#!/usr/bin/python
# Copyright 2013-2014  Lars Wirzenius
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# =*= License: GPL-3+ =*=


__version__ = '0.0'


import cliapp
import os
import re
import sys


copyright_pattern = re.compile(
      r'Copyright\s+(\([cC]\)\s+)?(?P<years>\d+((,|-|\s)|\d+)*)\s(?P<names>.*)')


class CopyrightStatementLint(cliapp.Application):

      def add_settings(self):
            self.settings.integer(
                  ['debug-commit-year'],
                  'pretend the commit is from YEAR',
                  metavar='YEAR')

      def setup(self):
            self.errors = False

      def cleanup(self):
            if self.errors:
                  sys.exit(1)

      def process_input(self, filename):
            self.statements = []
            cliapp.Application.process_input(self, filename)
            if self.statements:
                  commit_year = self.get_commit_year(filename)
                  if not self.statements_contain_year(commit_year):
                        years = [m.group('years') for m in self.statements]
                        sys.stderr.write(
                              '%s: commit year %s not contained in '
                              'copyright statement years: %s\n' %
                              (filename, commit_year, ' '.join(years)))
                        self.errors = True
            else:
                  sys.stderr.write('%s: no copyright statements\n' % filename)
                  self.errors = True

      def process_input_line(self, filename, line):
            m = copyright_pattern.search(line)
            if m:
                  self.statements.append(m)

      def get_commit_year(self, filename):
            if self.settings['debug-commit-year']:
                  return self.settings['debug-commit-year']

            output = cliapp.runcmd(['git', 'log', '-n1', filename])
            for line in output.splitlines():

                  if line.startswith('Date:'):
                        words = line.split()
                        return int(words[5]) # return year
            return 0 # dummy year

      def statements_contain_year(self, year):
            for match in self.statements:
                  pairs = self.parse_years(match.group('years'))
                  for start, end in pairs:
                        if start <= year <= end:
                              return True
            return False

      def parse_years(self, years):
            pairs = []
            words = [s.strip() for s in years.split(',')]
            for word in words:
                  if '-' in word:
                        start, end = word.split('-', 1)
                  else:
                        start = end = word
                  pairs.append((int(start), int(end)))
            return pairs


CopyrightStatementLint(version=__version__).run()