#!/usr/bin/env python3
# -*- coding: utf-8 -*-


__author__ = "ipetrash"


import time
import traceback
import sys

try:
    from PyQt5.QtWidgets import *
    from PyQt5.QtCore import *

except:
    try:
        from PyQt4.QtGui import *
        from PyQt4.QtCore import *

    except:
        from PySide.QtGui import *
        from PySide.QtCore import *


def log_uncaught_exceptions(ex_cls, ex, tb):
    text = f"{ex_cls.__name__}: {ex}:\n"
    text += "".join(traceback.format_tb(tb))

    print(text)
    QMessageBox.critical(None, "Error", text)
    sys.exit(1)


sys.excepthook = log_uncaught_exceptions


class MainWindow(QWidget):
    ESCAPE_RULES = [
        ('"', '"', r"\"", True),
        ("'", "'", r"\'", False),
        (r"\n", "\n", r"\n", True),
        (r"\t", "\t", r"\t", False),
        (r"\b", "\b", r"\b", False),
        (r"\f", "\f", r"\f", False),
        ("\\", "\\", "\\\\", False),
    ]
    TITLE = "EscapeString"

    def __init__(self, parent=None):
        super().__init__(parent)

        self.setWindowTitle(self.TITLE)

        self.escape_char_by_checkbox = {}
        self.char_by_escape = {}

        button_layout = QHBoxLayout()
        for title, char, escape, checked in self.ESCAPE_RULES:
            checkbox = QCheckBox(title)
            checkbox.setChecked(checked)
            checkbox.clicked.connect(self.input_text_changed)

            font = checkbox.font()
            font.setBold(True)
            font.setPointSize(font.pointSize() + 2)
            checkbox.setFont(font)

            button_layout.addWidget(checkbox)
            self.escape_char_by_checkbox[char] = checkbox
            self.char_by_escape[char] = escape

        button_layout.addStretch()

        self.cb_save_multiline = QCheckBox("Save multiline")
        self.cb_save_multiline.setChecked(False)
        self.cb_save_multiline.clicked.connect(self.input_text_changed)
        button_layout.addWidget(self.cb_save_multiline)

        self.cb_string_literal = QCheckBox("String literal")
        self.cb_string_literal.setChecked(True)
        self.cb_string_literal.clicked.connect(self.input_text_changed)
        button_layout.addWidget(self.cb_string_literal)

        self.cb_semicolon = QCheckBox(";")
        self.cb_semicolon.setChecked(True)
        self.cb_semicolon.clicked.connect(self.input_text_changed)
        button_layout.addWidget(self.cb_semicolon)

        layout = QVBoxLayout()
        layout.addLayout(button_layout)

        self.text_edit_input = QPlainTextEdit()

        self.text_edit_output = QPlainTextEdit()
        self.text_edit_output.setReadOnly(True)

        self.label_error = QLabel()
        self.label_error.setStyleSheet("QLabel { color : red; }")
        self.label_error.setTextInteractionFlags(Qt.TextSelectableByMouse)
        self.label_error.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Preferred)

        self.button_detail_error = QPushButton("...")
        self.button_detail_error.setFixedSize(20, 20)
        self.button_detail_error.setToolTip("Detail error")
        self.button_detail_error.clicked.connect(self.show_detail_error_massage)
        self.button_detail_error.hide()

        self.last_error_message = None
        self.last_detail_error_message = None

        self.text_edit_input.textChanged.connect(self.input_text_changed)

        self.label_input_number = QLabel()
        self.label_output_number = QLabel()

        splitter = QSplitter()
        splitter.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
        splitter.addWidget(self.text_edit_input)
        splitter.addWidget(self.text_edit_output)

        layout.addWidget(splitter)

        layout_error = QHBoxLayout()
        layout_error.addWidget(self.label_error)
        layout_error.addWidget(self.button_detail_error)

        layout.addLayout(layout_error)

        self.setLayout(layout)

    def show_detail_error_massage(self):
        if not self.last_error_message or not self.last_detail_error_message:
            return

        message = self.last_error_message + "\n\n" + self.last_detail_error_message

        mb = QErrorMessage()
        mb.setWindowTitle("Error")
        # Сообщение ошибки содержит отступы, символы-переходы на следующую строку,
        # которые поломаются при вставке через QErrorMessage.showMessage, и нет возможности
        # выбрать тип текста, то делаем такой хак.
        mb.findChild(QTextEdit).setPlainText(message)

        mb.exec_()

    def _escape(self, in_text: str, ignored="") -> str:
        out_text = []
        for char in in_text:
            # Если char нет в словаре экранирования, или флаг экранирования для char выключен,
            # или char среди игнорируемых
            if (
                char not in self.escape_char_by_checkbox
                or not self.escape_char_by_checkbox[char].isChecked()
                or char in ignored
            ):
                out_text.append(char)
                continue

            out_text.append(self.char_by_escape[char])

        return "".join(out_text)

    def input_text_changed(self):
        self.label_error.clear()
        self.button_detail_error.hide()

        self.last_error_message = None
        self.last_detail_error_message = None

        try:
            t = time.perf_counter()

            in_text = self.text_edit_input.toPlainText()

            if self.cb_save_multiline.isChecked():
                lines = []
                for line in in_text.splitlines(keepends=True):
                    line = self._escape(line)
                    lines.append(f'"{line}"')

                out_text = " +\n".join(lines)

            else:
                out_text = self._escape(in_text)

            if self.cb_string_literal.isChecked():
                if not out_text.startswith('"'):
                    out_text = '"' + out_text
                if not out_text.endswith('"'):
                    out_text += '"'

            if self.cb_semicolon.isChecked():
                out_text += ";"

            self.text_edit_output.setPlainText(out_text)

            self.setWindowTitle(
                f"{self.TITLE} (number of characters: "
                f"{len(self.text_edit_input.toPlainText())} -> "
                f"{len(self.text_edit_output.toPlainText())})"
            )
            print(f"Escape for {time.perf_counter() - t:.6f} secs")

        except Exception as e:
            # Выводим ошибку в консоль
            traceback.print_exc()

            # Сохраняем в переменную
            tb = traceback.format_exc()

            self.last_error_message = str(e)
            self.last_detail_error_message = str(tb)
            self.button_detail_error.show()

            self.label_error.setText("Error: " + self.last_error_message)


if __name__ == "__main__":
    app = QApplication([])

    mw = MainWindow()
    mw.resize(650, 500)
    mw.show()

    sys.exit(app.exec_())