# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import sys
import hashlib
import functools
from mozbuild.preprocessor import Preprocessor
from mozbuild.util import DefinesAction
from mozpack.packager.unpack import UnpackFinder
from mozpack.files import DeflatedFile
from collections import OrderedDict
from io import StringIO
import argparse
import buildconfig

"""
Find files duplicated in a given packaged directory, independently of its
package format.
"""


def normalize_osx_path(p):
    """
    Strips the first 3 elements of an OSX app path

    >>> normalize_osx_path('Nightly.app/foo/bar/baz')
    'baz'
    """
    bits = p.split("/")
    if len(bits) > 3 and bits[0].endswith(".app"):
        return "/".join(bits[3:])
    return p


def is_l10n_file(path):
    return (
        "/locale/" in path
        or "/localization/" in path
        or path.startswith("localization/")
    )


def normalize_path(p):
    return normalize_osx_path(p)


class AllowedDupes:
    files = set()
    paths = set()

    def add(self, string):
        if string.endswith("/*"):
            self.paths.add(string.rstrip("*"))
        else:
            self.files.add(string)

    def is_allowed(self, candidate):
        if candidate in self.files:
            return True
        for path in self.paths:
            if candidate.startswith(path):
                return True
        return False


def find_dupes(source, allowed_dupes, bail=True):
    chunk_size = 1024 * 10
    checksums = OrderedDict()
    for p, f in UnpackFinder(source):
        checksum = hashlib.sha1()
        content_size = 0
        for buf in iter(functools.partial(f.open().read, chunk_size), b""):
            checksum.update(buf)
            content_size += len(buf)
        m = checksum.digest()
        if m not in checksums:
            if isinstance(f, DeflatedFile):
                compressed = f.file.compressed_size
            else:
                compressed = content_size
            checksums[m] = (content_size, compressed, [])
        checksums[m][2].append(p)
    total = 0
    total_compressed = 0
    num_dupes = 0
    unexpected_dupes = []
    for m, (size, compressed, paths) in sorted(
        checksums.items(), key=lambda x: x[1][1]
    ):
        if len(paths) > 1:
            _compressed = " (%d compressed)" % compressed if compressed != size else ""
            _times = " (%d times)" % (len(paths) - 1) if len(paths) > 2 else ""
            print("Duplicates {} bytes{}{}:".format(size, _compressed, _times))
            print("".join("  %s\n" % p for p in paths))
            total += (len(paths) - 1) * size
            total_compressed += (len(paths) - 1) * compressed
            num_dupes += 1

            for p in paths:
                if not is_l10n_file(p) and not allowed_dupes.is_allowed(normalize_path(p)):
                    unexpected_dupes.append(p)

    if num_dupes:
        total_compressed = (
            "%d compressed" % total_compressed
            if total_compressed != total
            else "uncompressed"
        )
        print(
            "WARNING: Found {} duplicated files taking {} bytes ({})".format(
                num_dupes, total, total_compressed
            )
        )

    if unexpected_dupes:
        errortype = "ERROR" if bail else "WARNING"
        print("{}: The following duplicated files are not allowed:".format(errortype))
        print("\n".join(unexpected_dupes))
        if bail:
            sys.exit(1)


def main():
    parser = argparse.ArgumentParser(description="Find duplicate files in directory.")
    parser.add_argument(
        "--warning",
        "-w",
        action="store_true",
        help="Only warn about duplicates, do not exit with an error",
    )
    parser.add_argument(
        "--file",
        "-f",
        action="append",
        dest="dupes_files",
        default=[],
        help="Add exceptions to the duplicate list from this file",
    )
    parser.add_argument("-D", action=DefinesAction)
    parser.add_argument("-U", action="append", default=[])
    parser.add_argument("directory", help="The directory to check for duplicates in")

    args = parser.parse_args()

    allowed_dupes = AllowedDupes()
    for filename in args.dupes_files:
        pp = Preprocessor()
        pp.context.update(buildconfig.defines["ALLDEFINES"])
        if args.D:
            pp.context.update(args.D)
        for undefine in args.U:
            if undefine in pp.context:
                del pp.context[undefine]
        pp.out = StringIO()
        pp.do_filter("substitution")
        pp.do_include(filename)
        for line in pp.out.getvalue().splitlines():
            allowed_dupes.add(line.partition("#")[0].rstrip())

    find_dupes(args.directory, bail=not args.warning, allowed_dupes=allowed_dupes)


if __name__ == "__main__":
    main()
