#!/usr/bin/env python3
# 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 os
import subprocess
import json
import argparse
import sys
import shutil
from functools import reduce


def check_run(args, path):
    print(" ".join(args) + " in " + path, file=sys.stderr)
    subprocess.run(args, cwd=path, check=True)


def run_in(path, args, extra_env=None):
    """
    Runs the given commands in the directory specified by <path>.
    """
    env = dict(os.environ)
    env.update(extra_env or {})
    check_run(args, path)
    subprocess.run(args, cwd=path)


def build_tar_package(tar, name, base, directories):
    name = os.path.realpath(name)
    run_in(
        base,
        [tar, "-c", "-%s" % ("J" if ".xz" in name else "j"), "-f", name] + directories,
    )


def is_git_repo(dir):
    """Check whether the given directory is a git repository."""
    from subprocess import CalledProcessError

    try:
        check_run(["git", "rev-parse"], dir)
        return True
    except CalledProcessError:
        return False


def git_clone(main_dir, url, clone_dir, commit):
    """
    Clones the repository from <url> into <clone_dir>, and brings the
    repository to the state of <commit>.
    """
    run_in(main_dir, ["git", "clone", url, clone_dir])
    run_in(clone_dir, ["git", "checkout", commit])


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-c",
        "--config",
        required=True,
        type=argparse.FileType("r"),
        help="Infer configuration file",
    )
    parser.add_argument(
        "-b", "--base-dir", help="Base directory for code and build artifacts"
    )
    parser.add_argument(
        "--clean", action="store_true", help="Clean the build directory"
    )
    parser.add_argument(
        "--skip-tar", action="store_true", help="Skip tar packaging stage"
    )

    args = parser.parse_args()

    # The directories end up in the debug info, so the easy way of getting
    # a reproducible build is to run it in a know absolute directory.
    # We use a directory that is registered as a volume in the Docker image.
    if args.base_dir:
        base_dir = args.base_dir
    else:
        base_dir = reduce(
            os.path.join, [os.sep + "builds", "worker", "workspace", "moz-toolchain"]
        )
    infer_dir = os.path.join(base_dir, "infer")
    source_dir = os.path.join(infer_dir, "src")
    build_dir = os.path.join(infer_dir, "build")

    if args.clean:
        shutil.rmtree(build_dir)
        os.sys.exit(0)

    config = json.load(args.config)
    infer_revision = config["infer_revision"]
    infer_repo = config["infer_repo"]

    for folder in [infer_dir, source_dir, build_dir]:
        os.makedirs(folder, exist_ok=True)

    # clone infer
    if not is_git_repo(source_dir):
        # git doesn't like cloning into a non-empty folder. If src is not a git
        # repo then just remove it in order to reclone
        shutil.rmtree(source_dir)
        git_clone(infer_dir, infer_repo, source_dir, infer_revision)
    # apply a few patches
    dir_path = os.path.dirname(os.path.realpath(__file__))
    # clean the git directory by reseting all changes
    git_commands = [["clean", "-f"], ["reset", "--hard"]]
    for command in git_commands:
        run_in(source_dir, ["git"] + command)
    for p in config.get("patches", []):
        run_in(source_dir, ["git", "apply", os.path.join(dir_path, p)])
    # configure opam
    run_in(source_dir, ["opam", "init", "--no-setup", "--disable-sandboxing"])
    # build infer
    run_in(source_dir, ["./build-infer.sh", "java"], extra_env={"NO_CMAKE_STRIP": "1"})

    package_name = "infer"
    infer_package = os.path.join(os.getcwd(), package_name)
    # We need to create a package with all of the depended libraries injected in it
    run_in(
        source_dir,
        [
            "make",
            "install-with-libs",
            "BUILD_MODE=opt",
            "PATCHELF=patchelf",
            "DESTDIR={}".format(infer_package),
            "libdir_relative_to_bindir=../lib",
        ],
    )

    infer_package_with_pref = os.path.join(infer_package, "usr")
    if not args.skip_tar:
        os.rename(
            os.path.join(infer_package_with_pref, "local"),
            os.path.join(infer_package_with_pref, "infer"),
        )
        build_tar_package(
            "tar",
            "%s.tar.xz" % (package_name),
            infer_package_with_pref,
            [
                os.path.join("infer", "bin"),
                os.path.join("infer", "lib"),
                os.path.join("infer", "share"),
            ],
        )