#!/usr/bin/env python3

# Zephyr launcher which is interoperable with:
#
# 1. "mono-repo" Zephyr installations that have 'make flash'
#    etc. supplied by a copy of some west code in scripts/meta.
#
# 2. "multi-repo" Zephyr installations where west is provided in a
#    separate Git repository elsewhere.
#
# This is basically a copy of the "wrapper" functionality in the west
# bootstrap script for the multi-repo case, plus a fallback onto the
# copy in scripts/meta/west for mono-repo installs.

import os
import sys

import colorama

if sys.version_info < (3,):
    sys.exit('fatal error: you are running Python 2')

# Top-level west directory, containing west itself and the manifest.
WEST_DIR = 'west'
# Subdirectory to check out the west source repository into.
WEST = 'west'
# File inside of WEST_DIR which marks it as the top level of the
# Zephyr project installation.
#
# (The WEST_DIR name is not distinct enough to use when searching for
# the top level; other directories named "west" may exist elsewhere,
# e.g. zephyr/doc/west.)
WEST_MARKER = '.west_topdir'


class WestNotFound(RuntimeError):
    '''Neither the current directory nor any parent has a West installation.'''


def find_west_topdir(start):
    '''Find the top-level installation directory, starting at ``start``.

    If none is found, raises WestNotFound.'''
    cur_dir = start

    while True:
        if os.path.isfile(os.path.join(cur_dir, WEST_DIR, WEST_MARKER)):
            return cur_dir

        parent_dir = os.path.dirname(cur_dir)
        if cur_dir == parent_dir:
            # At the root
            raise WestNotFound()
        cur_dir = parent_dir


def wrap(west_dir, argv):
    # Pull in the west main module, after adding the directory
    # containing the package to sys.path.
    sys.path.append(west_dir)
    import west.main

    # Invoke west's main with our arguments. It needs to be run from
    # this process for 'west debug' to work properly, so don't change
    # this code to running main in a subprocess.
    west.main.main(sys.argv[1:])


def main():
    # Figure out which west to run. If we're in a multirepo
    # installation, prefer the standalone west. Otherwise, we're in a
    # monorepo installation, so we need to fall back on the copy of
    # west in the Zephyr repository's scripts/meta directory.
    try:
        topdir = find_west_topdir(__file__)
        west_dir = os.path.join(topdir, 'west', 'west', 'src')
    except WestNotFound:
        west_dir = os.path.join(os.environ['ZEPHYR_BASE'], 'scripts', 'meta')

    try:
        wrap(west_dir, sys.argv[1:])
    finally:
        print(colorama.Fore.LIGHTRED_EX, end='')
        print('NOTE: you just ran a copy of west from {};'.
              format(os.path.dirname(__file__)),
              'this will be removed from the Zephyr repository in the future.',
              'West is now developed separately.')
        print(colorama.Style.RESET_ALL, end='', flush=True)


if __name__ == '__main__':
    main()