"""
@package wxplot.histogram

@brief Histogramming using PyPlot

Classes:
 - histogram::HistogramPlotFrame
 - histogram::HistogramPlotToolbar

(C) 2011-2013 by the GRASS Development Team

This program is free software under the GNU General Public License
(>=v2). Read the file COPYING that comes with GRASS for details.

@author Michael Barton, Arizona State University
"""

import sys

import wx

import grass.script as grass
import wx.lib.plot as plot
from gui_core.wrap import StockCursor
from gui_core.toolbars import BaseToolbar, BaseIcons
from wxplot.base import BasePlotFrame, PlotIcons
from wxplot.dialogs import HistRasterDialog, PlotStatsFrame
from core.gcmd import RunCommand, GException, GError


class HistogramPlotFrame(BasePlotFrame):
    """Mainframe for displaying histogram of raster map. Uses wx.lib.plot.
    """

    def __init__(self, parent, giface, id=wx.ID_ANY, style=wx.DEFAULT_FRAME_STYLE,
                 size=wx.Size(700, 400), rasterList=[], **kwargs):
        BasePlotFrame.__init__(self, parent, giface=giface, size=size, **kwargs)

        self.toolbar = HistogramPlotToolbar(parent=self)
        # workaround for http://trac.wxwidgets.org/ticket/13888
        if sys.platform != 'darwin':
            self.SetToolBar(self.toolbar)
        self.SetTitle(_("Histogram Tool"))

        #
        # Init variables
        #
        self.rasterList = rasterList
        self.plottype = 'histogram'
        self.group = ''
        self.ptitle = _('Histogram of')         # title of window
        self.xlabel = _("Raster cell values")   # default X-axis label
        self.ylabel = _("Cell counts")          # default Y-axis label
        self.maptype = 'raster'                 # default type of histogram to plot
        self.histtype = 'count'
        self.bins = 255
        self.colorList = [
            "blue",
            "green",
            "red",
            "yellow",
            "magenta",
            "cyan",
            "aqua",
            "black",
            "grey",
            "orange",
            "brown",
            "purple",
            "violet",
            "indigo"]

        self._initOpts()

        if len(
                self.rasterList) > 0:  # set raster name(s) from layer manager if a map is selected
            self.raster = self.InitRasterOpts(self.rasterList, self.plottype)
            wx.CallAfter(self.OnCreateHist, None)
        else:
            self.raster = {}

    def _initOpts(self):
        """Initialize plot options
        """
        self.InitPlotOpts('histogram')

    def OnCreateHist(self, event):
        """Main routine for creating a histogram. Uses r.stats to
        create a list of cell value and count/percent/area pairs. This is passed to
        plot to create a line graph of the histogram.
        """
        try:
            self.SetCursor(StockCursor(wx.CURSOR_ARROW))
        except:
            pass

        self.SetGraphStyle()
        wx.BeginBusyCursor()
        wx.SafeYield()
        self.SetupHistogram()
        p = self.CreatePlotList()
        self.DrawPlot(p)
        wx.EndBusyCursor()

    def OnSelectRaster(self, event):
        """Select raster map(s) to profile
        """
        dlg = HistRasterDialog(parent=self)

        if dlg.ShowModal() == wx.ID_OK:
            self.rasterList = dlg.rasterList
            self.group = dlg.group
            self.bins = dlg.bins
            self.histtype = dlg.histtype
            self.maptype = dlg.maptype
            self.raster = self.InitRasterOpts(self.rasterList, self.plottype)

            # plot histogram
            if len(self.rasterList) > 0:
                self.OnCreateHist(event=None)

        dlg.Destroy()

    def SetupHistogram(self):
        """Build data list for ploting each raster
        """

        #
        # populate raster dictionary
        #
        if len(self.rasterList) == 0:
            return  # nothing selected

        for r in self.rasterList:
            self.raster[r]['datalist'] = self.CreateDatalist(r)

        #
        # update title
        #
        if self.maptype == 'group':
            self.ptitle = _('Histogram of image group <%s>') % self.group
        else:
            if len(self.rasterList) == 1:
                self.ptitle = _(
                    'Histogram of raster map <%s>') % self.rasterList[0]
            else:
                self.ptitle = _('Histogram of selected raster maps')

        #
        # set xlabel based on first raster map in list to be histogrammed
        #
        units = self.raster[self.rasterList[0]]['units']
        if units != '' and units != '(none)' and units is not None:
            self.xlabel = _('Raster cell values %s') % units
        else:
            self.xlabel = _('Raster cell values')

        #
        # set ylabel from self.histtype
        #
        if self.histtype == 'count':
            self.ylabel = _('Cell counts')
        if self.histtype == 'percent':
            self.ylabel = _('Percent of total cells')
        if self.histtype == 'area':
            self.ylabel = _('Area')

    def CreateDatalist(self, raster):
        """Build a list of cell value, frequency pairs for histogram
            frequency can be in cell counts, percents, or area
        """
        datalist = []

        if self.histtype == 'count':
            freqflag = 'cn'
        if self.histtype == 'percent':
            freqflag = 'pn'
        if self.histtype == 'area':
            freqflag = 'an'

        try:
            ret = RunCommand("r.stats",
                             parent=self,
                             input=raster,
                             flags=freqflag,
                             nsteps=self.bins,
                             sep=',',
                             quiet=True,
                             read=True)

            if not ret:
                return datalist

            for line in ret.splitlines():
                cellval, histval = line.strip().split(',')
                histval = histval.strip()
                if self.raster[raster]['datatype'] != 'CELL':
                    if cellval[0] == '-':
                        cellval = '-' + cellval.split('-')[1]
                    else:
                        cellval = cellval.split('-')[0]

                if self.histtype == 'percent':
                    histval = histval.rstrip('%')

                datalist.append((cellval, histval))

            return datalist
        except GException as e:
            GError(parent=self,
                   message=e.value)
            return None

    def CreatePlotList(self):
        """Make list of elements to plot
        """

        # graph the cell value, frequency pairs for the histogram
        self.plotlist = []

        for r in self.rasterList:
            if len(self.raster[r]['datalist']) > 0:
                col = wx.Colour(self.raster[r]['pcolor'][0],
                                self.raster[r]['pcolor'][1],
                                self.raster[r]['pcolor'][2],
                                255)

                self.raster[r]['pline'] = plot.PolyLine(
                    self.raster[r]['datalist'],
                    colour=col, width=self.raster[r]['pwidth'],
                    style=self.linestyledict[self.raster[r]['pstyle']],
                    legend=self.raster[r]['plegend'])

                self.plotlist.append(self.raster[r]['pline'])

        if len(self.plotlist) > 0:
            return self.plotlist
        else:
            return None

    def Update(self):
        """Update histogram after changing options
        """
        self.SetGraphStyle()
        p = self.CreatePlotList()
        self.DrawPlot(p)

    def OnStats(self, event):
        """Displays regression information in messagebox
        """
        message = []
        title = _('Statistics for Map(s) Histogrammed')

        for rast in self.rasterList:
            ret = grass.read_command(
                'r.univar', map=rast, flags='e', quiet=True)
            stats = _('Statistics for raster map <%s>') % rast + ':\n%s\n' % ret
            message.append(stats)

        stats = PlotStatsFrame(self, id=wx.ID_ANY, message=message,
                               title=title)

        if stats.Show() == wx.ID_CLOSE:
            stats.Destroy()


class HistogramPlotToolbar(BaseToolbar):
    """Toolbar for histogramming raster map
    """

    def __init__(self, parent):
        BaseToolbar.__init__(self, parent)

        # workaround for http://trac.wxwidgets.org/ticket/13888
        if sys.platform == 'darwin':
            parent.SetToolBar(self)

        self.InitToolbar(self._toolbarData())

        # realize the toolbar
        self.Realize()

    def _toolbarData(self):
        """Toolbar data"""
        return self._getToolbarData((('addraster', BaseIcons["addRast"],
                                      self.parent.OnSelectRaster),
                                     (None, ),
                                     ('draw', PlotIcons["draw"],
                                      self.parent.OnCreateHist),
                                     ('erase', BaseIcons["erase"],
                                      self.parent.OnErase),
                                     ('drag', BaseIcons['pan'],
                                      self.parent.OnDrag),
                                     ('zoom', BaseIcons['zoomIn'],
                                      self.parent.OnZoom),
                                     ('unzoom', BaseIcons['zoomExtent'],
                                      self.parent.OnRedraw),
                                     (None, ),
                                     ('statistics', PlotIcons['statistics'],
                                      self.parent.OnStats),
                                     ('image', BaseIcons["saveFile"],
                                      self.parent.SaveToFile),
                                     ('print', BaseIcons["print"],
                                      self.parent.PrintMenu),
                                     (None, ),
                                     ('settings', PlotIcons["options"],
                                      self.parent.PlotOptionsMenu),
                                     ('quit', PlotIcons["quit"],
                                      self.parent.OnQuit),
                                     )
                                    )