#!/usr/bin/python3

# For description and usage, see the argparse options at the end of the file

import argparse
import os
import sys
import yaml


def check_open_pull_requests():
    from github import Github

    g = Github()
    for formula, data in FORMULAS.items():
        open_pull_requests = data.get('pending', [])
        if open_pull_requests:
            namespace = data.get('original_namespace', 'saltstack-formulas')
            prefix = data.get('prefix', '')
            org = g.get_organization(namespace)
            for pull_request in open_pull_requests:
                pr = int(pull_request.split('/')[-1])
                state = org.get_repo('%s%s-formula' % (prefix, formula)).get_pull(pr).state
                print('%s is %s' % (pull_request, state))


def git(cmd, cwd=None):
    # pygit2 is not available for python3 in Leap, use plain git instead

    import subprocess

    status = subprocess.call(['git'] + cmd, cwd=cwd)
    if status != 0:
        sys.exit(status)


def clone(CLONE_FROM, CLONE_BRANCH, DEST, USE_PYGIT2):
    def clone_repo():
        FULL_PATH = '%s/%s-formula' % (DEST, formula)
        if os.path.isdir(FULL_PATH):
            return

        if USE_PYGIT2:
            import pygit2

            pygit2.clone_repository(url, FULL_PATH, bare=False)
        else:
            if not os.path.exists(DEST):
                os.mkdir(DEST)
            git(['clone', '-q', url, FULL_PATH] + branch_opts)

    branch_opts = []
    if CLONE_BRANCH:
        branch_opts = ['-b', CLONE_BRANCH, '--single-branch']
    if CLONE_FROM:
        for formula in FORMULAS.keys():
            url = '%s/%s-formula' % (CLONE_FROM, formula)
            clone_repo()
    else:
        for formula, data in FORMULAS.items():
            namespace = data.get('namespace', 'saltstack-formulas')
            prefix = data.get('prefix', '')
            url = 'https://github.com/%s/%s%s-formula' % (namespace, prefix, formula)
            clone_repo()


def create_symlinks(DEST):
    for formula in FORMULAS.keys():
        FULL_PATH = '/srv/salt/%s' % formula
        if not os.path.islink(FULL_PATH):
            os.symlink('%s/%s-formula/%s' % (DEST, formula, formula), FULL_PATH)


def remove_symlinks():
    for formula in FORMULAS.keys():
        FULL_PATH = '/srv/salt/%s' % formula
        if os.path.islink(FULL_PATH):
            os.unlink(FULL_PATH)


def fetch_remote(remote, formula):
    from pygit2.errors import GitError
    import pygit2

    remotecallbacks = None
    if not remote.url.startswith(('http://', 'https://', 'git://', 'ssh://', 'git+ssh://')):
        username = remote.url.split('@')[0]
        credentials = pygit2.KeypairFromAgent(username)
        remotecallbacks = pygit2.RemoteCallbacks(credentials=credentials)
    try:
        remote.fetch(callbacks=remotecallbacks)
    except GitError:
        print('%s-formula: Failed to fetch remote %s' % (formula, remote.name))


def add_remote(REMOTES, DEST):
    import pygit2

    for remote in REMOTES:
        namespace = None
        if len(remote) == 4:
            namespace = remote.pop()

        url = 'https://github.com'
        if len(remote) == 3:
            url = remote.pop()

        prefix = ''
        use_prefix = False
        if not remote[1].startswith('no'):
            use_prefix = True

        name = remote[0]

        for formula, data in FORMULAS.items():
            if not namespace:
                namespace = data.get('namespace', 'saltstack-formulas')
            if use_prefix:
                prefix = data.get('prefix', '')
            if not url.endswith(':'):
                url += '/'
            full_url = '%s%s/%s%s-formula' % (url, namespace, prefix, formula)
            FULL_PATH = '%s/%s-formula' % (DEST, formula)
            repo = pygit2.Repository(FULL_PATH)
            try:
                repo.create_remote(name, full_url)
            except ValueError:  # remote already exists
                continue
            fetch_remote(repo.remotes[name], formula)


def update(REMOTES, DEST):
    import pygit2

    for formula in FORMULAS.keys():
        FULL_PATH = '%s/%s-formula' % (DEST, formula)
        repo = pygit2.Repository(FULL_PATH)
        git(['checkout', '-qB', 'master', 'origin/master'], cwd=FULL_PATH)
        git(['pull', '-q'], cwd=FULL_PATH)
        if REMOTES:
            for remote in REMOTES:
                fetch_remote(repo.remotes[remote], formula)


def push(REMOTES, DEST):
    import pygit2

    for formula in FORMULAS.keys():
        FULL_PATH = '%s/%s-formula' % (DEST, formula)
        repo = pygit2.Repository(FULL_PATH)
        git(['checkout', '-qB', 'master', 'origin/master'], cwd=FULL_PATH)
        for remote in REMOTES:
            git(['push', '-qf', remote, 'master'], cwd=FULL_PATH)
            git(['push', '-qf', remote, 'master:production'], cwd=FULL_PATH)
            fetch_remote(repo.remotes[remote], formula)


def checkout_remote_and_branch(REMOTE_BRANCH, DEST):
    for formula in FORMULAS.keys():
        FULL_PATH = '%s/%s-formula' % (DEST, formula)
        branch = REMOTE_BRANCH.split('/')[1]
        git(['checkout', '-qB', branch, REMOTE_BRANCH], cwd=FULL_PATH)


with open('FORMULAS.yaml', 'r') as f:
    FORMULAS = yaml.load(f)

parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter, description='Loads the formulas from FORMULAS.yaml and performs one or more of the operations specified at the arguments.')
parser.add_argument('-q', '--pull-requests', action='store_true', help='Prints the status of the Pull Requests that are defined in FORMULAS.yaml under "pending".')
parser.add_argument('-d', '--destination', nargs=1, help='Destination absolute path of the cloned (or to-be-cloned) repositories of the formulas.')
parser.add_argument('-c', '--clone', action='store_true', help='Clone the formulas to the destination specified with "--destination".')
parser.add_argument('--clone-from', nargs=1, help='Specify the git provider to clone from together with the namespace.')
parser.add_argument('--clone-branch', nargs=1, help='Specify the branch to clone.')
parser.add_argument('-s', '--symlink', action='store_true', help='Creates symlink from the specified destination to /srv/salt.')
parser.add_argument('--remove-symlinks', action='store_true', help='Removes all symlinks that were created in /srv/salt.')
parser.add_argument('-r', '--add-remote', action='append', nargs='+', help='''Add the specified remotes on the local repositories. It can be passed multiple times.
Usage: REMOTE_NAME USE_PREFIXES [GIT_PROVIDER_URL] [NAMESPACE].
       - REMOTE is string
       - USE_PREFIXES should be a string starting with "no" (for no prefix usage), or whatever else string (for prefix usage)
       - GIT_URL (optional) can be in the form "https://gitlab.example.com" or "git@gitlab.example.com:" (make sure you have the trailing colon). If no git provider URL is given, https://github.com will be used.
       - NAMESPACE (optional) is string. If no namespace is given, the one defined in FORMULAS.yaml will be used.
Examples:
         -r forks_ro prefixes
         -r forks_rw prefixes git@github.com:
         -r mycompany no_prefixes https://gitlab.mycompany.com saltstack-formulas
         -r mycompany_forks no_prefixes git@gitlab.mycompany.com: saltstack-formulas''')
parser.add_argument('-u', '--update', nargs='*', help='Switch to origin/master and git pull. Optionally it can accept a list of remotes as arguments, that will be fetched.')
parser.add_argument('-p', '--push', nargs='+', help='Pushes (with --force) to the given list of remotes from origin/master to their master and production branch, and then fetches them.')
parser.add_argument('--checkout', nargs=1, help='Checkout to the specified remote/branch.')
parser.add_argument('--use-pygit2', action='store_true', help='Use pygit2 instead of invoking git whenever possible.')
args = parser.parse_args()

will_run = False

if args.pull_requests:
    will_run = True
    check_open_pull_requests()

if args.remove_symlinks:
    will_run = True
    remove_symlinks()

# Every option below requires the --destination argument to be set
if args.clone or args.symlink or args.clone_from or args.clone_branch or args.add_remote or type(args.update) == list or args.push or args.checkout:
    will_run = True

    if (args.clone_from or args.clone_branch) and not args.clone:
        parser.print_help()
        sys.exit(1)

    if not args.destination or not os.path.isabs(args.destination[0]):
        parser.print_help()
        sys.exit(1)

    if args.add_remote:
        for remote in args.add_remote:
            if len(remote) < 2:
                parser.print_help()
                sys.exit(1)

    if args.clone:
        clone_from = None
        clone_branch = None
        if args.clone_from:
            clone_from = args.clone_from[0]
        if args.clone_branch:
            clone_branch = args.clone_branch[0]
        clone(clone_from, clone_branch, args.destination[0], args.use_pygit2)

    if args.symlink:
        create_symlinks(args.destination[0])

    if args.add_remote:
        add_remote(args.add_remote, args.destination[0])

    if type(args.update) == list:
        update(args.update, args.destination[0])

    if args.push:
        push(args.push, args.destination[0])

    if args.checkout:
        checkout_remote_and_branch(args.checkout[0], args.destination[0])

if not will_run:
    parser.print_help()
    sys.exit(1)