import json
import sys
import urllib.request
from urllib.error import HTTPError, URLError
from datetime import datetime

HISTORY_PATH = ".\\History.json"

with open(HISTORY_PATH, "r") as f:
    # backup
    with open(HISTORY_PATH + "." + datetime.now().strftime("%Y-%m-%d_%H-%M-%S") + ".bak", "w+") as bak:
        bak.write(f.read())

    history = json.loads("[" + f.read() + "]")

    for item in history:
        # check if it's been uploaded
        if not item.get("URL"):
            continue

        try:
            # try fetching the url, and raise HTTPError if an error occured
            urllib.request.urlopen(item["URL"])
        except HTTPError as e:
            code = e.getcode()
            # delete item in history dictionary
            if code == 200:
                print(f"Succeeded with {item['FileName']}.")
            elif code == 404:
                print(f"{item['FileName']} failed, removing..", file=sys.stderr)
                history.remove(item)
            else:
                print(f"{item['FileName']} returned unknown status code ({code}). Ignoring.", file=sys.stderr)
        except URLError:
            print("Internet connection failed.")
            sys.exit(1)
    
    # dump new history
    with open(HISTORY_PATH, "w") as hist:
        jsonContent = ""

        for item in history:
            if history.index(item) != 0:
                jsonContent += ",\n"
            jsonContent += json.dumps(item, indent=2)

        hist.write(jsonContent)