#!/usr/bin/env python

from __future__ import print_function
from contextlib import contextmanager
import os
import argparse
import functools
import glob
import shutil
import tempfile

from git import Repo
import crayons
import twine.commands.upload
import setuptools.sandbox

REPO_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
repo = Repo(REPO_DIR)
git = repo.git

@contextmanager
def cd(newdir):
    prevdir = os.getcwd()
    os.chdir(os.path.expanduser(newdir))
    try:
        yield
    finally:
        os.chdir(prevdir)

def _generate_dist(dist_type, setup_file, package_name, setup_args):
    message = 'Generating {dist_type} for {package_name}.'.format(
        dist_type=dist_type,
        package_name=package_name,
    )
    print(crayons.white(message, bold=True))

    setup_dir = os.path.dirname(setup_file)
    with cd(setup_dir):
        setuptools.sandbox.run_setup(setup_file, setup_args)

    message = '{dist_type} for {package_name} generated under {dir}.\n'.format(
        dist_type=dist_type,
        package_name=package_name,
        dir=setup_dir,
    )
    print(crayons.green(message, bold=True))

def generate_sdist(setup_file, package_name):
    _generate_dist('sdist', setup_file, package_name, ['sdist'])

def generate_bdist_wheel_universal(setup_file, package_name):
    _generate_dist('bdist_wheel', setup_file, package_name,
                   ['bdist_wheel', '--universal'])

def twine_upload(dist_dirs):
    message = 'Uploading distributions under the following directories:'
    print(crayons.green(message, bold=True))
    for dist_dir in dist_dirs:
        print(crayons.yellow(dist_dir))
    twine.commands.upload.main(dist_dirs)

def cleanup(package_dir):
    build_dir = os.path.join(package_dir, 'build')
    temp_dir = os.path.join(package_dir, 'temp')
    dist_dir = os.path.join(package_dir, 'dist')
    egg_info = os.path.join(
        package_dir,
        '{}.egg-info'.format(os.path.basename(package_dir))
    )
    version_symlink = os.path.join(package_dir, 'version.py')

    def _rm_if_it_exists(directory):
        if os.path.isdir(directory):
            print(crayons.green('Removing {}/*.'.format(directory), bold=True))
            shutil.rmtree(directory)

    map(_rm_if_it_exists, [build_dir, temp_dir, dist_dir, egg_info])

    if os.path.islink(version_symlink):
        print(crayons.green('Removing {}.'.format(version_symlink), bold=True))
        os.remove(version_symlink)

def set_variable(fp, variable, value):
    fh, temp_abs_path = tempfile.mkstemp()
    with os.fdopen(fh, 'w') as new_file, open(fp) as old_file:
        for line in old_file:
            if line.startswith(variable):
                if isinstance(value, bool):
                    template = '{variable} = {value}\n'
                else:
                    template = '{variable} = "{value}"\n'
                new_file.write(template.format(variable=variable, value=value))
            else:
                new_file.write(line)

    os.remove(fp)
    shutil.move(temp_abs_path, fp)

    message = 'Set {variable} in {fp} to {value}.'.format(
        fp=fp, variable=variable, value=value)
    print(crayons.white(message, bold=True))

def push_release_tag(version, upstream_or_origin):
    print(crayons.yellow('Pushing release tag {}...'.format(version), bold=True))
    git.tag(version)
    git.push(upstream_or_origin, version)

def commit_and_push_version_changes(version, init_files, upstream_or_origin):
    message = 'Committing version number changes...{}'.format(version)
    print(crayons.yellow(message, bold=True))

    if upstream_or_origin == 'origin':
        branch = 'release-{}'.format(version)
        git.checkout('-b', branch)
    else:
        branch = 'master'
        git.checkout(branch)

    print(crayons.yellow('Diff:'))
    print(git.diff())

    git.add(*init_files)
    commit_msg = 'python-zulip-api: Upgrade package versions to {}.'.format(
        version)
    print(crayons.yellow('Commit message: {}'.format(commit_msg), bold=True))
    git.commit('-m', commit_msg)

    git.push(upstream_or_origin, branch)

def update_requirements_in_zulip_repo(zulip_repo_dir, version, hash_or_tag):
    common = os.path.join(zulip_repo_dir, 'requirements', 'common.txt')
    prod_lock = os.path.join(zulip_repo_dir, 'requirements', 'prod_lock.txt')
    dev_lock = os.path.join(zulip_repo_dir, 'requirements', 'dev_lock.txt')
    version_py = os.path.join(zulip_repo_dir, 'version.py')

    def _edit_reqs_file(reqs, zulip_bots_line, zulip_line):
        fh, temp_abs_path = tempfile.mkstemp()
        with os.fdopen(fh, 'w') as new_file, open(reqs) as old_file:
            for line in old_file:
                if 'python-zulip-api' in line and 'zulip==' in line:
                    new_file.write(zulip_line)
                elif 'python-zulip-api' in line and 'zulip_bots' in line:
                    new_file.write(zulip_bots_line)
                else:
                    new_file.write(line)

        os.remove(reqs)
        shutil.move(temp_abs_path, reqs)

    url_zulip = 'git+https://github.com/zulip/python-zulip-api.git@{tag}#egg={name}=={version}_git&subdirectory={name}\n'
    url_zulip_bots = 'git+https://github.com/zulip/python-zulip-api.git@{tag}#egg={name}=={version}+git&subdirectory={name}\n'
    zulip_bots_line = url_zulip_bots.format(tag=hash_or_tag, name='zulip_bots',
                                            version=version)
    zulip_line = url_zulip.format(tag=hash_or_tag, name='zulip',
                                  version=version)

    map(functools.partial(
        _edit_reqs_file,
        zulip_bots_line=zulip_bots_line,
        zulip_line=zulip_line,
    ), [prod_lock, dev_lock])

    editable_zulip = '-e "{}"\n'.format(url_zulip.rstrip())
    editable_zulip_bots = '-e "{}"\n'.format(url_zulip_bots.rstrip())

    _edit_reqs_file(
        common,
        editable_zulip_bots.format(tag=hash_or_tag, name='zulip_bots', version=version),
        editable_zulip.format(tag=hash_or_tag, name='zulip', version=version),
    )

    message = 'Updated zulip API package requirements in the main repo.'
    print(crayons.white(message, bold=True))

    fh, temp_abs_path = tempfile.mkstemp()
    with os.fdopen(fh, 'w') as new_file, open(version_py) as old_file:
        variable_exists = False
        for line in old_file:
            if line.startswith('PROVISION_VERSION'):
                variable_exists = True
                version_num = float(line.split('=')[-1].strip().replace("'", ''))
                version_num = version_num + 0.01
                new_file.write("PROVISION_VERSION = '{}'\n".format(version_num))
            else:
                new_file.write(line)

        if not variable_exists:
            raise Exception('There is no variable named PROVISION_VERSION in {}'.format(version_py))

    os.remove(version_py)
    shutil.move(temp_abs_path, version_py)

    message = 'Incremented PROVISION_VERSION in the main repo.'
    print(crayons.white(message, bold=True))

def commit_and_push_requirements_changes(version, upstream_or_origin,
                                         zulip_repo_dir):
    zulip_repo_dir = os.path.abspath(zulip_repo_dir)
    common = os.path.join(zulip_repo_dir, 'requirements', 'common.txt')
    prod_lock = os.path.join(zulip_repo_dir, 'requirements', 'prod_lock.txt')
    dev_lock = os.path.join(zulip_repo_dir, 'requirements', 'dev_lock.txt')
    version_py = os.path.join(zulip_repo_dir, 'version.py')

    with cd(zulip_repo_dir):
        zulip_git = Repo(zulip_repo_dir).git

        message = 'Committing requirements changes...{}'.format(version)
        print(crayons.yellow(message, bold=True))

        if upstream_or_origin == 'origin':
            branch = 'upgrade-zulip-packages-{}'.format(version)
            zulip_git.checkout('-b', branch)
        else:
            branch = 'master'
            zulip_git.checkout(branch)

        print(crayons.yellow('Diff:'))
        print(zulip_git.diff())

        zulip_git.add(common, prod_lock, dev_lock, version_py)

        commit_msg = 'requirements: Upgrade to version {} of the Zulip API packages.'.format(version)
        print(crayons.yellow('Commit message: {}'.format(commit_msg), bold=True))
        zulip_git.commit('-m', commit_msg)

        zulip_git.push(upstream_or_origin, branch)

def parse_args():
    usage = """
Script to automate the PyPA release of the zulip, zulip_bots and
zulip_botserver packages.

To make a release, execute the following steps in order:

1. Run ./tools/provision
2. Activate the virtualenv created by tools/provision
3. For example, to make a release for version 0.3.5, run the
   following command:

./tools/release-packages 0.3.5 --build --release --push origin \
    --update-zulip-main-repo "/home/username/zulip"

The above command would accomplish the following (in order):

1. Increment the __version__ in zulip/__init__.py,
   zulip_bots/__init__.py and zulip_botserver/__init__.py.
2. --build: Build sdists and universal wheels for all packages.
   The sdists and wheels for a specific package are under
   <package_name>/dist/.
3. --release: Upload all dists under <package_name>/dist/* to
   PyPA using twine.
4. --update-zulip-main-repo: Update the requirements/ in the main
   zulip repo to install off of the newest version of the packages.
   Also increments PROVISION_VERSION in the main repo.
5. --push origin: Commit the changes produced in Step 1 and 4,
   checkout a new branch named release-<version>, generate a commit
   message, commit the changes and push the branch to origin.
"""
    parser = argparse.ArgumentParser(usage=usage)

    parser.add_argument('release_version',
                        help='The new version number of the packages.')

    parser.add_argument('--cleanup', '-c',
                        action='store_true',
                        default=False,
                        help='Remove build directories (dist/, build/, egg-info/, etc).')

    parser.add_argument('--build', '-b',
                        action='store_true',
                        default=False,
                        help=('Build sdists and wheels for all packages.'
                              ' sdists and wheels are stored in <package_name>/dist/*.'))

    parser.add_argument('--release', '-r',
                        action='store_true',
                        default=False,
                        help='Upload the packages to PyPA using twine.')

    parser.add_argument('--push',
                        metavar='origin or upstream',
                        help=('Commit and push a commit changing package versions'
                              ' (can be either "origin" or "upstream"). If "origin'
                              ' is specified, a new branch named release-<version> is'
                              ' checked out before committing and pushing. If'
                              ' "upstream" is supplied, then master is checked out'
                              ' before committing and pushing. The process is the'
                              ' same for changes made to both repos.'))

    parser.add_argument('--update-zulip-main-repo',
                        metavar='PATH_TO_ZULIP_DIR',
                        help='Update requirements/* in the main zulip repo and'
                             ' increment PROVISION_VERSION.')

    parser.add_argument('--hash',
                        help=('Commit hash to install off of in the main zulip'
                              ' repo (used in conjunction with'
                              ' --update-requirements). If not supplied,'
                              ' release_version is used as a tag.'))

    return parser.parse_args()

def main():
    options = parse_args()

    zulip_init = os.path.join(REPO_DIR, 'zulip', 'zulip', '__init__.py')
    set_variable(zulip_init, '__version__', options.release_version)
    bots_setup = os.path.join(REPO_DIR, 'zulip_bots', 'setup.py')
    set_variable(bots_setup, 'ZULIP_BOTS_VERSION', options.release_version)
    set_variable(bots_setup, 'IS_PYPA_PACKAGE', True)
    botserver_setup = os.path.join(REPO_DIR, 'zulip_botserver', 'setup.py')
    set_variable(botserver_setup, 'ZULIP_BOTSERVER_VERSION', options.release_version)

    glob_pattern = os.path.join(REPO_DIR, '*', 'setup.py')
    setup_py_files = glob.glob(glob_pattern)

    if options.build:
        for setup_file in setup_py_files:
            package_name = os.path.basename(os.path.dirname(setup_file))
            if package_name == 'zulip_bots':
                setuptools.sandbox.run_setup(
                    setup_file, ['gen_manifest', '--release']
                )
            generate_sdist(setup_file, package_name)
            generate_bdist_wheel_universal(setup_file, package_name)

    if options.release:
        dist_dirs = glob.glob(os.path.join(REPO_DIR, '*', 'dist', '*'))
        twine_upload(dist_dirs)

    if options.update_zulip_main_repo:
        if options.hash:
            update_requirements_in_zulip_repo(
                options.update_zulip_main_repo,
                options.release_version,
                options.hash
            )
        else:
            update_requirements_in_zulip_repo(
                options.update_zulip_main_repo,
                options.release_version,
                options.release_version
            )

    if options.push:
        set_variable(zulip_bots_init, 'IS_PYPA_PACKAGE', False)
        if options.update_zulip_main_repo:
            commit_and_push_requirements_changes(
                options.release_version,
                options.push,
                options.update_zulip_main_repo,
            )
        push_release_tag(options.release_version, options.push)
        commit_and_push_version_changes(options.release_version,
                                        init_files, options.push)

    if options.cleanup:
        package_dirs = map(os.path.dirname, setup_py_files)
        map(cleanup, package_dirs)

if __name__ == '__main__':
    main()