#!/usr/bin/env python

import os, sys, time
import sets, cgi, shlex
import ConfigParser
import rrdtool

# TODO: Temporary
if not os.environ.has_key("CONFDIR") or not os.environ.has_key("WORKDIR"):
    raise "not setup properly. CONFDIR and WORKDIR env variables must be set"

CONFDIR = os.environ["CONFDIR"]
WORKDIR = os.environ["WORKDIR"]

# We always have this as our current directory.
# It helps when constructing graphs and the like
os.chdir(WORKDIR)

class GraphDef:
    filename = None
    filedata = None
    title = ""
    height = 0
    width = 0
    options = ""
    commands = ""
    category = ""
    name = ""
    valid = False

    __config = None

    def __init__(self, name):
        self.filename = "%s/%s" % (CONFDIR, name)
        self.filedata = "%s/%s.rrd" % (WORKDIR, name)
        self.category = "All"
        self.name = name
        self.interval = 0
        self.valid = False

        cfg = self.__config = ConfigParser.RawConfigParser()
        cfg.read(self.filename)

        # Loading general stuff
        if cfg.has_option("general", "title"):
            self.title = cfg.get("general", "title")
        if cfg.has_option("general", "category"):
            self.category = cfg.get("general", "category")

        # Loading graph stuff
        if cfg.has_section("graph"):
            if not cfg.has_option("graph", "commands"):
                raise "Missing commands attribute in: %s" % self.filename
            self.commands = cfg.get("graph", "commands")
            if cfg.has_option("graph", "width"):
                self.width = int(cfg.get("graph", "width"))
            if cfg.has_option("graph", "height"):
                self.height = int(cfg.get("graph", "height"))
            if cfg.has_option("graph", "options"):
                self.options = cfg.get("graph", "options")
            self.valid = True

        # Polling stuff
        if cfg.has_option("poll", "interval"):
            self.interval = cfg.get("poll", "interval")


def loadGraphs(path = ""):

    # List files and add appropriate paths
    graphs = []
    for file in os.listdir(CONFDIR + "/" + path):
        if os.path.isdir(CONFDIR + "/" + path + file):
            if file != "." and file != "..":
                graphs.extend(loadGraphs(path + file + "/"))
            continue
        graphs.append(GraphDef(path + file))
    return graphs


def listGraphs():

    graphs = loadGraphs()
    categories = {}
    for item in graphs:
        if not item.valid:
            continue
        if not categories.has_key(item.category):
            categories[item.category] = []
        categories[item.category].append(item)

    groups = categories.keys()
    groups.sort()

    print "Content-Type: text/xml\n"
    print "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
    print "<data>"
    for group in groups:
        print "    <category name=\"%s\">" % group
        categories[group].sort()
        for item in categories[group]:
            print "        <graph name=\"%s\" width=\"%d\" height=\"%d\" title=\"%s\" interval=\"%s\"/>" % \
                    (item.name, item.width, item.height, item.title, item.interval)
        print "    </category>"
    print "</data>"


def displayGraph():

    # print "Content-Type: text/plain"
    print "Content-Type: image/png"
    print ""

    form = cgi.FieldStorage()
    if not form.has_key("category") or not form.has_key("name"):
        raise "Required arguments not specified"

    name = form["name"].value
    item = GraphDef(name)

    # Default to one day display
    end = int(time.time())
    start = end - 86400
    if form.has_key("start"):
        start = int(form["start"].value)
    if form.has_key("end"):
        end = int(form["end"].value)

    # Default to Height and Width in graph
    height = item.height
    width = item.width
    if form.has_key("width"):
        width = int(form["width"].value)
    if form.has_key("height"):
        height = int(form["height"].value)


    args = ["-", "--imgformat=PNG", "--rigid",
            "--start=%d" % start,
            "--end=%d" % end,
            "--title=%s" % item.title,
            "--height=%d" % height,
            "--width=%d" % width ]

    # TODO Check color syntax
    if form.has_key("color"):
        colors = form.getlist("color");
        for color in colors:
            args.append("--color")
            args.append(color.replace(":", "#"))

    commands = item.commands.replace("{START}",
                    time.strftime("%Y-%m-%d %H\\:%M", time.localtime(start)))
    commands = commands.replace("{END}",
                    time.strftime("%Y-%m-%d %H\\:%M", time.localtime(end)))
    commands = commands.replace("{RRD}", item.filedata)
    args.extend(shlex.split(commands))

    args.extend(shlex.split(item.options))

    print >> sys.stderr, str(args)
    rrdtool.graph(*args)


if os.environ.has_key("PATH_INFO"):
    path = os.environ["PATH_INFO"].strip("/")
else:
    path = ""

parts = path.split("/")

method = parts[0]
del parts[0]
if not method:
    method = "list"


if method == "list":
    listGraphs()
elif method == "graph":
    displayGraph()
else:
    raise "Invalid request: %s" % method