# Copyright (C) Ivan Kravets <me@ikravets.com>
# See LICENSE for details.

from email.utils import parsedate_tz
from math import ceil
from os.path import getsize, join
from time import mktime

from click import progressbar
from requests import get

from platformio.exception import (FDSHASumMismatch, FDSizeMismatch,
                                  FDUnrecognizedStatusCode)
from platformio.util import change_filemtime, exec_command


class FileDownloader(object):

    CHUNK_SIZE = 1024

    def __init__(self, url, dest_dir=None):
        self._url = url
        self._fname = url.split("/")[-1]

        self._destination = self._fname
        if dest_dir:
            self.set_destination(join(dest_dir, self._fname))
        self._progressbar = None

        self._request = get(url, stream=True)
        if self._request.status_code != 200:
            raise FDUnrecognizedStatusCode(self._request.status_code, url)

    def set_destination(self, destination):
        self._destination = destination

    def get_filepath(self):
        return self._destination

    def get_lmtime(self):
        return self._request.headers['last-modified']

    def get_size(self):
        return int(self._request.headers['content-length'])

    def start(self):
        itercontent = self._request.iter_content(chunk_size=self.CHUNK_SIZE)
        f = open(self._destination, "wb")
        chunks = int(ceil(self.get_size() / float(self.CHUNK_SIZE)))

        with progressbar(length=chunks, label="Downloading") as pb:
            for _ in pb:
                f.write(next(itercontent))
        f.close()
        self._request.close()

        self._preserve_filemtime(self.get_lmtime())

    def verify(self, sha1=None):
        _dlsize = getsize(self._destination)
        if _dlsize != self.get_size():
            raise FDSizeMismatch(_dlsize, self._fname, self.get_size())

        if not sha1:
            return

        dlsha1 = None
        try:
            result = exec_command(["sha1sum", self._destination])
            dlsha1 = result['out']
        except OSError:
            try:
                result = exec_command(["shasum", "-a", "1", self._destination])
                dlsha1 = result['out']
            except OSError:
                pass

        if dlsha1:
            dlsha1 = dlsha1[1:41] if dlsha1.startswith("\\") else dlsha1[:40]
            if sha1 != dlsha1:
                raise FDSHASumMismatch(dlsha1, self._fname, sha1)

    def _preserve_filemtime(self, lmdate):
        timedata = parsedate_tz(lmdate)
        lmtime = mktime(timedata[:9])
        change_filemtime(self._destination, lmtime)

    def __del__(self):
        self._request.close()