#!/usr/bin/env python

import sys, getopt, os, popen2
import pickle
from StringIO import StringIO

# Python 2.3 is required by PyRSS2Gen
py_version  = sys.version_info
if sys.version_info[0:2] < (2,3):
    sys.stderr.write("Error: Python 2.3 or higher required")
    sys.exit(1)
    
import datetime

try:
    import PyRSS2Gen
except ImportError:
    sys.stderr.write("Please install PyRSS2Gen before running this script\n")
    sys.stderr.write("PyRSS2Gen can be downloaded from: \n")
    sys.stderr.write("http://www.dalkescientific.com/Python/PyRSS2Gen.html\n")

def usage():
    print "Usage: svn2rss.py [-h|--help] [--svn-path] --revision <rev> "
    print "                  --repos-path <path> "
    print "                  --url <url> --rss-file <file>"
    print "       svn-path : path where svn binaries are installed"
    print "       url      : link in the rss item that points to the"
    print "                  viewcvs page for the revision"

if len(sys.argv) == 1:
    usage()
    sys.exit(2)
   
try:
    opts, args = getopt.getopt(sys.argv[1:],"h", ["help", "svn-path=",
                                                    "revision=",                                                                    "repos-path=", "url=",
                                                    "rss-file="])
except getopt.GetoptError, msg:
    print msg
    sys.stderr.write(usage())
    sys.exit(2)

for opt, arg in opts:
    if opt in ("-h", "--help"):
        usage()
        sys.exit(0)
    elif opt == "--svn-path":
        svn_path = arg
    elif opt == "--revision":
        commit_rev = arg
    elif opt == "--repos-path":
        repos_path = arg
    elif opt == "--url":
        url = arg
    elif opt == "--rss-file":
        rss_file = arg

class SVN2RSS:
    def __init__(self, svn_path, revision, repos_path, url, rss_file):
        self.max_items = 20
        self.svn_path = svn_path
        self.revision = revision
        self.repos_path = repos_path
        self.url = url
        self.rss_file = rss_file
        self.rss_item_desc = self.make_rss_item_desc()
        self.svnlook = os.path.join(self.svn_path, "svnlook")
        (file, ext) = os.path.splitext(self.rss_file)
        self.pickle_file = file + ".pickle"
        self.rss_item = self.make_rss_item()
        self.rss = self.make_rss()
        
    def make_rss_item_desc(self):
        cmd = "svnlook info -r " + self.revision + " " + self.repos_path
        out, x, y = popen2.popen3(cmd)
        cmd_out = out.readlines()
        Author = "\nAuthor: " + cmd_out[0]
        Date = "Date: " + cmd_out[1]
        New_Revision = "Revision: " + self.revision
        Log = "Log: " + cmd_out[3]
        out.close()
        x.close()
        y.close()
        
        cmd = "svnlook changed -r " + self.revision + " " + self.repos_path
        out, x, y = popen2.popen3(cmd)
        cmd_out = out.readlines()
        changed_files = "Modified: \n"
        for item in cmd_out:
            changed_files = changed_files + item
        item_desc = Author + Date + New_Revision + "\n" + \
                    Log + changed_files
        out.close()
        x.close()
        y.close()
        
        return item_desc
        
    def pickle(self):
        s = StringIO()    
        pickle.dump(self.rss, s)
        f = open(self.pickle_file,"w")
        f.write (s.getvalue())
        f.close()

    def make_rss_item(self):
        """ Generate PyRSS2Gen Item from the commit info """
        item_title = "Revision " + self.revision
        item_link = url + "?rev=" + self.revision
        rss_item = PyRSS2Gen.RSSItem(title = item_title,
                                     link = item_link,
                                     description = self.make_rss_item_desc(),
                                     guid = PyRSS2Gen.Guid(item_link),
                                     pubDate = datetime.datetime.now())
        return rss_item

    def make_rss(self):
        """ Generate a PyRSS2Gen RSS2 object """
        if os.path.exists(self.pickle_file):
            f = open(self.pickle_file, "r")
            rss = pickle.load(f)
            f.close()
            if len(rss.items) == self.max_items :
                rss.items.pop()
            rss.items.insert(0, self.rss_item)
        else:
            rss_item = self.rss_item
            rss = PyRSS2Gen.RSS2(
                              title = "Foo's SVN Commits Feed",
                              link = "http://www.foo.com/project",
                              description = "The latest SVN commits",
                              lastBuildDate = datetime.datetime.now(),
                              items = [rss_item])

        return rss

svn2rss = SVN2RSS(svn_path, commit_rev, repos_path, url, rss_file)
rss = svn2rss.rss
svn2rss.pickle()
rss.write_xml(open(rss_file, "w"))