import re
from PyQt6.QtCore import Qt, QPoint, QStringListModel
from PyQt6.QtWidgets import (
	QDockWidget, QTextEdit, QPlainTextEdit,
	QSplitter, QMenu, QCompleter,
)
from PyQt6.QtGui import (
	QFont, QTextCursor, QKeySequence,
	QAction, QPalette, QColorConstants,
)
from IPython.core.completer import (
    provisionalcompleter, cursor_to_position,
    _deduplicate_completions
)

from text_term import text_term

class completer_py(QCompleter):
	def __init__(self, widget, *args):
		super().__init__(*args)
		model = QStringListModel([], self)
		self.setWidget(widget)
		self.setModel(model)
		self.setModelSorting(QCompleter.ModelSorting.CaseInsensitivelySortedModel)
		self.setCaseSensitivity(Qt.CaseSensitivity.CaseInsensitive)
		self.setWrapAround(False)
		self.setCompletionMode(QCompleter.CompletionMode.PopupCompletion)
		self.setCaseSensitivity(Qt.CaseSensitivity.CaseInsensitive)
		self.activated.connect(widget.insertCompletion)

class text_input(QPlainTextEdit):
	def __init__(self, window, *arg):
		super().__init__(*arg)
		self.window = window
		self.setTabStopDistance(40)
		self.setPlaceholderText(
			"按 %s 发送命令\n"
			"按 %s 自动补全\n"
			"按 %s 或 %s 浏览命令历史\n"
			% (
				QKeySequence("Ctrl+Enter").toString(QKeySequence.SequenceFormat.NativeText),
				QKeySequence("Ctrl+E").toString(QKeySequence.SequenceFormat.NativeText),
				QKeySequence("Ctrl+Up").toString(QKeySequence.SequenceFormat.NativeText),
				QKeySequence("Ctrl+Down").toString(QKeySequence.SequenceFormat.NativeText),
			)
		)
		self.completer_py = completer_py(self)
		self.history = [""]
		self.history_idx = 0

	def insertCompletion(self, completion):
		tc = self.textCursor()
		extra = len(completion) - len(self.completer_py.completionPrefix())
		tc.movePosition(QTextCursor.MoveOperation.Left)
		tc.movePosition(QTextCursor.MoveOperation.EndOfWord)
		tc.insertText(completion[-extra:])
		self.setTextCursor(tc)

	def textUnderCursor(self):
		tc = self.textCursor()
		tc.select(QTextCursor.SelectionType.WordUnderCursor)

		return tc.selectedText()

	def focusInEvent(self, event):
		if self.completer_py is not None:
			self.completer_py.setWidget(self)

		super().focusInEvent(event)

	def keyPressEvent(self, event):
		if(
			event.key() in (Qt.Key.Key_Enter, Qt.Key.Key_Return)
			and bool(event.modifiers() & Qt.KeyboardModifier.ControlModifier)
		):
			s = self.toPlainText()
			if not s:
				return
			self.window.process(s)
			self.history[-1] = s
			if len(self.history) >= 2 and self.history[-1] == self.history[-2]:
				self.history.pop()
			self.history_idx = len(self.history)
			self.history.append("")
			self.clear()
			return

		if(
			event.key() == Qt.Key.Key_Up
			and bool(event.modifiers() & Qt.KeyboardModifier.ControlModifier)
			and self.history_idx > 0
		):
			if self.history_idx == len(self.history) - 1:
				self.history[-1] = self.toPlainText()
			self.history_idx -= 1
			self.setPlainText(self.history[self.history_idx])
			return

		if(
			event.key() == Qt.Key.Key_Down
			and bool(event.modifiers() & Qt.KeyboardModifier.ControlModifier)
			and self.history_idx < len(self.history) - 1
		):
			self.history_idx += 1
			self.setPlainText(self.history[self.history_idx])
			return

		if self.completer_py is not None and self.completer_py.popup().isVisible():
			# The following keys are forwarded by the completer to the widget.
			if event.key() in (Qt.Key.Key_Enter, Qt.Key.Key_Return, Qt.Key.Key_Escape, Qt.Key.Key_Tab, Qt.Key.Key_Backtab):
				event.ignore()
				# Let the completer do default behavior.
				return

		isShortcut = (bool(event.modifiers() & Qt.KeyboardModifier.ControlModifier) and event.key() == Qt.Key.Key_E)
		if self.completer_py is None or not isShortcut:
			# Do not process the shortcut when we have a completer.
			super().keyPressEvent(event)

		ctrlOrShift = event.modifiers() & (Qt.KeyboardModifier.ControlModifier | Qt.KeyboardModifier.ShiftModifier)
		if self.completer_py is None or (ctrlOrShift and len(event.text()) == 0):
			return

		eow = "~!@#$%^&*()_+{}|:\"<>?,./;'[]\\-="
		hasModifier = (event.modifiers() != Qt.KeyboardModifier.NoModifier) and not ctrlOrShift
		completionPrefix = self.textUnderCursor()

		if not isShortcut and (hasModifier or len(event.text()) == 0 or len(completionPrefix) < 3 or event.text()[-1] in eow):
			self.completer_py.popup().hide()
			return

		pos = self.textCursor().position()
		value = self.document().toRawText()
		hint = re.search(r"[_0-9a-zA-Z.%]*$", value[:pos]).group()
		pos_hint = pos - len(hint)
		hint += re.search(r"^[_0-9a-zA-Z.%]*", value[pos:]).group()
		with provisionalcompleter():
			complete_list = _deduplicate_completions(hint, self.window.ipshell.Completer.completions(hint, pos - pos_hint))
			complete_list = list(complete_list)
		complete_list = [i.text for i in complete_list]
		# complete_list = self.window.ipshell.complete(hint, cursor_pos = pos - pos_hint)
		# print(complete_list)
		self.completer_py.model().setStringList(complete_list)

		if completionPrefix != self.completer_py.completionPrefix():
			self.completer_py.setCompletionPrefix(completionPrefix)
			self.completer_py.popup().setCurrentIndex(
					self.completer_py.completionModel().index(0, 0))

		cr = self.cursorRect()
		cr.setWidth(self.completer_py.popup().sizeHintForColumn(0) + self.completer_py.popup().verticalScrollBar().sizeHint().width())
		self.completer_py.complete(cr)

class widget_term(QDockWidget):
	def __init__(self, window, *arg):
		super().__init__(*arg)
		self.window = window

		self.setAllowedAreas(
			Qt.DockWidgetArea.LeftDockWidgetArea | Qt.DockWidgetArea.RightDockWidgetArea
			| Qt.DockWidgetArea.TopDockWidgetArea | Qt.DockWidgetArea.BottomDockWidgetArea
		)
		font = QFont("consolas", 12)
		font.setFamilies(["consolas", "黑体"])
		self.setFont(font)
		split = QSplitter(Qt.Orientation.Horizontal)
		self.setWidget(split)

		self.text_term = text_term(window, limit = 2 ** 16)
		split.addWidget(self.text_term)

		self.text_input = text_input(window)
		split.addWidget(self.text_input)