#!/usr/bin/env python
# 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/.

# This script provides one-line bootstrap support to configure systems to build
# the tree. It does so by cloning the repo before calling directly into `mach
# bootstrap`.

# mozboot bootstrap.py was mangled and maimed in the creation of this script.

# Note that this script can't assume anything in particular about the host
# Python environment (except that it's run with a sufficiently recent version of
# Python 3), so we are restricted to stdlib modules.

import sys

major, minor = sys.version_info[:2]
if (major < 3) or (major == 3 and minor < 5):
    print("Bootstrap currently only runs on Python 3.5+." "Please try re-running with python3.5+.")
    sys.exit(1)

import ctypes
import os
import shutil
import subprocess
import tempfile
from optparse import OptionParser
from pathlib import Path

CLONE_MERCURIAL_PULL_FAIL = """
Failed to pull from hg.mozilla.org.

This is most likely because of unstable network connection.
Try running `cd %s && hg pull https://hg.mozilla.org/comm-central` manually,
or download a mercurial bundle and use it:
https://firefox-source-docs.mozilla.org/contributing/vcs/mercurial_bundles.html"""

WINDOWS = sys.platform.startswith("win32") or sys.platform.startswith("msys")
VCS_HUMAN_READABLE = {
    "hg": "Mercurial",
    "git": "Git",
}


def which(name):
    """Python implementation of which.

    It returns the path of an executable or None if it couldn't be found.
    """
    # git-cinnabar.exe doesn't exist, but .exe versions of the other executables
    # do.
    if WINDOWS and name != "git-cinnabar":
        name += ".exe"
    search_dirs = os.environ["PATH"].split(os.pathsep)

    for path in search_dirs:
        test = Path(path) / name
        if test.is_file() and os.access(test, os.X_OK):
            return test

    return None


def validate_clone_dest(dest: Path):
    dest = dest.resolve()

    if not dest.exists():
        return dest

    if not dest.is_dir():
        print(f"ERROR! Destination {dest} exists but is not a directory.")
        return None

    if not any(dest.iterdir()):
        return dest
    else:
        print(f"ERROR! Destination directory {dest} exists but is nonempty.")
        print(
            f"To re-bootstrap the existing checkout, go into '{dest}' and run './mach bootstrap'."
        )
        return None


def input_clone_dest(vcs, no_interactive):
    repo_name = "mozilla-unified"
    print(f"Cloning into {repo_name} using {VCS_HUMAN_READABLE[vcs]}...")
    while True:
        dest = None
        if not no_interactive:
            dest = input(
                f"Destination directory for clone (leave empty to use "
                f"default destination of {repo_name}): "
            ).strip()
        if not dest:
            dest = repo_name
        dest = validate_clone_dest(Path(dest).expanduser())
        if dest:
            return dest
        if no_interactive:
            return None


def hg_clone(hg: Path, repo, dest: Path, watchman: Path):
    print(f"Cloning {repo} to {dest}...")
    # We create an empty repo then modify the config before adding data.
    # This is necessary to ensure storage settings are optimally
    # configured.
    args = [
        str(hg),
        # The unified repo is generaldelta, so ensure the client is as
        # well.
        "--config",
        "format.generaldelta=true",
        "init",
        str(dest),
    ]
    res = subprocess.call(args)
    if res:
        print("unable to create destination repo; please try cloning manually")
        return None

    # Strictly speaking, this could overwrite a config based on a template
    # the user has installed. Let's pretend this problem doesn't exist
    # unless someone complains about it.
    with open(dest / ".hg" / "hgrc", "a") as fh:
        fh.write("[paths]\n")
        fh.write("default = https://hg.mozilla.org/{}\n".format(repo))
        fh.write("\n")

        # The server uses aggressivemergedeltas which can blow up delta chain
        # length. This can cause performance to tank due to delta chains being
        # too long. Limit the delta chain length to something reasonable
        # to bound revlog read time.
        fh.write("[format]\n")
        fh.write("# This is necessary to keep performance in check\n")
        fh.write("maxchainlen = 10000\n")

    res = subprocess.call(
        [str(hg), "pull", "https://hg.mozilla.org/{}".format(repo)], cwd=str(dest)
    )
    print("")
    if res:
        print(CLONE_MERCURIAL_PULL_FAIL % dest)
        return None

    update_rev = {"mozilla-unified": "central", "comm-central": "tip"}[repo]
    print("updating to {}".format(update_rev))
    res = subprocess.call([str(hg), "update", "-r", update_rev], cwd=str(dest))
    if res:
        print(
            f"error updating; you will need to `cd {dest} && hg update -r {update_rev}` "
            "manually"
        )
    return dest


def git_clone(git: Path, repo, dest: Path, watchman: Path):
    print(f"Cloning {repo} to {dest}...")
    tempdir = None
    cinnabar = None
    env = dict(os.environ)
    try:
        cinnabar = which("git-cinnabar")
        if not cinnabar:
            cinnabar_url = "https://github.com/glandium/git-cinnabar/"
            # If git-cinnabar isn't installed already, that's fine; we can
            # download a temporary copy. `mach bootstrap` will clone a full copy
            # of the repo in the state dir; we don't want to copy all that logic
            # to this tiny bootstrapping script.
            tempdir = Path(tempfile.mkdtemp())
            cinnabar_dir = tempdir / "git-cinnabar-master"
            subprocess.check_call(
                [str(git), "clone", "--depth=1", str(cinnabar_url), str(cinnabar_dir)],
                cwd=str(tempdir),
                env=env,
            )
            env["PATH"] = str(cinnabar_dir) + os.pathsep + env["PATH"]
            subprocess.check_call(
                [sys.executable, str(cinnabar_dir / "download.py")],
                cwd=str(cinnabar_dir),
                env=env,
            )
            print(
                "WARNING! git-cinnabar is required for Firefox development  "
                "with git. After the clone is complete, the bootstrapper "
                "will ask if you would like to configure git; answer yes, "
                "and be sure to add git-cinnabar to your PATH according to "
                "the bootstrapper output."
            )

        # We're guaranteed to have `git-cinnabar` installed now.
        # Configure git per the git-cinnabar requirements.
        cmd = [
            str(git),
            "clone",
        ]
        if repo == "mozilla-unified":
            cmd += [
                "-b",
                "bookmarks/central",
            ]
        cmd += [
            "hg::https://hg.mozilla.org/{}".format(repo),
            str(dest),
        ]
        subprocess.check_call(cmd, env=env)
        subprocess.check_call([str(git), "config", "fetch.prune", "true"], cwd=str(dest), env=env)
        subprocess.check_call([str(git), "config", "pull.ff", "only"], cwd=str(dest), env=env)

        watchman_sample = dest / ".git/hooks/fsmonitor-watchman.sample"
        # Older versions of git didn't include fsmonitor-watchman.sample.
        if watchman and watchman_sample.exists():
            print("Configuring watchman")
            watchman_config = dest / ".git/hooks/query-watchman"
            if not watchman_config.exists():
                print(f"Copying {watchman_sample} to {watchman_config}")
                copy_args = [
                    "cp",
                    ".git/hooks/fsmonitor-watchman.sample",
                    ".git/hooks/query-watchman",
                ]
                subprocess.check_call(copy_args, cwd=str(dest))

            config_args = [
                str(git),
                "config",
                "core.fsmonitor",
                ".git/hooks/query-watchman",
            ]
            subprocess.check_call(config_args, cwd=str(dest), env=env)
        return dest
    finally:
        if not cinnabar:
            print(
                "Failed to install git-cinnabar. Try performing a manual "
                "installation: https://github.com/glandium/git-cinnabar/wiki/"
                "Mozilla:-A-git-workflow-for-Gecko-development"
            )
        if tempdir:
            shutil.rmtree(str(tempdir))


def add_microsoft_defender_antivirus_exclusions(dest, no_system_changes):
    if no_system_changes:
        return

    if not WINDOWS:
        return

    powershell_exe = which("powershell")

    if not powershell_exe:
        return

    def print_attempt_exclusion(path):
        print(f"Attempting to add exclusion path to Microsoft Defender Antivirus for: {path}")

    powershell_exe = str(powershell_exe)
    paths = []

    # mozilla-unified / clone dest
    repo_dir = Path.cwd() / dest
    paths.append(repo_dir)
    print_attempt_exclusion(repo_dir)

    # MOZILLABUILD
    mozillabuild_dir = os.getenv("MOZILLABUILD")
    if mozillabuild_dir:
        paths.append(mozillabuild_dir)
        print_attempt_exclusion(mozillabuild_dir)

    # .mozbuild
    mozbuild_dir = Path.home() / ".mozbuild"
    paths.append(mozbuild_dir)
    print_attempt_exclusion(mozbuild_dir)

    args = ";".join(f"Add-MpPreference -ExclusionPath '{path}'" for path in paths)
    command = f'-Command "{args}"'

    # This will attempt to run as administrator by triggering a UAC prompt
    # for admin credentials. If "No" is selected, no exclusions are added.
    ctypes.windll.shell32.ShellExecuteW(None, "runas", powershell_exe, command, None, 0)


def clone(options):
    vcs = options.vcs
    no_interactive = options.no_interactive
    no_system_changes = options.no_system_changes

    hg = which("hg")
    if not hg:
        print(
            "Mercurial is not installed. Mercurial is required to clone "
            "Thunderbird%s." % (", even when cloning with Git" if vcs == "git" else "")
        )
        try:
            # We're going to recommend people install the Mercurial package with
            # pip3. That will work if `pip3` installs binaries to a location
            # that's in the PATH, but it might not be. To help out, if we CAN
            # import "mercurial" (in which case it's already been installed),
            # offer that as a solution.
            import mercurial  # noqa: F401

            print(
                "Hint: have you made sure that Mercurial is installed to a "
                "location in your PATH?"
            )
        except ImportError:
            print("Try installing hg with `pip3 install Mercurial`.")
        return None

    if vcs == "hg":
        binary = hg
    else:
        binary = which(vcs)
        if not binary:
            print("Git is not installed.")
            print("Try installing git using your system package manager.")
            return None

    dest = input_clone_dest(vcs, no_interactive)
    if not dest:
        return None

    add_microsoft_defender_antivirus_exclusions(dest, no_system_changes)

    if vcs == "hg":
        clone_func = hg_clone
    else:
        clone_func = git_clone
    watchman = which("watchman")

    mc = clone_func(binary, "mozilla-unified", dest, watchman)
    # Funny logic... the return value if successful needs to be the path
    # to mozilla-central. Only return "cc" if cloning comm-central
    # fails.
    if mc == dest:
        cc_dest = Path(dest) / "comm"
        cc = clone_func(binary, "comm-central", cc_dest, watchman)
        if cc:
            return mc
        else:
            return cc
    return mc


def bootstrap(srcdir: Path, artifact_mode, no_interactive, no_system_changes):
    args = [sys.executable, "mach"]

    if no_interactive:
        # --no-interactive is a global argument, not a command argument,
        # so it needs to be specified before "bootstrap" is appended.
        args += ["--no-interactive"]

    args += ["bootstrap"]

    if artifact_mode:
        args += ["--application-choice", "Firefox for Desktop Artifact Mode"]
    else:
        args += ["--application-choice", "Firefox for Desktop"]
    if no_system_changes:
        args += ["--no-system-changes"]

    print("Running `%s`" % " ".join(args))
    return subprocess.call(args, cwd=str(srcdir))


def mozconfig(srcdir):
    """Build Thunderbird, not Firefox!"""
    mozconfig = os.path.join(srcdir, "mozconfig")
    with open(mozconfig, "a") as mfp:
        mfp.write("ac_add_options --enable-project=comm/mail")
    return True


def main(args):
    parser = OptionParser()
    parser.add_option(
        "--artifact-mode",
        dest="artifact_mode",
        help="Build Thunderbird in Artifact mode. "
        "See https://firefox-source-docs.mozilla.org/contributing/build"
        "/artifact_builds.html for details.",
    )
    parser.add_option(
        "--vcs",
        dest="vcs",
        default="hg",
        choices=["git", "hg"],
        help="VCS (hg or git) to use for downloading the source code, "
        "instead of using the default interactive prompt.",
    )
    parser.add_option(
        "--no-interactive",
        dest="no_interactive",
        action="store_true",
        help="Answer yes to any (Y/n) interactive prompts.",
    )
    parser.add_option(
        "--no-system-changes",
        dest="no_system_changes",
        action="store_true",
        help="Only executes actions that leave the system " "configuration alone.",
    )

    options, leftover = parser.parse_args(args)

    try:
        srcdir = clone(options)
        if not srcdir:
            return 1
        print("Clone complete.")
        print(
            "If you need to run the tooling bootstrapping again, "
            "then consider running './mach bootstrap' instead."
        )
        if not options.no_interactive:
            remove_bootstrap_file = input(
                "Unless you are going to have more local copies of Firefox source code, "
                "this 'bootstrap.py' file is no longer needed and can be deleted. "
                "Clean up the bootstrap.py file? (Y/n)"
            )
            if not remove_bootstrap_file:
                remove_bootstrap_file = "y"
        if options.no_interactive or remove_bootstrap_file == "y":
            try:
                Path(sys.argv[0]).unlink()
            except FileNotFoundError:
                print("File could not be found !")
        bootstrap(
            srcdir,
            options.artifact_mode,
            options.no_interactive,
            options.no_system_changes,
        )
        return mozconfig(srcdir)
    except Exception:
        print("Could not bootstrap Thunderbird! Consider filing a bug.")
        raise


if __name__ == "__main__":
    sys.exit(main(sys.argv))