#!/usr/bin/env python

import os
import subprocess
import sys


SOURCE_ROOT = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
PATCHES_DIR = os.path.join(SOURCE_ROOT, 'patches')
VENDOR_DIR = os.path.join(SOURCE_ROOT, 'vendor')
SRC_DIR = os.path.join(SOURCE_ROOT, '..', '..', 'src')
PATCH_PY = os.path.join(VENDOR_DIR, 'python-patch', 'patch.py')


def main():
    error = apply_patches_for_dir(PATCHES_DIR)
    if not error:
        return

    sys.stderr.write(error + '\n')
    sys.stderr.flush()
    revert_changes_for_dir(PATCHES_DIR)
    return 1


def apply_patches_for_dir(directory):
    for root, files in os.walk(directory):
        prefix = os.path.relpath(root, directory)
        target = os.path.join(SRC_DIR, prefix)
        args = [sys.executable, PATCH_PY, '--directory', target, '--quiet']
        for name in sorted(files):
            if not name.endswith('.patch'):
                continue
            patch = os.path.join(root, name)
            if subprocess.call(args + [patch]):
                return '{0} failed to apply'.format(os.path.basename(patch))


def revert_changes_for_dir(directory):
    for root, files in reversed(list(os.walk(directory))):
        prefix = os.path.relpath(root, directory)
        target = os.path.join(SRC_DIR, prefix)
        args = [sys.executable, PATCH_PY, '--directory', target, '--quiet',
                '--revert']
        for name in reversed(sorted(files)):
            if not name.endswith('.patch'):
                continue
            patch = os.path.join(root, name)
            subprocess.call(args + [patch])


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