#!/usr/bin/env python

import os.path, fnmatch
import optparse, logging

from rrdweb import graph, html


def parse_args (args) :
    global options

    parser = optparse.OptionParser(
        usage   = "%prog [options] <target> [...]"
    )

    parser.add_option('-R', "--rrd-dir", default="rrd", help="Path to directory containing .rrd files")
    parser.add_option('-I', "--img-dir", default="img", help="Path to directory containing .png files")
    parser.add_option('-W', "--web-dir", default="web", help="Path to directory containing .html files")
    parser.add_option('-T', "--tpl-dir", default="templates", help="Path to directory containing .html templates files")
    parser.add_option('-P', "--url-prefix", default="", help="Prefix for URLs")
    parser.add_option(      "--img-url", default="img", help="URL to directory containing .png files")
    parser.add_option(      "--web-url", default="web", help="URL to directory containing .html files")
    
    options, targets = parser.parse_args(args)
    
    return targets

def setup_img_dir (style, interval) :
    """
        Generate output dir for given name
    """

    base_dir = options.img_dir
    style_dir = os.path.join(base_dir, style)
    interval_dir = os.path.join(base_dir, style, interval)

    if not os.path.exists(options.img_dir) :
        raise Exception("img_dir does not exist: " + options.img_dir)
    

    if not os.path.exists(style_dir) :
        logging.warn("Create img_dir for style=%s: %s" % (style, style_dir))
        os.mkdir(style_dir)

    if not os.path.exists(interval_dir) :
        logging.warn("Create img_dir for style=%s, interval=%s: %s" % (style, interval, interval_dir))
        os.mkdir(interval_dir)

def setup_dirs () :
    """
        Generate output dirs
    """

    setup_img_dir("overview", "daily")

    for interval in ("daily", "weekly", "yearly") :
        setup_img_dir("detail", interval)

def target_graph (target, style, interval) : 
    """
        Generate .rrd -> .png for given target
    """

    # XXX: title..
    title = target

    # compose paths
    rrd_path = os.path.join(options.rrd_dir, target) + '.rrd'
    out_path = os.path.join(options.img_dir, style, interval, target) + '.png'

    # graph
    graph.mrtg(style, interval, title, rrd_path, out_path)

def target_html (target, formatter) :
    """
        Generate .html for given target
    """

    # XXX: title..
    title = target
    
    # build paths
    html_path = os.path.join(options.web_dir, target + '.html')
    
    # render
    open(html_path, 'w').write(formatter.target(target, title))

def overview_html (targets, formatter) :
    """
        Generate .html index
    """
    
    # paths
    overview_path = os.path.join(options.web_dir, "index.html")
    
    # as (target, title) pairs
    open(overview_path, 'w').write(formatter.overview((target, target) for target in targets))

def generate (targets, filters=None):
    if filters :
        # filter targets
        targets = [target for target in targets if any(fnmatch.fnmatch(target.name, filter) for filter in filters)]

    # dirs
    setup_dirs()
    
    logging.info("Updating %d targets", len(targets))

    # overview
    formatter = html.Formatter(
        url_prefix      = options.url_prefix,
        img_url         = "%(prefix)s/" + options.img_url + "/%(style)s/%(interval)s/%(target)s.png",
        target_url      = "%(prefix)s/" + options.web_url + "/%(target)s.html",
    )
    
    # html for overview
    overview_html(targets, formatter)

    for target in targets :
        logging.info("Target: %s", target)
        
        # overview
        target_graph(target, 'overview', 'daily')
        
        # details
        for interval in ('daily', 'weekly', 'yearly') :
            target_graph(target, 'detail', interval)
    
        # html for target
        target_html(target, formatter)

def main (args) :
    # parse args
    targets = parse_args(args)
    
    # run
    generate(targets)

if __name__ == '__main__' :
    from sys import argv

    main(argv[1:])