import json
import time
import random
import re
import logging

import requests


API_KEY = 'AIzaSyA-dlBUjVQeuc4a6ZN4RkNUYDFddrVLxrA'
BASE_URL = 'https://www.googleapis.com/youtube/v3/'


## Creates error logger with handler
def make_error_logger(filename):
    handler = logging.FileHandler(filename)
    handler.setLevel(logging.ERROR)
    formatter = logging.Formatter("%(asctime)s|%(levelname)s|%(message)s",
                                  "%Y-%m-%d %H:%M:%S")
    handler.setFormatter(formatter)
    logger = logging.getLogger(__name__)
    logger.addHandler(handler)
    return logger


## Input: list
## Output: unique list (ordered)
def unique_list(_list):
    (unique_list,seen) = ([],{})
    for item in _list:
        if item in seen: continue
        else:
            seen[item] = 1
            unique_list.append(item)
    return unique_list


def __sleep(x,y=None):
    if y is None: y = x
    sleep_time = round(random.uniform(x,y),3)
    print(f'Sleeping for {sleep_time} seconds...')
    time.sleep(sleep_time)
    return


def __get_response(url,session=None,exit_codes=[200],sleep=[1,3]):

    if session is None: session = requests.Session()
    if not isinstance(sleep,list): sleep = [sleep]
    while True:
        if session.params:
            full_url = url + '?' + '&'.join(
                '{}={}'.format(k,v) for k,v in session.params.items())
        print(f'Retrieving {full_url}')
        try:
            response = session.get(url,timeout=10)
        except Exception as e:
            print(f'Exception: {e}')
            __sleep(*sleep)
            continue

        ## Check status code
        status_code = response.status_code
        print(f'Status: {status_code}')
        if status_code in exit_codes: break
        else:
            print('Retrying...')
            api_params = session.params
            session = requests.Session()
            session.params = api_params
            __sleep(*sleep)
    
    return {'response':response,'session':session}


## Pages through API request and returns list of all items
## Params must be in the Session object
def get_api_items(endpoint,session):

    ## Get response
    js_api = []
    session.params['key'] = API_KEY
    err_msg = None
    while True:
        exit_codes = [200,400,401,403,404,409]
        ret = __get_response(
            BASE_URL+endpoint,session=session,exit_codes=exit_codes,
            sleep=[1,3])
        (response,session) = (ret['response'],ret['session'])
        js = json.loads(response.text)

        ## Skip if 4** status code
        if response.status_code // 100 == 4:
            errs = ','.join([x['reason'] for x in js['error']['errors']])
            err_msg = '{} {}'.format(js['error']['code'],errs)
            print(f'Error: {err_msg}')
            print('Skipping...')
            break
            
        ## Concatenate API
        js_api.extend(js['items'])

        ## Continue if nextPageToken
        next_page_token = js.get('nextPageToken')
        if next_page_token is None: break
        else:
            session.params['pageToken'] = next_page_token

    return {'json': js_api, 'session': session, 'error': err_msg}


## Returns Ids of _type (videoId,playlistId,channelId)
def get_ids(f_input,_type):
    ids = []
    match_dict = {
        'videoId': '^([a-zA-Z0-9_-]{11})$',
        'playlistId': '^([a-zA-Z0-9_-]{34}|[a-zA-Z0-9_-]{18})$',
        'channelId': '^(UC[a-zA-Z0-9_-]{22})$'}
    with open(f_input, 'r', encoding='utf-8', errors='ignore') as f:
        matches = [re.match(match_dict[_type],x.rstrip()) for x in f]
    ids = unique_list([m.group(1) for m in matches if m])
    return ids


## Write Ids of _type to file
def write_ids(ids, f_out, _type):
    urls = {
        'videoId': 'https://www.youtube.com/watch?v={}',
        'playlistId': 'https://www.youtube.com/playlist?list={}'}
    url = urls[_type]
    with open(f_out, 'w', encoding='utf-8') as f:
        [f.write(url.format(x)+'\n') for x in ids]
    return


def write_api(f_api, js):
    with open(f_api, 'w', encoding='utf-8') as f:
        json.dump(js, f, indent=4)
    return