeq" user directory)
        - credentials_file + directory

    Parameters
    ----------
    username : str, optional
        Username for login purposes. See credentials_file argument for
        alternative.

    password : str, optional
        Password for login purposes. See credentials_file argument for
        alternative.

    access_key: str, optional
        Access Key for login purposes. Access Keys are created by individual
        users via the Seeq user interface in the upper-right user profile
        menu. An Access Key has an associated password that is presented
        to the user (once!) upon creation of the Access Key, and it must be
        supplied via the "password" argument. The "directory" argument must
        NOT be supplied.

    url : str, default 'http://localhost:34216'
        Seeq Server url. You can copy this from your browser and cut off
        everything to the right of the port (if present).
        E.g. https://myseeqserver:34216

    directory : str, default 'Seeq'
        The authentication directory to use. You must be able to supply a
        username/password, so some passwordless Windows Authentication
        (NTLM) scenarios will not work. OpenID Connect is also not
        supported. If you need to use such authentication schemes, set up
        a Seeq Data Lab server.

    ignore_ssl_errors : bool, default False
        If True, SSL certificate validation errors are ignored. Use this
        if you're in a trusted network environment but Seeq Server's SSL
        certificate is not from a common root authority.

    proxy : str, default '__auto__'
        Specifies the proxy server to use for all requests. The default
        value is "__auto__", which examines the standard HTTP_PROXY and
        HTTPS_PROXY environment variables. If you specify None for this
        parameter, no proxy server will be used.

    credentials_file : str, optional
        Reads username and password from the specified file. If specified, the
        file should be plane text and contain two lines, the first line being
        the username, the second being the user's password.

    force : str, default True
        If True, re-logs in even if already already logged in. If False, skips
        login if already logged in. You should include a spy.login(force=False)
        cell if you are creating example notebooks that may be used in Jupyter
        environments like Anaconda, AWS SageMaker or Azure Notebooks.)

    quiet : bool, default False
        If True, suppresses progress output.

    status : spy.Status, optional
        If supplied, this Status object will be updated as the command
        progresses.

    auth_provider : str, deprecated
        Use directory instead.

    auth_token : str, deprecated
        Use Access Keys instead, see "access_key" argument.
    """
    _common.validate_argument_types([
        (username, 'username', str),
        (password, 'password', str),
        (access_key, 'access_key', str),
        (url, 'url', str),
        (directory, 'directory', str),
        (ignore_ssl_errors, 'ignore_ssl_errors', bool),
        (proxy, 'proxy', str),
        (credentials_file, 'credentials_file', str),
        # Note: Although auth_token is no longer a supported authentication method for non-Seeq Data Lab scenarios,
        # it is still used by Seeq Data Lab code to log the user in.
        (auth_token, 'auth_token', str),
        (force, 'force', bool),
        (quiet, 'quiet', bool),
        (status, 'status', _common.Status)
    ])

    status = Status.validate(status, quiet)

    try:
        _login(username, password, access_key, url, directory, ignore_ssl_errors, proxy,
               credentials_file, auth_token, force, status, auth_provider)
    except (RuntimeError, ValueError, TypeError) as e:
        status.update(str(e), Status.FAILURE)
        raise

    user_string = user.username
    user_profile = ''
    if user.first_name:
        user_profile = user.first_name
    if user.last_name:
        user_profile += ' ' + user.last_name
    if user.is_admin:
        user_profile += ' [Admin]'
    if len(user_profile) > 0:
        user_string += ' (%s)' % user_profile.strip()

    status.update(f'Logged in to <strong>{_config.get_seeq_url()}</strong> '
                  f'successfully as <strong>{user_string}</strong>.\n'
                  f'Seeq Server Version: <strong>{spy.server_version}</strong>\n'
                  f'Seeq Python Module Version: <strong>{seeq.__version__}</strong>',
                  Status.SUCCESS)


def _login(username, password, access_key, url, directory, ignore_ssl_errors, proxy, credentials_file, auth_token,
           force, status, auth_provider):
    if auth_provider is not None:
        raise ValueError('"auth_provider" argument has been renamed to "directory"')

    if access_key and username:
        raise ValueError('"username" argument must be omitted when supplying "access_key" argument')

    if access_key and directory != 'Seeq':
        raise ValueError('"directory" argument must be omitted when supplying "access_key" argument')

    global client, user, supported_units, corporate_folder

    try:
        if force or not client:
            # Clear out any global state before attempting to log in
            _clear_login_state(quiet=True, status=None)

            if url:
                _config.set_seeq_url(_url.cleanse_url(url))

            _client_login(auth_token, credentials_file, directory, ignore_ssl_errors, password, proxy, status,
                          _config.get_api_url(), username, access_key)

        system_api = SystemApi(client)
        server_status = system_api.get_server_status()  # type: ServerStatusOutputV1
        spy.server_version = server_status.version
        server_major, server_minor, server_patch = validate_seeq_server_version(
            status,
            # We allow a version mismatch here because in the case of Data Lab, this login call happens when the
            # kernel is initialized, and if an exception is thrown, it is not seen by the user. Then subsequent calls to
            # other functions like spy.search() fail with a "not logged in" error instead of failing with a version
            # mismatch error. That's confusing. So instead, we just warn during login (but succeed) and then fail later
            # when other functions are called.
            allow_version_mismatch=True)

        if server_minor >= 46:
            validate_data_lab_license()

        users_api = UsersApi(client)
        user = users_api.get_me()  # type: UserOutputV1
        spy.user = user

        folders_api = FoldersApi(client)

        # noinspection PyBroadException
        try:
            corporate_folder = folders_api.get_folder(folder_id='corporate')
        except BaseException:
            # This can happen in cases where the user does not have access rights to the Corporate folder
            corporate_folder = None

    except BaseException:
        logout(quiet=True)
        raise


def _client_login(auth_token, credentials_file, directory, ignore_ssl_errors, password, proxy, status, api_client_url,
                  username, access_key):
    # Annoying warnings are printed to stderr if connections fail
    logging.getLogger("requests").setLevel(logging.FATAL)
    logging.getLogger("urllib3").setLevel(logging.FATAL)
    urllib3.disable_warnings()

    cert_file = _config.get_seeq_cert_path()
    if cert_file and os.path.exists(cert_file):
        Configuration().set_certificate_path(cert_file)

    key_file = _config.get_seeq_key_path()
    if key_file and os.path.exists(key_file):
        Configuration().key_file = key_file

    Configuration().verify_ssl = not ignore_ssl_errors

    if proxy == AUTOMATIC_PROXY_DETECTION:
        if api_client_url.startswith('https') and 'HTTPS_PROXY' in os.environ:
            Configuration().proxy = os.environ['HTTPS_PROXY']
        elif 'HTTP_PROXY' in os.environ:
            Configuration().proxy = os.environ['HTTP_PROXY']
    elif proxy is not None:
        Configuration().proxy = proxy

    _client = ApiClient(api_client_url)
    _client.set_default_header('x-sq-origin', 'Data Lab')

    if auth_token:
        if username or password or credentials_file:
            raise ValueError('username, password and/or credentials_file cannot be provided along with auth_token')

        _client.auth_token = auth_token
    else:
        auth_api = AuthApi(_client)
        auth_input = AuthInputV1()

        if access_key:
            username = access_key

        if credentials_file:
            if username is not None or password is not None or access_key is not None:
                raise ValueError('If credentials_file is specified, username, access_key and password must be omitted')

            if not os.path.exists(credentials_file):
                repo_root_dir = system.get_repo_root_dir(windows_long_path=False)
                if repo_root_dir:
                    agent_key_file = os.path.join(system.get_repo_root_dir(windows_long_path=False), 'sq-run-data-dir',
                                                  'keys', 'agent.key')
                    if os.path.exists(agent_key_file):
                        # This is a hack to make it easier to run the Documentation notebooks without having to create a
                        # credentials file. It was too easy to forget to delete the credentials file when you created
                        # it, and it would wind up in the distribution.
                        credentials_file = agent_key_file

            if not os.path.exists(credentials_file):
                raise ValueError(f'credentials_file "{credentials_file}" not found')

            try:
                with open(credentials_file) as f:
                    lines = f.readlines()
            except Exception as e:
                raise RuntimeError('Could not read credentials_file "%s": %s' % (credentials_file, e))

            if len(lines) < 2:
                raise RuntimeError('credentials_file "%s" must have two lines: username then password')

            username = lines[0].strip()
            password = lines[1].strip()

        if not username or not password:
            if access_key:
                raise ValueError('Both access_key and password must be supplied')
            else:
                raise ValueError('Both username and password must be supplied')

        auth_input.username = username
        auth_input.password = password

        status.update('Logging in to <strong>%s</strong> as <strong>%s</strong>' % (
            api_client_url, username), Status.RUNNING)

        directories = dict()
        try:
            auth_providers_output = auth_api.get_auth_providers()  # type: AuthProvidersOutputV1
        except MaxRetryError as e:
            if isinstance(e.reason, SSLError):
                raise RuntimeError(f'SSL certificate error. If you trust your network, you can add '
                                   f'the spy.login(ignore_ssl_errors=True) argument.\n\nMore info:\n{e.reason}')

            raise RuntimeError(
                '"%s" could not be reached. Is the server or network down?\n%s' % (api_client_url, e))

        for datasource_output in auth_providers_output.auth_providers:  # type: DatasourceOutputV1
            directories[datasource_output.name] = datasource_output

        if directory not in directories:
            raise RuntimeError('directory "%s" not recognized. Possible directory(s) for this server: %s' %
                               (directory, ', '.join(directories.keys())))

        datasource_output = directories[directory]
        auth_input.auth_provider_class = datasource_output.datasource_class
        auth_input.auth_provider_id = datasource_output.datasource_id

        try:
            auth_api.login(body=auth_input)
        except ApiException as e:
            if e.status == 401:
                if access_key:
                    seeq_module_major, _, _, _ = get_module_version_tuple()
                    if seeq_module_major < 50:
                        raise RuntimeError(
                            f'Access Key "{access_key}" is not valid. Log out of the Seeq user interface  (if logged '
                            'in) and then log back in again to reset Access Key validity. If you are still seeing '
                            'this error after doing so, make sure the "access_key" and "password" arguments are '
                            'correct and match an Access Key that you have created in the Seeq user interface.'
                        )
                    else:
                        raise RuntimeError(
                            f'Access Key "{access_key}" is not valid. Log in to the Seeq user interface to reset its '
                            'validity. If you are still seeing this error after doing so, make sure the "access_key" '
                            'and "password" arguments are correct and match an Access Key that you have created in '
                            'the Seeq user interface.'
                        )
                else:
                    raise RuntimeError(
                        f'"{auth_input.username}" could not be logged in with supplied credentials, check username and '
                        'password.')
            else:
                raise
        except MaxRetryError as e:
            raise RuntimeError(
                f'"{api_client_url}" could not be reached. Is the server or network down?\n{e}')
        except Exception as e:
            raise RuntimeError(
                f'Could not connect to Seeq\'s API at {api_client_url} with login "{auth_input.username}".\n{e}')

    # Now that we have succeeded, set all the global variables
    global client, https_verify_ssl, https_key_file, https_cert_file
    client = _client
    spy.client = client

    https_verify_ssl = not ignore_ssl_errors
    https_key_file = key_file
    https_cert_file = cert_file


def logout(quiet=False, status=None):
    """
    Logs you out of your current session.

    Parameters
    ----------

    quiet : bool, default False
        If True, suppresses progress output.

    status : spy.Status, optional
        If supplied, this Status object will be updated as the command
        progresses.
    """

    _clear_login_state(quiet, status, call_logout=True)


def _clear_login_state(quiet, status, call_logout=False):
    """
    Clear out any global state and optionally logs you out of your current session.

    Parameters
    ----------

    quiet : bool
        If True, suppresses progress output.

    status : spy.Status, optional
        If supplied, this Status object will be updated as the command
        progresses.

    call_logout : bool
        If True, auth_api.logout is called otherwise just the global state is cleared
    """

    status = Status.validate(status, quiet)
    global client, supported_units, user, https_verify_ssl, https_key_file, https_cert_file

    if client is None:
        status.update('No action taken because you are not currently logged in.', Status.FAILURE)
    else:
        if call_logout:
            auth_api = AuthApi(client)
            auth_api.logout()

        client.logout()
        client = None
        spy.client = None

    user = None
    spy.user = None
    supported_units = None
    https_verify_ssl = True
    https_key_file = None
    https_cert_file = None

    status.update('Logged out.', Status.SUCCESS)


def find_user(query):
    """
    Finds a user by using Seeq's user/group autocomplete functionality. Must result in exactly one match or a
    RuntimeError is raised.
    :param query: A user/group fragment to use for the search
    :return: The identity of the matching user.
    :rtype: UserOutputV1
    """
    users_api = UsersApi(client)

    if _common.is_guid(query):
        user_id = query
    else:
        identity_preview_list = users_api.autocomplete_users_and_groups(query=query)  # type: IdentityPreviewListV1
        if len(identity_preview_list.items) == 0:
            raise RuntimeError('User "%s" not found' % query)
        if len(identity_preview_list.items) > 1:
            raise RuntimeError('Multiple users found that match "%s":\n%s' % (
                query, '\n'.join([('%s (%s)' % (u.username, u.id)) for u in identity_preview_list.items])))

        user_id = identity_preview_list.items[0].id

    return users_api.get_user(id=user_id)


def get_user_timezone():
    # noinspection PyBroadException
    try:
        workbench_dict = json.loads(user.workbench)
        return workbench_dict['state']['stores']['sqWorkbenchStore']['userTimeZone']
    except BaseException:
        # This can happen if the user has never logged in interactively (e.g., agent_api_key)
        return 'UTC'


def get_module_version_tuple():
    match = re.match(r'^(\d+)\.(\d+)\.(\d+)\.(\d+)', seeq.__version__)
    seeq_module_major = int(match.group(1))
    seeq_module_minor = int(match.group(2))
    seeq_module_patch = int(match.group(3))
    seeq_module_functional = int(match.group(4))
    return seeq_module_major, seeq_module_minor, seeq_module_patch, seeq_module_functional


def get_server_version_tuple():
    match = re.match(r'^R?(?:\d+\.)?(\d+)\.(\d+)\.(\d+)(-v\w+)?(-[-\w]+)?', spy.server_version)
    seeq_server_major = int(match.group(1))
    seeq_server_minor = int(match.group(2))
    seeq_server_patch = int(match.group(3))
    return seeq_server_major, seeq_server_minor, seeq_server_patch


def validate_seeq_server_version(status: Status, allow_version_mismatch=False):
    seeq_module_major, seeq_module_minor, _, _ = get_module_version_tuple()
    seeq_server_major, seeq_server_minor, seeq_server_patch = get_server_version_tuple()

    # The old versioning scheme is like 0.49.3 whereas the new scheme is like 50.1.8
    # See https://seeq.atlassian.net/wiki/spaces/SQ/pages/947225963/Seeq+Versioning+Simplification
    using_old_versioning_scheme = (seeq_server_major == 0)

    message = None

    if using_old_versioning_scheme:
        if seeq_module_major != seeq_server_major or \
                seeq_module_minor != seeq_server_minor:
            message = (f'The major/minor version of the seeq module ({seeq_module_major}.{seeq_module_minor}) '
                       f'does not match the major/minor version of the Seeq Server you are connected to '
                       f'({seeq_server_major}.{seeq_server_minor}) and is incompatible.')
    else:
        if seeq_module_major != seeq_server_major:
            message = (f'The major version of the seeq module ({seeq_module_major}) '
                       f'does not match the major version of the Seeq Server you are connected to '
                       f'({seeq_server_major}) and is incompatible.')

    if message:
        compatible_module_folder = find_compatible_module()
        if not compatible_module_folder:
            message += (f'\n\nIt is recommended that you issue the following PIP command to '
                        f'install a compatible version of the seeq module:\n')
            if using_old_versioning_scheme:
                message += f'pip install -U seeq~={seeq_server_major}.{seeq_server_minor}.{seeq_server_patch}'
            else:
                message += f'pip install -U seeq~={seeq_server_major}.{seeq_server_minor}'
        else:
            message += (f'\n\nA compatible module was found here: {compatible_module_folder}\n'
                        f'Consider uninstalling your project-specific seeq module by issuing the following PIP '
                        f'command:\n'
                        f'pip uninstall -y seeq')

        if allow_version_mismatch or _config.options.allow_version_mismatch:
            status.warn(message)
        else:
            raise RuntimeError(message)

    return seeq_server_major, seeq_server_minor, seeq_server_patch


def find_compatible_module():
    """
    Uses pkg_resources tools to look for a seeq module that is compatible with the version of Seeq Server we're
    connected to. This function is useful in Seeq Data Lab scenarios where the user has installed a "private" version of
    the seeq module (presumably to get a bugfix for SPy) but Seeq Server and Seeq Data Lab have been upgraded in the
    meantime and the user's best course of action is to remove the private version and resume using the "built-in"
    version, which will update with Seeq Data Lab as it is upgraded.
    :return: Path to a compatible module, None if a compatible module is not found.
    """
    seeq_module_major, seeq_module_minor, _, _ = get_module_version_tuple()
    seeq_server_major, seeq_server_minor, seeq_server_patch = get_server_version_tuple()

    pkg_env = pkg_resources.Environment()
    seeq_modules = pkg_env['seeq']
    for seeq_module in seeq_modules:  # type: pkg_resources.Distribution
        if seeq_server_major >= 50 and seeq_module.version.startswith(f'{seeq_server_major}.'):
            return seeq_module.location
        elif seeq_server_major < 50 and seeq_module.version.startswith(f'{seeq_server_major}.{seeq_server_minor}.'):
            return seeq_module.location

    return None


def validate_data_lab_license():
    global client
    system_api = SystemApi(client)
    license_status_output = system_api.get_license()  # type: LicenseStatusOutputV1
    for additional_feature in license_status_output.additional_features:  # type: LicensedFeatureStatusOutputV1
        if additional_feature.name == 'Data_Lab':
            if additional_feature.validity == 'Valid':
                return

            raise RuntimeError(f'Seeq Data Lab license is "{additional_feature.validity}", could not log in. Contact '
                               'your administrator or speak with Seeq Support at support@seeq.com.')

    raise RuntimeError('Seeq Data Lab is not licensed for this server, could not log in. Contact your administrator '
                       'or speak with Seeq Support at support@seeq.com.')


def validate_login(status: Status):
    global client
    if client is None:
        raise RuntimeError('Not logged in. Execute spy.login() before calling this function.')

    validate_seeq_server_version(status)


def localize_datetime(dt, default_timezone=None):
    if not dt.tz:
        dt = dt.tz_localize(default_timezone if default_timezone else get_user_timezone())
    return dt


def parse_datetime_with_timezone(dt, nanoseconds_multiplier=1000000, default_timezone=None):
    # type: (str, int, object) -> pd.Timestamp

    if isinstance(dt, pd.Timestamp):
        return localize_datetime(dt, default_timezone=default_timezone)

    if isinstance(dt, (float, int)):
        # Assume it's in milliseconds because it came from the front-end
        return pd.Timestamp(int(float(dt) * nanoseconds_multiplier)).tz_localize('UTC')

    match = re.fullmatch(r'^([^\[\]]+)(\[(.+)\])?$', dt)
    if not match or not match.group(3):
        return localize_datetime(pd.to_datetime(dt))

    datetime_part = match.group(1)
    tz_part = match.group(3)
    return pd.Timestamp(datetime_part).tz_localize(tz_part)


# The list of units that come back from system_api.get_supported_units() is a curated set of compound units that are
# meant to be human-friendly in Formula tool help. But it's the only thing available in the API to figure out what
# base units are supported, so we have to split the compound unit string into its components. I.e., S/cm³ gets split
# into S and cm so that we can add those two "base" units to the set we use to determine validity.
UNITS_SPLIT_REGEX = r'[/*²³·]'


def is_valid_unit(unit):
    """
    Returns True if the supplied unit will be recognized by the Seeq calculation engine. This can be an important
    function to use if you are attempting to supply a "Value Unit Of Measure" property on a Signal or a "Unit Of
    Measure" property on a Scalar.
    :param unit: The unit of measure for which to assess validity
    :return: True if unit is valid, False if not
    """
    global supported_units, client
    if not supported_units:
        system_api = SystemApi(client)
        support_units_output = system_api.get_supported_units()  # type: SupportedUnitsOutputV1

        supported_units = set()
        for supported_unit_family in support_units_output.units.values():
            for supported_unit in supported_unit_family:
                unit_parts = re.split(UNITS_SPLIT_REGEX, supported_unit)
                supported_units.update([u for u in unit_parts if len(u) > 0])

    unit_parts = re.split(UNITS_SPLIT_REGEX, unit)
    for unit_part in [u for u in unit_parts if len(u) > 0]:
        if unit_part not in supported_units:
            return False

    return True


def pull_image(url):
    return requests.get(url, headers={
        "Accept": "application/vnd.seeq.v1+json",
        "x-sq-auth": client.auth_token
    }, verify=https_verify_ssl).content
