#!/usr/bin/python
'''
Provides IPython console widget.

@author: Eitan Isaacson
@organization: IBM Corporation
@copyright: Copyright (c) 2007 IBM Corporation
@license: BSD

All rights reserved. This program and the accompanying materials are made 
available under the terms of the BSD which accompanies this distribution, and 
is available at U{http://www.opensource.org/licenses/bsd-license.php}
'''

import gi

from gi.repository import Gtk as gtk
from gi.repository import Gdk as gdk
from gi.repository import GObject
from gi.repository import Pango

import re
import sys
import os

from StringIO import StringIO

try:
  import IPython
except ImportError:
  IPython = None

class IterableIPShell:
  '''
  Create an IPython instance. Does not start a blocking event loop,
  instead allow single iterations. This allows embedding in GTK+ 
  without blockage.

  @ivar IP: IPython instance.
  @type IP: IPython.iplib.InteractiveShell
  @ivar iter_more: Indicates if the line executed was a complete command,
  or we should wait for more.
  @type iter_more: integer
  @ivar history_level: The place in history where we currently are 
  when pressing up/down.
  @type history_level: integer
  @ivar complete_sep: Seperation delimeters for completion function.
  @type complete_sep: _sre.SRE_Pattern
  '''
  def __init__(self,argv=[],user_ns=None,user_global_ns=None, 
               cin=None, cout=None,cerr=None, input_func=None):
    '''
    
    
    @param argv: Command line options for IPython
    @type argv: list
    @param user_ns: User namespace.
    @type user_ns: dictionary
    @param user_global_ns: User global namespace.
    @type user_global_ns: dictionary.
    @param cin: Console standard input.
    @type cin: IO stream
    @param cout: Console standard output.
    @type cout: IO stream 
    @param cerr: Console standard error.
    @type cerr: IO stream
    @param input_func: Replacement for builtin raw_input()
    @type input_func: function
    '''
    io = IPython.utils.io
    if input_func:
      IPython.frontend.terminal.interactiveshell.raw_input_original = input_func
    if cin:
      io.stdin = io.IOStream(cin)
    if cout:
      io.stdout = io.IOStream(cout)
    if cerr:
      io.stderr = io.IOStream(cerr)

    # This is to get rid of the blockage that accurs during 
    # IPython.Shell.InteractiveShell.user_setup()

    io.raw_input = lambda x: None

    os.environ['TERM'] = 'dumb'
    excepthook = sys.excepthook 

    from IPython.config.loader import Config
    cfg = Config()
    cfg.InteractiveShell.colors = "Linux"

    # InteractiveShell's __init__ overwrites io.stdout,io.stderr with 
    # sys.stdout, sys.stderr, this makes sure they are right
    old_stdout, old_stderr = sys.stdout, sys.stderr
    sys.stdout, sys.stderr = io.stdout.stream, io.stderr.stream

    # InteractiveShell inherits from SingletonConfigurable, so use instance()
    self.IP = IPython.frontend.terminal.embed.InteractiveShellEmbed.instance(config=cfg, user_ns=user_ns)
    
    sys.stdout, sys.stderr = old_stdout, old_stderr
    
    self.IP.system = lambda cmd: self.shell(self.IP.var_expand(cmd),
                                            header='IPython system call: ')
#                                            local_ns=user_ns) 
                                            #global_ns=user_global_ns)
                                            #verbose=self.IP.rc.system_verbose)

    self.IP.raw_input = input_func
    sys.excepthook = excepthook
    self.iter_more = 0
    self.history_level = 0
    self.complete_sep =  re.compile('[\s\{\}\[\]\(\)]')
    self.updateNamespace({'exit':lambda:None})
    self.updateNamespace({'quit':lambda:None})
    self.IP.readline_startup_hook(self.IP.pre_readline)
    # Workaround for updating namespace with sys.modules
    #
    #self.__update_namespace()

    # help() is blocking which hangs Gtk
    self.updateNamespace({'help':lambda *x:'help() command incompatible with gtk'})

  def __update_namespace(self):
    '''
    Update self.IP namespace for autocompletion with sys.modules
    '''
    for k,v in sys.modules.items():
        if not '.' in k:
          self.IP.user_ns.update({k:v})

  def execute(self):
    '''
    Executes the current line provided by the shell object.
    '''
    self.history_level = 0

    # this is needed because some functions in IPython use 'print' to print output
    # (like 'who')
    orig_stdout = sys.stdout
    sys.stdout = IPython.utils.io.stdout

    orig_stdin = sys.stdin
    sys.stdin = IPython.utils.io.stdin;
    self.prompt = self.generatePrompt(self.iter_more)

    self.IP.hooks.pre_prompt_hook()
    if self.iter_more:
        try:
            self.prompt = self.generatePrompt(True)
        except:
            self.IP.showtraceback()
        if self.IP.autoindent:
            self.IP.rl_do_indent = True

    try:
      line = self.IP.raw_input(self.prompt)
    except KeyboardInterrupt:
      self.IP.write('\nKeyboardInterrupt\n')
      self.IP.input_splitter.reset()
    except:
      self.IP.showtraceback()
    else:
      self.IP.input_splitter.push(line)
      self.iter_more = self.IP.input_splitter.push_accepts_more()
      self.prompt = self.generatePrompt(self.iter_more)
      if (self.IP.SyntaxTB.last_syntax_error and
          self.IP.autoedit_syntax):
          self.IP.edit_syntax_error()
      if not self.iter_more:
          source_raw = self.IP.input_splitter.source_raw_reset()[1]
          self.IP.run_cell(source_raw, store_history=True)
      else:
          # TODO: Auto-indent
          #
          pass

    sys.stdout = orig_stdout
    sys.stdin = orig_stdin

  def generatePrompt(self, is_continuation):
    '''
    Generate prompt depending on is_continuation value

    @param is_continuation
    @type is_continuation: boolean 

    @return: The prompt string representation
    @rtype: string

    '''

    # Backwards compatibility with ipyton-0.11
    #
    ver = IPython.__version__
    if '0.11' in ver:
        prompt = self.IP.hooks.generate_prompt(is_continuation)
    else:
        if is_continuation:
            prompt = self.IP.prompt_manager.render('in2')
        else:
            prompt = self.IP.prompt_manager.render('in')

    return prompt


  def historyBack(self):
    '''
    Provides one history command back.
    
    @return: The command string.
    @rtype: string
    '''
    self.history_level -= 1
    if not self._getHistory():
      self.history_level +=1
    return self._getHistory()
  
  def historyForward(self):
    '''
    Provides one history command forward.
    
    @return: The command string.
    @rtype: string
    '''
    if self.history_level < 0:
      self.history_level += 1
    return self._getHistory()
  
  def _getHistory(self):
    '''
    Get's the command string of the current history level.
    
    @return: Historic command string.
    @rtype: string
    '''
    try:
      rv = self.IP.user_ns['In'][self.history_level].strip('\n')
    except IndexError:
      rv = ''
    return rv

  def updateNamespace(self, ns_dict):
    '''
    Add the current dictionary to the shell namespace.
    
    @param ns_dict: A dictionary of symbol-values.
    @type ns_dict: dictionary
    '''
    self.IP.user_ns.update(ns_dict)

  def complete(self, line):
    '''
    Returns an auto completed line and/or posibilities for completion.
    
    @param line: Given line so far.
    @type line: string
    
    @return: Line completed as for as possible, 
    and possible further completions.
    @rtype: tuple
    '''
    split_line = self.complete_sep.split(line)
    if split_line[-1]:
      possibilities = self.IP.complete(split_line[-1])
    else:
      completed = line
      possibilities = ['',[]]
    if possibilities:
      def _commonPrefix(str1, str2):
        '''
        Reduction function. returns common prefix of two given strings.
        
        @param str1: First string.
        @type str1: string
        @param str2: Second string
        @type str2: string
        
        @return: Common prefix to both strings.
        @rtype: string
        '''
        for i in range(len(str1)):
          if not str2.startswith(str1[:i+1]):
            return str1[:i]
        return str1
      if possibilities[1]:
        common_prefix = reduce(_commonPrefix, possibilities[1]) or line[-1]
        completed = line[:-len(split_line[-1])]+common_prefix
      else:
        completed = line
    else:
      completed = line
    return completed, possibilities[1]
  

  def shell(self, cmd,verbose=0,debug=0,header=''):
    '''
    Replacement method to allow shell commands without them blocking.
    
    @param cmd: Shell command to execute.
    @type cmd: string
    @param verbose: Verbosity
    @type verbose: integer
    @param debug: Debug level
    @type debug: integer
    @param header: Header to be printed before output
    @type header: string
    '''
    stat = 0
    if verbose or debug: print header+cmd
    # flush stdout so we don't mangle python's buffering
    if not debug:
      input, output = os.popen4(cmd)
      print output.read()
      output.close()
      input.close()

class ConsoleView(gtk.TextView):
  '''
  Specialized text view for console-like workflow.

  @cvar ANSI_COLORS: Mapping of terminal colors to X11 names.
  @type ANSI_COLORS: dictionary

  @ivar text_buffer: Widget's text buffer.
  @type text_buffer: gtk.TextBuffer
  @ivar color_pat: Regex of terminal color pattern
  @type color_pat: _sre.SRE_Pattern
  @ivar mark: Scroll mark for automatic scrolling on input.
  @type mark: gtk.TextMark
  @ivar line_start: Start of command line mark.
  @type line_start: gtk.TextMark
  '''
  ANSI_COLORS =  {'0;30': 'Black',     '0;31': 'Red',
                  '0;32': 'Green',     '0;33': 'Brown',
                  '0;34': 'Blue',      '0;35': 'Purple',
                  '0;36': 'Cyan',      '0;37': 'LightGray',
                  '1;30': 'DarkGray',  '1;31': 'DarkRed',
                  '1;32': 'SeaGreen',  '1;33': 'Yellow',
                  '1;34': 'LightBlue', '1;35': 'MediumPurple',
                  '1;36': 'LightCyan', '1;37': 'White'}

  def __init__(self):
    '''
    Initialize console view.
    '''
    gtk.TextView.__init__(self)
    self.modify_font(Pango.FontDescription('Mono'))
    self.set_cursor_visible(True)
    self.text_buffer = self.get_buffer()
    self.mark = self.text_buffer.create_mark('scroll_mark', 
                                             self.text_buffer.get_end_iter(),
                                             False)
    for code in self.ANSI_COLORS:
      self.text_buffer.create_tag(code, 
                                  foreground=self.ANSI_COLORS[code], 
                                  weight=700)
    self.text_buffer.create_tag('0')
    self.text_buffer.create_tag('notouch', editable=False)
    self.color_pat = re.compile('\x01?\x1b\[(.*?)m\x02?')
    self.line_start = \
        self.text_buffer.create_mark('line_start', 
                                     self.text_buffer.get_end_iter(), True)
    self.connect('key-press-event', self.onKeyPress)
    
  def write(self, text, editable=False):
    GObject.idle_add(self._write, text, editable)

  def _write(self, text, editable=False):
    '''
    Write given text to buffer.
    
    @param text: Text to append.
    @type text: string
    @param editable: If true, added text is editable.
    @type editable: boolean
    '''
    segments = self.color_pat.split(text)
    segment = segments.pop(0)
    start_mark = self.text_buffer.create_mark(None, 
                                              self.text_buffer.get_end_iter(), 
                                              True)
    self.text_buffer.insert(self.text_buffer.get_end_iter(), segment)

    if segments:
      ansi_tags = self.color_pat.findall(text)
      for tag in ansi_tags:
        i = segments.index(tag)
        self.text_buffer.insert_with_tags_by_name(self.text_buffer.get_end_iter(),
                                             segments[i+1], tag)
        segments.pop(i)
    if not editable:
      self.text_buffer.apply_tag_by_name('notouch',
                                         self.text_buffer.get_iter_at_mark(start_mark),
                                         self.text_buffer.get_end_iter())
    self.text_buffer.delete_mark(start_mark)
    self.scroll_mark_onscreen(self.mark)


  def showPrompt(self, prompt):
    GObject.idle_add(self._showPrompt, prompt)

  def _showPrompt(self, prompt):
    '''
    Prints prompt at start of line.
    
    @param prompt: Prompt to print.
    @type prompt: string
    '''
    self._write(prompt)
    self.text_buffer.move_mark(self.line_start,
                               self.text_buffer.get_end_iter())

  def changeLine(self, text):
    GObject.idle_add(self._changeLine, text)

  def _changeLine(self, text):
    '''
    Replace currently entered command line with given text.
    
    @param text: Text to use as replacement.
    @type text: string
    '''
    iter = self.text_buffer.get_iter_at_mark(self.line_start)
    iter.forward_to_line_end()
    self.text_buffer.delete(self.text_buffer.get_iter_at_mark(self.line_start), iter)
    self._write(text, True)

  def getCurrentLine(self):
    '''
    Get text in current command line.
    
    @return: Text of current command line.
    @rtype: string
    '''
    rv = self.text_buffer.get_slice(
      self.text_buffer.get_iter_at_mark(self.line_start),
      self.text_buffer.get_end_iter(), False)
    return rv

  def showReturned(self, text):
    GObject.idle_add(self._showReturned, text)

  def _showReturned(self, text):
    '''
    Show returned text from last command and print new prompt.
    
    @param text: Text to show.
    @type text: string
    '''
    iter = self.text_buffer.get_iter_at_mark(self.line_start)
    iter.forward_to_line_end()
    self.text_buffer.apply_tag_by_name(
      'notouch', 
      self.text_buffer.get_iter_at_mark(self.line_start),
      iter)
    self._write('\n'+text)
    if text:
      self._write('\n')
    self._write('\n')               # add extra line, like normal IPython
    self._showPrompt(self.prompt)
    self.text_buffer.move_mark(self.line_start,self.text_buffer.get_end_iter())
    self.text_buffer.place_cursor(self.text_buffer.get_end_iter())

  def onKeyPress(self, widget, event):
    '''
    Key press callback used for correcting behavior for console-like 
    interfaces. For example 'home' should go to prompt, not to begining of
    line.
    
    @param widget: Widget that key press accored in.
    @type widget: gtk.Widget
    @param event: Event object
    @type event: gtk.gdk.Event
    
    @return: Return True if event should not trickle.
    @rtype: boolean
    '''
    insert_mark = self.text_buffer.get_insert()
    insert_iter = self.text_buffer.get_iter_at_mark(insert_mark)
    selection_mark = self.text_buffer.get_selection_bound()
    selection_iter = self.text_buffer.get_iter_at_mark(selection_mark)
    start_iter = self.text_buffer.get_iter_at_mark(self.line_start)
    if event.keyval == gdk.KEY_Home:
      if event.state & gdk.ModifierType.CONTROL_MASK or \
              event.state & gdk.ModifierType.MOD1_MASK:
        pass
      elif event.state & gdk.ModifierType.SHIFT_MASK:
        self.text_buffer.move_mark(insert_mark, start_iter)
        return True
      else:
        self.text_buffer.place_cursor(start_iter)
        return True
    elif event.keyval == gdk.KEY_Left:
      insert_iter.backward_cursor_position()
      if not insert_iter.editable(True):
        return True
    elif not event.string:
      pass
    elif start_iter.compare(insert_iter) <= 0 and \
          start_iter.compare(selection_iter) <= 0:
      pass
    elif start_iter.compare(insert_iter) > 0 and \
          start_iter.compare(selection_iter) > 0:
      self.text_buffer.place_cursor(start_iter)
    elif insert_iter.compare(selection_iter) < 0:
      self.text_buffer.move_mark(insert_mark, start_iter)
    elif insert_iter.compare(selection_iter) > 0:
      self.text_buffer.move_mark(selection_mark, start_iter)             

    return self.onKeyPressExtend(event)

  def onKeyPressExtend(self, event):
    '''
    For some reason we can't extend onKeyPress directly (bug #500900).
    '''
    pass

class IPythonView(ConsoleView, IterableIPShell):
  '''
  Sub-class of both modified IPython shell and L{ConsoleView} this makes
  a GTK+ IPython console.
  '''
  def __init__(self):
    '''
    Initialize. Redirect I/O to console.
    '''
    ConsoleView.__init__(self)
    self.cout = StringIO()
    IterableIPShell.__init__(self, cout=self.cout,cerr=self.cout, 
                             input_func=self.raw_input)
#    self.connect('key_press_event', self.keyPress)
    self.interrupt = False
    self.execute()
    self.prompt = self.generatePrompt(False)
    self.cout.truncate(0)
    self.showPrompt(self.prompt)

  def raw_input(self, prompt=''):
    '''
    Custom raw_input() replacement. Get's current line from console buffer.
    
    @param prompt: Prompt to print. Here for compatability as replacement.
    @type prompt: string
    
    @return: The current command line text.
    @rtype: string
    '''
    if self.interrupt:
      self.interrupt = False
      raise KeyboardInterrupt
    return self.getCurrentLine()

  def onKeyPressExtend(self, event):
    '''
    Key press callback with plenty of shell goodness, like history, 
    autocompletions, etc.
    
    @param widget: Widget that key press occured in.
    @type widget: gtk.Widget
    @param event: Event object.
    @type event: gtk.gdk.Event
    
    @return: True if event should not trickle.
    @rtype: boolean
    '''
    if event.state & gdk.ModifierType.CONTROL_MASK and event.keyval == 99:
      self.interrupt = True
      self._processLine()
      return True
    elif event.keyval == gdk.KEY_Return:
      self._processLine()
      return True
    elif event.keyval == gdk.KEY_Up:
      self.changeLine(self.historyBack())
      return True
    elif event.keyval == gdk.KEY_Down:
      self.changeLine(self.historyForward())
      return True
    elif event.keyval == gdk.KEY_Tab:
      if not self.getCurrentLine().strip():
        return False
      completed, possibilities = self.complete(self.getCurrentLine())
      if len(possibilities) > 1:
        slice = self.getCurrentLine()
        self.write('\n')
        for symbol in possibilities:
          self.write(symbol+'\n')
        self.showPrompt(self.prompt)
      self.changeLine(completed or slice)
      return True

  def _processLine(self):
    '''
    Process current command line.
    '''
    self.history_pos = 0
    self.execute()
    rv = self.cout.getvalue()
    if rv: rv = rv.strip('\n')
    self.showReturned(rv)
    self.cout.truncate(0)
    
if __name__ == "__main__":
  window = gtk.Window()
  window.set_default_size(640, 320)
  window.connect('delete-event', lambda x, y: gtk.main_quit())
  window.add(IPythonView())
  window.show_all()
  gtk.main()
    

