try:
    from pydrive.auth import GoogleAuth
    from pydrive.drive import GoogleDrive
    from apiclient import errors
except ImportError:
    pass
import os

from ub import config

from sqlalchemy import *
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import *


import web


dbpath = os.path.join(os.path.normpath(os.path.dirname(os.path.realpath(__file__)) + os.sep + ".." + os.sep), "gdrive.db")
engine = create_engine('sqlite:///{0}'.format(dbpath), echo=False)
Base = declarative_base()

# Open session for database connection
Session = sessionmaker()
Session.configure(bind=engine)
session = scoped_session(Session)

class GdriveId(Base):
    __tablename__='gdrive_ids'

    id = Column(Integer, primary_key=True)
    gdrive_id = Column(Integer, unique=True)
    path = Column(String)
    __table_args__ = (UniqueConstraint('gdrive_id', 'path', name='_gdrive_path_uc'),)

    def __repr__(self):
        return str(self.path)

class PermissionAdded(Base):
    __tablename__='permissions_added'

    id = Column(Integer, primary_key=True)
    gdrive_id = Column(Integer, unique=True)

    def __repr__(self):
        return str(self.gdrive_id)

def migrate():
    if not engine.dialect.has_table(engine.connect(), "permissions_added"):
        PermissionAdded.__table__.create(bind = engine)
    for sql in session.execute("select sql from sqlite_master where type='table'"):
        if 'CREATE TABLE gdrive_ids' in sql[0]:
            currUniqueConstraint='UNIQUE (gdrive_id)'
            if currUniqueConstraint in sql[0]:
                sql=sql[0].replace(currUniqueConstraint, 'UNIQUE (gdrive_id, path)')
                sql=sql.replace(GdriveId.__tablename__, GdriveId.__tablename__+ '2')
                session.execute(sql)
                session.execute('INSERT INTO gdrive_ids2 (id, gdrive_id, path) SELECT id, gdrive_id, path FROM gdrive_ids;')
                session.commit()
                session.execute('DROP TABLE %s' % 'gdrive_ids')
                session.execute('ALTER TABLE gdrive_ids2 RENAME to gdrive_ids')
            break

if not os.path.exists(dbpath):
    try:
        Base.metadata.create_all(engine)
    except Exception:
        raise

migrate()

def getDrive(gauth=None):
    if not gauth:
        gauth=GoogleAuth(settings_file='settings.yaml')
    # Try to load saved client credentials
    gauth.LoadCredentialsFile("gdrive_credentials")
    if gauth.access_token_expired:
        # Refresh them if expired
        gauth.Refresh()
    else:
        # Initialize the saved creds
        gauth.Authorize()
    # Save the current credentials to a file
    return GoogleDrive(gauth)

def getEbooksFolder(drive=None):
    if not drive:
        drive = getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    ebooksFolder= "title = '%s' and 'root' in parents and mimeType = 'application/vnd.google-apps.folder' and trashed = false" % config.config_google_drive_folder

    fileList = drive.ListFile({'q': ebooksFolder}).GetList()
    return fileList[0]

def getEbooksFolderId(drive=None):
    storedPathName=session.query(GdriveId).filter(GdriveId.path == '/').first()
    if storedPathName:
        return storedPathName.gdrive_id
    else:
        gDriveId=GdriveId()
        gDriveId.gdrive_id=getEbooksFolder(drive)['id']
        gDriveId.path='/'
        session.merge(gDriveId)
        session.commit()
        return

def getFolderInFolder(parentId, folderName, drive=None):
    if not drive:
        drive = getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    folder= "title = '%s' and '%s' in parents and mimeType = 'application/vnd.google-apps.folder' and trashed = false"  % (folderName.replace("'", "\\'"), parentId)
    fileList = drive.ListFile({'q': folder}).GetList()
    return fileList[0]

def getFile(pathId, fileName, drive=None):
    if not drive:
        drive = getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    metaDataFile="'%s' in parents and trashed = false and title = '%s'" % (pathId, fileName.replace("'", "\\'"))

    fileList = drive.ListFile({'q': metaDataFile}).GetList()
    return fileList[0]

def getFolderId(path, drive=None):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    currentFolderId=getEbooksFolderId(drive)
    sqlCheckPath=path if path[-1] =='/' else path + '/'
    storedPathName=session.query(GdriveId).filter(GdriveId.path == sqlCheckPath).first()

    if not storedPathName:
        dbChange=False
        s=path.split('/')
        for i, x in enumerate(s):
            if len(x) > 0:
                currentPath="/".join(s[:i+1])
                if currentPath[-1] != '/':
                    currentPath = currentPath + '/'
                storedPathName=session.query(GdriveId).filter(GdriveId.path == currentPath).first()
                if storedPathName:
                    currentFolderId=storedPathName.gdrive_id
                else:
                    currentFolderId=getFolderInFolder(currentFolderId, x, drive)['id']
                    gDriveId=GdriveId()
                    gDriveId.gdrive_id=currentFolderId
                    gDriveId.path=currentPath
                    session.merge(gDriveId)
                    dbChange=True
        if dbChange:
            session.commit()
    else:
        currentFolderId=storedPathName.gdrive_id
    return currentFolderId


def getFileFromEbooksFolder(drive, path, fileName):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    if path:
        # sqlCheckPath=path if path[-1] =='/' else path + '/'
        folderId=getFolderId(path, drive)
    else:
        folderId=getEbooksFolderId(drive)

    return getFile(folderId, fileName, drive)

def copyDriveFileRemote(drive, origin_file_id, copy_title):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    copied_file = {'title': copy_title}
    try:
        file_data = drive.auth.service.files().copy(
        fileId=origin_file_id, body=copied_file).execute()
        return drive.CreateFile({'id': file_data['id']})
    except errors.HttpError as error:
        print ('An error occurred: %s' % error)
    return None

def downloadFile(drive, path, filename, output):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    f=getFileFromEbooksFolder(drive, path, filename)
    f.GetContentFile(output)

def backupCalibreDbAndOptionalDownload(drive, f=None):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    metaDataFile="'%s' in parents and title = 'metadata.db' and trashed = false" % getEbooksFolderId()

    fileList = drive.ListFile({'q': metaDataFile}).GetList()

    databaseFile=fileList[0]

    if f:
        databaseFile.GetContentFile(f)


def copyToDrive(drive, uploadFile, createRoot, replaceFiles,
        ignoreFiles=[],
        parent=None, prevDir=''):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    isInitial=not bool(parent)
    if not parent:
        parent=getEbooksFolder(drive)
    if os.path.isdir(os.path.join(prevDir,uploadFile)):
        existingFolder=drive.ListFile({'q' : "title = '%s' and '%s' in parents and trashed = false" % (os.path.basename(uploadFile), parent['id'])}).GetList()
        if len(existingFolder) == 0 and (not isInitial or createRoot):
            parent = drive.CreateFile({'title': os.path.basename(uploadFile), 'parents' : [{"kind": "drive#fileLink", 'id' : parent['id']}],
                "mimeType": "application/vnd.google-apps.folder" })
            parent.Upload()
        else:
            if (not isInitial or createRoot) and len(existingFolder) > 0:
                parent=existingFolder[0]
        for f in os.listdir(os.path.join(prevDir,uploadFile)):
            if f not in ignoreFiles:
                copyToDrive(drive, f, True, replaceFiles, ignoreFiles, parent, os.path.join(prevDir,uploadFile))
    else:
        if os.path.basename(uploadFile) not in ignoreFiles:
            existingFiles=drive.ListFile({'q' : "title = '%s' and '%s' in parents and trashed = false" % (os.path.basename(uploadFile), parent['id'])}).GetList()
            if len(existingFiles) > 0:
                driveFile=existingFiles[0]
            else:
                driveFile = drive.CreateFile({'title': os.path.basename(uploadFile), 'parents' : [{"kind": "drive#fileLink", 'id' : parent['id']}], })
            driveFile.SetContentFile(os.path.join(prevDir,uploadFile))
            driveFile.Upload()

def uploadFileToEbooksFolder(drive, destFile, f):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    parent=getEbooksFolder(drive)
    splitDir=destFile.split('/')
    for i, x in enumerate(splitDir):
        if i == len(splitDir)-1:
            existingFiles=drive.ListFile({'q' : "title = '%s' and '%s' in parents and trashed = false" % (x, parent['id'])}).GetList()
            if len(existingFiles) > 0:
                driveFile=existingFiles[0]
            else:
                driveFile = drive.CreateFile({'title': x, 'parents' : [{"kind": "drive#fileLink", 'id' : parent['id']}], })
            driveFile.SetContentFile(f)
            driveFile.Upload()
        else:
            existingFolder=drive.ListFile({'q' : "title = '%s' and '%s' in parents and trashed = false" % (x, parent['id'])}).GetList()
            if len(existingFolder) == 0:
                parent = drive.CreateFile({'title': x, 'parents' : [{"kind": "drive#fileLink", 'id' : parent['id']}],
                    "mimeType": "application/vnd.google-apps.folder" })
                parent.Upload()
            else:
                parent=existingFolder[0]


def watchChange(drive, channel_id, channel_type, channel_address,
              channel_token=None, expiration=None):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    # Watch for all changes to a user's Drive.
    # Args:
    # service: Drive API service instance.
    # channel_id: Unique string that identifies this channel.
    # channel_type: Type of delivery mechanism used for this channel.
    # channel_address: Address where notifications are delivered.
    # channel_token: An arbitrary string delivered to the target address with
    #               each notification delivered over this channel. Optional.
    # channel_address: Address where notifications are delivered. Optional.
    # Returns:
    # The created channel if successful
    # Raises:
    # apiclient.errors.HttpError: if http request to create channel fails.
    body = {
    'id': channel_id,
    'type': channel_type,
    'address': channel_address
    }
    if channel_token:
        body['token'] = channel_token
    if expiration:
        body['expiration'] = expiration
    return  drive.auth.service.changes().watch(body=body).execute()

def watchFile(drive, file_id, channel_id, channel_type, channel_address,
              channel_token=None, expiration=None):
    """Watch for any changes to a specific file.
    Args:
    service: Drive API service instance.
    file_id: ID of the file to watch.
    channel_id: Unique string that identifies this channel.
    channel_type: Type of delivery mechanism used for this channel.
    channel_address: Address where notifications are delivered.
    channel_token: An arbitrary string delivered to the target address with
                   each notification delivered over this channel. Optional.
    channel_address: Address where notifications are delivered. Optional.
    Returns:
    The created channel if successful
    Raises:
    apiclient.errors.HttpError: if http request to create channel fails.
    """
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()

    body = {
        'id': channel_id,
        'type': channel_type,
        'address': channel_address
    }
    if channel_token:
        body['token'] = channel_token
    if expiration:
        body['expiration'] = expiration
    return drive.auth.service.files().watch(fileId=file_id, body=body).execute()

def stopChannel(drive, channel_id, resource_id):
    """Stop watching to a specific channel.
    Args:
    service: Drive API service instance.
    channel_id: ID of the channel to stop.
    resource_id: Resource ID of the channel to stop.
    Raises:
    apiclient.errors.HttpError: if http request to create channel fails.
    """
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    # service=drive.auth.service
    body = {
    'id': channel_id,
    'resourceId': resource_id
    }
    return drive.auth.service.channels().stop(body=body).execute()

def getChangeById (drive, change_id):
    if not drive:
        drive=getDrive()
    if drive.auth.access_token_expired:
        drive.auth.Refresh()
    # Print a single Change resource information.
    #
    # Args:
    # service: Drive API service instance.
    # change_id: ID of the Change resource to retrieve.
    try:
        change = drive.auth.service.changes().get(changeId=change_id).execute()
        return change
    except errors.HttpError, error:
        web.app.logger.exception(error)
        return None
