import asyncio
import aiohttp
import requests
import sqlite3
import time
from bs4 import BeautifulSoup
from tqdm import tqdm

con = sqlite3.connect("bcbs_data.db")
cur = con.cursor()
cur.execute("CREATE TABLE IF NOT EXISTS index_files(url PRIMARY KEY UNIQUE, size)")
cur.execute("CREATE TABLE IF NOT EXISTS in_network_files(url PRIMARY KEY UNIQUE, size)")
cur.execute("CREATE TABLE IF NOT EXISTS fetched_index_files(url PRIMARY KEY UNIQUE)")

mrfs_url = 'https://www.bluecrossnc.com/about-us/policies-and-best-practices/transparency-coverage-mrf'

r = requests.get(mrfs_url)
soup = BeautifulSoup(r.content, features = "lxml")

links = soup.find_all('a')
urls = []
for link in links:
    if (url := link.get('href')) is not None and 'index.json' in url:
        urls.append(url)


async def fetch_url_sizes(table, urls):
    """
    simple async function for getting all the file sizes in a list of urls
    and writing those to a SQLite table
    """
    async with aiohttp.ClientSession() as session:
        
        fs = [session.head(url) for url in urls]
    
        for f in asyncio.as_completed(fs):
            resp = await f
            url = str(resp.url)
            size = int(resp.headers.get('content-length', -1))
            cur.execute(f"""INSERT OR IGNORE INTO {table} VALUES ("{url}", {size})""")
            con.commit()
            
# Get all the MRF files on the main BCBS page
asyncio.run(fetch_url_sizes('index_files', urls))

# Sort from smallest to largest (some are multiple GB)
index_file_urls = cur.execute("SELECT url FROM index_files ORDER BY size").fetchall()

for url in tqdm(index_file_urls):

    url = url[0]

    if cur.execute(f"""SELECT url FROM fetched_index_files where url = "{url}" """).fetchone() is None:

        resp = requests.get(url, stream = True)
        size_mb = int(resp.headers['Content-Length'])/1_000_000

        if size_mb > 1_000:
            print(f"\nCannot download file of size: {size_mb} MB. Do this manually.")
            print(url)
            continue

        urls = [file['location'] for file in r.json()['reporting_structure'][0]['in_network_files']]

        asyncio.run(fetch_url_sizes('in_network_files', urls))

        cur.execute(f"""INSERT OR IGNORE INTO fetched_index_files VALUES ("{url}")""")
        con.commit()
