from asap.parameters import rcParams
from asap.utils import _n_bools, mask_and, mask_or
from asap.scantable import scantable
from asap.logging import asaplog, asaplog_post_dec

class interactivemask:
    """
    The class for interactive mask selection.

    Example:
       my_mask=interactivemask(plotter,scan)
       my_mask.set_basemask(masklist=[[0,10],[90,100]],invert=False)
       # Do interactive mask selection
       my_mask.select_mask()
       finish=raw_input('Press return to finish selection.\n')
       my_mask.finish_selection(callback=func)
       mask=my_mask.get_mask()

    Modify mask region by selecting a region on a plot with mouse.
    """

    def __init__(self,plotter=None, scan=None):
        """
        Create a interactive masking object.
        Either or both 'plotter' or/and 'scan' should be defined.

        Parameters:
           plotter: an ASAP plotter object for interactive selection
           scan: a scantable to create a mask interactively
        """
        # Return if GUI is not active
        if not rcParams['plotter.gui']:
            msg = 'GUI plotter is disabled.\n'
            msg += 'Exit interactive mode.'
            asaplog.push(msg)
            asaplog.post("ERROR")
            return
        # Verify input parameters
        if scan is None and plotter is None:
            msg = "Either scantable or plotter should be defined."
            raise TypeError(msg)

        self.scan = None
        self.p = None
        self.newplot = False
        if scan and isinstance(scan, scantable):
            self.scan = scan
        from asap.asapplotter import asapplotter
        if plotter and isinstance(plotter,asapplotter):
            self.p = plotter
            if self.scan is None and isinstance(self.p._data,scantable):
                self.scan = self.p._data
        if self.scan is None:
            msg = "Invalid scantable."
            raise TypeError(msg)

        self.mask = _n_bools(self.scan.nchan(self.scan.getif(0)),True)
        self.callback = None
        self.event = None
        self.once = False
        self.showmask = True
        self.rect = {}
        self.xold = None
        self.yold = None
        self.xdataold = None
        self.ydataold = None
        self._polygons = []


    def set_basemask(self,masklist=[],invert=False):
        """
        Set initial channel mask.

        Parameters:
            masklist:  [[min, max], [min2, max2], ...]
                       A list of pairs of start/end points (inclusive)
                               specifying the regions to be masked
            invert:    optional argument. If specified as True,
                       return an inverted mask, i.e. the regions
                   specified are excluded
        You can reset the mask selection by running this method with
        the default parameters.
        """
        # Verify input parameters
        if not (isinstance(masklist, list) or isinstance(masklist, tuple)) \
           or not isinstance(invert, bool):
            msg = 'Invalid mask definition'
            raise TypeError(msg)

        # Create base mask
        if ( len(masklist) > 0 ):
            self.mask = self.scan.create_mask(masklist,invert=invert)
        elif invert == True:
            self.mask = _n_bools(self.scan.nchan(self.scan.getif(0)),False)
        else:
            self.mask = _n_bools(self.scan.nchan(self.scan.getif(0)),True)


    def set_startevent(self,event):
        """
        Inherit an event from the parent function.

        Parameters:
            event: 'button_press_event' object to be inherited to
                   start interactive region selection .
        """
        from matplotlib.backend_bases import MouseEvent
        if isinstance(event,MouseEvent) and event.name == 'button_press_event':
            self.event = event
        else:
            msg = "Invalid event."
            raise TypeError(msg)

    def set_callback(self,callback):
        """
        Set callback function to run when finish_selection() is executed.
            callback: The post processing function to run after
                      the mask selections are completed.
                  This will be overwritten if callback is defined in
                  finish_selection(callback=func)
        """
        self.callback = callback

    def select_mask(self,once=False,showmask=True):
        """
        Do interactive mask selection.
        Modify masks interactively by adding/deleting regions with
        mouse drawing.(left-button: mask; right-button: UNmask)
        Note that the interactive region selection is available only
        when GUI plotter is active.

        Parameters:
            once:     If specified as True, you can modify masks only
                      once. Else if False, you can modify them repeatedly.
            showmask: If specified as True, the masked regions are plotted
                      on the plotter.
                  Note this parameter is valid only when once=True.
                  Otherwise, maskes are forced to be plotted for reference.
        """
        # Return if GUI is not active
        if not rcParams['plotter.gui']:
            msg = 'GUI plotter is disabled.\n'
            msg += 'Exit interactive mode.'
            asaplog.push(msg)
            asaplog.post("ERROR")
            return

        self.once = once
        if self.once:
            self.showmask = showmask
        else:
            if not showmask:
                asaplog.post()
                asaplog.push('showmask spcification is ignored. Mask regions are plotted anyway.')
                asaplog.post("WARN")
            self.showmask = True

        #if not self.p._plotter or self.p._plotter.is_dead:
        if not self.p:
            asaplog.push('A new ASAP plotter will be loaded')
            asaplog.post()
            from asap.asapplotter import asapplotter
            self.p = asapplotter()
            self.newplot = True
        self.p._assert_plotter(action='reload')
        
        # Plot selected spectra if needed
        if self.scan != self.p._data:
            if len(self.scan.getifnos()) > 16:
                asaplog.post()
                asaplog.push("Number of panels > 16. Plotting the first 16...")
                asaplog.post("WARN")
            # Need replot
            self.p._legendloc = 1
            self.p.plot(self.scan)
            # disable casa toolbar
            if self.p._plotter.figmgr.casabar:
                self.p._plotter.figmgr.casabar.disable_button()
                self.p._plotter.figmgr.casabar.disable_prev()
                self.p._plotter.figmgr.casabar.disable_next()
            for panel in self.p._plotter.subplots:
                xmin, xmax = panel['axes'].get_xlim()
                marg = 0.05*abs(xmax-xmin)
                panel['axes'].set_xlim(xmin-marg, xmax+marg)
                if rcParams['plotter.ganged']: break
            self.p._plotter.show()

        # Plot initial mask region
        #if self.showmask or not self.once:
        if self.showmask:
            self._plot_mask()
            print ''
            print 'Selected regions are shaded with yellow. (gray: projections)'
            print 'Now you can modify the selection.'
            print 'Draw rectangles with Left-mouse to add the regions,'
            print 'or with Right-mouse to exclude the regions.'


        if self.event != None:
            self._region_start(self.event)
        else:
            self.p._plotter.register('button_press',None)
            self.p._plotter.register('button_press',self._region_start)


    def _region_start(self,event):
        # Do not fire event when in zooming/panning mode
        mode = self.p._plotter.figmgr.toolbar.mode
        if not mode == '':
            return
        # Return if selected point is out of panel
        if event.inaxes == None: return
        # Select mask/unmask region with mask
        self.rect = {'button': event.button, 'axes': event.inaxes,
                     'x': event.x, 'y': event.y,
                     'world': [event.xdata, event.ydata,
                                event.xdata, event.ydata],
                     'pixel': [event.x, event.y,
                                event.x, event.y]}
        self.p._plotter.register('motion_notify', self._region_draw)
        self.p._plotter.register('button_release', self._region_end)

    def _region_draw(self,event):
        sameaxes=(event.inaxes == self.rect['axes'])
        if sameaxes:
            xnow = event.x
            ynow = event.y
            self.xold = xnow
            self.yold = ynow
            self.xdataold = event.xdata
            self.ydataold = event.ydata
        else:
            xnow = self.xold
            ynow = self.yold

        self.p._plotter.figmgr.toolbar.draw_rubberband(event, xnow, ynow, self.rect['x'], self.rect['y'])

    def _region_end(self,event):
        self.p._plotter.register('motion_notify', None)
        self.p._plotter.register('button_release', None)

        # Delete the rubber band
        self.p._plotter.figmgr.toolbar.release(event)

        if event.inaxes == self.rect['axes']:
            xend = event.x
            yend = event.y
            xdataend = event.xdata
            ydataend = event.ydata
        else:
            xend = self.xold
            yend = self.yold
            xdataend = self.xdataold
            ydataend = self.ydataold

        self.rect['world'][2:4] = [xdataend, ydataend]
        self.rect['pixel'][2:4] = [xend, yend]
        self._update_mask()
        # Clear up region selection
        self.rect = {}
        self.xold = None
        self.yold = None
        self.xdataold = None
        self.ydataold = None
        if self.once: self.finish_selection(callback=self.callback)

    def _update_mask(self):
        # Min and Max for new mask
        xstart = self.rect['world'][0]
        xend = self.rect['world'][2]
        if xstart <= xend: newlist=[xstart,xend]
        else: newlist = [xend,xstart]
        # Mask or unmask
        invmask = None
        if self.rect['button'] == 1:
            invmask = False
            mflg = 'Mask'
        elif self.rect['button'] == 3:
            invmask = True
            mflg = 'UNmask'
        asaplog.push(mflg+': '+str(newlist))
        asaplog.post()
        newmask = self.scan.create_mask(newlist,invert=invmask)
        # Logic operation to update mask
        if invmask:
            self.mask = mask_and(self.mask,newmask)
        else:
            self.mask = mask_or(self.mask,newmask)
        # Plot masked regions
        #if self.showmask or not self.once: self._plot_mask()
        if self.showmask: self._plot_mask()

    # Plot masked regions
    def _plot_mask(self):
        msks = []
        msks = self.scan.get_masklist(self.mask,row=0)
        # Get projection masks for multi-IF
        ifs = self.scan.getifnos()
        projs = []
        if len(ifs) > 1:
            row0if = self.scan.getif(0)
            for ifno in ifs:
                if ifno == row0if: continue
                for row in xrange(self.scan.nrow()):
                    if self.scan.getif(row) == ifno:
                        projs.append(self.scan.get_masklist(self.mask,row=row))
                        break
        if len(self._polygons)>0:
            # Remove old polygons
            for polygon in self._polygons: polygon.remove()
            self._polygons = []
        # Plot new polygons
        if len(msks) > 0:
            npanel = len(self.p._plotter.subplots)
            j = -1
            for iloop in range(len(msks)*npanel):
                i = iloop % len(msks)
                if  i == 0 : j += 1
                if len(ifs) > 1:
                    for k in xrange(len(ifs)-1):
                        self._polygons.append(self.p._plotter.subplots[j]['axes'].axvspan(projs[k][i][0],projs[k][i][1],facecolor='#aaaaaa'))
                self._polygons.append(self.p._plotter.subplots[j]['axes'].axvspan(msks[i][0],msks[i][1],facecolor='yellow'))
        self.p._plotter.canvas.draw()

    def finish_selection(self, callback=None):
        """
        Execute callback function, reset or close plotter window as
        necessary.

        Parameters:
            callback: The post processing function to run after
                      the mask selections are completed.
                  Specifying the callback function here will overwrite
                  the one set by set_callback(func)

        Note this function is automatically called at the end of
        select_mask() if once=True.
        """
        if callback: self.callback=callback
        if self.callback: self.callback()
        if not self.event: self.p._plotter.register('button_press',None)
        # Finish the plot
        if not self.newplot:
            self.clear_polygon()
        else:
            self.p._plotter.unmap()
            self.p._plotter = None
            del self.p
            self.p = None
            self._polygons = []


    def clear_polygon(self):
        """
        Erase masks plots from the plotter.
        """
        if len(self._polygons) > 0:
            # Remove old polygons
            for polygon in self._polygons: polygon.remove()
            self.p._plotter.show()
            self._polygons = []


    def get_mask(self):
        """
        Get the interactively selected channel mask.
        Returns:
            A list of channel mask.
        """
        return self.mask
