#!/usr/bin/env python3
from __future__ import absolute_import
from __future__ import print_function

import os
import glob
import subprocess
import sys
import time

# check for the venv
from lib import sanity_check
sanity_check.check_venv(__file__)

sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
os.environ['DJANGO_SETTINGS_MODULE'] = 'zproject.settings'
from django.conf import settings

from typing import Dict, List

os.chdir(settings.DEPLOY_ROOT)
STATIC_PATH = 'static/'

def get_templates():
    # type: () -> List[str]
    return (glob.glob(os.path.join(STATIC_PATH, 'templates/*.handlebars')) +
            glob.glob(os.path.join(STATIC_PATH, 'templates/settings/*.handlebars')))

def run():
    # type: () -> None
    subprocess.check_call(['node', 'node_modules/.bin/handlebars'] +
                          get_templates() +
                          ['--output', os.path.join(STATIC_PATH, 'templates/compiled.js'),
                           '--known', 'if,unless,each,with'])


def add_error_stamp_file(file_path):
    # type: (str) -> None
    file_dir = os.path.dirname(file_path)
    if not os.path.exists(file_dir):
        os.makedirs(file_dir)
    open(file_path, 'a').close()


def remove_error_stamp_file(file_path):
    # type: (str) -> None
    if os.path.exists(file_path):
        os.remove(file_path)


def run_forever():
    # type: () -> None
    # Keep polling for file changes, similar to how Django does it in
    # django/utils/autoreload.py.  If any of our templates change, rebuild
    # compiled.js
    mtimes = {}  # type: Dict[str, float]
    error_file_path = os.path.join(settings.DEPLOY_ROOT,
                                   'var/handlebars-templates/compile.error')
    while True:
        changed = False
        for fn in get_templates():
            new_mtime = os.stat(fn).st_mtime
            if new_mtime != mtimes.get(fn, None):
                changed = True
            mtimes[fn] = new_mtime
        if changed:
            print('Recompiling templates')
            try:
                run()
                remove_error_stamp_file(error_file_path)
                print('done')
            except Exception:
                add_error_stamp_file(error_file_path)
                print('\n\n\n\033[91mPLEASE FIX!!\033[0m\n\n')

        time.sleep(0.200)

if __name__ == '__main__':
    if len(sys.argv) == 2 and sys.argv[1] == 'forever':
        try:
            run_forever()
        except KeyboardInterrupt:
            print(sys.argv[0], "exited after receiving KeyboardInterrupt")
    else:
        run()