import wget
from constants.constants import BASE_URL
import re
import hashlib
import requests
import shutil
import csv
from pathlib import Path

def convert_filename(name, hash):
    _name = name.split('.')
    if len(_name) > 1:
        _name[-2] += ("["+hash+"]")
    else:
        _name[0] += ("["+hash+"]")
    return '.'.join(_name)

class RequestStack:
    def __init__(self,token):
        self.request_stack = []
        self.token = token
        super().__init__()

    def add_file(self,url,path):
        self.request_stack.append(Asset(url,path))
    
    def download_all(self):
        for file in self.request_stack:
            file.download(self.token)

class Asset:
    def __init__(self,url,path):
        self.path = Path(path)
        self.url = re.sub("^"+BASE_URL,"",url)
        # self.file_id = re.findall('file_id=(.+)&',url)
        self.path.mkdir(parents=True, exist_ok=True)
        super().__init__()

    def download(self,req_headers):
        response = requests.get(BASE_URL+self.url, stream=True, headers=req_headers, allow_redirects=False)
        headers = response.headers
        if response.status_code == 302 and len(headers['location']) > 0:
            Asset(headers['location'], self.path).download(req_headers)
            return
        elif response.status_code != 200:
            print("Error "+str(response.status_code))
            return response.status_code
        headers = { x:re.sub(r'^"*|"*?$', '', headers.get(x)) for x in headers } # ewww regex
        if 'Content-Disposition' in headers.keys():
            self.original_filename = re.findall('filename="(.+)"', headers['Content-Disposition'])[0]
        else:
            self.original_filename = re.sub(".*/","",self.url)
        self.etag_hash = hashlib.md5(headers['ETag'].encode()).hexdigest()
        self.filename = convert_filename(self.original_filename, self.etag_hash[0:6])

        with open(self.path.joinpath(self.filename), 'wb') as f:
            shutil.copyfileobj(response.raw, f)
        self.write_metadata(headers)

    def write_metadata(self,headers):
        metacsv = [
            ["original_filename",   self.original_filename],
            ["readable_filename",   self.filename],
            ["url",                 self.url],
            ["pathhash",            hashlib.md5(self.url.encode()).hexdigest()],
            ["etag",                headers['ETag']],
            ["etaghash",            self.etag_hash],
            ["last-modified",       headers["Last-Modified"]],
            ["content-length",      headers["Content-Length"]],
            ["age",                 ""],
        ]
        csvpath = self.path.joinpath("ZZZ_metadata")
        csvpath.mkdir(parents=True, exist_ok=True)
        with open(csvpath.joinpath(self.filename+"__metadata.csv"), "w", newline="") as f:
            writer = csv.writer(f)
            writer.writerows(metacsv)