from __future__ import with_statement
from fabric.api import env, local, sudo, settings, hide, run, prompt
from fabric.utils import warn

def vagrant():
    env.user = 'vagrant'
    env.hosts = ['127.0.0.1:2222']

    result = local('vagrant global-status | grep running', capture=True)
    machineId = result.split()[0]

    result = local('vagrant ssh-config | grep IdentityFile'.format(machineId), capture=True)
    env.key_filename = result.split()[1]

def install_postgresql():
    # First ensure that MySQL has not already been installed
    if package_installed('postgresql') and package_installed('postgresql-contrib'):
        warn('PostgreSQL has already been installed')
        return

    # Prompt the user for a Postgres username and password
    pg_username = prompt('Please input your postgres username:')
    if (pg_username == "user"):
        warn('Cannot name your user "user"')
        return
    pg_password = prompt('Please input your postgres password:')
    pg_password_again = prompt('Please input your postgres password again:')
    if (pg_password != pg_password_again):
        warn('Passwords must match')
        return
    pg_db = prompt('Please input your postgres database name:')

    if not package_installed('postgresql'):
        apt_get('postgresql')

    if not package_installed('postgresql-contrib'):
        apt_get('postgresql-contrib')

    # Update config files
    postgresqlconf_path = sudo('find / -name "postgresql.conf"')

    sudo('sed -i "/^#listen_addresses.*/ s/^#//" %s' % postgresqlconf_path)
    sudo('sed -i "/^listen_addresses.*/ s/\'localhost\'/\'\*\'/" %s' % postgresqlconf_path)

    pg_hba_conf_path = sudo('find / -name "pg_hba.conf"')
    lines = "host all all 0.0.0.0/0 md5\nhost all all ::/0 md5"
    sudo("echo '%s' >> %s" % (lines, pg_hba_conf_path))
    sudo('service postgresql restart')

    # Create postgres user and password
    if not is_pg_user(pg_username):
        run_pg_command('''psql -t -A -c "CREATE USER %s WITH PASSWORD '%s';"''' % (pg_username, pg_password))

    # Create database
    if not is_pg_db(pg_db):
        run_pg_command('createdb %s -O %s' % (pg_db, pg_username))

# Utils
def run_pg_command(command):
    return sudo('sudo -u postgres %s' % command)

def is_pg_user(username):
    with settings(hide('running', 'stdout', 'stderr', 'warnings'), warn_only=True):
        return run_pg_command('''psql -t -A -c "SELECT COUNT(*) FROM pg_user WHERE usename = '%s';"''' % username) == "1"

def is_pg_db(db):
    with settings(hide('running', 'stdout', 'stderr', 'warnings'), warn_only=True):
        return run_pg_command('''psql -t -A -c "SELECT COUNT(*) FROM pg_database WHERE datname = '%s';"''' % db) == "1"

def package_installed(pkg_name):
    cmd_f = 'dpkg-query -l "%s" | grep -q ^.i'
    cmd = cmd_f % (pkg_name)
    with settings(hide('warnings', 'stderr'), warn_only=True):
        result = run(cmd)
    return result.succeeded

def apt_get(*packages):
    sudo('apt-get -y --no-upgrade install %s' % ' '.join(packages), shell=False)