#!/usr/bin/env python

try:
    from email.generator import _make_boundary as choose_boundary
    from urllib.request import urlopen
    from io import BufferedReader as file
except ImportError:
    from mimetools import choose_boundary
    from urllib2 import urlopen
import mimetypes
import os
import re
import sys

from .error import TelegramError

DEFAULT_MIME_TYPE = 'application/octet-stream'
USER_AGENT = 'Python Telegram Bot' \
             ' (https://github.com/leandrotoledo/python-telegram-bot)'


class InputFile(object):
    def __init__(self,
                 data):
        self.data = data
        self.boundary = choose_boundary()

        if 'audio' in data:
            self.input_name = 'audio'
            self.input_file = data.pop('audio')
        if 'document' in data:
            self.input_name = 'document'
            self.input_file = data.pop('document')
        if 'photo' in data:
            self.input_name = 'photo'
            self.input_file = data.pop('photo')
        if 'video' in data:
            self.input_name = 'video'
            self.input_file = data.pop('video')

        if isinstance(self.input_file, file):
            self.input_file_content = self.input_file.read()
            self.filename = os.path.basename(self.input_file.name)
            self.mimetype = mimetypes.guess_type(self.filename)[0] or \
                DEFAULT_MIME_TYPE

        if 'http' in self.input_file:
            self.input_file_content = urlopen(self.input_file).read()
            self.mimetype = InputFile.is_image(self.input_file_content)
            self.filename = self.mimetype.replace('/', '.')

    @property
    def headers(self):
        return {'User-agent': USER_AGENT,
                'Content-type': self.content_type}

    @property
    def content_type(self):
        return 'multipart/form-data; boundary=%s' % self.boundary

    def to_form(self):
        form = []
        form_boundary = '--' + self.boundary

        # Add data fields
        for name, value in self.data.items():
            form.extend([
                form_boundary,
                'Content-Disposition: form-data; name="%s"' % name,
                '',
                str(value)
            ])

        # Add input_file to upload
        form.extend([
            form_boundary,
            'Content-Disposition: form-data; name="%s"; filename="%s"' % (
                self.input_name, self.filename
                ),
            'Content-Type: %s' % self.mimetype,
            '',
            self.input_file_content
        ])

        form.append('--' + self.boundary + '--')
        form.append('')

        return self._parse(form)

    def _parse(self, form):
        if sys.version_info > (3,):
            # on Python 3 form needs to be byte encoded
            encoded_form = []
            for item in form:
                try:
                    encoded_form.append(item.encode())
                except AttributeError:
                    encoded_form.append(item)

            return b'\r\n'.join(encoded_form)
        return '\r\n'.join(form)

    @staticmethod
    def is_image(stream):
        """Check if the content file is an image by analyzing its headers.

        Args:
          stream:
            A str representing the content of a file.

        Returns:
          The str mimetype of an image.
        """
        try:
            header = stream[:10]

            if re.match(b'GIF8', header):
                return 'image/gif'

            if re.match(b'\x89PNG', header):
                return 'image/png'

            if re.match(b'\xff\xd8\xff\xe0\x00\x10JFIF', header) or \
               re.match(b'\xff\xd8\xff\xe1(.*){2}Exif', header):
                return 'image/jpeg'
        except IndexError as e:
            raise TelegramError(str(e))

        raise TelegramError({'message': 'Could not parse file content'})

    @staticmethod
    def is_inputfile(data):
        """Check if the request is a file request
        Args:
          data:
            A dict of (str, unicode) key/value pairs

        Returns:
            bool
        """
        if data:
            file_types = ['audio', 'document', 'photo', 'video']
            file_type = [i for i in list(data.keys()) if i in file_types]

            if file_type:
                file_content = data[file_type[0]]

                if file_type[0] == 'photo':
                    return isinstance(file_content, file) or \
                        str(file_content).startswith('http')

                return isinstance(file_content, file)

        return False