import logging
import os
import signal

from PyQt6 import QtCore
from PyQt6.QtWidgets import *
from PyQt6.QtCore import *
from PyQt6.QtGui import *
import sys

import urlutils
from aboutdialog import AboutDialog
from ravenui import RavenUI
from settingsstore import SettingsStore
from tabs import Tabs
from urlutils import url_is_file

MAX_LINE_LENGTH = 4096

logging.basicConfig(level=logging.INFO)
log = logging.getLogger("main")


class MainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)

        self.settings = SettingsStore.load()
        self.setWindowTitle(self.tr("RavenLog"))
        self.setGeometry(0, 0, 640, 480)
        self.setDockNestingEnabled(True)
        self.setAcceptDrops(True)

        self.tabs = Tabs(self.settings)
        self.tabs.create_tab("/home/andi/ws/performanceDb/data/production/logs_2018-09-06_2018-09-06.csv")
        self.tabs.create_tab("/home/andi/ws/performanceDb/data/production/vapbdcom.csv")
        self.tabs.create_tab("/home/andi/ws/ravenlog/example.log")
        self.tabs.create_tab("/var/log/syslog")

        self._menu_recent_files = QMenu(self.tr("Open &Recent"), self)

        self.setCentralWidget(self.tabs)
        self.setStatusBar(QStatusBar(self))
        self.setMenuBar(self.create_menu_bar())

    def create_menu_bar(self) -> QMenuBar:
        menu_bar = QMenuBar()

        menu_bar.addMenu(self.file_menu())
        menu_bar.addMenu(self.help_menu())

        return menu_bar

    def file_menu(self) -> QMenu:
        file_menu = QMenu(self.tr("&File", "name of the file menu"), self)

        open_file = QAction(self.tr("&Open..."), self)
        open_file.triggered.connect(self._open_file_dialog)

        close_action = QAction(self.tr("E&xit", "menu item to close the application"), self)
        close_action.triggered.connect(self.destruct)

        self._update_recent_files_menu()

        file_menu.addAction(open_file)
        file_menu.addMenu(self._menu_recent_files)
        file_menu.addAction(close_action)
        return file_menu

    def help_menu(self) -> QMenu:
        help_menu = QMenu(self.tr("&Help", "name of the help menu"), self)

        about_action = QAction(self.tr("&About"), self)
        about_action.triggered.connect(lambda: AboutDialog().exec())
        help_menu.addAction(about_action)

        return help_menu

    def _update_recent_files_menu(self):
        self._menu_recent_files.clear()
        files = self._get_recent_files()
        for file in files:
            action = QAction(os.path.basename(file), self)
            action.triggered.connect(lambda x, f=file: self._open_file(f))
            self._menu_recent_files.addAction(action)

    def _open_file_dialog(self) -> None:
        current_file = self.tabs.current_file()
        directory = os.path.dirname(current_file) if current_file else ''

        dialog = QFileDialog(self)
        (selected_file, _filter) = dialog.getOpenFileName(
            caption=self.tr("Open File"),
            directory=directory
        )
        if selected_file:
            self.tabs.create_tab(selected_file)
            self._remember_recent_file(selected_file)

    def _open_file(self, file: str) -> None:
        self.tabs.create_tab(file)
        self._remember_recent_file(file)

    def _get_recent_files(self) -> [str]:
        recent_files = self.settings.session.get('general', 'recent_files', fallback='')
        files = recent_files.split(os.pathsep)
        if "" in files:
            files.remove("")
        return files

    def _remember_recent_file(self, file: str):
        files = self._get_recent_files()
        if file in files:
            files.remove(file)
        files.insert(0, file)
        recent_files = os.pathsep.join(files[:10])
        self.settings.set_session('general', 'recent_files', recent_files)
        self._update_recent_files_menu()

    def dragEnterEvent(self, e: QDragEnterEvent):
        if e.mimeData().hasFormat('text/plain') and url_is_file(e.mimeData().text()):
            e.accept()
        else:
            e.ignore()

    def dropEvent(self, e):
        file = urlutils.url_to_path(e.mimeData().text())
        self._open_file(file)

    def closeEvent(self, event):
        self.destruct()

    def destruct(self):
        self.tabs.destruct()
        self.close()
        SettingsStore.save(self.settings)


def stop_signal(signum, _stackframe):
    """ Handle terminate signal """
    try:
        log.info("Terminate signal received. %s", signum)
        QtCore.QCoreApplication.quit()
    except Exception:
        log.exception("Exception occurred while terminating")
        sys.exit(1)
    sys.exit(0)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setWindowIcon(QIcon("icon7.png"))

    # translator = QTranslator()
    # if translator.load(QLocale("de"), "messages_de.ts"):
    #    app.installTranslator(translator)

    # workaround to make signals work in QT apps.
    # They do not work out of the box, because the main thread
    # is running in C++ code once app.exec() is executed
    # Forcing an empty lambda to be executed periodically gives
    # control back to python and allows python to react to signals
    timer = QTimer()
    timer.timeout.connect(lambda: None)
    timer.start(100)

    window = MainWindow()
    RavenUI.window = window
    window.show()

    signal.signal(signal.SIGINT, stop_signal)
    signal.signal(signal.SIGTERM, stop_signal)

    app.exec()