import logging
import os
import sys
import time

from PySide6 import QtCore, QtGui, QtWidgets
from PySide6.QtCore import QMimeDatabase, QUrl
from PySide6.QtGui import QDesktopServices

import sas.qtgui.Utilities.GuiUtils as GuiUtils
from sas.qtgui.Plotting.PlotterData import Data1D
from sas.qtgui.Utilities.UI.GridPanelUI import Ui_GridPanelUI

DICT_KEYS = ["Calculator", "PrPlot", "DataPlot"]

logger = logging.getLogger(__name__)


class BatchOutputPanel(QtWidgets.QMainWindow, Ui_GridPanelUI):
    """
    Class for stateless grid-like printout of model parameters for multiple models
    """
    ERROR_COLUMN_CAPTION = " (Err)"
    IS_WIN = (sys.platform == 'win32')
    windowClosedSignal = QtCore.Signal()
    def __init__(self, parent=None, output_data=None):

        super(BatchOutputPanel, self).__init__(parent._parent)
        self.setupUi(self)

        self.parent = parent
        self.communicator = GuiUtils.communicator

        self.addToolbarActions()

        # file name for the dataset
        self.grid_filename = ""

        self.has_data = False if output_data is None else True
        # Tab numbering
        self.tab_number = 1

        # save state
        self.data_dict = {}

        # list of QTableWidgets, indexed by tab number
        self.tables = []
        self.tables.append(self.tblParams)

        # context menu on the table
        self.tblParams.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
        self.tblParams.customContextMenuRequested.connect(self.showContextMenu)

        self.tabWidget.tabCloseRequested.connect(self.closeTab)


        # Command buttons
        self.cmdHelp.clicked.connect(self.onHelp)
        self.cmdPlot.clicked.connect(self.onPlot)
        self.saveButton.clicked.connect(self.actionSaveFile)

        # Fill in the table from input data
        self.setupTable(widget=self.tblParams, data=output_data)

    def closeEvent(self, event):
        """
        Overwrite QDialog close method to allow for custom widget close
        """
        # notify the parent so it hides this window
        self.windowClosedSignal.emit()
        event.ignore()

    def addToolbarActions(self):
        """
        Assing actions and callbacks to the File menu items
        """
        self.actionOpen.triggered.connect(self.actionLoadData)
        self.actionOpen_with_Excel.triggered.connect(self.actionSendToExcel)
        self.actionSave.triggered.connect(self.actionSaveFile)

    def actionLoadData(self):
        """
        Open file load dialog and load a .csv file
        """
        datafile = QtWidgets.QFileDialog.getOpenFileName(
            self, "Choose a file with results", "", "CSV files (*.csv)", None,
            QtWidgets.QFileDialog.DontUseNativeDialog)[0]

        if not datafile:
            logger.info("No data file chosen.")
            return

        with open(datafile) as csv_file:
            lines = csv_file.readlines()

        self.setupTableFromCSV(lines)
        self.has_data = True

    def currentTable(self):
        """
        Returns the currently shown QTabWidget
        """
        return self.tables[self.tabWidget.currentIndex()]

    def showContextMenu(self, position):
        """
        Show context specific menu in the tab table widget.
        """
        menu = QtWidgets.QMenu()
        rows = [s.row() for s in self.currentTable().selectionModel().selectedRows()]
        num_rows = len(rows)
        if num_rows <= 0:
            return
        # Find out which items got selected and in which row
        # Select for fitting

        self.actionPlotResults = QtGui.QAction(self)
        self.actionPlotResults.setObjectName("actionPlot")
        self.actionPlotResults.setText(QtCore.QCoreApplication.translate("self", "Plot selected fits."))

        menu.addAction(self.actionPlotResults)

        # Define the callbacks
        self.actionPlotResults.triggered.connect(self.onPlot)
        try:
            menu.exec_(self.currentTable().viewport().mapToGlobal(position))
        except AttributeError as ex:
            logger.error("Error generating context menu: %s" % ex)
        return

    def addTabPage(self, name=None):
        """
        Add new tab page with QTableWidget
        """
        layout = QtWidgets.QVBoxLayout()
        tab_widget = QtWidgets.QTableWidget(parent=self)
        # Same behaviour as the original tblParams
        tab_widget.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
        tab_widget.setAlternatingRowColors(True)
        tab_widget.setSelectionBehavior(QtWidgets.QAbstractItemView.SelectRows)
        tab_widget.setLayout(layout)
        # Simple naming here.
        # One would think naming the tab with current model name would be good.
        # However, some models have LONG names, which doesn't look well on the tab bar.
        self.tab_number += 1
        if name is not None:
            tab_name = name
        else:
            tab_name = "Batch Result " + str(self.tab_number)
        # each table needs separate slots.
        tab_widget.customContextMenuRequested.connect(self.showContextMenu)
        self.tables.append(tab_widget)
        self.tabWidget.addTab(tab_widget, tab_name)
        # Make the new tab active
        self.tabWidget.setCurrentIndex(self.tab_number-1)

    def addFitResults(self, results):
        """
        Create a new tab with batch results
        """
        # pull out page name from results
        page_name = None
        if len(results)>=2:
            if isinstance(results[-1], str):
                page_name = results[-1]
                _ = results.pop(-1)

        if self.has_data:
            self.addTabPage(name=page_name)
        else:
            self.tabWidget.setTabText(0, page_name)
        # Update the new widget
        # Fill in the table from input data in the last/newest page
        assert(self.tables)
        self.setupTable(widget=self.tables[-1], data=results)
        self.has_data = True

        # Set a table tooltip describing the model
        model_name = results[0][0].model.id
        self.tabWidget.setTabToolTip(self.tabWidget.count()-1, model_name)
        self.data_dict[page_name] = results

    def onHelp(self):
        """
        Open a local url in the default browser
        """
        url = "/user/qtgui/Perspectives/Fitting/fitting_help.html#batch-fit-mode"
        self.parent.showHelp(url)

    def onPlot(self):
        """
        Plot selected fits by sending signal to the parent
        """
        rows = [s.row() for s in self.currentTable().selectionModel().selectedRows()]
        if not rows:
            msg = "Nothing to plot!"
            self.communicator.statusBarUpdateSignal.emit(msg)
            return
        data = self.dataFromTable(self.currentTable())
        # data['Data'] -> ['filename1', 'filename2', ...]
        # look for the 'Data' column and extract the filename
        for row in rows:
            try:
                name = data['Data'][row]
                # emit a signal so the plots are being shown
                self.communicator.plotFromNameSignal.emit(name)
                # This is an important processEvent.
                # This allows charts to be properly updated in order
                # of plots being applied.
                QtWidgets.QApplication.processEvents()
            except (IndexError, AttributeError):
                # data messed up.
                logger.error('Issue with data')
                return

    @classmethod
    def dataFromTable(cls, table):
        """
        Creates a dictionary {<parameter>:[list of values]} from the parameter table
        """
        assert(isinstance(table, QtWidgets.QTableWidget))
        params = {}
        for column in range(table.columnCount()):
            value = [table.item(row, column).data(0) for row in range(table.rowCount())]
            key = table.horizontalHeaderItem(column).data(0)
            params[key] = value
        return params

    def actionSendToExcel(self):
        """
        Generates a .csv file and opens the default CSV reader
        """
        if not self.grid_filename:
            import tempfile
            tmpfile = tempfile.NamedTemporaryFile(delete=False, mode="w+", suffix=".csv")
            self.grid_filename = tmpfile.name
            data = self.dataFromTable(self.currentTable())
            t = time.localtime(time.time())
            time_str = time.strftime("%b %d %H:%M of %Y", t)
            details = "File Generated by SasView "
            details += "on %s.\n" % time_str
            self.writeBatchToFile(data=data, tmpfile=tmpfile, details=details)
            tmpfile.close()

        mime_type = QMimeDatabase().mimeTypeForFile(self.grid_filename)

        if mime_type.isValid():
            url = QUrl.fromLocalFile(self.grid_filename)

            if QDesktopServices.openUrl(url):
                self.communicator.statusBarUpdateSignal.emit("Success: "
                "The batch results CSV file successfully opened in your system CSV viewer.")
            else:
                self.communicator.statusBarUpdateSignal.emit("Failure: A CSV viewer "
                    "is required to view the batch results. Please set one in your default "
                    "app settings to change this behavior.")

    def actionSaveFile(self):
        """
        Generate a .csv file and dump it to disk
        """
        t = time.localtime(time.time())
        time_str = time.strftime("%b %d %H %M of %Y", t)
        default_name = "Batch_Fitting_"+time_str+".csv"

        wildcard = "CSV files (*.csv)"
        caption =  'Save As'
        directory =  default_name
        filter =  wildcard
        parent =  None
        # Query user for filename.
        filename_tuple = QtWidgets.QFileDialog.getSaveFileName(parent, caption, directory, filter)
        filename = filename_tuple[0]

        # User cancelled.
        if not filename:
            return
        data = self.dataFromTable(self.currentTable())
        details = "File generated by SasView\n"
        with open(filename, 'w') as csv_file:
            self.writeBatchToFile(data=data, tmpfile=csv_file, details=details)

    def setupTableFromCSV(self, csv_data):
        """
        Create tablewidget items and show them, based on params
        """
        # Is this an empty grid?
        if self.has_data:
            # Add a new page
            self.addTabPage()
            # Access the newly created QTableWidget
            current_page = self.tables[-1]
        else:
            current_page = self.tblParams
        # headers
        param_list = csv_data[1].rstrip().split(',')
        # need to remove the 2 header rows to get the total data row number
        rows = len(csv_data) -2
        assert(rows > -1)
        columns = len(param_list)
        current_page.setColumnCount(columns)
        current_page.setRowCount(rows)

        for i, param in enumerate(param_list):
            current_page.setHorizontalHeaderItem(i, QtWidgets.QTableWidgetItem(param))

        # first - Chi2 and data filename
        for i_row, row in enumerate(csv_data[2:]):
            for i_col, col in enumerate(row.rstrip().split(',')):
                current_page.setItem(i_row, i_col, QtWidgets.QTableWidgetItem(col))

        current_page.resizeColumnsToContents()

    def setupTable(self, widget=None, data=None):
        """
        Create tablewidget items and show them, based on params
        """
        # quietly leave is nothing to show

        if data is None or widget is None:
            return
        # Figure out the headers
        model = data[0][0]

        disperse_params = list(model.model.dispersion.keys())
        magnetic_params = model.model.magnetic_params
        optimized_params = model.param_list
        # Create the main parameter list
        param_list = [m for m in model.model.params.keys() if (m not in model.model.magnetic_params and ".width" not in m)]

        # add fitted polydisp parameters
        param_list += [m+".width" for m in disperse_params if m+".width" in optimized_params]

        # add fitted magnetic params
        param_list += [m for m in magnetic_params if m in optimized_params]

        # Check if 2D model. If not, remove theta/phi
        if isinstance(model.data.sas_data, Data1D):
            if 'theta' in param_list:
                param_list.remove('theta')
            if 'phi' in param_list:
                param_list.remove('phi')

        rows = len(data)
        columns = len(param_list)

        widget.setColumnCount(columns+2) # add 2 initial columns defined below
        widget.setRowCount(rows)

        # Insert two additional columns
        param_list.insert(0, "Data")
        param_list.insert(0, "Chi2")
        for i, param in enumerate(param_list):
            widget.setHorizontalHeaderItem(i, QtWidgets.QTableWidgetItem(param))

        # dictionary of parameter errors for post-processing
        # [param_name] = [param_column_nr, error_for_row_1, error_for_row_2,...]
        error_columns = {}
        # first - Chi2 and data filename
        for i_row, row in enumerate(data):
            # each row corresponds to a single fit
            chi2 = row[0].fitness
            name = ""
            if hasattr(row[0].data, "sas_data"):
                name = row[0].data.sas_data.name
            widget.setItem(i_row, 0, QtWidgets.QTableWidgetItem(GuiUtils.formatNumber(chi2, high=True)))
            widget.setItem(i_row, 1, QtWidgets.QTableWidgetItem(str(name)))
            # Now, all the parameters
            for i_col, param in enumerate(param_list[2:]):
                if param in row[0].param_list:
                    # parameter is on the to-optimize list - get the optimized value
                    par_value = row[0].pvec[row[0].param_list.index(param)]
                    # parse out errors and store them for later use
                    err_value = row[0].stderr[row[0].param_list.index(param)]
                    if param in error_columns:
                        error_columns[param].append(err_value)
                    else:
                        error_columns[param] = [i_col, err_value]
                else:
                    # parameter was not varied
                    par_value = row[0].model.params[param]

                widget.setItem(i_row, i_col+2, QtWidgets.QTableWidgetItem(
                    GuiUtils.formatNumber(par_value, high=True)))

        # Add errors
        error_list = list(error_columns.keys())
        for error_param in error_list[::-1]: # must be reverse to keep column indices
            # the offset for the err column: +2 from the first two extra columns, +1 to append this column
            error_column = error_columns[error_param][0]+3
            error_values = error_columns[error_param][1:]
            widget.insertColumn(error_column)

            column_name = error_param + self.ERROR_COLUMN_CAPTION
            widget.setHorizontalHeaderItem(error_column, QtWidgets.QTableWidgetItem(column_name))

            for i_row, error in enumerate(error_values):
                item = QtWidgets.QTableWidgetItem(GuiUtils.formatNumber(error, high=True))
                # Fancy, italic font for errors
                font = QtGui.QFont()
                font.setItalic(True)
                item.setFont(font)
                widget.setItem(i_row, error_column, item)

        # resize content
        widget.resizeColumnsToContents()

    @classmethod
    def writeBatchToFile(cls, data, tmpfile, details=""):
        """
        Helper to write result from batch into cvs file
        """
        name = tmpfile.name
        if data is None or name is None or name.strip() == "":
            return
        _, ext = os.path.splitext(name)
        separator = "\t"
        if ext.lower() == ".csv":
            separator = ","
        tmpfile.write(details)
        for col_name in data.keys():
            tmpfile.write(col_name)
            tmpfile.write(separator)
        tmpfile.write('\n')
        max_list = [len(value) for value in data.values()]
        if len(max_list) == 0:
            return
        max_index = max(max_list)
        index = 0
        while index < max_index:
            for value_list in data.values():
                if index < len(value_list):
                    tmpfile.write(str(value_list[index]))
                    tmpfile.write(separator)
                else:
                    tmpfile.write('')
                    tmpfile.write(separator)
            tmpfile.write('\n')
            index += 1

    def closeTab(self, currentIndex):
        self.tables.pop(currentIndex)
        self.tabWidget.removeTab(currentIndex)



class BatchInversionOutputPanel(BatchOutputPanel):
    """
        Class for stateless grid-like printout of P(r) parameters for any number
        of data sets
    """
    def __init__(self, parent=None, output_data=None):

        super(BatchInversionOutputPanel, self).__init__(parent.parent, output_data)
        _translate = QtCore.QCoreApplication.translate
        self.setWindowTitle(_translate("GridPanelUI", "Batch P(r) Results"))
        self.parent = parent
        self.batch_results = output_data


    def setupTable(self, widget=None,  data=None):
        """
        Create tablewidget items and show them, based on params
        """
        # headers
        param_list = ['Filename','Number Of Terms','Reg. Const','Max Distance [Å]',
                      'Rg [Å]', 'Chi^2/dof', 'I(Q=0) [cm^-1]', 'Oscillations',
                      'Background [cm^-1]', 'P+ Fraction', 'P+1-theta Fraction',
                      'Calc. Time [sec]', 'Q Min [Å^-1]', 'Q Max [Å^-1]']


        if data is None:
            return

        keys = data.keys()
        rows = len(keys)
        columns = len(param_list)
        self.tblParams.setColumnCount(columns)
        self.tblParams.setRowCount(rows)

        for i, param in enumerate(param_list):
            self.tblParams.setHorizontalHeaderItem(i, QtWidgets.QTableWidgetItem(param))

        # first - Chi2 and data filename
        failedCells = False

        for i_row, (filename, pr) in enumerate(data.items()):
            pr = pr.get(DICT_KEYS[0])
            out = pr.out
            cov = pr.cov
            self.tblParams.setItem(i_row, 0, QtWidgets.QTableWidgetItem(
                f"{filename}"))
            if out is None:
                logger.warning(f"P(r) for {filename} did not converge.")
                continue
            try:
                self.tblParams.setItem(i_row, 1, QtWidgets.QTableWidgetItem(
                    f"{pr.noOfTerms:.3g}"))
            except TypeError:
                failedCells = True
            try:
                self.tblParams.setItem(i_row, 2, QtWidgets.QTableWidgetItem(
                    f"{pr.alpha:.3g}"))
            except TypeError:
                failedCells = True
            try:
                self.tblParams.setItem(i_row, 3, QtWidgets.QTableWidgetItem(
                    f"{pr.dmax:.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 4, QtWidgets.QTableWidgetItem(
                    f"{pr.rg(out):.3g}"))
            except TypeError:
                failedCells = True
            try:
                self.tblParams.setItem(i_row, 5, QtWidgets.QTableWidgetItem(
                f"{pr.chi2:.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 6, QtWidgets.QTableWidgetItem(
                    f"{pr.iq0(out):.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 7, QtWidgets.QTableWidgetItem(
                    f"{pr.oscillations(out):.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 8, QtWidgets.QTableWidgetItem(
                    f"{pr.background:.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 9, QtWidgets.QTableWidgetItem(
                    f"{pr.get_positive(out):.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 10, QtWidgets.QTableWidgetItem(
                    f"{pr.get_pos_err(out, cov):.3g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 11, QtWidgets.QTableWidgetItem(
                    f"{pr.elapsed:.2g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 12, QtWidgets.QTableWidgetItem(
                    f"{pr.q_min:.2g}"))
            except TypeError:
                failedCells = True
            try:
                    self.tblParams.setItem(i_row, 13, QtWidgets.QTableWidgetItem(
                    f"{pr.q_max:.2g}"))
            except TypeError:
                failedCells = True
        if failedCells:
            GuiUtils.logger.warning("Some of the cells failed to receive outputs.")
        self.tblParams.resizeColumnsToContents()

    def newTableTab(self, tab_name=None, data=None):
        # creating a BatchInversionOutputPanel object and taking out the .tblParams is not the cleanest.
        # this can be changed when setupTable is made more flexible
        self.tab_number += 1
        if tab_name is None:
            tab_name = "Batch Result " + str(self.tab_number)
        tableItem = BatchInversionOutputPanel(parent=self, output_data=data.get(DICT_KEYS[0])).tblParams
        tableItem.customContextMenuRequested.connect(self.showContextMenu)
        self.tables.append(tableItem)
        self.tabWidget.addTab(tableItem, tab_name)
        self.tabWidget.setCurrentIndex(self.tab_number-1)

    def onPlot(self):
        """
        Plot selected fits by sending signal to the parent
        """
        rows = [s.row() for s in self.currentTable().selectionModel().selectedRows()]
        if not rows:
            msg = "Nothing to plot!"
            self.communicator.statusBarUpdateSignal.emit(msg)
            return
        data = self.dataFromTable(self.currentTable())
        # data['Data'] -> ['filename1', 'filename2', ...]
        # look for the 'Data' column and extract the filename
        for row in rows:
            try:
                name = data['Filename'][row]
                self.prPlot = self.batch_results[name].get(DICT_KEYS[1])
                self.dataPlot = self.batch_results[name].get(DICT_KEYS[2])
                # emit a signal so the plots are being shown
                self.parent.showPlots(self.batch_results[name]['Result'])
                # This is an important processEvent.
                # This allows charts to be properly updated in order
                # of plots being applied.
                QtWidgets.QApplication.processEvents()
            except (IndexError, AttributeError):
                # data messed up.
                logging.error('Issue with data')
                return

    def onHelp(self):
        self.parent.onHelp()

    def closeEvent(self, event):
        """Tell the parent window the window closed"""
        self.parent.batchResultsWindow = None
        event.accept()
