#!/usr/bin/env python

import re
import sys
import traceback

from gi.repository import GObject
from gi.repository import Gdk
from gi.repository import Gtk
from gi.repository import Pango
from six import exec_

from virtaal.controllers.baseplugin import BasePlugin


class PythonConsole(Gtk.ScrolledWindow):
    def __init__(self, namespace = {}, destroy_cb = None):
        super(PythonConsole, self).__init__()

        self.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC);
        self.set_shadow_type(Gtk.ShadowType.IN)
        self.view = Gtk.TextView()
        self.view.modify_font(Pango.FontDescription('Monospace'))
        self.view.set_editable(True)
        self.view.set_wrap_mode(Gtk.WrapMode.WORD_CHAR)
        self.add(self.view)
        self.view.show()

        buffer = self.view.get_buffer()
        self.normal = buffer.create_tag("normal")
        self.error  = buffer.create_tag("error")
        self.error.set_property("foreground", "red")
        self.command = buffer.create_tag("command")
        self.command.set_property("foreground", "blue")

        self.__spaces_pattern = re.compile(r'^\s+')
        self.namespace = namespace

        self.destroy_cb = destroy_cb

        self.block_command = False

        # Init first line
        buffer.create_mark("input-line", buffer.get_end_iter(), True)
        buffer.insert(buffer.get_end_iter(), ">>> ")
        buffer.create_mark("input", buffer.get_end_iter(), True)

        # Init history
        self.history = ['']
        self.history_pos = 0
        self.current_command = ''
        self.namespace['__history__'] = self.history

        # Set up hooks for standard output.
        self.stdout = gtkoutfile(self, sys.stdout.fileno(), self.normal)
        self.stderr = gtkoutfile(self, sys.stderr.fileno(), self.error)

        # Signals
        self.view.connect("key-press-event", self.__key_press_event_cb)
        buffer.connect("mark-set", self.__mark_set_cb)


    def __key_press_event_cb(self, view, event):
        if event.keyval == Gdk.KEY_d and \
                event.get_state() == Gdk.ModifierType.CONTROL_MASK:
            self.destroy()

        elif event.keyval == Gdk.KEY_Return and \
                event.get_state() == Gdk.ModifierType.CONTROL_MASK:
            # Get the command
            buffer = view.get_buffer()
            inp_mark = buffer.get_mark("input")
            inp = buffer.get_iter_at_mark(inp_mark)
            cur = buffer.get_end_iter()
            line = buffer.get_text(inp, cur)
            self.current_command = self.current_command + line + "\n"
            self.history_add(line)

            # Prepare the new line
            cur = buffer.get_end_iter()
            buffer.insert(cur, "\n... ")
            cur = buffer.get_end_iter()
            buffer.move_mark(inp_mark, cur)

            # Keep indentation of precendent line
            spaces = re.match(self.__spaces_pattern, line)
            if spaces is not None:
                buffer.insert(cur, line[spaces.start() : spaces.end()])
                cur = buffer.get_end_iter()

            buffer.place_cursor(cur)
            GObject.idle_add(self.scroll_to_end)
            return True

        elif event.keyval == Gdk.KEY_Return:
            # Get the marks
            buffer = view.get_buffer()
            lin_mark = buffer.get_mark("input-line")
            inp_mark = buffer.get_mark("input")

            # Get the command line
            inp = buffer.get_iter_at_mark(inp_mark)
            cur = buffer.get_end_iter()
            line = buffer.get_text(inp, cur)
            self.current_command = self.current_command + line + "\n"
            self.history_add(line)

            # Make the line blue
            lin = buffer.get_iter_at_mark(lin_mark)
            buffer.apply_tag(self.command, lin, cur)
            buffer.insert(cur, "\n")

            cur_strip = self.current_command.rstrip()

            if cur_strip.endswith(":") \
            or (self.current_command[-2:] != "\n\n" and self.block_command):
                # Unfinished block command
                self.block_command = True
                com_mark = "... "
            elif cur_strip.endswith("\\"):
                com_mark = "... "
            else:
                # Eval the command
                self.__run(self.current_command)
                self.current_command = ''
                self.block_command = False
                com_mark = ">>> "

            # Prepare the new line
            cur = buffer.get_end_iter()
            buffer.move_mark(lin_mark, cur)
            buffer.insert(cur, com_mark)
            cur = buffer.get_end_iter()
            buffer.move_mark(inp_mark, cur)
            buffer.place_cursor(cur)
            GObject.idle_add(self.scroll_to_end)
            return True

        elif event.keyval == Gdk.KEY_KP_Down or \
                event.keyval == Gdk.KEY_Down:
            # Next entry from history
            view.emit_stop_by_name("key_press_event")
            self.history_down()
            GObject.idle_add(self.scroll_to_end)
            return True

        elif event.keyval == Gdk.KEY_KP_Up or \
                event.keyval == Gdk.KEY_Up:
            # Previous entry from history
            view.emit_stop_by_name("key_press_event")
            self.history_up()
            GObject.idle_add(self.scroll_to_end)
            return True

        elif event.keyval == Gdk.KEY_KP_Left or \
                event.keyval == Gdk.KEY_Left or \
                event.keyval == Gdk.KEY_BackSpace:
            buffer = view.get_buffer()
            inp = buffer.get_iter_at_mark(buffer.get_mark("input"))
            cur = buffer.get_iter_at_mark(buffer.get_insert())
            return inp.compare(cur) == 0

        elif event.keyval == Gdk.KEY_Home:
            # Go to the begin of the command instead of the begin of
            # the line
            buffer = view.get_buffer()
            inp = buffer.get_iter_at_mark(buffer.get_mark("input"))
            if event.get_state() == Gdk.ModifierType.SHIFT_MASK:
                buffer.move_mark_by_name("insert", inp)
            else:
                buffer.place_cursor(inp)
            return True

    def __mark_set_cb(self, buffer, iter, name):
        input = buffer.get_iter_at_mark(buffer.get_mark("input"))
        pos   = buffer.get_iter_at_mark(buffer.get_insert())
        self.view.set_editable(pos.compare(input) != -1)

    def get_command_line(self):
        buffer = self.view.get_buffer()
        inp = buffer.get_iter_at_mark(buffer.get_mark("input"))
        cur = buffer.get_end_iter()
        return buffer.get_text(inp, cur)

    def set_command_line(self, command):
        buffer = self.view.get_buffer()
        mark = buffer.get_mark("input")
        inp = buffer.get_iter_at_mark(mark)
        cur = buffer.get_end_iter()
        buffer.delete(inp, cur)
        buffer.insert(inp, command)
        buffer.select_range(buffer.get_iter_at_mark(mark),
                            buffer.get_end_iter())
        self.view.grab_focus()

    def history_add(self, line):
        if line.strip() != '':
            self.history_pos = len(self.history)
            self.history[self.history_pos - 1] = line
            self.history.append('')

    def history_up(self):
        if self.history_pos > 0:
            self.history[self.history_pos] = self.get_command_line()
            self.history_pos = self.history_pos - 1
            self.set_command_line(self.history[self.history_pos])

    def history_down(self):
        if self.history_pos < len(self.history) - 1:
            self.history[self.history_pos] = self.get_command_line()
            self.history_pos = self.history_pos + 1
            self.set_command_line(self.history[self.history_pos])

    def scroll_to_end(self):
        iter = self.view.get_buffer().get_end_iter()
        self.view.scroll_to_iter(iter, 0.0)
        return False

    def write(self, text, tag = None):
        buffer = self.view.get_buffer()
        if tag is None:
            buffer.insert(buffer.get_end_iter(), text)
        else:
            buffer.insert_with_tags(buffer.get_end_iter(), text, tag)
        GObject.idle_add(self.scroll_to_end)

    def eval(self, command, display_command = False):
        buffer = self.view.get_buffer()
        lin = buffer.get_mark("input-line")
        buffer.delete(buffer.get_iter_at_mark(lin),
                      buffer.get_end_iter())

        if isinstance(command, list) or isinstance(command, tuple):
            for c in command:
                if display_command:
                    self.write(">>> " + c + "\n", self.command)
                self.__run(c)
        else:
            if display_command:
                self.write(">>> " + c + "\n", self.command)
            self.__run(command)

        cur = buffer.get_end_iter()
        buffer.move_mark_by_name("input-line", cur)
        buffer.insert(cur, ">>> ")
        cur = buffer.get_end_iter()
        buffer.move_mark_by_name("input", cur)
        self.view.scroll_to_iter(buffer.get_end_iter(), 0.0)

    def __run(self, command):
        sys.stdout, self.stdout = self.stdout, sys.stdout
        sys.stderr, self.stderr = self.stderr, sys.stderr

        try:
            try:
                r = eval(command, self.namespace, self.namespace)
                if r is not None:
                    print(r)
            except SyntaxError:
                exec_(command, globals=self.namespace)
        except:
            if hasattr(sys, 'last_type') and sys.last_type == SystemExit:
                self.destroy()
            else:
                traceback.print_exc()

        sys.stdout, self.stdout = self.stdout, sys.stdout
        sys.stderr, self.stderr = self.stderr, sys.stderr

    def destroy(self):
        if self.destroy_cb is not None:
            self.destroy_cb()


class gtkoutfile:
    """A fake output file object.  It sends output to a TK test widget,
    and if asked for a file number, returns one set on instance creation"""
    def __init__(self, console, fn, tag):
        self.fn = fn
        self.console = console
        self.tag = tag
    def close(self):         pass
    def flush(self):         pass
    def fileno(self):        return self.fn
    def isatty(self):        return 0
    def read(self, a):       return ''
    def readline(self):      return ''
    def readlines(self):     return []
    def write(self, s):      self.console.write(s, self.tag)
    def writelines(self, l): self.console.write(l, self.tag)

    def seek(self, a):       raise IOError(29, 'Illegal seek')

    def tell(self):          raise IOError(29, 'Illegal seek')
    truncate = tell


class Plugin(BasePlugin):
    description = _("Run-time access to Virtaal's internals (for developers).")
    display_name = _('Python Console')
    version = 0.1

    # INITIALIZERS #
    def __init__(self, internal_name, main_controller):
        self.internal_name = internal_name
        self.main_controller = main_controller

        self._init_plugin()

    def _init_plugin(self):
        self.window = None

        self._setup_key_bindings()
        self._setup_menu_item()

    def _setup_key_bindings(self):
        """Setup Gtk+ key bindings (accelerators)."""

        Gtk.AccelMap.add_entry("<Virtaal>/View/Python Console", Gdk.KEY_y, Gdk.ModifierType.CONTROL_MASK)

        self.accel_group = Gtk.AccelGroup()
        self.accel_group.connect_by_path("<Virtaal>/View/Python Console", self._on_menuitem_activated)

        self.main_controller.view.add_accel_group(self.accel_group)

    def _setup_menu_item(self):
        self.menu = self.main_controller.view.gui.get_object('menu_view')
        self.menuitem = Gtk.MenuItem(label=_('P_ython Console'))
        self.menuitem.show()
        self.menu.append(self.menuitem)

        Gtk.AccelMap.add_entry("<Virtaal>/View/Python Console", Gdk.KEY_F9, 0)
        accel_group = self.menu.get_accel_group()
        if accel_group is None:
            accel_group = self.accel_group
            self.menu.set_accel_group(self.accel_group)
        self.menuitem.set_accel_path("<Virtaal>/View/Python Console")
        self.menu.set_accel_group(accel_group)

        self.menuitem.connect('activate', self._on_menuitem_activated)


    # METHODS #
    def show_console(self, *args):
        if not self.window:
            ns = {
                '__builtins__' : __builtins__,
                'mc': self.main_controller,
                'sc': self.main_controller.store_controller,
                'uc': self.main_controller.unit_controller,
                'mv': self.main_controller.view,
                'sv': self.main_controller.store_controller.view,
                'uv': self.main_controller.unit_controller.view,
            }
            console = PythonConsole(namespace = ns, destroy_cb = self._on_console_destroyed)
            console.set_size_request(600, 400)

            self.window = Gtk.Window()
            self.window.set_title('Virtaal Python Console')
            self.set_transient_for(self.main_controller.view.main_window)
            self.window.add(console)
            self.window.connect('destroy', self._on_console_destroyed)
        self.window.show_all()
        self.window.grab_focus()


    # EVENT HANDLERS #
    def _on_console_destroyed(self, *args):
        self.window = None

    def _on_menuitem_activated(self, *args):
        self.show_console()
