import os
import sys
from requests.compat import urlparse, is_windows


class Environment(object):
    """Holds information about the execution context.

    Groups various aspects of the environment in a changeable object
    and allows for mocking.

    """
    stdin_isatty = sys.stdin.isatty()
    stdin = sys.stdin

    if is_windows:
        # `colorama` patches `sys.stdout` so its initialization
        # needs to happen before the default environment is set.
        import colorama
        colorama.init()
        del colorama

    stdout_isatty = sys.stdout.isatty()
    stdout = sys.stdout

    stderr = sys.stderr

    # Can be set to 0 to disable colors completely.
    colors = 256 if '256color' in os.environ.get('TERM', '') else 88

    def __init__(self, **kwargs):
        self.__dict__.update(**kwargs)


class HTTPMessage(object):
    """Model representing an HTTP message."""

    def __init__(self, line, headers, body, content_type=None):
        # {Request,Status}-Line
        self.line = line
        self.headers = headers
        self.body = body
        self.content_type = content_type

    def format(self, prettifier=None, with_headers=True, with_body=True):
        """Return a `unicode` representation of `self`. """
        pretty = prettifier is not None
        bits = []

        if with_headers:
            bits.append(self.line)
            bits.append(self.headers)
            if pretty:
                bits = [
                    prettifier.process_headers('\n'.join(bits))
                ]
            if with_body and self.body:
                bits.append('\n')

        if with_body and self.body:
            if pretty and self.content_type:
                bits.append(prettifier.process_body(
                    self.body, self.content_type))
            else:
                bits.append(self.body)

        return '\n'.join(bit.strip() for bit in bits)

    @staticmethod
    def from_request(request):
        """Make an `HTTPMessage` from `requests.models.Request`."""

        url = urlparse(request.url)

        # Querystring
        qs = ''
        if url.query or request.params:
            qs = '?'
            if url.query:
                qs += url.query
            # Requests doesn't make params part of ``request.url``.
            if request.params:
                if url.query:
                    qs += '&'
                #noinspection PyUnresolvedReferences
                qs += type(request)._encode_params(request.params)

        # Request-Line
        request_line = '{method} {path}{query} HTTP/1.1'.format(
            method=request.method,
            path=url.path or '/',
            query=qs
        )

        # Headers
        headers = dict(request.headers)
        content_type = headers.get('Content-Type')
        if 'Host' not in headers:
            headers['Host'] = url.netloc
        headers = '\n'.join(
            str('%s: %s') % (name, value)
            for name, value
            in headers.items()
        )

        # Body
        try:
            body = request.data
        except AttributeError:
            # requests < 0.12.1
            body = request._enc_data
        if isinstance(body, dict):
            #noinspection PyUnresolvedReferences
            body = type(request)._encode_params(body)

        return HTTPMessage(
            line=request_line,
            headers=headers,
            body=body,
            content_type=content_type
        )

    @classmethod
    def from_response(cls, response):
        """Make an `HTTPMessage` from `requests.models.Response`."""
        encoding = response.encoding or 'ISO-8859-1'
        original = response.raw._original_response
        response_headers = response.headers
        status_line = 'HTTP/{version} {status} {reason}'.format(
            version='.'.join(str(original.version)),
            status=original.status,
            reason=original.reason
        )
        body = response.content.decode(encoding) if response.content else ''
        return cls(
            line=status_line,
            headers=str(original.msg),
            body=body,
            content_type=response_headers.get('Content-Type'))