#!/usr/bin/env python3

# Copyright 2015 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Verifies that all source files contain the necessary copyright boilerplate
# snippet.

import argparse
import datetime
import glob
import os
import re
import sys

AUTHORS = r"TestGrid|Kubernetes"
YEAR = r"YEAR"

def get_args():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "filenames", help="list of files to check, all files if unspecified", nargs='*')

    rootdir = os.path.dirname(__file__) + "/../"
    rootdir = os.path.abspath(rootdir)
    parser.add_argument("--rootdir", default=rootdir,
                        help="root directory to examine")

    default_boilerplate_dir = os.path.join(rootdir, "hack/boilerplate")
    parser.add_argument("--boilerplate-dir", default=default_boilerplate_dir)
    return parser.parse_args()


def get_refs():
    refs = {}

    for path in glob.glob(os.path.join(ARGS.boilerplate_dir, "boilerplate.*.txt")):
        extension = os.path.basename(path).split(".")[1]

        # Pass the encoding parameter to avoid ascii decode error for some
        # platform.
        ref_file = open(path, 'r', encoding='utf-8')
        ref = ref_file.read().splitlines()
        ref_file.close()
        refs[extension] = ref

    return refs


GENERATED_GO_MARKERS = [
    "// Code generated by client-gen. DO NOT EDIT.",
    "// Code generated by deepcopy-gen. DO NOT EDIT.",
    "// Code generated by informer-gen. DO NOT EDIT.",
    "// Code generated by lister-gen. DO NOT EDIT.",
    "// Code generated by protoc-gen-go. DO NOT EDIT.",
]

# given the file contents, return true if the file appears to be generated


def is_generated(data):
    for marker in GENERATED_GO_MARKERS:
        if marker in data:
            return True
    return False


def file_passes(filename, refs, regexs):  # pylint: disable=too-many-locals
    try:
        # Pass the encoding parameter to avoid ascii decode error for some
        # platform.
        with open(filename, 'r', encoding='utf-8') as fp:
            data = fp.read()
    except IOError:
        return False

    basename = os.path.basename(filename)
    extension = file_extension(filename)
    if extension != "":
        ref = refs[extension]
    else:
        ref = refs[basename]

    # check for and skip generated files
    if is_generated(data):
        return True

    # remove build tags from the top of Go files
    if extension == "go":
        con = regexs["go_build_constraints"]
        (data, found) = con.subn("", data, 1)

    # remove shebang from the top of shell files
    if extension in ("sh", "py"):
        she = regexs["shebang"]
        (data, found) = she.subn("", data, 1)

    data = data.splitlines()

    # if our test file is smaller than the reference it surely fails!
    if len(ref) > len(data):
        return False

    # trim our file to the same number of lines as the reference file
    data = data[:len(ref)]

    year = regexs["year"]
    for datum in data:
        if year.search(datum):
            return False

    # Replace all occurrences of the regex "2017|2016|2015|2014" with "YEAR"
    when = regexs["date"]
    for idx, datum in enumerate(data):
        (data[idx], found) = when.subn("YEAR", datum)
        if found != 0:
            break

    # Replace all occurrences of the regex "Testgrid|Kubernetes" with "AUTHOR"
    author = regexs["author"]
    for idx, datum in enumerate(data):
        (data[idx], found) = author.subn("AUTHOR", datum)
        if found != 0:
            break

    # if we don't match the reference at this point, fail
    if ref != data:
        return False

    return True


def file_extension(filename):
    return os.path.splitext(filename)[1].split(".")[-1].lower()


SKIPPED_DIRS = [
    'external',
    '.git',
    'Godeps',
    '_gopath',
    '__init__.py',
    'node_modules',
    '_output',
    'third_party',
    'vendor',
]

# even when generated by bazel we will complain about some generated files
# not having the headers. since they're just generated, ignore them
IGNORE_HEADERS = [
    '// Code generated by go-bindata.'
]


def has_ignored_header(pathname):
    # Pass the encoding parameter to avoid ascii decode error for some
    # platform.
    with open(pathname, 'r', encoding='utf-8') as myfile: