#!/bin/sh
# 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/.

# The beginning of this script is both valid POSIX shell and valid Python,
# such that the script starts with the shell and is reexecuted with
# the right Python.

# Embeds a shell script inside a Python triple quote. This pattern is valid
# shell because `''':'`, `':'` and `:` are all equivalent, and `:` is a no-op.
''':'
py2commands="
    analyze
    android
    android-emulator
    artifact
    awsy-test
    browsertime
    build
    build-backend
    buildsymbols
    cargo
    check-spidermonkey
    clang-format
    compileflags
    configure
    cppunittest
    cramtest
    crashtest
    devtools-css-db
    doctor
    empty-makefiles
    file-info
    firefox-ui-functional
    geckodriver
    geckodriver-test
    geckoview-junit
    gradle
    gtest
    hazards
    ide
    install
    jsapi-tests
    jsshell-bench
    jstestbrowser
    jstests
    marionette-test
    mochitest
    mozbuild-reference
    mozharness
    mozregression
    package
    package-multi-locale
    pastebin
    power
    prettier-format
    puppeteer-test
    python
    python-test
    raptor
    raptor-test
    reftest
    release
    release-history
    remote
    repackage
    resource-usage
    robocop
    run
    rusttests
    show-log
    static-analysis
    talos-test
    taskcluster-build-image
    taskcluster-load-image
    taskgraph
    telemetry-tests-client
    test
    test-info
    tps-build
    try
    valgrind-test
    visualmetrics
    warnings-list
    watch
    web-platform-tests
    web-platform-tests-update
    webidl-example
    webidl-parser-test
    webrtc-gtest
    wpt
    wpt-manifest-update
    wpt-metadata-merge
    wpt-metadata-summary
    wpt-serve
    wpt-test-paths
    wpt-unittest
    wpt-update
    xpcshell-test
"

run_py() {
    # Try to run a specific Python interpreter. Fall back to the system
    # default Python if the specific interpreter couldn't be found.
    py_executable="$1"
    shift
    if which "$py_executable" > /dev/null
    then
        exec "$py_executable" "$0" "$@"
    elif [ "$py_executable" = "python2.7" ]; then
        exec python "$0" "$@"
    else
        echo "This mach command requires $py_executable, which wasn't found on the system!"
        exit 1
    fi
}

first_arg=$1
if [ "$first_arg" = "help" ]; then
    # When running `./mach help <command>`, the correct Python for <command>
    # needs to be used.
    first_arg=$2
elif [ "$first_arg" = "mach-completion" ]; then
    # When running `./mach mach-completion /path/to/mach <command>`, the
    # correct Python for <command> needs to be used.
    first_arg=$3
fi

if [ -z "$first_arg" ]; then
    # User ran `./mach` or `./mach help`, use Python 3.
    run_py python3 "$@"
fi

case "${first_arg}" in
    "-"*)
        # We have global arguments which are tricky to parse from this shell
        # script. So invoke `mach` with a special --print-command argument to
        # return the name of the command. This adds extra overhead when using
        # global arguments, but global arguments are an edge case and this hack
        # is only needed temporarily for the Python 3 migration. We use Python
        # 2.7 because using Python 3 hits this error in build tasks:
        # https://searchfox.org/mozilla-central/rev/c7e8bc4996f9/build/moz.configure/init.configure#319
        command=`run_py python2.7 --print-command "$@" | tail -n1`
        ;;
    *)
        # In the common case, the first argument is the command.
        command=${first_arg};
        ;;
esac

# Check for the mach subcommand in the Python 2 commands list and run it
# with the correct interpreter.
case " $(echo $py2commands) " in
    *\ $command\ *)
        run_py python2.7 "$@"
        ;;
    *)
        run_py python3 "$@"
        ;;
esac

# Run Python 3 for everything else.
run_py python3 "$@"
'''

from __future__ import absolute_import, print_function, unicode_literals

import os
import sys

def ancestors(path):
    while path:
        yield path
        (path, child) = os.path.split(path)
        if child == "":
            break

def load_mach(dir_path, mach_path):
    if sys.version_info < (3, 5):
        import imp
        mach_bootstrap = imp.load_source('mach_bootstrap', mach_path)
    else:
        import importlib.util
        spec = importlib.util.spec_from_file_location('mach_bootstrap', mach_path)
        mach_bootstrap = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(mach_bootstrap)

    return mach_bootstrap.bootstrap(dir_path)


def check_and_get_mach(dir_path):
    bootstrap_paths = (
        'build/mach_bootstrap.py',
        # test package bootstrap
        'tools/mach_bootstrap.py',
    )
    for bootstrap_path in bootstrap_paths:
        mach_path = os.path.join(dir_path, bootstrap_path)
        if os.path.isfile(mach_path):
            return load_mach(dir_path, mach_path)
    return None


def setdefaultenv(key, value):
    """Compatibility shim to ensure the proper string type is used with
    os.environ for the version of Python being used.
    """
    encoding = "mbcs" if sys.platform == "win32" else "utf-8"

    if sys.version_info[0] == 2:
        if isinstance(key, unicode):
            key = key.encode(encoding)
        if isinstance(value, unicode):
            value = value.encode(encoding)
    else:
        if isinstance(key, bytes):
            key = key.decode(encoding)
        if isinstance(value, bytes):
            value = value.decode(encoding)

    os.environ.setdefault(key, value)


def get_mach():
    # Check whether the current directory is within a mach src or obj dir.
    for dir_path in ancestors(os.getcwd()):
        # If we find a "config.status" and "mozinfo.json" file, we are in the objdir.
        config_status_path = os.path.join(dir_path, 'config.status')
        mozinfo_path = os.path.join(dir_path, 'mozinfo.json')
        if os.path.isfile(config_status_path) and os.path.isfile(mozinfo_path):
            import json
            info = json.load(open(mozinfo_path))
            if 'mozconfig' in info:
                # If the MOZCONFIG environment variable is not already set, set it
                # to the value from mozinfo.json.  This will tell the build system
                # to look for a config file at the path in $MOZCONFIG rather than
                # its default locations.
                setdefaultenv('MOZCONFIG', info['mozconfig'])

            if 'topsrcdir' in info:
                # Continue searching for mach_bootstrap in the source directory.
                dir_path = info['topsrcdir']

        mach = check_and_get_mach(dir_path)
        if mach:
            return mach

    # If we didn't find a source path by scanning for a mozinfo.json, check
    # whether the directory containing this script is a source directory. We
    # follow symlinks so mach can be run even if cwd is outside the srcdir.
    return check_and_get_mach(os.path.dirname(os.path.realpath(__file__)))

def main(args):
    mach = get_mach()
    if not mach:
        print('Could not run mach: No mach source directory found.')
        sys.exit(1)
    sys.exit(mach.run(args))


if __name__ == '__main__':
    main(sys.argv[1:])