importKml.py

# -*- coding: utf-8 -*-
"""
/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
"""

import os
import re
from qgis.PyQt.QtCore import QObject, QVariant, QCoreApplication, QUrl, pyqtSignal
from qgis.PyQt.QtGui import QIcon

from qgis.core import (
    QgsCoordinateReferenceSystem, QgsPoint,
    QgsLineString, QgsMultiLineString, QgsPolygon, QgsMultiPolygon,
    QgsFeature, QgsGeometry, QgsFields, QgsField, QgsWkbTypes)

from qgis.core import (
    QgsProcessingAlgorithm,
    QgsProcessingParameterFile,
    QgsProcessingException,
    QgsProcessingParameterFeatureSink)

from zipfile import ZipFile
import xml.sax
import xml.sax.handler
# import traceback

epsg4326 = QgsCoordinateReferenceSystem("EPSG:4326")

def tr(string):
    return QCoreApplication.translate('Processing', string)

class ImportKmlAlgorithm(QgsProcessingAlgorithm):
    """
    Algorithm to import KML and KMZ files.
    """
    PrmInput = 'Input'
    PrmPointOutputLayer = 'PointOutputLayer'
    PrmLineOutputLayer = 'LineOutputLayer'
    PrmPolygonOutputLayer = 'PolygonOutputLayer'

    def initAlgorithm(self, config):
        self.addParameter(
            QgsProcessingParameterFile(
                self.PrmInput,
                tr('Import KML/KMZ file (*.kml, *.txt, or *.kmz)'))
        )
        self.addParameter(
            QgsProcessingParameterFeatureSink(
                self.PrmPointOutputLayer,
                tr('Output point layer'),
                optional=True)
        )
        self.addParameter(
            QgsProcessingParameterFeatureSink(
                self.PrmLineOutputLayer,
                tr('Output line layer'),
                optional=True)
        )
        self.addParameter(
            QgsProcessingParameterFeatureSink(
                self.PrmPolygonOutputLayer,
                tr('Output polygon layer'),
                optional=True)
        )

    def processAlgorithm(self, parameters, context, feedback):
        self.parameters = parameters
        self.context = context
        filename = self.parameterAsFile(parameters, self.PrmInput, context)
        f, extension = os.path.splitext(filename)
        extension = extension.lower()
        kmz_doc_file = 'doc.kml'
        try:
            if extension == '.kmz':
                kmz = ZipFile(filename, 'r')
                try:
                    kml = kmz.open(kmz_doc_file, 'r')
                except Exception:
                    # there was not a doc.kml file, lets see if there another kml file
                    files = kmz.namelist()
                    kmz_doc_file = None
                    for f in files:
                        if f.endswith('.kml'):
                            kmz_doc_file = f
                            break
                    if kmz_doc_file:
                        kml = kmz.open(kmz_doc_file, 'r')
                    else:
                        msg = "Couldn't find kml document in kmz file"
                        raise QgsProcessingException(msg)
                       
            elif extension == '.kml' or extension == '.txt':
                kml = open(filename, encoding="utf-8", errors="backslashreplace")
            else:
                msg = "Invalid extension: Should be *.kml, *.txt, or *.kmz."
                feedback.reportError(msg)
                raise QgsProcessingException(msg)
        except Exception:
            msg = "Failed to open file."
            raise QgsProcessingException(msg)

        skipPt = True if self.PrmPointOutputLayer not in parameters or parameters[self.PrmPointOutputLayer] is None else False
        skipline = True if self.PrmLineOutputLayer not in parameters or parameters[self.PrmLineOutputLayer] is None else False
        skipPoly = True if self.PrmPolygonOutputLayer not in parameters or parameters[self.PrmPolygonOutputLayer] is None else False
        self.cntPt = 0
        self.cntLine = 0
        self.cntPoly = 0
        parser = xml.sax.make_parser()
        # Do a pre-pass through the KML to see if there are any extended data fields
        preprocess = PreProcessHandler()
        parser.setContentHandler(preprocess)
        try:
            input_source = xml.sax.xmlreader.InputSource()
            input_source.setByteStream(kml)
            input_source.setEncoding('utf-8')
            parser.parse(input_source)
        except Exception:
            preprocess.endDocument()
        # Reset the KML/KMZ file to the beginning. The handler seems to automatically close the file
        # which is why we are reopening it.
        if extension == '.kmz':
            kmz.close()
        else:
            kml.close()
        if extension == '.kmz':
            kmz = ZipFile(filename, 'r')
            kml = kmz.open(kmz_doc_file, 'r')
        else:
            kml = open(filename, encoding="utf-8", errors="backslashreplace")

        # Set up the handler for doing the main processing
        self.extData = preprocess.getExtendedDataFields()
        self.extData.sort()
        self.extDataMap = {}
        index = 0
        for item in self.extData:
            self.extDataMap[item] = index
            index += 1
        handler = PlacemarkHandler(skipPt, skipline, skipPoly, self.extDataMap, feedback)
        handler.addpoint.connect(self.addpoint)
        handler.addline.connect(self.addline)
        handler.addpolygon.connect(self.addpolygon)
        parser.setContentHandler(handler)
        try:
            input_source = xml.sax.xmlreader.InputSource()
            input_source.setByteStream(kml)
            input_source.setEncoding('utf-8')
            parser.parse(input_source)
        except Exception:
            '''s = traceback.format_exc()
            feedback.pushInfo(s)'''
            feedback.pushInfo(tr('Failure in kml extraction - May return partial results.'))
            handler.endDocument()

        if extension == '.kmz':
            kmz.close()
        else:
            kml.close()
        
        if handler.hasGoundOverlay:
            feedback.pushInfo(tr('NOTICE: This file may contain GroundOverlay images.'))
            feedback.pushInfo(tr('Run "Raster->KML Tools->Extract KML/KMZ Ground Overlasys" to extract them if embedded.'))
            feedback.pushInfo('')

        feedback.pushInfo('{} points extracted'.format(self.cntPt))
        feedback.pushInfo('{} lines extracted'.format(self.cntLine))
        feedback.pushInfo('{} polygons extracted'.format(self.cntPoly))

        r = {}
        if self.cntPt > 0:
            r[self.PrmPointOutputLayer] = self.dest_id_pt
        if self.cntLine > 0:
            r[self.PrmLineOutputLayer] = self.dest_id_line
        if self.cntPoly > 0:
            r[self.PrmPolygonOutputLayer] = self.dest_id_poly

        return (r)

    def addpoint(self, feature):
        if self.cntPt == 0:
            f = QgsFields()
            f.append(QgsField("name", QVariant.String))
            f.append(QgsField("folders", QVariant.String))
            f.append(QgsField("description", QVariant.String))
            f.append(QgsField("altitude", QVariant.Double))
            f.append(QgsField("alt_mode", QVariant.String))
            f.append(QgsField("time_begin", QVariant.String))
            f.append(QgsField("time_end", QVariant.String))
            f.append(QgsField("time_when", QVariant.String))
            for item in self.extData:
                f.append(QgsField(item, QVariant.String))
            (self.sinkPt, self.dest_id_pt) = self.parameterAsSink(
                self.parameters,
                self.PrmPointOutputLayer, self.context, f,
                QgsWkbTypes.PointZ, epsg4326)

        self.cntPt += 1
        self.sinkPt.addFeature(feature)

    def addline(self, feature):
        if self.cntLine == 0:
            f = QgsFields()
            f.append(QgsField("name", QVariant.String))
            f.append(QgsField("folders", QVariant.String))
            f.append(QgsField("description", QVariant.String))
            f.append(QgsField("altitude", QVariant.Double))
            f.append(QgsField("alt_mode", QVariant.String))
            f.append(QgsField("time_begin", QVariant.String))
            f.append(QgsField("time_end", QVariant.String))
            f.append(QgsField("time_when", QVariant.String))
            for item in self.extData:
                f.append(QgsField(item, QVariant.String))
            (self.sinkLine, self.dest_id_line) = self.parameterAsSink(
                self.parameters,
                self.PrmLineOutputLayer, self.context, f,
                QgsWkbTypes.MultiLineStringZ, epsg4326)

        self.cntLine += 1
        self.sinkLine.addFeature(feature)

    def addpolygon(self, feature):
        if self.cntPoly == 0:
            f = QgsFields()
            f.append(QgsField("name", QVariant.String))
            f.append(QgsField("folders", QVariant.String))
            f.append(QgsField("description", QVariant.String))
            f.append(QgsField("altitude", QVariant.Double))
            f.append(QgsField("alt_mode", QVariant.String))
            f.append(QgsField("time_begin", QVariant.String))
            f.append(QgsField("time_end", QVariant.String))
            f.append(QgsField("time_when", QVariant.String))
            for item in self.extData:
                f.append(QgsField(item, QVariant.String))
            (self.sinkPoly, self.dest_id_poly) = self.parameterAsSink(
                self.parameters,
                self.PrmPolygonOutputLayer, self.context, f,
                QgsWkbTypes.MultiPolygonZ, epsg4326)
        self.cntPoly += 1
        self.sinkPoly.addFeature(feature)

    def name(self):
        return 'importkml'

    def icon(self):
        return QIcon(os.path.dirname(__file__) + '/icons/import.svg')

    def displayName(self):
        return tr('Import KML/KMZ')

    def group(self):
        return tr('Vector conversion')

    def groupId(self):
        return 'vectorconversion'

    def helpUrl(self):
        file = os.path.dirname(__file__) + '/index.html'
        if not os.path.exists(file):
            return ''
        return QUrl.fromLocalFile(file).toString(QUrl.FullyEncoded)

    def createInstance(self):
        return ImportKmlAlgorithm()

class PlacemarkHandler(xml.sax.handler.ContentHandler, QObject):
    addpoint = pyqtSignal(QgsFeature)
    addline = pyqtSignal(QgsFeature)
    addpolygon = pyqtSignal(QgsFeature)

    def __init__(self, skipPt, skipLine, skipPoly, extDataMap, feedback):
        QObject.__init__(self)
        xml.sax.handler.ContentHandler.__init__(self)
        self.schema = {}
        self.skipPt = skipPt
        self.skipLine = skipLine
        self.skipPoly = skipPoly
        self.extDataMap = extDataMap
        self.feedback = feedback
        self.extDataSize = len(extDataMap)
        self.hasGoundOverlay = False

        self.inPlacemark = False
        self.resetSettings()
        self.folders = []

    def resetSettings(self):
        '''Set all settings to a default new placemark.'''
        self.inFolder = False
        self.inName = False
        self.inDescription = False
        self.inCoordinates = False
        self.inLatitude = False
        self.inLongitude = False
        self.inAltitude = False
        self.inAltitudeMode = False
        self.inLocation = False
        self.inOuterBoundary = False
        self.inInnerBoundary = False
        self.inTimeSpan = False
        self.inBegin = False
        self.inEnd = False
        self.inTimeStamp = False
        self.inWhen = False
        self.inExtendedData = False
        self.inData = False
        self.inSimpleData = False
        self.inDataValue = False
        self.inPoint = False
        self.inLineString = False
        self.inPolygon = False
        self.lineStrings = []  # List of QgsLineString
        self.ptPts = []
        self.ptAltitude = []
        self.polygons = []
        self.innerPoly = []
        self.outerPoly = ""
        self.folder = ""
        self.name = ""
        self.description = ""
        self.coord = ""
        self.lon = ""
        self.lat = ""
        self.altitude = ""
        self.altitudeMode = ""
        self.begin = ""
        self.end = ""
        self.when = ""
        self.dataName = None
        self.dataValue = ""
        self.extendedData = {}

    def schemaBaseLookup(self, name):
        if name in self.schema:
            return(self.schema[name])
        return(name)

    def addSchema(self, name, parent):
        parent = self.schemaBaseLookup(parent)
        self.schema[name] = parent

    def startElement(self, name, attr):
        if name.startswith('kml:'):
            name = name[4:]
        if name == "Schema":
            n = None
            p = None
            for (k, v) in list(attr.items()):
                if k == 'name':
                    n = v
                if k == 'parent':
                    p = v
                if n and p:
                    self.addSchema(n, p)

        name = self.schemaBaseLookup(name)

        if name == "Folder":
            self.inFolder = True
            self.name = ""

        elif self.inFolder and not self.inPlacemark and name == "name":
            self.inName = True
            self.name = ""

        elif name == "Placemark":
            self.inPlacemark = True
            self.resetSettings()

        elif self.inPlacemark:
            if name == "Point":
                self.inPoint = True
            elif name == "LineString":
                self.inLineString = True
            elif name == "Polygon":
                self.inPolygon = True
            elif name == "Location":
                self.inLocation = True
            elif name == "name":
                self.inName = True
                self.name = ""
            elif name == "description":
                self.inDescription = True
                self.description = ""
            elif name == "coordinates":
                self.inCoordinates = True
                self.coord = ""
            elif name == "outerBoundaryIs":
                self.inOuterBoundary = True
                self.coord = ""
            elif name == "innerBoundaryIs":
                self.inInnerBoundary = True
                self.coord = ""
            elif name == "TimeSpan":
                self.inTimeSpan = True
            elif name == "TimeStamp":
                self.inTimeStamp = True
            elif name == "begin":
                self.inBegin = True
            elif name == "end":
                self.inEnd = True
            elif name == "when":
                self.inWhen = True
            elif name == "longitude" and self.inLocation:
                self.inLongitude = True
                self.lon = ""
            elif name == "latitude" and self.inLocation:
                self.inLatitude = True
                self.lat = ""
            elif name == "altitude" and self.inLocation:
                self.inAltitude = True
                self.altitude = ""
            elif name == "altitudeMode":
                self.inAltitudeMode = True
                self.altitudeMode = ""
            elif name == "Data" and self.inExtendedData:
                self.inData = True
                self.dataName = None
                for (k, v) in list(attr.items()):
                    if k == 'name':
                        self.dataName = v
            elif name == "SimpleData" and self.inExtendedData:
                self.inSimpleData = True
                self.dataName = None
                for (k, v) in list(attr.items()):
                    if k == 'name':
                        self.dataName = v
            elif name == 'value' and self.inData:
                self.inDataValue = True
            elif name == "ExtendedData":
                self.inExtendedData = True

        elif name == 'GroundOverlay':
            self.hasGoundOverlay = True

    def characters(self, data):
        if self.inName:  # on text within tag
            self.name += data  # save text if in title
        elif self.inDescription:
            self.description += data
        elif self.inCoordinates:
            self.coord += data
        elif self.inLongitude and self.inLocation:
            self.lon += data
        elif self.inLatitude and self.inLocation:
            self.lat += data
        elif self.inAltitude and self.inLocation:
            self.altitude += data
        elif self.inBegin and self.inTimeSpan:
            self.begin += data
        elif self.inEnd and self.inTimeSpan:
            self.end += data
        elif self.inWhen and self.inTimeStamp:
            self.when += data
        elif self.inAltitudeMode:
            self.altitudeMode += data
        elif self.inDataValue:
            self.dataValue += data
        elif self.inSimpleData:
            self.dataValue += data

    def endElement(self, name):
        if name.startswith('kml:'):
            name = name[4:]
        name = self.schemaBaseLookup(name)
        if self.inPlacemark:
            if name == "name":
                self.inName = False  # on end title tag
                self.name = self.name.strip()
            elif name == "description":
                self.inDescription = False
                self.description = self.description.strip()
            elif name == "Point":
                self.processPoint(self.coord)
                self.inPoint = False
            elif name == "LineString":
                self.processLineString(self.coord)
                self.inLineString = False
            elif name == "coordinates":
                self.inCoordinates = False
                if self.inPolygon:
                    if self.inOuterBoundary:
                        self.outerPoly = self.coord.strip()
                    elif self.inInnerBoundary:
                        self.innerPoly.append(self.coord.strip())
                else:
                    self.coord = self.coord.strip()
            elif name == "longitude" and self.inLocation:
                self.inLongitude = False
                self.lon = self.lon.strip()
            elif name == "latitude" and self.inLocation:
                self.inLatitude = False
                self.lat = self.lat.strip()
            elif name == "altitude" and self.inLocation:
                self.inAltitude = False
                self.altitude = self.altitude.strip()
            elif name == "Location":
                self.processLocation(self.lon, self.lat, self.altitude)
                self.inLocation = False
                self.inLongitude = False
                self.inLatitude = False
                self.inAltitude = False
            elif name == "Polygon":
                self.processPolygon()
                self.inPolygon = False
                self.inOuterBoundary = False
                self.inInnerBoundary = False
                self.outerPoly = ""
                self.innerPoly = []
            elif name == "outerBoundaryIs":
                self.inOuterBoundary = False
            elif name == "innerBoundaryIs":
                self.inInnerBoundary = False
            elif name == "TimeSpan":
                self.inTimeSpan = False
            elif name == "TimeStamp":
                self.inTimeStamp = False
            elif name == "begin":
                self.inBegin = False
            elif name == "end":
                self.inEnd = False
            elif name == "when":
                self.inWhen = False
            elif name == "altitudeMode":
                self.inAltitudeMode = False
            elif name == "Placemark":
                self.process(self.name, self.description, self.altitudeMode, self.begin, self.end, self.when)
                self.inPlacemark = False
                self.resetSettings()
            elif name == 'Data' and self.inExtendedData:
                self.inData = False
            elif name == 'SimpleData' and self.inExtendedData:
                self.inSimpleData = False
                if self.dataName:
                    self.extendedData[self.dataName] = self.dataValue.strip()
                self.dataValue = ''
            elif name == 'value' and self.inData:
                if self.dataName:
                    self.extendedData[self.dataName] = self.dataValue.strip()
                self.inDataValue = False
                self.dataValue = ''
            elif name == 'ExtendedData':
                self.inExtendedData = False
                self.inData = False
        elif name == 'Folder':
            self.inFolder = False
            if len(self.folders) > 0:
                del self.folders[-1]
        elif self.inFolder:
            if name == 'name':
                self.inName = False  # on end title tag
                self.inFolder = False
                self.name = self.name.strip()
                self.folders.append(self.name)

    def folderString(self):
        if len(self.folders) > 0:
            return(u"; ".join(self.folders))
        else:
            return("")

    def processLineString(self, coord):
        if self.skipLine:
            return
        lineStr = coord2ptsZ(coord)
        self.lineStrings.append(lineStr)

    def processPoint(self, coord):
        if self.skipPt:
            return

        c = coord.split(',')
        lat = 0.0
        lon = 0.0
        altitude = 0.0
        try:
            lon = float(c[0])
            lat = float(c[1])
            if len(c) >= 3:
                altitude = float(c[2])
        except Exception:
            return
        pt = QgsPoint(lon, lat, altitude)
        self.ptPts.append(pt)
        self.ptAltitude.append(altitude)

    def processLocation(self, lon, lat, altitude):
        if self.skipPt:
            return

        try:
            lon = float(lon)
            lat = float(lat)
        except Exception:
            return
        altitude = 0.0
        try:
            if altitude:
                altitude = float(altitude)
        except Exception:
            pass
        pt = QgsPoint(lon, lat, altitude)
        self.ptPts.append(pt)
        self.ptAltitude.append(altitude)

    def processPolygon(self):
        if self.skipPoly:
            return
        interior_ring = []
        poly = QgsPolygon()
        outerLineStr = coord2ptsZ(self.outerPoly)
        poly.setExteriorRing(outerLineStr)
        if len(self.innerPoly) > 0:
            for p in self.innerPoly:
                innerLineStr = coord2ptsZ(p)
                interior_ring.append(innerLineStr)
            poly.setInteriorRings(interior_ring)
        self.polygons.append(poly)

    def process(self, name, desc, alt_mode, begin, end, when):
        if self.extDataSize > 0:
            extAttr = [''] * self.extDataSize
        for key in self.extendedData.keys():
            if key in self.extDataMap:
                extAttr[self.extDataMap[key]] = self.extendedData[key]
        # POINTS
        if len(self.ptPts) != 0:
            for x, pt in enumerate(self.ptPts):
                feature = QgsFeature()
                feature.setGeometry(QgsGeometry(pt))
                attr = [name, self.folderString(), desc, self.ptAltitude[x], alt_mode, begin, end, when]
                if self.extDataSize > 0:
                    attr.extend(extAttr)
                feature.setAttributes(attr)
                self.addpoint.emit(feature)

        # LINES - lineStrings is a list of QgsLineString
        if len(self.lineStrings) != 0:
            feature = QgsFeature()
            if len(self.lineStrings) == 1:
                feature.setGeometry(QgsGeometry(self.lineStrings[0]))
            else:
                g = QgsMultiLineString()
                for lineStr in self.lineStrings:
                    g.addGeometry(lineStr)
                feature.setGeometry(QgsGeometry(g))
            attr = [name, self.folderString(), desc, 0, alt_mode, begin, end, when]
            if self.extDataSize > 0:
                attr.extend(extAttr)
            feature.setAttributes(attr)
            self.addline.emit(feature)

        # POLYGONS
        if len(self.polygons) != 0:
            feature = QgsFeature()
            if len(self.polygons) == 1:
                feature.setGeometry(QgsGeometry(self.polygons[0]))
            else:
                g = QgsMultiPolygon()
                for poly in self.polygons:
                    g.addGeometry(poly)
                feature.setGeometry(QgsGeometry(g))
            attr = [name, self.folderString(), desc, 0, alt_mode, begin, end, when]
            if self.extDataSize > 0:
                attr.extend(extAttr)
            feature.setAttributes(attr)
            self.addpolygon.emit(feature)

def coord2ptsZ(coords):
    lineStr = QgsLineString()
    coords = coords.strip()
    clist = re.split('\s+', coords)

    for pt in clist:
        c = pt.split(',')
        if len(c) >= 6:
            '''This is invalid KML syntax, but given some KMLs have been formatted
            this way the invalid exception is looked for. There should be a space
            between line string coordinates. This looks for a comma between them and
            also assumes it is formatted as lat,lon,altitude,lat,lon,altitude...'''
            i = 0
            while i < len(c) - 1:
                try:
                    lon = float(c[i])
                    lat = float(c[i + 1])
                except Exception:
                    lon = 0.0
                    lat = 0.0
                try:
                    altitude = float(c[i + 2])
                except Exception:
                    altitude = 0
                lineStr.addVertex(QgsPoint(lon, lat, altitude))
                i += 3
        else:
            altitude = 0
            try:
                lon = float(c[0])
                lat = float(c[1])
                if len(c) >= 3:
                    altitude = float(c[2])
            except Exception:
                lon = 0.0
                lat = 0.0

            lineStr.addVertex(QgsPoint(lon, lat, altitude))

    return(lineStr)

class PreProcessHandler(xml.sax.handler.ContentHandler, QObject):
    def __init__(self):
        QObject.__init__(self)
        xml.sax.handler.ContentHandler.__init__(self)

        self.extendedData = set()
        self.inExtendedData = False

    def startElement(self, name, attr):

        if name == "Data" and self.inExtendedData:
            self.dataName = None
            for (k, v) in list(attr.items()):
                if k == 'name':
                    if v:
                        self.extendedData.add(v)
        elif name == "SimpleData" and self.inExtendedData:
            self.dataName = None
            for (k, v) in list(attr.items()):
                if k == 'name':
                    if v:
                        self.extendedData.add(v)
        elif name == "ExtendedData":
            self.inExtendedData = True

    def endElement(self, name):
        if name == 'ExtendedData':
            self.inExtendedData = False

    def getExtendedDataFields(self):
        return(list(self.extendedData))