#!/usr/bin/env python3

import sys
import http.server
import socketserver
import threading
import os
import time
import select

import inotify.adapters

PORT = 8000

MONITORED_EVENT_TYPES = (
    'IN_CREATE',
    # 'IN_MODIFY',
    'IN_CLOSE_WRITE',
    'IN_DELETE',
    'IN_MOVED_FROM',
    'IN_MOVED_TO',
    'IN_DELETE_SELF',
    'IN_MOVE_SELF',
)

WAITING_RESPONSES = []
SLEEP_TIME = 0.5
COUNTER = 0
MAX_WAITS = 100

class Server(http.server.SimpleHTTPRequestHandler):
    def do_GET(self):
        if self.path.strip('/') == '__wait_for_changes':
            WAITING_RESPONSES.append(self)
            print(len(WAITING_RESPONSES), "waiting responses")
            global COUNTER
            ticket, COUNTER = COUNTER, COUNTER + 1

            while self in WAITING_RESPONSES:
                # This is an horribe way to wait! ... but it may work for quick tests 🤷

                if COUNTER - ticket > MAX_WAITS:
                    # Connection closed by the other side
                    print("Manually closed for cleanup")
                    WAITING_RESPONSES.remove(self)
                    # send 502 response, timeout
                    self.send_response(502)
                    # send response headers
                    self.end_headers()

                    return

                time.sleep(SLEEP_TIME)
            return

        # send 200 response
        self.send_response(200)
        # send response headers
        self.end_headers()

        with open(self.path.strip('/'), 'rb') as f:
            # send the body of the response
            self.wfile.write(f.read())

        if not self.path.endswith('.html'):
            return
        else:
            # Append update waiter
            with open('wait_for_update.js', 'rb') as f:
                new_data = b'<script>' + f.read() + b'</script>'
            self.wfile.write(new_data)
            new_data_len = len(new_data)

            return

def notify_reloads():
    while len(WAITING_RESPONSES) > 0:
        # Close opened connections
        res = WAITING_RESPONSES.pop(0)

        try:
            # send 200 response
            res.send_response(200)
            # send response headers
            res.end_headers()
        except Exception as e:
            print("ERROR:", e)

    global COUNTER
    COUNTER = 0


def start_notifier():
    notifier = inotify.adapters.InotifyTree(os.getcwd())
    for event in notifier.event_gen(yield_nones=False):
        (ev, types, directory, file) = event
        if any([type in MONITORED_EVENT_TYPES for type in types]):
            notify_reloads()

def serve():
    Handler = Server
    notifier_thread = threading.Thread(target=start_notifier)

    with http.server.ThreadingHTTPServer(("127.0.0.1", PORT), Handler) as httpd:
        print("serving at port", PORT)
        notifier_thread.start()
        httpd.serve_forever()


if __name__ == '__main__':
    serve()