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

"""
/***************************************************************************
Name                 : Virtual layers plugin for DB Manager
Date                 : December 2015
copyright            : (C) 2015 by Hugo Mercier
email                : hugo dot mercier at oslandia 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.                                   *
 *                                                                         *
 ***************************************************************************/
"""

from ..data_model import TableDataModel, BaseTableModel

from .connector import VLayerRegistry, getQueryGeometryName
from .plugin import LVectorTable
from ..plugin import DbError

from PyQt4.QtCore import QUrl, QTime, QTemporaryFile
from qgis.core import QGis, QgsVectorLayer


class LTableDataModel(TableDataModel):

    def __init__(self, table, parent=None):
        TableDataModel.__init__(self, table, parent)

        self.layer = None

        if isinstance(table, LVectorTable):
            self.layer = VLayerRegistry.instance().getLayer(table.name)
        else:
            self.layer = VLayerRegistry.instance().getLayer(table)

        if not self.layer:
            return
        # populate self.resdata
        self.resdata = []
        for f in self.layer.getFeatures():
            self.resdata.append(f.attributes())

        self.fetchedFrom = 0
        self.fetchedCount = len(self.resdata)

    def rowCount(self, index=None):
        if self.layer:
            return self.layer.featureCount()
        return 0


class LSqlResultModel(BaseTableModel):
    # BaseTableModel

    def __init__(self, db, sql, parent=None):
        # create a virtual layer with non-geometry results
        q = QUrl.toPercentEncoding(sql)
        t = QTime()
        t.start()

        tf = QTemporaryFile()
        tf.open()
        tmp = tf.fileName()
        tf.close()

        p = QgsVectorLayer("%s?query=%s" % (QUrl.fromLocalFile(tmp).toString(), q), "vv", "virtual")
        self._secs = t.elapsed() / 1000.0

        if not p.isValid():
            data = []
            header = []
            raise DbError(p.dataProvider().error().summary(), sql)
        else:
            header = [f.name() for f in p.fields()]
            has_geometry = False
            if p.geometryType() != QGis.WKBNoGeometry:
                gn = getQueryGeometryName(tmp)
                if gn:
                    has_geometry = True
                    header += [gn]

            data = []
            for f in p.getFeatures():
                a = f.attributes()
                if has_geometry:
                    if f.geometry():
                        a += [f.geometry().exportToWkt()]
                    else:
                        a += [None]
                data += [a]

        self._secs = 0
        self._affectedRows = len(data)

        BaseTableModel.__init__(self, header, data, parent)

    def secs(self):
        return self._secs

    def affectedRows(self):
        return self._affectedRows