import os

from cachetools import lru_cache

import pytest
import shutil
from flask import Flask, jsonify
from flask_login import LoginManager
from flask_principal import identity_loaded, Permission, Identity, identity_changed, Principal
from flask_mail import Mail
from peewee import SqliteDatabase, InternalError

from app import app as application
from auth.permissions import on_identity_loaded
from data import model
from data.database import close_db_filter, db, configure
from data.model.user import LoginWrappedDBUser
from data.userfiles import Userfiles
from endpoints.api import api_bp
from endpoints.appr import appr_bp
from endpoints.web import web
from endpoints.v1 import v1_bp
from endpoints.v2 import v2_bp
from endpoints.verbs import verbs as verbs_bp
from endpoints.webhooks import webhooks

from initdb import initialize_database, populate_database

from path_converters import APIRepositoryPathConverter, RegexConverter, RepositoryPathConverter
from test.testconfig import FakeTransaction

INIT_DB_PATH = 0

@pytest.fixture(scope="session")
def init_db_path(tmpdir_factory):
  """ Creates a new database and appropriate configuration. Note that the initial database
      is created *once* per session. In the non-full-db-test case, the database_uri fixture
      makes a copy of the SQLite database file on disk and passes a new copy to each test.
  """
  # NOTE: We use a global here because pytest runs this code multiple times, due to the fixture
  # being imported instead of being in a conftest. Moving to conftest has its own issues, and this
  # call is quite slow, so we simply cache it here.
  global INIT_DB_PATH
  INIT_DB_PATH = INIT_DB_PATH or _init_db_path(tmpdir_factory)
  return INIT_DB_PATH

def _init_db_path(tmpdir_factory):
  if os.environ.get('TEST_DATABASE_URI'):
    return _init_db_path_real_db(os.environ.get('TEST_DATABASE_URI'))

  return _init_db_path_sqlite(tmpdir_factory)

def _init_db_path_real_db(db_uri):
  """ Initializes a real database for testing by populating it from scratch. Note that this does
      *not* add the tables (merely data). Callers must have migrated the database before calling
      the test suite.
  """
  configure({
    "DB_URI": db_uri,
    "DB_CONNECTION_ARGS": {
      'threadlocals': True,
      'autorollback': True,
    },
    "DB_TRANSACTION_FACTORY": _create_transaction,
  })

  populate_database()
  return db_uri

def _init_db_path_sqlite(tmpdir_factory):
  """ Initializes a SQLite database for testing by populating it from scratch and placing it into
      a temp directory file.
  """
  sqlitedbfile = str(tmpdir_factory.mktemp("data").join("test.db"))
  sqlitedb = 'sqlite:///{0}'.format(sqlitedbfile)
  conf = {"TESTING": True,
          "DEBUG": True,
          "DB_URI": sqlitedb}
  os.environ['DB_URI'] = str(sqlitedb)
  db.initialize(SqliteDatabase(sqlitedbfile))
  application.config.update(conf)
  application.config.update({"DB_URI": sqlitedb})
  initialize_database()

  db.obj.execute_sql('PRAGMA foreign_keys = ON;')

  populate_database()
  close_db_filter(None)
  return str(sqlitedbfile)


@pytest.fixture()
def database_uri(monkeypatch, init_db_path, sqlitedb_file):
  """ Returns the database URI to use for testing. In the SQLite case, a new, distinct copy of
      the SQLite database is created by copying the initialized database file (sqlitedb_file)
      on a per-test basis. In the non-SQLite case, a reference to the existing database URI is
      returned.
  """
  if os.environ.get('TEST_DATABASE_URI'):
    db_uri = os.environ['TEST_DATABASE_URI']
    monkeypatch.setenv("DB_URI", db_uri)
    return db_uri

  # Copy the golden database file to a new path.
  shutil.copy2(init_db_path, sqlitedb_file)

  # Monkeypatch the DB_URI.
  db_path = 'sqlite:///{0}'.format(sqlitedb_file)
  monkeypatch.setenv("DB_URI", db_path)
  return db_path


@pytest.fixture()
def sqlitedb_file(tmpdir):
  """ Returns the path at which the initialized, golden SQLite database file will be placed. """
  test_db_file = tmpdir.mkdir("quaydb").join("test.db")
  return str(test_db_file)

def _create_transaction(db):
  return FakeTransaction()

@pytest.fixture()
def appconfig(database_uri):
  """ Returns application configuration for testing that references the proper database URI. """
  conf = {
    "TESTING": True,
    "DEBUG": True,
    "DB_URI": database_uri,
    "SECRET_KEY": 'superdupersecret!!!1',
    "DB_CONNECTION_ARGS": {
      'threadlocals': True,
      'autorollback': True,
    },
    "DB_TRANSACTION_FACTORY": _create_transaction,
    "DATA_MODEL_CACHE_CONFIG": {
      'engine': 'inmemory',
    },
    "USERFILES_PATH": "userfiles/",
    "MAIL_SERVER": "",
    "MAIL_DEFAULT_SENDER": 'support@quay.io',
  }
  return conf

@pytest.fixture()
def initialized_db(appconfig):
  """ Configures the database for the database found in the appconfig. """
  under_test_real_database = bool(os.environ.get('TEST_DATABASE_URI'))

  # Configure the database.
  configure(appconfig)

  # Initialize caches.
  model._basequery._lookup_team_roles()
  model._basequery.get_public_repo_visibility()
  model.log.get_log_entry_kinds()

  if not under_test_real_database:
    # Make absolutely sure foreign key constraints are on.
    db.obj.execute_sql('PRAGMA foreign_keys = ON;')
    assert db.obj.execute_sql('PRAGMA foreign_keys;').fetchone()[0] == 1

  # If under a test *real* database, setup a savepoint.
  if under_test_real_database:
    with db.transaction():
      test_savepoint = db.savepoint()
      test_savepoint.__enter__()

      yield # Run the test.

      try:
        test_savepoint.rollback()
        test_savepoint.__exit__(None, None, None)
      except InternalError:
        # If postgres fails with an exception (like IntegrityError) mid-transaction, it terminates
        # it immediately, so when we go to remove the savepoint, it complains. We can safely ignore
        # this case.
        pass
  else:
    yield

@pytest.fixture()
def app(appconfig, initialized_db):
  """ Used by pytest-flask plugin to inject a custom app instance for testing. """
  app = Flask(__name__)
  login_manager = LoginManager(app)

  @app.errorhandler(model.DataModelException)
  def handle_dme(ex):
    response = jsonify({'message': ex.message})
    response.status_code = 400
    return response

  @login_manager.user_loader
  def load_user(user_uuid):
    return LoginWrappedDBUser(user_uuid)

  @identity_loaded.connect_via(app)
  def on_identity_loaded_for_test(sender, identity):
    on_identity_loaded(sender, identity)

  Principal(app, use_sessions=False)

  app.url_map.converters['regex'] = RegexConverter
  app.url_map.converters['apirepopath'] = APIRepositoryPathConverter
  app.url_map.converters['repopath'] = RepositoryPathConverter

  app.register_blueprint(api_bp, url_prefix='/api')
  app.register_blueprint(appr_bp, url_prefix='/cnr')
  app.register_blueprint(web, url_prefix='/')
  app.register_blueprint(verbs_bp, url_prefix='/c1')
  app.register_blueprint(v1_bp, url_prefix='/v1')
  app.register_blueprint(v2_bp, url_prefix='/v2')
  app.register_blueprint(webhooks, url_prefix='/webhooks')

  app.config.update(appconfig)

  Userfiles(app)
  Mail(app)

  return app