File indexing completed on 2024-05-05 03:55:01

 # SPDX-FileCopyrightText: 2021 Volker Krause <vkrause@kde.org>
 # SPDX-License-Identifier: LGPL-2.0-or-later
 
 import os
 import requests
 from qgis import *
 from qgis.core import *
 import time
 import zipfile
 from config import *
 
 # Download and unpack Shapefiles
 class LayerDownloadTask(QgsTask):
     def __init__(self, url, dest):
         super().__init__('Download Shapefile', QgsTask.CanCancel)
         self.url = url
         self.dest = dest
 
     def run(self):
         try:
             QgsMessageLog.logMessage(f"Downloading and unpacking {self.dest}...", LOG_CATEGORY, Qgis.Info)
             if not os.path.exists(self.dest):
                 r = requests.get(self.url)
                 if r.status_code < 400:
                     with open(self.dest, 'wb') as f:
                         f.write(r.content)
             with zipfile.ZipFile(self.dest, 'r') as z:
                 z.extractall('.')
             QgsMessageLog.logMessage(f"Downloaded and unpacked {self.dest}.", LOG_CATEGORY, Qgis.Info)
         except Exception as e:
             QgsMessageLog.logMessage(f"Exception in task: {e}", LOG_CATEGORY, Qgis.Critical)
         return True
 
 
 # Load and simplify Shapefile layers
 # Simplification is done to massively speed up geometry intersection computation
 # (for reference: the original KItinerary tz spatial index took 8h to compute without simplification,
 # and about 15 minutes with a Douglas Peucker simplification with a 0.001 threshold, with no practical
 # loss of precision
 class LoadLayerTask(QgsTask):
     def __init__(self, url, fileName, context, layerName):
         super().__init__(f"Loading layer {fileName}", QgsTask.CanCancel)
         self.layer = None
         self.url = url
         self.fileName = fileName
         self.context = context
         self.layerName = layerName
         self.downloadTask = LayerDownloadTask(url, fileName)
         self.addSubTask(self.downloadTask, [], QgsTask.ParentDependsOnSubTask)
 
     def run(self):
         QgsMessageLog.logMessage(f"Simplifying layer {self.fileName}", LOG_CATEGORY, Qgis.Info)
         fullLayer = QgsVectorLayer(self.fileName, f"{self.fileName}-full-resolution", 'ogr')
         if not fullLayer.isValid():
             QgsMessageLog.logMessage(f"Failed to load layer {self.fileName}!", LOG_CATEGORY, Qgis.Critical)
         result = processing.run('qgis:simplifygeometries', {'INPUT': fullLayer, 'METHOD': 0, 'TOLERANCE': 0.001, 'OUTPUT': 'TEMPORARY_OUTPUT' })
         self.layer = result['OUTPUT']
         self.layer.setName(f"{self.fileName}-simplified")
         self.context[self.layerName] = self.layer
         QgsMessageLog.logMessage(f"Simplified layer {self.fileName}", LOG_CATEGORY, Qgis.Info)
         return True
 
     def finished(self, result):
         QgsProject.instance().addMapLayer(self.layer)
 
 
 # Filter out too small elements in the ISO 3166-2 layer
 class Iso3166_2FilterTask(QgsTask):
     def __init__(self, context):
         super().__init__('Filtering ISO 3166-2 layer', QgsTask.CanCancel)
         self.context = context
 
     def run(self):
         QgsMessageLog.logMessage('Filtering ISO 3166-2 layer', LOG_CATEGORY, Qgis.Info)
         subdivLayer = self.context['subdivLayer']
         toBeRemoved = []
         for feature in subdivLayer.getFeatures():
             # sic: the key is really "admin_leve" in the input file, due to length restrictions in the Shapefile...
             level = feature['admin_leve']
             country = feature['ISO3166-2'][:2]
             if not isinstance(level, str) or not isinstance(country, str):
                 continue
             for filter in ISO3166_2_FILTER:
                 if int(level) == filter['admin_level'] and country == filter['country']:
                     toBeRemoved.append(feature.id())
                     break
         subdivLayer.dataProvider().deleteFeatures(toBeRemoved)
         return True
 
 
 # Setup all data layers we need
 class LoadLayersTask(QgsTask):
     def __init__(self, context):
         super().__init__('Loading layers...', QgsTask.CanCancel)
         self.context = context
         self.tasks = [
             LoadLayerTask(TZDATA_URL, f"timezones.shapefile-{TZDATA_VERSION}.zip", context, 'tzLayer'),
             LoadLayerTask(ISO3166_1_URL, f"iso3166-1-boundaries.shp-{ISO3166_1_VERSION}.zip", context, 'countryLayer'),
             LoadLayerTask(ISO3166_2_URL, f"iso3166-2-boundaries.shp-{ISO3166_2_VERSION}.zip", context, 'subdivLayer')
         ]
         for task in self.tasks:
             self.addSubTask(task, [], QgsTask.ParentDependsOnSubTask)
 
         self.filterTask = Iso3166_2FilterTask(context)
         self.addSubTask(self.filterTask, [self.tasks[2]], QgsTask.ParentDependsOnSubTask)
 
     def run(self):
         return True