"""
.. module: lemur.certificate.cli
    :platform: Unix
    :copyright: (c) 2015 by Netflix Inc., see AUTHORS for more
    :license: Apache, see LICENSE for more details.
.. moduleauthor:: Kevin Glisson <kglisson@netflix.com>
"""
import sys
import multiprocessing
from tabulate import tabulate
from sqlalchemy import or_

from flask import current_app

from flask_script import Manager
from flask_principal import Identity, identity_changed


from lemur import database
from lemur.extensions import sentry
from lemur.extensions import metrics
from lemur.plugins.base import plugins
from lemur.constants import SUCCESS_METRIC_STATUS, FAILURE_METRIC_STATUS
from lemur.deployment import service as deployment_service
from lemur.endpoints import service as endpoint_service
from lemur.notifications.messaging import send_rotation_notification
from lemur.domains.models import Domain
from lemur.authorities.models import Authority
from lemur.certificates.schemas import CertificateOutputSchema
from lemur.certificates.models import Certificate
from lemur.certificates.service import (
    reissue_certificate,
    get_certificate_primitives,
    get_all_pending_reissue,
    get_by_name,
    get_all_certs,
    get
)

from lemur.certificates.verify import verify_string

manager = Manager(usage="Handles all certificate related tasks.")


def print_certificate_details(details):
    """
    Print the certificate details with formatting.
    :param details:
    :return:
    """
    details, errors = CertificateOutputSchema().dump(details)
    print("[+] Re-issuing certificate with the following details: ")
    print(
        "\t[+] Common Name: {common_name}\n"
        "\t[+] Subject Alternate Names: {sans}\n"
        "\t[+] Authority: {authority_name}\n"
        "\t[+] Validity Start: {validity_start}\n"
        "\t[+] Validity End: {validity_end}\n".format(
            common_name=details['commonName'],
            sans=",".join(x['value'] for x in details['extensions']['subAltNames']['names']) or None,
            authority_name=details['authority']['name'],
            validity_start=details['validityStart'],
            validity_end=details['validityEnd']
        )
    )


def validate_certificate(certificate_name):
    """
    Ensuring that the specified certificate exists.
    :param certificate_name:
    :return:
    """
    if certificate_name:
        cert = get_by_name(certificate_name)

        if not cert:
            print("[-] No certificate found with name: {0}".format(certificate_name))
            sys.exit(1)

        return cert


def validate_endpoint(endpoint_name):
    """
    Ensuring that the specified endpoint exists.
    :param endpoint_name:
    :return:
    """
    if endpoint_name:
        endpoint = endpoint_service.get_by_name(endpoint_name)

        if not endpoint:
            print("[-] No endpoint found with name: {0}".format(endpoint_name))
            sys.exit(1)

        return endpoint


def request_rotation(endpoint, certificate, message, commit):
    """
    Rotates a certificate and handles any exceptions during
    execution.
    :param endpoint:
    :param certificate:
    :param message:
    :param commit:
    :return:
    """
    status = FAILURE_METRIC_STATUS
    if commit:
        try:
            deployment_service.rotate_certificate(endpoint, certificate)

            if message:
                send_rotation_notification(certificate)

            status = SUCCESS_METRIC_STATUS

        except Exception as e:
            print(
                "[!] Failed to rotate endpoint {0} to certificate {1} reason: {2}".format(
                    endpoint.name,
                    certificate.name,
                    e
                )
            )

    metrics.send('endpoint_rotation', 'counter', 1, metric_tags={'status': status})


def request_reissue(certificate, commit):
    """
    Reissuing certificate and handles any exceptions.
    :param certificate:
    :param commit:
    :return:
    """
    status = FAILURE_METRIC_STATUS
    try:
        print("[+] {0} is eligible for re-issuance".format(certificate.name))

        # set the lemur identity for all cli commands
        identity_changed.send(current_app._get_current_object(), identity=Identity(1))

        details = get_certificate_primitives(certificate)
        print_certificate_details(details)

        if commit:
            new_cert = reissue_certificate(certificate, replace=True)
            print("[+] New certificate named: {0}".format(new_cert.name))

        status = SUCCESS_METRIC_STATUS

    except Exception as e:
        sentry.captureException()
        current_app.logger.exception("Error reissuing certificate.", exc_info=True)
        print(
            "[!] Failed to reissue certificates. Reason: {}".format(
                e
            )
        )

    metrics.send('certificate_reissue', 'counter', 1, metric_tags={'status': status})


@manager.option('-e', '--endpoint', dest='endpoint_name', help='Name of the endpoint you wish to rotate.')
@manager.option('-n', '--new-certificate', dest='new_certificate_name', help='Name of the certificate you wish to rotate to.')
@manager.option('-o', '--old-certificate', dest='old_certificate_name', help='Name of the certificate you wish to rotate.')
@manager.option('-a', '--notify', dest='message', action='store_true', help='Send a rotation notification to the certificates owner.')
@manager.option('-c', '--commit', dest='commit', action='store_true', default=False, help='Persist changes.')
def rotate(endpoint_name, new_certificate_name, old_certificate_name, message, commit):
    """
    Rotates an endpoint and reissues it if it has not already been replaced. If it has
    been replaced, will use the replacement certificate for the rotation.
    """
    if commit:
        print("[!] Running in COMMIT mode.")

    print("[+] Starting endpoint rotation.")

    status = FAILURE_METRIC_STATUS

    try:
        old_cert = validate_certificate(old_certificate_name)
        new_cert = validate_certificate(new_certificate_name)
        endpoint = validate_endpoint(endpoint_name)

        if endpoint and new_cert:
            print("[+] Rotating endpoint: {0} to certificate {1}".format(endpoint.name, new_cert.name))
            request_rotation(endpoint, new_cert, message, commit)

        elif old_cert and new_cert:
            print("[+] Rotating all endpoints from {0} to {1}".format(old_cert.name, new_cert.name))

            for endpoint in old_cert.endpoints:
                print("[+] Rotating {0}".format(endpoint.name))
                request_rotation(endpoint, new_cert, message, commit)

        else:
            print("[+] Rotating all endpoints that have new certificates available")
            for endpoint in endpoint_service.get_all_pending_rotation():
                if len(endpoint.certificate.replaced) == 1:
                    print("[+] Rotating {0} to {1}".format(endpoint.name, endpoint.certificate.replaced[0].name))
                    request_rotation(endpoint, endpoint.certificate.replaced[0], message, commit)
                else:
                    metrics.send('endpoint_rotation', 'counter', 1, metric_tags={'status': FAILURE_METRIC_STATUS})
                    print("[!] Failed to rotate endpoint {0} reason: Multiple replacement certificates found.".format(
                        endpoint.name
                    ))

        status = SUCCESS_METRIC_STATUS
        print("[+] Done!")

    except Exception as e:
        sentry.captureException()

    metrics.send('endpoint_rotation_job', 'counter', 1, metric_tags={'status': status})


@manager.option('-o', '--old-certificate', dest='old_certificate_name', help='Name of the certificate you wish to reissue.')
@manager.option('-c', '--commit', dest='commit', action='store_true', default=False, help='Persist changes.')
def reissue(old_certificate_name, commit):
    """
    Reissues certificate with the same parameters as it was originally issued with.
    If not time period is provided, reissues certificate as valid from today to
    today + length of original.
    """
    if commit:
        print("[!] Running in COMMIT mode.")

    print("[+] Starting certificate re-issuance.")

    status = FAILURE_METRIC_STATUS

    try:
        old_cert = validate_certificate(old_certificate_name)

        if not old_cert:
            for certificate in get_all_pending_reissue():
                request_reissue(certificate, commit)
        else:
            request_reissue(old_cert, commit)

        status = SUCCESS_METRIC_STATUS
        print("[+] Done!")
    except Exception as e:
        sentry.captureException()
        current_app.logger.exception("Error reissuing certificate.", exc_info=True)
        print(
            "[!] Failed to reissue certificates. Reason: {}".format(
                e
            )
        )

    metrics.send('certificate_reissue_job', 'counter', 1, metric_tags={'status': status})


@manager.option('-f', '--fqdns', dest='fqdns', help='FQDNs to query. Multiple fqdns specified via comma.')
@manager.option('-i', '--issuer', dest='issuer', help='Issuer to query for.')
@manager.option('-o', '--owner', dest='owner', help='Owner to query for.')
@manager.option('-e', '--expired', dest='expired', type=bool, default=False, help='Include expired certificates.')
def query(fqdns, issuer, owner, expired):
    """Prints certificates that match the query params."""
    table = []

    q = database.session_query(Certificate)

    sub_query = database.session_query(Authority.id) \
        .filter(Authority.name.ilike('%{0}%'.format(issuer))) \
        .subquery()

    q = q.filter(
        or_(
            Certificate.issuer.ilike('%{0}%'.format(issuer)),
            Certificate.authority_id.in_(sub_query)
        )
    )

    q = q.filter(Certificate.owner.ilike('%{0}%'.format(owner)))

    if not expired:
        q = q.filter(Certificate.expired == False)  # noqa

    for f in fqdns.split(','):
        q = q.filter(
            or_(
                Certificate.cn.ilike('%{0}%'.format(f)),
                Certificate.domains.any(Domain.name.ilike('%{0}%'.format(f)))
            )
        )

    for c in q.all():
        table.append([c.id, c.name, c.owner, c.issuer])

    print(tabulate(table, headers=['Id', 'Name', 'Owner', 'Issuer'], tablefmt='csv'))


def worker(data, commit, reason):
    parts = [x for x in data.split(' ') if x]
    try:
        cert = get(int(parts[0].strip()))
        plugin = plugins.get(cert.authority.plugin_name)

        print('[+] Revoking certificate. Id: {0} Name: {1}'.format(cert.id, cert.name))
        if commit:
            plugin.revoke_certificate(cert, reason)

        metrics.send('certificate_revoke', 'counter', 1, metric_tags={'status': SUCCESS_METRIC_STATUS})

    except Exception as e:
        sentry.captureException()
        metrics.send('certificate_revoke', 'counter', 1, metric_tags={'status': FAILURE_METRIC_STATUS})
        print(
            "[!] Failed to revoke certificates. Reason: {}".format(
                e
            )
        )


@manager.command
def clear_pending():
    """
    Function clears all pending certificates.
    :return:
    """
    v = plugins.get('verisign-issuer')
    v.clear_pending_certificates()


@manager.option('-p', '--path', dest='path', help='Absolute file path to a Lemur query csv.')
@manager.option('-r', '--reason', dest='reason', help='Reason to revoke certificate.')
@manager.option('-c', '--commit', dest='commit', action='store_true', default=False, help='Persist changes.')
def revoke(path, reason, commit):
    """
    Revokes given certificate.
    """
    if commit:
        print("[!] Running in COMMIT mode.")

    print("[+] Starting certificate revocation.")

    with open(path, 'r') as f:
        args = [[x, commit, reason] for x in f.readlines()[2:]]

    with multiprocessing.Pool(processes=3) as pool:
        pool.starmap(worker, args)


@manager.command
def check_revoked():
    """
    Function attempts to update Lemur's internal cache with revoked
    certificates. This is called periodically by Lemur. It checks both
    CRLs and OCSP to see if a certificate is revoked. If Lemur is unable
    encounters an issue with verification it marks the certificate status
    as `unknown`.
    """
    for cert in get_all_certs():
        try:
            if cert.chain:
                status = verify_string(cert.body, cert.chain)
            else:
                status = verify_string(cert.body, "")

            cert.status = 'valid' if status else 'revoked'

        except Exception as e:
            sentry.captureException()
            current_app.logger.exception(e)
            cert.status = 'unknown'

        database.update(cert)