#!/usr/bin/env python
# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Lists branches with closed and abandoned issues."""

import optparse
import os
import sys
import urllib2

BASE_DIR = os.path.dirname(os.path.abspath(__file__))
DEPOT_TOOLS_DIR = os.path.dirname(BASE_DIR)
sys.path.insert(0, DEPOT_TOOLS_DIR)

import git_cl


def get_branches():
  """Get list of all local git branches."""
  branches = [l.split() for l in git_cl.RunGit(
      ["for-each-ref",
      "--format=%(refname:short) %(upstream:short)",
      "refs/heads"]).splitlines()]
  return [Branch(*b) for b in branches] 

def get_change_count(start, end):
  return int(git_cl.RunGit(["rev-list", "%s..%s" % (start, end), "--count" ]))


class Branch(git_cl.Changelist):
  def __init__(self, name, upstream):
    git_cl.Changelist.__init__(self, branchref=name)
    self._upstream = upstream
    self._distance = None
    self._issue_status = None

  def GetStatus(self):
    if not self._issue_status:
      if self.GetIssue():
        try:
          issue_properties = self.RpcServer().get_issue_properties(
              self.GetIssue(), None)
          if issue_properties['closed']:
            self._issue_status = 'closed'
          else:
            self._issue_status = 'pending'
        except urllib2.HTTPError, e:
          if e.code == 404:
            self._issue_status = 'abandoned'
      else:
        self._issue_status = 'no-issue'
      if (self._issue_status != 'pending'
         and not self.GetDistance()[0]
         and not self._upstream.startswith("origin/")):
        self._issue_status = 'empty'
    return self._issue_status
    
  def GetDistance(self):
    if not self._distance:
      self._distance = [get_change_count(self._upstream, self.GetBranch()),
          get_change_count(self.GetBranch(), self._upstream)]
    return self._distance

  def GetDistanceInfo(self):
    formatted_dist = ", ".join(["%s %d" % (x,y)
        for (x,y) in zip(["ahead","behind"], self.GetDistance()) if y])
    return "[%s%s]" % (
        self._upstream, ": " + formatted_dist if formatted_dist else "")

def main():
  parser = optparse.OptionParser(usage=sys.modules['__main__'].__doc__)
  options, args = parser.parse_args()
  if args:
    parser.error('Unsupported arg: %s' % args)

  branches = get_branches()
  filtered = { 'closed' : [],
               'empty' : [],
               'pending' : [],
               'abandoned' : [],
               'no-issue' : []}

  for branch in branches:
    filtered[branch.GetStatus()].append(branch)

  print "# Branches with closed issues"
  for branch in filtered['closed']:
    print "git branch -D %s # Issue %s is closed." % (branch.GetBranch(),
                                                        branch.GetIssue())

  print "# Empty branches"
  for branch in filtered['empty']:
    print "git branch -D %s # Empty." % (branch.GetBranch())

  print "\n# Pending Branches"
  for branch in filtered['pending']:
    print "# Branch %s - Issue %s - %s" % (
        branch.GetBranch(), branch.GetIssue(), branch.GetDistanceInfo())

  print "\n# Branches with abandoned issues"
  for branch in filtered['abandoned']:
    print "# Branch %s - was issue %s - %s" % (
        branch.GetBranch(), branch.GetIssue(), branch.GetDistanceInfo())

  print "\n# Branches without associated issues"
  for branch in filtered['no-issue']:
    print "# Branch %s - %s" % (branch.GetBranch(), branch.GetDistanceInfo())

  return 0


if __name__ == '__main__':
  sys.exit(main())