# Copyright 2008-2009 WebDriver committers
# Copyright 2008-2009 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""The WebDriver implementation."""

from command import Command
from webelement import WebElement
from remote_connection import RemoteConnection
from errorhandler import ErrorHandler

class WebDriver(object):
    """Controls a browser by sending commands to a remote server.

    This server is expected to be running the WebDriver wire protocol as defined
    here:
      http://code.google.com/p/selenium/wiki/JsonWireProtocol

    Attributes:
      command_executor - The command.CommandExecutor object used to execute
          commands.
      error_handler - errorhandler.ErrorHandler object used to verify that the
          server did not return an error.
      session_id - The session ID to send with every command.
      capabilities - A dictionary of capabilities of the underlying browser for
          this instance's session.
    """

    def __init__(self, command_executor, browser_name, platform, version='',
                 javascript_enabled=True):
        """Create a new driver that will issue commands using the wire protocol.

        Args:
          command_executor - Either a command.CommandExecutor object or a string
              that specifies the URL of a remote server to send commands to.
          browser_name - A string indicating which browser to request a new
              session for from the remote server.  Should be one of
              {mobile safari|firefox|internet explorer|htmlunit|chrome}.
          platform - A string indicating the desired platform to request from
              the remote server. Should be one of
              {WINDOWS|XP|VISTA|MAC|LINUX|UNIX|ANY}.
          version - A string indicating a specific browser version to request,
              or an empty string ot use any available browser. Defaults to the
              empty string.
          javascript_enabled - Whether the requested browser should support
              JavaScript.  Defaults to True.
        """
        self.command_executor = command_executor
        if type(self.command_executor) is str:
            self.command_executor = RemoteConnection(command_executor)

        self.session_id = None
        self.capabilities = {}
        self.error_handler = ErrorHandler()

        self.start_client()
        self.start_session(browser_name=browser_name,
                           platform=platform,
                           version=version,
                           javascript_enabled=javascript_enabled)
        
    @property
    def name(self):
        """Returns the name of the underlying browser for this instance."""
        if 'browserName' in self.capabilities:
            return self.capabilities['browserName']
        else:
            raise KeyError('browserName not specified in session capabilities')

    def start_client(self):
        """Called before starting a new session.

        This method may be overridden to define custom startup behavior.
        """
        pass

    def stop_client(self):
        """Called after executing a quit command.

        This method may be overridden to define custom shutdown behavior.
        """
        pass

    def start_session(self, browser_name, platform=None, version=None,
                      javascript_enabled=False):
        """Creates a new session with the desired capabilities.

        Args:
          browser_name: The name of the browser to request.
          version: Which browser version to request.
          platform: Which platform to request the browser on.
          javascript_enabled: Whether the new session should support JavaScript.
        """
        response =  self._execute(Command.NEW_SESSION, {
            'desiredCapabilities': {
                'browserName': browser_name,
                'platform': platform or 'ANY',
                'version': version or '',
                'javascriptEnabled': javascript_enabled
            }
        })
        self.session_id = response['sessionId']
        self.capabilities = response['value']

    def _wrap_value(self, value):
        if isinstance(value, dict):
            converted = {}
            for key, val in value.items():
              converted[key] = self._wrap_value(val)
            return converted
        elif isinstance(value, WebElement):
            return {'ELEMENT': value.id}
        elif isinstance(value, list):
            return list(self._wrap_value(item) for item in value)
        else:
            return value
            
    def create_web_element(self, element_id):
        return WebElement(self, element_id)

    def _unwrap_value(self, value):
        if isinstance(value, dict) and 'ELEMENT' in value:
            return self.create_web_element(value['ELEMENT'])
        elif isinstance(value, list):
            return list(self._unwrap_value(item) for item in value)
        else:
            return value

    def _execute(self, driver_command, params=None):
        """Sends a command to be executed by a command.CommandExecutor.

        Args:
          driver_command: The name of the command to execute as a string.
          params: A dictionary of named parameters to send with the command.

        Returns:
          The command's JSON response loaded into a dictionary object.
        """
        if not params:
            params = {'sessionId': self.session_id}
        elif 'sessionId' not in params:
            params['sessionId'] = self.session_id

        params = self._wrap_value(params)
        response = self.command_executor.execute(driver_command, params)
        if response:
            self.error_handler.check_response(response)
            response['value'] = self._unwrap_value(
                response.get('value', None))
            return response
        # If the server doesn't send a response, assume the command was
        # a success
        return {'success': 0, 'value': None}

    def get(self, url):
        """Loads a web page in the current browser."""
        self._execute(Command.GET, {'url': url})

    def get_title(self):
        """Gets the title of the current page."""
        resp = self._execute(Command.GET_TITLE)
        return resp['value']

    def find_element_by_id(self, id_):
        """Finds element by id."""
        return self._find_element_by("id", id_)

    def find_elements_by_xpath(self, xpath):
        """Finds multiple elements by xpath."""
        return self._find_elements_by("xpath", xpath)

    def find_element_by_xpath(self, xpath):
        """Finds an element by xpath."""
        return self._find_element_by("xpath", xpath)

    def find_element_by_link_text(self, link_text):
        """Finds an element by its link text."""
        return self._find_element_by("link text", link_text)

    def find_element_by_partial_link_text(self, link_text):
        """Finds an element by a partial match of its link text."""
        return self._find_element_by("partial link text", link_text)

    def find_elements_by_link_text(self, link_text):
        """Finds elements by their link text."""
        return self._find_elements_by("link text", link_text)

    def find_elements_by_partial_link_text(self, link_text):
        """Finds elements by a partial match of their link text."""
        return self._find_elements_by("partial link text", link_text)

    def find_element_by_name(self, name):
        """Finds an element by its name."""
        return self._find_element_by("name", name)

    def find_elements_by_name(self, name):
        """Finds elements by their name."""
        return self._find_elements_by("name", name)

    def find_element_by_tag_name(self, name):
        """Finds an element by its tag name."""
        return self._find_element_by("tag name", name)

    def find_elements_by_tag_name(self, name):
        """Finds elements by their tag name."""
        return self._find_elements_by("tag name", name)

    def find_element_by_class_name(self, name):
        """Finds an element by their class name."""
        return self._find_element_by("class name", name)

    def find_elements_by_class_name(self, name):
        """Finds elements by their class name."""
        return self._find_elements_by("class name", name)

    def execute_script(self, script, *args):
        if len(args) == 1:
            converted_args = args[0]
        else:
            converted_args = list(args)
        converted_args = list(args)
        return self._execute(
            Command.EXECUTE_SCRIPT,
            {'script': script, 'args':converted_args})['value']

    def get_current_url(self):
        """Gets the current url."""
        return self._execute(Command.GET_CURRENT_URL)['value']

    def get_page_source(self):
        """Gets the page source."""
        return self._execute(Command.GET_PAGE_SOURCE)['value']

    def close(self):
        """Closes the current window."""
        self._execute(Command.CLOSE)

    def quit(self):
        """Quits the driver and close every associated window."""
        try:
            self._execute(Command.QUIT)
        finally:
            self.stop_client()
        
    def get_current_window_handle(self):
        return self._execute(Command.GET_CURRENT_WINDOW_HANDLE)['value']

    def get_window_handles(self):
        return self._execute(Command.GET_WINDOW_HANDLES)['value']
        
    def switch_to_active_element(self):
        """Returns the element with focus, or BODY if nothing has focus."""
        return self._execute(Command.GET_ACTIVE_ELEMENT)['value']

    def switch_to_window(self, window_name):
        """Switches focus to a window."""
        self._execute(Command.SWITCH_TO_WINDOW, {'name': window_name})

    def switch_to_frame(self, index_or_name):
        """Switches focus to a frame by index or name."""
        self._execute(Command.SWITCH_TO_FRAME, {'id': index_or_name})

    def back(self):
        """Goes back in browser history."""
        self._execute(Command.GO_BACK)

    def forward(self):
        """Goes forward in browser history."""
        self._execute(Command.GO_FORWARD)
    # Options
    def get_cookies(self):
        """Gets all the cookies. Return a set of dicts."""
        return self._execute(Command.GET_ALL_COOKIES)['value']
        
    def get_cookie(self, name):
        """Get a single cookie.  Returns the desired cookie dict or None."""
        cookies = self.get_cookies()
        for cookie in cookies:
            if cookie['name'] == name:
                return cookie
        return None

    def delete_cookie(self, name):
        """Delete a cookie with the given name."""
        self._execute(Command.DELETE_COOKIE, {'name': name})

    def delete_all_cookies(self):
        """Delete all the cookies."""
        self._execute(Command.DELETE_ALL_COOKIES)

    def add_cookie(self, cookie_dict):
        self._execute(Command.ADD_COOKIE, {'cookie': cookie_dict})

    def _find_element_by(self, by, value):
        return self._execute(Command.FIND_ELEMENT,
                             {'using': by, 'value': value})['value']

    def _find_elements_by(self, by, value):
        return self._execute(Command.FIND_ELEMENTS,
                             {'using': by, 'value': value})['value']


def connect(name, version="", server="http://localhost:4444", platform=None,
            javascript_enabled=True, path="/wd/hub"):
    """Convenience function to connect to a server
       Args:
           name - A string indicating which browser to request a new
               session for from the remote server.  Should be one of
               {mobile safari|firefox|internet explorer|htmlunit|chrome}.
           version - A string indicating a specific browser version to request,
               or an empty string ot use any available browser. Defaults to the
               empty string.
           server - Server location (without path). Defaults to
               "http://localhost:4444".
           platform - A string indicating the desired platform to request from
               the remote server. Should be one of
               {WINDOWS|XP|VISTA|MAC|LINUX|UNIX|ANY} or None. Defaults to None.
           javascript_enabled - Whether the requested browser should support
               JavaScript.  Defaults to True.
           path - path in server url. Defaults to "/wd/hub/"
    """
    if not path.startswith("/"):
        path = "/" + path
    url = "%s%s" % (server, path)
    wd = WebDriver(url, name, platform, version, javascript_enabled)

    return wd
