#!/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 datetime
import os
import subprocess
import sys
import time
from distutils.spawn import find_executable
from textwrap import wrap

here = os.path.dirname(os.path.abspath(__file__))
MOZHARNESS_WORKDIR = os.path.expanduser(os.path.join('~', 'workspace', 'build'))

MACH_SETUP_FINISHED = """
Mozharness has finished downloading the build and tests to:
{}

A limited mach environment has also been set up and added to the $PATH, but
it may be missing the command you need. To see a list of commands, run:
    $ mach help
""".lstrip().format(MOZHARNESS_WORKDIR)

MACH_SETUP_FAILED = """
Could not set up mach environment, no mach binary detected.
""".lstrip()


def call(cmd, **kwargs):
    print(" ".join(cmd))
    return subprocess.call(cmd, **kwargs)


def wait_for_run_mozharness(timeout=60):
    starttime = datetime.datetime.now()
    while datetime.datetime.now() - starttime < datetime.timedelta(seconds=timeout):
        if os.path.isfile(os.path.join(here, 'run-mozharness')):
            break
        time.sleep(0.2)
    else:
        print("Timed out after %d seconds waiting for the 'run-mozharness' binary" % timeout)
        return 1


def setup_mach_environment():
    mach_src = os.path.join(MOZHARNESS_WORKDIR, 'tests', 'mach')
    if not os.path.isfile(mach_src):
        return 1

    mach_dest = os.path.expanduser(os.path.join('~', 'bin', 'mach'))
    if os.path.exists(mach_dest):
        os.remove(mach_dest)
    os.symlink(mach_src, mach_dest)
    return 0


def run_mozharness(*args):
    wait_for_run_mozharness()
    try:
        return call(['run-mozharness'] + list(args))
    finally:
        setup_mach_environment()


def setup():
    """Run the mozharness script without the 'run-tests' action.

    This will do all the necessary setup steps like creating a virtualenv and
    downloading the tests and firefox binary. But it stops before running the
    tests.
    """
    status = run_mozharness('--no-run-tests')

    if find_executable('mach'):
        print(MACH_SETUP_FINISHED)
    else:
        print(MACH_SETUP_FAILED)

    return status


def clone():
    """Clone the correct gecko repository and update to the proper revision."""
    base_repo = os.environ['GECKO_HEAD_REPOSITORY']
    dest = os.path.expanduser(os.path.join('~', 'gecko'))

    # Specify method to checkout a revision. This defaults to revisions as
    # SHA-1 strings, but also supports symbolic revisions like `tip` via the
    # branch flag.
    if os.environ.get('GECKO_HEAD_REV'):
        revision_flag = b'--revision'
        revision = os.environ['GECKO_HEAD_REV']
    elif os.environ.get('GECKO_HEAD_REF'):
        revision_flag = b'--branch'
        revision = os.environ['GECKO_HEAD_REF']
    else:
        print('revision is not specified for checkout')
        return 1

    # TODO Bug 1301382 - pin hg.mozilla.org fingerprint.
    call([
        b'/usr/bin/hg', b'robustcheckout',
        b'--sharebase', os.environ['HG_STORE_PATH'],
        b'--purge',
        b'--upstream', b'https://hg.mozilla.org/mozilla-unified',
        revision_flag, revision,
        base_repo, dest
    ])
    print("Finished cloning to {} at revision {}.".format(dest, revision))


def exit():
    pass


OPTIONS = [
    ('Resume task', run_mozharness,
     "Resume the original task without modification. This can be useful for "
     "passively monitoring it from another shell."),
    ('Setup task', setup,
     "Setup the task (download the application and tests) but don't run the "
     "tests just yet. The tests can be run with a custom configuration later. "
     "This will provide a mach environment (experimental)."),
    ('Clone gecko', clone,
     "Perform a clone of gecko using the task's repo and update it to the "
     "task's revision."),
    ('Exit', exit, "Exit this wizard and return to the shell.")
]


def _fmt_options():
    max_line_len = 60
    max_name_len = max(len(o[0]) for o in OPTIONS)

    # TODO Pad will be off if there are more than 9 options.
    pad = ' ' * (max_name_len+6)

    msg = []
    for i, (name, _, desc) in enumerate(OPTIONS):
        desc = wrap(desc, width=max_line_len)
        desc = [desc[0]] + [pad + l for l in desc[1:]]

        optstr = '{}) {} - {}\n'.format(
            i+1, name.ljust(max_name_len), '\n'.join(desc))
        msg.append(optstr)
    msg.append("Select one of the above options: ")
    return '\n'.join(msg)


def wizard():
    print("This wizard can help you get started with some common debugging "
          "workflows.\nWhat would you like to do?\n")
    print(_fmt_options(), end="")
    choice = None
    while True:
        choice = raw_input().decode('utf8')
        try:
            choice = int(choice)-1
            if 0 <= choice < len(OPTIONS):
                break
        except ValueError:
            pass

        print("Must provide an integer from 1-{}:".format(len(OPTIONS)))

    func = OPTIONS[choice][1]
    ret = func()

    print("Use the 'run-wizard' command to start this wizard again.")
    return ret


if __name__ == '__main__':
    sys.exit(wizard())