#!/usr/bin/python

import requests
import re
import sys
import json
from datetime import datetime
from json.decoder import JSONDecodeError
import os


POLLING_TIMEOUT = 15 * 60  # 15 minutes

token = os.environ["MENSA_BOT_TOKEN"]  # the bot's token as obtained by the BotFather

pattern = re.compile("[a-zA-ZäöüÄÖÜ]{2}\s*@mensamap")

table_indices = {
    "a": [chr(i) for i in range(ord("a"), ord("o") + 1)],
    "b": [chr(i) for i in range(ord("a"), ord("t") + 1)],
    "c": [chr(i) for i in range(ord("a"), ord("z") + 1)] + ["ä", "ö", "ü"],
    "d": [chr(i) for i in range(ord("a"), ord("o") + 1)],
    "e": [chr(i) for i in range(ord("a"), ord("s") + 1)],
    "f": [chr(i) for i in range(ord("a"), ord("m") + 1)],
    "g": [chr(i) for i in range(ord("a"), ord("s") + 1)],
    "h": [chr(i) for i in range(ord("a"), ord("h") + 1)],
    "i": [chr(i) for i in range(ord("a"), ord("f") + 1)]
}

def log(text, log_file, prepend_time=False):
    if not log_file:
        return
    if prepend_time:
        log_file.write(str(datetime.now()) + ':\n')
        log_file.flush()
    log_file.buffer.write(text.encode("utf-8"))
    log_file.flush()

def send_image(path, chat_id, log_file):
    try:
        for old, new in [('ä', 'ae'), ('ö', 'oe'), ('ü', 'ue')]:
            path = path.replace(old, new)
        url = f"https://api.telegram.org/bot{token}/sendPhoto";
        data = {'chat_id' : chat_id, 'photo': f'http://leafbla.de/mensa/img/{path}'}
        log(f"  SENDING IMAGE:\n    file name = {path}\n    chat id = {chat_id}\n", log_file)
        r = requests.post(url, data=data)
    except:
        pass

def send_map(message, chat_id, log_file):
    try:
        m = pattern.search(message)
        command = m.group()
        loc = command[:2].lower()
        grp = loc[0]
        idx = loc[1]
        log(f"  FOUND COMMAND:\n    text = \"{command}\"\n    group = {grp}\n    table = {idx}\n", log_file)
        if idx in table_indices[grp]:
            send_image(f"{loc}.png", chat_id, log_file)
    except (AttributeError, IndexError, KeyError):
        pass

def get_inline_query_result(s):
    for old, new in [('ä', 'ae'), ('ö', 'oe'), ('ü', 'ue')]:
        s = s.replace(old, new)

    return {
        "type": "photo",
        "id": s,
        "photo_url": "http://leafbla.de/mensa/img/" + s + ".png",
        "thumb_url": "http://leafbla.de/mensa/thumbs/" + s + ".png",
        }

def answer_inline_query(query_id, request, log_file):
    print("answer_inline_query")
    print(query_id, request, log_file)
    if len(request) == 0:
        print("handle empty request")
        results = json.dumps(
                {
                    "type": "photo",
                    "id": 1,
                    "photo_url": "https://gitea.leafbla.de/img/gitea-lg.png",
                    "thumb_url": "https://gitea.leafbla.de/img/gitea-lg.png",
                    }
                )
    if len(request) == 1 and request in table_indices:
        results = json.dumps([get_inline_query_result(request + s1) for s1 in table_indices[request]])
    elif len(request) == 2 and request[0] in table_indices and request[1] in table_indices[request[0]]:
        results = json.dumps([get_inline_query_result(request)])
    else:
        results = "[]"

    data = {
        "inline_query_id": query_id,
        "results": results
    }
    log(f"  ANSWERING INLINE QUERY:\n    request = {request}\n    query id = {query_id}\n", log_file)
    requests.post(f"https://api.telegram.org/bot{token}/answerInlineQuery", data=data)

def run(log_file=None):
    update_id = None
    while True:
        url = f"https://api.telegram.org/bot{token}/getUpdates"
        data = {'timeout': POLLING_TIMEOUT}
        if update_id is not None:
            data['offset'] = update_id
        log(f"  REQUESTING UPDATE:\n    timeout = {data['timeout']}\n    offset = {update_id}\n", log_file, prepend_time=True)
        response = requests.post(url, data=data)
        log("  RECEIVED RESPONSE:\n", log_file, prepend_time=True)
        try:
            j = response.json()
            update_id = j["result"][-1]["update_id"] + 1
            result = j["result"][-1]
            if "message" in result:
                msg = result["message"]
                chat_id = msg["chat"]["id"]
                text = msg["text"]
                log(f"    update id = {update_id}\n    chat id = {chat_id}\n    text = \"{text}\"\n", log_file)
                send_map(text, chat_id, log_file)
            elif "inline_query" in result:
                msg = result["inline_query"]
                query_id = msg["id"]
                request = msg["query"]
                answer_inline_query(query_id, request, log_file)
        except (IndexError, KeyError, JSONDecodeError):
            log("    no new messages\n", log_file)

if __name__ == "__main__":
    try:
        path = sys.argv[1] if len(sys.argv) > 1 else None
        if path == "stdout":
            run(log_file=sys.stdout)
        elif path:
            run(log_file=open(path, 'a'))
        else:
            run()
    except KeyboardInterrupt:
        pass