#!/usr/bin/python
#
# Copyright 2010 Google Inc. All Rights Reserved.

"""Script to build the ChromeOS toolchain.

This script sets up the toolchain if you give it the gcctools directory.
"""

__author__ = "asharif@google.com (Ahmad Sharif)"

import datetime
import os
import optparse
import sys
from utils import email_sender


class SheriffHandler(object):
  SHERIFF_FILE = "/home/mobiletc-prebuild/sheriffs.txt"
  SUBJECT = "You (%s) are the sheriff for the week: %s - %s"
  BODY = "Please see instructions here: https://wiki.corp.google.com/twiki/bin/view/Main/SheriffDuties."

  def GetWeekInfo(self, day=datetime.datetime.today()):
    """Return week_start, week_end."""

    epoch = datetime.datetime.utcfromtimestamp(0)
    delta_since_epoch = day - epoch

    abs_days = abs(delta_since_epoch.days) - 2 # To get it to start from Sat.
    weeks_since_epoch = abs_days / 7
    day_of_week = abs_days % 7

    week_begin = day - datetime.timedelta(days=day_of_week)
    week_end = day + datetime.timedelta(days=(6 - day_of_week))

    strftime_format = "%A, %B %d %Y"

    return (week_begin.strftime(strftime_format),
            week_end.strftime(strftime_format))

  def GetCurrentSheriff(self):
    """Return the current sheriff."""
    return self.ReadSheriffsAsList()[0]

  def ReadSheriffsAsList(self):
    """Return the sheriff file contents."""
    contents = ""
    with open(self.SHERIFF_FILE, "r") as f:
      contents = f.read()
    return contents.splitlines()

  def WriteSheriffsAsList(self, to_write):
    with open(self.SHERIFF_FILE, "w") as f:
      f.write("\n".join(to_write))

  def GetRotatedSheriffs(self, num_rotations=1):
    """Return the sheriff file contents."""
    sheriff_list = self.ReadSheriffsAsList()

    new_sheriff_list = []
    num_rotations = num_rotations % len(sheriff_list)
    new_sheriff_list = (sheriff_list[num_rotations:] +
                        sheriff_list[:num_rotations])
    return new_sheriff_list

  def Email(self):
    es = email_sender.EmailSender()
    current_sheriff = self.GetCurrentSheriff()
    week_start, week_end = self.GetWeekInfo()
    subject = self.SUBJECT % (current_sheriff, week_start, week_end)
    es.SendEmail([current_sheriff],
                 subject,
                 self.BODY,
                 email_from=os.path.basename(__file__),
                 email_cc=["c-compiler-chrome"])


def Main(argv):
  parser = optparse.OptionParser()
  parser.add_option("-e",
                    "--email",
                    dest="email",
                    action="store_true",
                    help="Email the sheriff.")
  parser.add_option("-r",
                    "--rotate",
                    dest="rotate",
                    help="Print sheriffs after n rotations.")
  parser.add_option("-w",
                    "--write",
                    dest="write",
                    action="store_true",
                    default=False,
                    help="Wrote rotated contents to the sheriff file.")

  options, _ = parser.parse_args(argv)

  sheriff_handler = SheriffHandler()

  current_sheriff = sheriff_handler.GetCurrentSheriff()
  week_start, week_end = sheriff_handler.GetWeekInfo()

  print "Current sheriff: %s (%s - %s)" % (current_sheriff, week_start, week_end)

  if options.email:
    sheriff_handler.Email()

  if options.rotate:
    rotated_sheriffs = sheriff_handler.GetRotatedSheriffs(int(options.rotate))
    print "Rotated sheriffs (after %s rotations)" % options.rotate
    print "\n".join(rotated_sheriffs)
    if options.write:
      sheriff_handler.WriteSheriffsAsList(rotated_sheriffs)
      print "Rotated sheriffs written to file."

  return 0


if __name__ == "__main__":
  retval = Main(sys.argv)
  sys.exit(retval)