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

# Copyright (c) 2012 - 2018 Detlev Offenbach <detlev@die-offenbachs.de>
#


"""
Module implementing a class to read speed dial data files.
"""

from __future__ import unicode_literals

from PyQt5.QtCore import QXmlStreamReader, QIODevice, QFile, QCoreApplication


class SpeedDialReader(QXmlStreamReader):
    """
    Class implementing a reader object for speed dial data files.
    """
    def __init__(self):
        """
        Constructor
        """
        super(SpeedDialReader, self).__init__()
    
    def read(self, fileNameOrDevice):
        """
        Public method to read a user agent file.
        
        @param fileNameOrDevice name of the file to read (string)
            or reference to the device to read (QIODevice)
        @return list of speed dial pages (list of Page), number of pages per
            row (integer) and size of the speed dial pages (integer)
        """
        self.__pages = []
        self.__pagesPerRow = 0
        self.__sdSize = 0
        
        if isinstance(fileNameOrDevice, QIODevice):
            self.setDevice(fileNameOrDevice)
        else:
            f = QFile(fileNameOrDevice)
            if not f.exists():
                return self.__pages, self.__pagesPerRow, self.__sdSize
            opened = f.open(QFile.ReadOnly)
            if not opened:
                self.raiseError(QCoreApplication.translate(
                    "SpeedDialReader",
                    "The file {0} could not be opened. Error: {1}").format(
                    fileNameOrDevice, f.errorString()))
                return self.__pages, self.__pagesPerRow, self.__sdSize
            self.setDevice(f)
        
        while not self.atEnd():
            self.readNext()
            if self.isStartElement():
                version = self.attributes().value("version")
                if self.name() == "SpeedDial" and \
                   (not version or version == "1.0"):
                    self.__readSpeedDial()
                else:
                    self.raiseError(QCoreApplication.translate(
                        "SpeedDialReader",
                        "The file is not a SpeedDial version 1.0 file."))
        
        return self.__pages, self.__pagesPerRow, self.__sdSize
    
    def __readSpeedDial(self):
        """
        Private method to read the speed dial data.
        """
        if not self.isStartElement() and self.name() != "SpeedDial":
            return
        
        while not self.atEnd():
            self.readNext()
            if self.isEndElement():
                if self.name() in ["Pages", "Page"]:
                    continue
                else:
                    break
            
            if self.isStartElement():
                if self.name() == "Pages":
                    attributes = self.attributes()
                    pagesPerRow = attributes.value("row")
                    if pagesPerRow.isdigit():
                        self.__pagesPerRow = int(pagesPerRow)
                    sdSize = attributes.value("size")
                    if sdSize.isdigit():
                        self.__sdSize = int(sdSize)
                elif self.name() == "Page":
                    attributes = self.attributes()
                    url = attributes.value("url")
                    title = attributes.value("title")
                    if url:
                        if not title:
                            title = url
                        from .Page import Page
                        page = Page(url, title)
                        self.__pages.append(page)
                else:
                    self.__skipUnknownElement()
    
    def __skipUnknownElement(self):
        """
        Private method to skip over all unknown elements.
        """
        if not self.isStartElement():
            return
        
        while not self.atEnd():
            self.readNext()
            if self.isEndElement():
                break
            
            if self.isStartElement():
                self.__skipUnknownElement()
