import requests
import queue
import re
import logging as log
import time
import random
import json

# Init logging
log.basicConfig(level=log.INFO, format="%(asctime)-15s %(levelname)-8s %(message)s")
log.info("Shammer is getting ready...")

# Init config
try:
    log.info("Loading 'config.json'...")
    f = open("config.json", "r")
    config = json.load(f)
    f.close()
except IOError as e:
    # Doesn't exist yet
    log.warn("Couldn't open 'config.json'")
    log.warn("%s"%e)
    log.info("Creating default configuration file...")
    config = {"INDEX_URL":"https://bitscuit.be/", "MAX_CONTENT_LENGTH":500000, "REQUESTS_PER_MINUTE":10}
    f = open("config.json", "w")
    json.dump(config, f, indent="\t")
    f.close()
    log.info("Done. Please edit 'config.json' before running Shammer again!")
    exit()
except Exception as e:
    # Other error
    log.warn("Couldn't open 'config.json'")
    log.warn("%s"%e)
    exit()

# Init static vars
INDEX_URL = config["INDEX_URL"]
MAX_CONTENT_LENGTH = config["MAX_CONTENT_LENGTH"]
REQUESTS_PER_MINUTE = config["REQUESTS_PER_MINUTE"]

# Create session
session = requests.Session()

# Create website queue
urls = queue.Queue()
urls.put(INDEX_URL)

# Create list to store visited sites
visited = set([INDEX_URL])

# Loop
while not urls.empty():
    url = urls.get()

    # Perform request
    log.info("Fetching '%s'..."%url)
    try:
        r = session.get(url, stream=True, timeout=5)

        # Read response
        if r.status_code != 200:
            log.info("returned status %d"%r.status_code)
            continue
        
        # Check file size
        if ("Content-Length" in r.headers.keys() and int(r.headers["Content-Length"]) > MAX_CONTENT_LENGTH) or ("content-length" in r.headers.keys() and int(r.headers["content-length"]) > MAX_CONTENT_LENGTH):
            log.info("too large response")
            continue

        # Download full
        r = session.get(url, timeout=5)

    except Exception as e:
        log.info("failed")
        log.info(e)
    finally:
        r.close()

    # Filter page for hrefs
    hrefs = []
    try:
        hrefs = [res[0] for res in re.findall("(https*:\/\/([a-z0-9]+\.)*[a-z0-9]{3,}\.[a-z0-9]{2,}\/)", r.text)]
        pages = [(url[:(url.rfind("/")+1 if res[0][0] != "/" else url.find("/", 10))]+res[0]) for res in re.findall("href *= *[\"'](\/*([a-z0-9]*\/*)+(\.[a-z0-9]*)*)[\"']", r.text)]
        hrefs.extend(pages)
    except Exception as e:
        log.info("failed to parse page")
        log.info(e)

    # Add to queue
    numAdded = 0
    for href in hrefs:
        if href not in visited:
            urls.put(href)
            visited.add(href)
            numAdded += 1
    log.info("%d urls, %d new, queue length %d"%(len(hrefs), numAdded, urls.qsize()))

    # Wait random time
    l = random.uniform(0, 2*60/REQUESTS_PER_MINUTE)
    time.sleep(l)