# -*- coding: utf-8 -*-

"""
***************************************************************************
    ImportIntoPostGIS.py
    ---------------------
    Date                 : October 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf at gmail dot com
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = 'Victor Olaya'
__date__ = 'October 2012'
__copyright__ = '(C) 2012, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

import os
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import \
        GeoAlgorithmExecutionException
from processing.parameters.ParameterBoolean import ParameterBoolean
from processing.parameters.ParameterVector import ParameterVector
from processing.parameters.ParameterString import ParameterString
from processing.parameters.ParameterSelection import ParameterSelection
from processing.parameters.ParameterTableField import ParameterTableField
from processing.tools import dataobjects
from processing.algs.qgis import postgis_utils


class ImportIntoPostGIS(GeoAlgorithm):

    DATABASE = 'DATABASE'
    TABLENAME = 'TABLENAME'
    SCHEMA = 'SCHEMA'
    INPUT = 'INPUT'
    OVERWRITE = 'OVERWRITE'
    CREATEINDEX = 'CREATEINDEX'
    GEOMETRY_COLUMN = 'GEOMETRY_COLUMN'
    LOWERCASE_NAMES = 'LOWERCASE_NAMES'
    DROP_STRING_LENGTH = 'DROP_STRING_LENGTH'
    PRIMARY_KEY = 'PRIMARY_KEY'

    def processAlgorithm(self, progress):
        connection = self.DB_CONNECTIONS[self.getParameterValue(self.DATABASE)]
        schema = self.getParameterValue(self.SCHEMA)
        overwrite = self.getParameterValue(self.OVERWRITE)
        createIndex = self.getParameterValue(self.CREATEINDEX)
        convertLowerCase = self.getParameterValue(self.LOWERCASE_NAMES)
        dropStringLength = self.getParameterValue(self.DROP_STRING_LENGTH)
        primaryKeyField = self.getParameterValue(self.PRIMARY_KEY)
        settings = QSettings()
        mySettings = '/PostgreSQL/connections/' + connection
        try:
            database = settings.value(mySettings + '/database')
            username = settings.value(mySettings + '/username')
            host = settings.value(mySettings + '/host')
            port = settings.value(mySettings + '/port', type=int)
            password = settings.value(mySettings + '/password')
        except Exception, e:
            raise GeoAlgorithmExecutionException(
                    'Wrong database connection name: ' + connection)

        table = self.getParameterValue(self.TABLENAME)
        table.replace(' ', '')
        providerName = 'postgres'

        try:
            db = postgis_utils.GeoDB(host=host, port=port, dbname=database,
                                     user=username, passwd=password)
        except postgis_utils.DbError, e:
            raise GeoAlgorithmExecutionException(
                    "Couldn't connect to database:\n" + e.message)

        geomColumn = self.getParameterValue(self.GEOMETRY_COLUMN)
        if not geomColumn:
            geomColumn = 'the_geom'

        options = {}
        if overwrite:
            options['overwrite'] = True
        if convertLowerCase:
            options['lowercaseFieldNames'] = True
            geomColumn = geomColumn.lower()
        if dropStringLength:
            options['dropStringConstraints'] = True

        uri = QgsDataSourceURI()
        uri.setConnection(host, str(port), database, username, password)
        if primaryKeyField:
            uri.setDataSource(schema, table, geomColumn, '', primaryKeyField)
        else:
            uri.setDataSource(schema, table, geomColumn, '')

        layerUri = self.getParameterValue(self.INPUT)
        layer = dataobjects.getObjectFromUri(layerUri)
        (ret, errMsg) = QgsVectorLayerImport.importLayer(
            layer,
            uri.uri(),
            providerName,
            self.crs,
            False,
            False,
            options,
            )
        if ret != 0:
            raise GeoAlgorithmExecutionException(
                    'Error importing to PostGIS\n%s' % errMsg)

        if createIndex:
            db.create_spatial_index(table, schema, geomColumn)

        db.vacuum_analyze(table, schema)

    def dbConnectionNames(self):
        settings = QSettings()
        settings.beginGroup('/PostgreSQL/connections/')
        return settings.childGroups()

    def defineCharacteristics(self):
        self.name = 'Import into PostGIS'
        self.group = 'Database'
        self.addParameter(ParameterVector(self.INPUT, 'Layer to import'))

        self.DB_CONNECTIONS = self.dbConnectionNames()
        self.addParameter(ParameterSelection(self.DATABASE, 'Database (connection name)',
                          self.DB_CONNECTIONS))

        self.addParameter(ParameterString(self.SCHEMA, 'Schema (schema name)'))
        self.addParameter(ParameterString(self.TABLENAME, 'Table to import to'
                          ))
        self.addParameter(ParameterTableField(self.PRIMARY_KEY, 'Primary key field',
                          self.INPUT, optional=True))
        self.addParameter(ParameterString(self.GEOMETRY_COLUMN, 'Geometry column', 'geom'
                          ))
        self.addParameter(ParameterBoolean(self.OVERWRITE, 'Overwrite', True))
        self.addParameter(ParameterBoolean(self.CREATEINDEX,
                          'Create spatial index', True))
        self.addParameter(ParameterBoolean(self.LOWERCASE_NAMES,
                          'Convert field names to lowercase', True))
        self.addParameter(ParameterBoolean(self.DROP_STRING_LENGTH,
                          'Drop length constraints on character fields', False))