#! /usr/bin/env python2.7

import os
import subprocess
import sys
import tempfile


def is_skipped_folder(cpython_repo, path):
    skipped_folders = [
        '.hgtags',
        'Demo',
        'Doc',
        'Mac',
        'Makefile',
        'Misc',
        'PCbuild',
        'README',
        'Tools',
        'configure',
    ]
    for skipped_folder in skipped_folders:
        if path.startswith(os.path.join(cpython_repo, skipped_folder)):
            return True
    return False


def get_rev_file(path, rev):
    filepath = tempfile.mktemp(prefix='merge_helper_', suffix='.py')
    os.system('hg cat %s -r %s > %s' % (path, rev, filepath))
    return filepath


def main(cpython_repo, pyston_repo, skip):
    output = subprocess.check_output(['hg', 'status', cpython_repo, '--rev', 'v2.7.7:v2.7.8'])

    diff_files = [line.split()[1] for line in output.splitlines()]
    diff_files = filter(lambda x: not is_skipped_folder(cpython_repo, x), diff_files)
    diff_files = sorted(diff_files)


    for i, filepath in enumerate(diff_files):
        if i < skip:
            continue

        pyston_filepath = os.path.join(pyston_repo, filepath.lstrip(cpython_repo))
        print 'diff', i, ':', filepath
        args = (get_rev_file(filepath, 'v2.7.7'), get_rev_file(filepath, 'v2.7.8'), pyston_filepath)
        os.system('vimdiff %s %s %s' % args)
        


if __name__ == '__main__':
    if len(sys.argv) != 4:
        print 'Usage: ./merge_helper.py <cpython_hg_repo> <pyston_repo> <skip>'
        sys.exit(1)
    cpython_repo = sys.argv[1]
    pyston_repo = sys.argv[2]
    skip = int(sys.argv[3])
    main(cpython_repo, pyston_repo, skip)