#!/usr/bin/env python
# -*- coding: utf-8 -
#
# This file is part of gunicorn released under the MIT license. 
# See the NOTICE for more information.

from __future__ import with_statement

import codecs
import datetime
import os
import sys

from docutils.core import publish_parts
from jinja2 import Environment
from jinja2.loaders import FileSystemLoader
from jinja2.utils import open_if_exists

import conf

class Site(object):    
    def __init__(self):
        self.url = conf.SITE_URL.rstrip('/')

        fs_loader = FileSystemLoader(conf.TEMPLATES_PATH, encoding="utf-8")
        self.env = Environment(loader=fs_loader)
        self.env.charset = 'utf-8'
        self.env.filters['rel_url'] = self.rel_url

    def rel_url(self, value):
        return value.split(self.url)[1]

    def render(self):
        for curr_path, dirs, files in os.walk(conf.INPUT_PATH):
            tgt_path = curr_path.replace(conf.INPUT_PATH, conf.OUTPUT_PATH)
            if not os.path.isdir(tgt_path):
                os.makedirs(tgt_path)
            self.process(files, curr_path, tgt_path)

    def process(self, files, curr_path, tgt_path):
        for f in files:
            page = Page(self, f, curr_path, tgt_path)
            if not page.needed():
                continue

            print "Page: %s" % page.source
            page.write()
            
    def get_template(self, name):
        return self.env.get_template(name)

class Page(object):
    
    def __init__(self, site, filename, curr_path, tgt_path):
        self.site = site
        self.filename = filename
        self.source = os.path.join(curr_path, filename)
        self.headers = {}
        self.body = ""

        with open(self.source, 'Ur') as handle:
            raw = handle.read()
        
        try:
            headers, body = raw.split("\n\n", 1)
        except ValueError:
            headers, body = "", raw

        try:
            for line in headers.splitlines():
                name, value = line.split(':', 1)
                self.headers[name.strip()] = value.strip()
        except ValueError:
            self.headers = {}
            body = "\n\n".join([headers, body])
        self.headers['pubDate'] = ctime = os.stat(self.source).st_ctime
        self.headers['published'] = datetime.datetime.fromtimestamp(ctime)

        basename, oldext = os.path.splitext(filename)
        oldext = oldext.lower()[1:]
        converter = getattr(self, "convert_%s" % oldext, lambda x: x)
        self.body = converter(body)

        newext = self.headers.get('ext', '.html')
        self.target = os.path.join(tgt_path, "%s%s" % (basename, newext))
                
    def url(self):
        path = self.target.split(conf.OUTPUT_PATH)[1].lstrip('/')
        return "/".join([self.site.url, path])

    def needed(self):
        for f in "force --force -f":
            if f in sys.argv[1:]:
                return True
        
        if not os.path.exists(self.target):
            return True
        
        smtime = os.stat(self.source).st_mtime
        tmtime = os.stat(self.target).st_mtime
        return smtime > tmtime

    def write(self):
        contents = self.render()
        with codecs.open(self.target, 'w', 'utf-8') as tgt:
            tgt.write(contents)

    def render(self):
        tmpl_name = self.headers.get('template')
        if not tmpl_name:
            return self.body

        kwargs = {"conf": conf, "body": self.body, "url": self.url()}
        kwargs.update(self.headers)
        return self.site.get_template(tmpl_name).render(kwargs)

    def convert_rst(self, body):
        parts = publish_parts(source=body, writer_name="html")
        return parts['html_body']

def main():
    Site().render()
    
if __name__ == "__main__":
    main()