#!/usr/bin/env python3
# Copyright 2021 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Run inside `cros_sdk` to uprev dependency versions between Cargo.lock and
# chromiumos-overlay ebuild files.

import re
import glob
import os
import sys
import subprocess
from distutils.version import StrictVersion
from datetime import datetime

# Ideally we would install a toml parser, but this will do for a quick little
# tool.
CARGO_LOCK_REGEX = re.compile(
    r"""name = "([^"]+)"
version = "([^"]+)"
source ="""
)

IGNORED_PACKAGES = ["pin-utils", "pkg-config"]

DEV_RUST_PATH = "../../third_party/chromiumos-overlay/dev-rust"
EBUILD_FILE_GLOB = f"{DEV_RUST_PATH}/*/*.ebuild"
EBUILD_FILE_REGEX = re.compile(r"([\w\-_]+)-([0-9\.]+)\.ebuild")
YEAR = datetime.today().year


def ebuild_template(package: str):
    return f"""\
# Copyright {YEAR} The Chromium OS Authors. All rights reserved.
# Distributed under the terms of the GNU General Public License v2

EAPI="7"

CROS_RUST_REMOVE_DEV_DEPS=1

inherit cros-rust

DESCRIPTION="Build file for the {package} crate."
HOMEPAGE="https://crates.io/crates/{package}"
SRC_URI="https://crates.io/api/v1/crates/${{PN}}/${{PV}}/download -> ${{P}}.crate"

LICENSE="|| ( MIT Apache-2.0 )"
SLOT="${{PV}}/${{PR}}"
KEYWORDS="*"

# TODO: Add crate dependencies
DEPEND=""
"""


def ebuild_file_path(package: str, version: str):
    return f"{DEV_RUST_PATH}/{package}/{package}-{version}.ebuild"


def parse_cargo_lock():
    """Parses Cargo.lock file and returns (package, version) pairs."""
    with open("Cargo.lock", "r") as lock_file:
        lock_str = lock_file.read()
    for match in CARGO_LOCK_REGEX.finditer(lock_str):
        yield (match.group(1), match.group(2))


def all_ebuild_versions():
    """Returns (package, version) pairs of ebuild files in dev-rust."""
    for ebuild_path in glob.glob(EBUILD_FILE_GLOB):
        ebuild_name = os.path.basename(ebuild_path)
        match = EBUILD_FILE_REGEX.match(ebuild_name)
        if match:
            yield (match.group(1), match.group(2))


def ebuild_versions_dict():
    """Returns a dict of package versions of all ebuild files in dev-rust."""
    versions: dict[str, list[str]] = {}
    for (package, version) in all_ebuild_versions():
        if package in versions:
            versions[package].append(version)
            versions[package].sort(key=StrictVersion)
        else:
            versions[package] = [version]
    return versions


def update_manifest(package: str, version: str):
    """Regenerate ebuild manifest for the provided package/version."""
    cmd = ["ebuild", ebuild_file_path(package, version), "manifest"]
    print(" ", " ".join(cmd))
    subprocess.run(cmd)


def uprev_ebuild(package: str, new_version: str, old_version: str):
    """Updates the ebuild file from `old_version` to `new_version`."""
    old_path = ebuild_file_path(package, old_version)
    new_path = ebuild_file_path(package, new_version)
    print(f"  {old_path} -> {new_path}")
    os.rename(old_path, new_path)
    update_manifest(package, new_version)


def add_ebuild(package: str, version: str):
    """Creates a new ebuild file for the provided package."""
    ebuild_path = ebuild_file_path(package, version)
    print(f"  Writing {ebuild_path}")
    open(ebuild_path, "w").write(ebuild_template(package))
    update_manifest(package, version)


def update_cargo(package: str, latest_version: str):
    """Runs `cargo update` to update the version in Cargo.lock."""
    cmd = ["cargo", "update", "-p", package, "--precise", latest_version]
    print(" ", " ".join(cmd))
    subprocess.run(cmd)


def confirm(question: str):
    print(f"{question} [y/N]")
    return sys.stdin.readline().strip().lower() == "y"


def main():
    ebuild_packages = ebuild_versions_dict()
    for (package, cargo_version) in parse_cargo_lock():
        ebuild_versions = ebuild_packages.get(package, [])
        if package in IGNORED_PACKAGES:
            continue
        if cargo_version in ebuild_versions:
            continue
        if not ebuild_versions:
            print(f"{package}: No ebuild file.")
            if confirm("Create ebuild?"):
                add_ebuild(package, cargo_version)
        elif StrictVersion(ebuild_versions[-1]) > StrictVersion(cargo_version):
            print(
                f"{package}: Cargo version {cargo_version} is older than "
                f"latest ebuild version ({', '.join(ebuild_versions)})."
            )
            if confirm("Update Cargo.lock?"):
                update_cargo(package, ebuild_versions[-1])
        else:
            print(
                f"{package}: Ebuild versions ({', '.join(ebuild_versions)}) "
                f"are older than cargo version {cargo_version}."
            )
            if confirm("Uprev ebuild?"):
                uprev_ebuild(package, cargo_version, ebuild_versions[-1])


if __name__ == "__main__":
    main()