from __future__ import annotations

from functools import lru_cache
from os import getenv, stat
from os.path import exists
import hashlib
import subprocess
from datetime import datetime
from contextlib import contextmanager
from pathlib import Path

import requests
from numpy import linspace
from scipy.interpolate import interp1d

from nmreval.lib.logger import logger

from ..Qt import QtGui, QtWidgets, QtCore


@contextmanager
def busy_cursor():
    try:
        cursor = QtGui.QCursor(QtCore.Qt.ForbiddenCursor)
        QtWidgets.QApplication.setOverrideCursor(cursor)
        yield

    finally:
        QtWidgets.QApplication.restoreOverrideCursor()


class RdBuCMap:
    # taken from Excel sheet from colorbrewer.org
    _rdbu = [
        (103, 0, 31),
        (178, 24, 43),
        (214, 96, 77),
        (244, 165, 130),
        (253, 219, 199),
        (247, 247, 247),
        (209, 229, 240),
        (146, 197, 222),
        (67, 147, 195),
        (33, 102, 172),
        (5, 48, 97)
    ]

    def __init__(self, vmin=-1., vmax=1.):
        self.min = vmin
        self.max = vmax

        self.spline = [interp1d(linspace(self.max, self.min, num=11), [rgb[i] for rgb in RdBuCMap._rdbu])
                       for i in range(3)]

    def color(self, val: float):
        if val > self.max:
            col = QtGui.QColor.fromRgb(*RdBuCMap._rdbu[0])
        elif val < self.min:
            col = QtGui.QColor.fromRgb(*RdBuCMap._rdbu[-1])
        else:
            col = QtGui.QColor.fromRgb(*(float(self.spline[i](val)) for i in range(3)))

        return col


class UpdateDialog(QtWidgets.QDialog):
    startDownload = QtCore.pyqtSignal(list)

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

        if filename is None:
            filename = getenv('APPIMAGE')
        self._appfile = filename

        self.success = False
        self.updater = Updater()

        self.thread = QtCore.QThread(self)
        self.thread.start()
        self.helper = Downloader()
        self.startDownload.connect(self.helper.run_download)
        self.helper.progressChanged.connect(self.status.setText)
        self.helper.finished.connect(self.finish_update)
        self.helper.started.connect(self.status.show)
        self.helper.moveToThread(self.thread)

        self.look_for_updates(self._appfile)

    def _init_ui(self):
        self.setWindowTitle('Updates')

        layout = QtWidgets.QVBoxLayout()

        self.label = QtWidgets.QLabel()
        layout.addWidget(self.label)

        layout.addSpacing(10)

        self.status = QtWidgets.QLabel()
        self.status.hide()
        layout.addWidget(self.status)
        layout.addSpacing(10)

        self.dialog_button = QtWidgets.QDialogButtonBox()
        self.dialog_button.accepted.connect(self.update_appimage)
        self.dialog_button.rejected.connect(self.close)
        layout.addWidget(self.dialog_button)

        self.setLayout(layout)

    def look_for_updates(self, filename=None):
        logger.info(f'Looking for updates, compare to file {filename}')
        # Download zsync file of latest Appimage, look for SHA-1 hash and compare with hash of AppImage
        is_updateble, m_time_file, m_time_zsync = self.updater.get_update_information(filename)

        label_text = ''

        if is_updateble is None:
            label_text += '<p>Could not determine if this version is newer, please update manually (if necessary).</p>'
            dialog_bttns = QtWidgets.QDialogButtonBox.Close
        elif is_updateble:
            label_text += '<p>Newer version available. Press Ok to download new version, Cancel to ignore.</p>'
            dialog_bttns = QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel
        else:
            label_text += '<p>Version may be already up-to-date.</p>'
            dialog_bttns = QtWidgets.QDialogButtonBox.Close

        if m_time_zsync is None:
            label_text += '<p>Creation date of remote version is unknown.</p>'
        else:
            label_text += f'<p>Date of most recent AppImage: {m_time_zsync.strftime("%d %B %Y %H:%M")}</p>'

        if m_time_file is None:
            label_text += 'No AppImage file found, press Ok to download latest version.'
            dialog_bttns = QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Close
        else:
            label_text += f'<p>Date of used AppImage: {m_time_file.strftime("%d %B %Y %H:%M")}</p>'

        self.label.setText(label_text)
        self.dialog_button.setStandardButtons(dialog_bttns)

    @QtCore.pyqtSlot()
    def update_appimage(self):
        if self._appfile is None:
            args = [self.updater.zsync_url]
        else:
            # this breaks the download for some reason
            args = ['-i', self._appfile, self.updater.zsync_url]

        args = [self.updater.zsync_url]

        self.dialog_button.setEnabled(False)

        self.startDownload.emit(args)
        self.status.show()

    @QtCore.pyqtSlot(int)
    def finish_update(self, retcode: int):
        # print('finished with', retcode)
        self.success = retcode == 0
        if retcode == 0:
            self.status.setText('Download complete.')
        else:
            self.status.setText(f'Download failed :( with return code {retcode}.')
        self.dialog_button.setStandardButtons(QtWidgets.QDialogButtonBox.Close)
        self.dialog_button.setEnabled(True)

    def closeEvent(self, evt):
        self.thread.quit()
        self.thread.wait()

        if self.success:
            appname = self.updater.get_zsync()[2]
            if self._appfile is not None:
                appimage_path = appname
                old_version = Path(self._appfile).rename(self._appfile+'.old')
                appimage_path = Path(appimage_path).replace(self._appfile)
            else:
                appimage_path = Path().cwd() / appname
                # rename to version-agnostic name
                appimage_path = appimage_path.rename('NMReval.AppImage')
                appimage_path.chmod(appimage_path.stat().st_mode | 73)  # 73 = 0o111 = a+x

            _ = QtWidgets.QMessageBox.information(self, 'Complete',
                                                  f'New AppImage available at<br>{appimage_path}')

        super().closeEvent(evt)


class Downloader(QtCore.QObject):
    started = QtCore.pyqtSignal()
    finished = QtCore.pyqtSignal(int)
    progressChanged = QtCore.pyqtSignal(str)

    @QtCore.pyqtSlot(list)
    def run_download(self, args: list[str]):
        logger.info(f'Download with args {args}')
        process = subprocess.Popen(['zsync'] + args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=1, universal_newlines=True)
        while True:
            nextline = process.stdout.readline().strip()
            if nextline:
                self.progressChanged.emit(nextline)

            # line  = process.stderr.readline().strip()

            if process.poll() is not None:
                break

        self.finished.emit(process.returncode)


class Updater:
    host = 'gitea.pkm.physik.tu-darmstadt.de/api/packages/IPKM/generic/NMReval/latest/'
    version = 'NMReval-latest-x86_64'

    @property
    def zsync_url(self):
        return f'https://{Updater.host}/{Updater.version}.AppImage.zsync'

    @staticmethod
    @lru_cache(3)
    def get_zsync():
        url_zsync = f'https://{Updater.host}/{Updater.version}.AppImage.zsync'
        m_time_zsync = None
        checksum_zsync = None
        zsync_file = None
        filename = None
        try:
            response = requests.get(url_zsync)
            if response.status_code == 200:
                zsync_file = response.content
            else:
                logger.error(f'Request for zsync returned code {response.status_code}')
        except Exception as e:
            logger.exception(f'Download of zsync failed with exception {e.args}')

        if zsync_file is not None:
            for line in zsync_file.split(b'\n'):
                try:
                    kw, val = line.split(b': ')
                    time_string = str(val, encoding='utf-8')
                    time_format = '%a, %d %b %Y %H:%M:%S %z'
                    if kw == b'MTime':
                        try:
                            m_time_zsync = datetime.strptime(time_string, time_format).astimezone(None)
                        except ValueError:
                            logger.warning(f'zsync time "{time_string}" does not match "{time_format}"')
                    elif kw == b'SHA-1':
                        checksum_zsync = str(val, encoding='utf-8')
                    elif kw == b'Filename':
                        filename = str(val, encoding='utf-8')

                except ValueError:
                    # stop when empty line is reached
                    break

        return m_time_zsync, checksum_zsync, filename

    @staticmethod
    def get_appimage_info(filename: str):
        if filename is None:
            return None, None

        if not exists(filename):
            return None, None

        stat_mtime = stat(filename).st_mtime
        m_time_file = datetime.fromtimestamp(stat_mtime).replace(microsecond=0)
        with open(filename, 'rb') as f:
            checksum_file = hashlib.sha1(f.read()).hexdigest()
            if checksum_file is None:
                logger.warning('No checksum for AppImage calculated')

        return m_time_file, checksum_file

    @staticmethod
    def get_update_information(filename: str) -> tuple[(bool | None), datetime, datetime]:
        m_time_zsync, checksum_zsync, appname = Updater.get_zsync()
        m_time_file, checksum_file = Updater.get_appimage_info(filename)

        logger.info(f'zsync information {m_time_zsync}, {checksum_zsync}, {appname}')
        logger.info(f'file information {m_time_file}, {checksum_file}')

        if not ((checksum_file is not None) and (checksum_zsync is not None)):
            return None, m_time_file, m_time_zsync
        else:
            return checksum_file != checksum_zsync, m_time_file, m_time_zsync


def open_bug_report():
    form_entries = {
        'description': 'Please state the nature of the medical emergency.',
        'title': 'Everything is awesome?',
        'assign[0]': 'dominik',
        'subscribers[0]': 'dominik',
        'tag': 'nmreval',
        'priority': 'normal',
        'status': 'open',
    }
    full_url = 'https://chaos3.fkp.physik.tu-darmstadt.de/maniphest/task/edit/?'

    for k, v in form_entries.items():
        full_url += f'{k}={v}&'
    full_url.replace(' ', '+')

    import webbrowser
    webbrowser.open(full_url)