import re

from httpie.plugins import plugin_manager
from httpie.context import Environment


MIME_RE = re.compile(r'^[^/]+/[^/]+$')


def is_valid_mime(mime):
    return mime and MIME_RE.match(mime)


class Conversion(object):

    def get_converter(self, mime):
        if is_valid_mime(mime):
            for converter_class in plugin_manager.get_converters():
                if converter_class.supports(mime):
                    return converter_class(mime)


class Formatting(object):
    """A delegate class that invokes the actual processors."""

    def __init__(self, groups, env=Environment(), **kwargs):
        """
        :param groups: names of processor groups to be applied
        :param env: Environment
        :param kwargs: additional keyword arguments for processors

        """
        available_plugins = plugin_manager.get_formatters_grouped()
        self.enabled_plugins = []
        for group in groups:
            for cls in available_plugins[group]:
                p = cls(env=env, **kwargs)
                if p.enabled:
                    self.enabled_plugins.append(p)

    def format_headers(self, headers):
        for p in self.enabled_plugins:
            headers = p.format_headers(headers)
        return headers

    def format_body(self, content, mime):
        if is_valid_mime(mime):
            for p in self.enabled_plugins:
                content = p.format_body(content, mime)
        return content