#!/usr/bin/python

import sys

class Article:
    """Converts text files to HTML, for use in web pages.
    The output will not be a full HTML page, just the relevant HTML.
    
    The file:
    "Hello World.
    
    Paragraph 1.
    
    Paragraph 2.
    Another line."
    
    Would be converted to:
    "<h1>Hello World</h1>
    <p>Paragraph 1.</p>
    <p>Paragraph 2.<br/>
    Another line.</p>"
    
    All CSS should be done by the user, this would probably be made easy
     by encapsulating the article in a <div id='article> block.'"""
    def __init__(self, inFile):
        """Reads text from the files and then passes it through to the __parse() function"""
        try:
            textFile = open(inFile, 'r')
            self.text = textFile.read()
            textFile.close()
        except IOError:
            print "File failed to open or be read from, aborting."
            sys.exit(1)
        
        self.parse(self.text)
    
    def parse(self, text):
        """Splits text into paragraphs, calls __parseParagraph on each one, then joins them"""
        self.textParagraphs = self.text.strip().split('\n\n')
        self.htmlParagraphs = []
        for i in range(0, len(self.textParagraphs)):
            print "Parsing paragraph " + str(i+1)
            self.htmlParagraphs.append(self.__parseParagraph(self.textParagraphs[i]))
        
        self.html = "\n".join(self.htmlParagraphs)
    
    def __parseParagraph(self, paragraph):
        """Converts paragraph to HTML."""
        paragraph = '<p>' + paragraph.replace('\n', '<br/>\n')
        paragraph = self.__tagReplace(paragraph) + '</p>'
        return paragraph
    
    def __tagReplace(self, paragraph):
        """Converts BBCode to HTML"""
        tagStack, retParagraph = [], ""
        while 1:
            start = paragraph.find('[')
            if (start == -1):
                break
            retParagraph += paragraph[0:start]
            paragraph = paragraph.replace(paragraph[0:start], '')
            end = paragraph.find(']')
            tag = paragraph[1:end]
            if tag[0] == '\\':
                if tag[1:] != tagStack[-1]:
                    print "Unmatched " + '[' + tagStack.pop() + ']' + " tag, aborting."
                    print "Paragraphs contained: " + paragraph
                    sys.exit(1)
                else:
                    tagStack.pop()
            else:
                tagStack.append(tag)
            retParagraph += '<' + tag + '>'
            paragraph = paragraph.replace(paragraph[:end+1], '')
        retParagraph += paragraph
        while len(tagStack):
            tag = tagStack.pop()
            retParagraph += '<\\' + tag + '>'
        return retParagraph

if __name__ == "__main__":
    Test = Article('hello.txt')
    print Test.html