import os
from SupportedType import SupportedType
from xml.dom import Node
from xml.dom.ext.reader.Sax import FromXmlFile

"""
This class parses all of the information in the config file, and makes
it available through various methods.
"""

class XmlDataParser:
    
    def __init__(self, xml_file_path):
        self.__supported_types = []

        xml_doc = FromXmlFile(xml_file_path)

        supported_type_elements = xml_doc.getElementsByTagName('supported_type')
        
        for current_node in supported_type_elements:
            name = self.GetChildrenText(current_node, 'name')[0]
            descriptions = self.GetChildrenText(current_node, 'description')
            extensions = self.GetChildrenText(current_node, 'extension')
            template_files = self.GetChildrenText(current_node, 'template_file')        
            template_data = self.GetChildrenText(current_node, 'template_data')
            
            current_type = SupportedType()
            current_type.SetName(name)
            current_type.SetExtensions(extensions)

            if (len(descriptions) > 0):
                current_type.SetDescription(descriptions[0])

                
            if (len(template_files) > 0):
                # Allow for relative paths in the template field
                root_dir = os.path.dirname(xml_file_path)
                template_file_path = os.path.join(root_dir, template_files[0])
                current_type.SetTemplateFile(template_file_path)

                       
            if (len(template_data) > 0):
                current_type.SetTemplateData(template_data[0])

            self.__supported_types.append(current_type)

        return



    def GetAllExtensions(self):
        all_extensions = []
        
        for current_type in self.__supported_types:
            current_type_extensions = current_type.GetExtensions()
            for extension in current_type_extensions:
                all_extensions.append(extension)

        return all_extensions

    
        
    def GetTemplateByExtension(self, extension):
        # Get the (x)html template which corresponds to a mimetype
        # having the supplied extension.
        for current_type in self.__supported_types:
            current_type_extensions = current_type.GetExtensions()

            for current_extension in current_type_extensions:
                if (current_extension.lower() == extension.lower()):
                    return current_type.GetTemplate()
            
        return None



    def GetNameByExtension(self, extension):
        # Get the name of the mimetype that a particular extension
        # belongs to.
        for current_type in self.__supported_types:
            current_type_extensions = current_type.GetExtensions()

            for current_extension in current_type_extensions:
                if (current_extension.lower() == extension.lower()):
                    return current_type.GetName()
            
        return None

    
            
    def GetChildNodesByTagName(self, node, tag_name):
        found_children = []
        
        for child in node.childNodes:
            if (child.nodeName == tag_name):
                found_children.append(child)

        return found_children



    
    def GetChildrenText(self, node, child_tag_name):
        children_text = []
        
        children = self.GetChildNodesByTagName(node, child_tag_name)

        for child_node in children:
            for sub_child in child_node.childNodes:
                if (sub_child.nodeType == Node.TEXT_NODE):
                    children_text.append(sub_child.nodeValue)
                    break

                
        return children_text