# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import BaseHTTPServer
import thread
import urlparse

from autotest_lib.client.bin import test, utils
from autotest_lib.client.common_lib import error, utils

def _split_url(url):
    """Splits a URL into the URL base and path."""
    split_url = urlparse.urlsplit(url)
    url_base = urlparse.urlunsplit(
            (split_url.scheme, split_url.netloc, '', '', ''))
    url_path = split_url.path
    return url_base, url_path.lstrip('/')

class NanoOmahaDevserver(object):
    """Simple implementation of Omaha."""

    class Handler(BaseHTTPServer.BaseHTTPRequestHandler):
        """Inner class for handling HTTP requests."""

        _OMAHA_RESPONSE_TEMPLATE_HEAD = """
          <response protocol=\"3.0\">
            <daystart elapsed_seconds=\"44801\"/>
            <app appid=\"{87efface-864d-49a5-9bb3-4b050a7c227a}\" status=\"ok\">
              <ping status=\"ok\"/>
              <updatecheck status=\"ok\">
                <urls>
                  <url codebase=\"%s\"/>
                </urls>
                <manifest version=\"9999.0.0\">
                  <packages>
                    <package name=\"%s\" size=\"%d\" required=\"true\"/>
                  </packages>
                  <actions>
                    <action event=\"postinstall\"
              ChromeOSVersion=\"9999.0.0\"
              sha256=\"%s\"
              needsadmin=\"false\"
              IsDeltaPayload=\"false\"
"""

        _OMAHA_RESPONSE_TEMPLATE_TAIL = """ />
                  </actions>
                </manifest>
              </updatecheck>
            </app>
          </response>
"""

        def do_POST(self):
            """Handler for POST requests."""
            if self.path == '/update':
                (base, name) = _split_url(self.server._devserver._image_url)
                response = self._OMAHA_RESPONSE_TEMPLATE_HEAD % (
                        base + '/', name,
                        self.server._devserver._image_size,
                        self.server._devserver._sha256)
                if self.server._devserver._metadata_size:
                    response += '              MetadataSize="%d"\n' % (
                            self.server._devserver._metadata_size)
                if self.server._devserver._metadata_signature:
                    response += '              MetadataSignatureRsa="%s"\n' % (
                            self.server._devserver._metadata_signature)
                if self.server._devserver._public_key:
                    response += '              PublicKeyRsa="%s"\n' % (
                            self.server._devserver._public_key)
                response += self._OMAHA_RESPONSE_TEMPLATE_TAIL
                self.send_response(200)
                self.send_header('Content-Type', 'application/xml')
                self.end_headers()
                self.wfile.write(response)
            else:
                self.send_response(500)

    def start(self):
        """Starts the server."""
        self._httpd = BaseHTTPServer.HTTPServer(('127.0.0.1', 0), self.Handler)
        self._httpd._devserver = self
        # Serve HTTP requests in a dedicated thread.
        thread.start_new_thread(self._httpd.serve_forever, ())
        self._port = self._httpd.socket.getsockname()[1]

    def stop(self):
        """Stops the server."""
        self._httpd.shutdown()

    def get_port(self):
        """Returns the TCP port number the server is listening on."""
        return self._port

    def set_image_params(self, image_url, image_size, sha256,
                         metadata_size=None,
                         metadata_signature=None,
                         public_key=None):
        """Sets the values to return in the Omaha response. Only the
        |image_url|, |image_size| and |sha256| parameters are
        mandatory."""
        self._image_url = image_url
        self._image_size = image_size
        self._sha256 = sha256
        self._metadata_size = metadata_size
        self._metadata_signature = metadata_signature
        self._public_key = public_key


class autoupdate_CannedOmahaUpdate(test.test):
    """Client-side mechanism to update a DUT with a given image."""
    version = 1

    """Restarts update_engine and attempts an update from the image
    pointed to by |image_url| of size |image_size| with checksum
    |image_sha256|. The |metadata_size|, |metadata_signature| and
    |public_key| parameters are optional.

    If the |allow_failure| parameter is True, then the test will
    succeed even if the update failed."""
    def run_once(self, image_url, image_size, image_sha256,
                 allow_failure=False,
                 metadata_size=None,
                 metadata_signature=None,
                 public_key=None):
        utils.run('restart update-engine')

        omaha = NanoOmahaDevserver()
        omaha.set_image_params(image_url,
                               image_size,
                               image_sha256,
                               metadata_size,
                               metadata_signature,
                               public_key)
        omaha.start()
        try:
            utils.run('update_engine_client -omaha_url ' +
                      'http://127.0.0.1:%d/update ' % omaha.get_port() +
                      '-update')
        except error.CmdError:
            omaha.stop()
            if not allow_failure:
                raise error.TestFail('Update attempt failed.')