# -*- coding: utf-8 -*-
from ..Qt import QtGui, QtCore
try:
    from ..Qt import QtOpenGL
    HAVE_OPENGL = True
except:
    HAVE_OPENGL = False

import warnings
import numpy as np
from .GraphicsObject import GraphicsObject
from .. import functions as fn
from ..Point import Point
import struct, sys
from .. import getConfigOption
from .. import debug

__all__ = ['PlotCurveItem']
class PlotCurveItem(GraphicsObject):
    """
    Class representing a single plot curve. Instances of this class are created
    automatically as part of PlotDataItem; these rarely need to be instantiated
    directly.

    Features:

    - Fast data update
    - Fill under curve
    - Mouse interaction

    =====================  ===============================================
    **Signals:**
    sigPlotChanged(self)   Emitted when the data being plotted has changed
    sigClicked(self, ev)   Emitted when the curve is clicked
    =====================  ===============================================
    """

    sigPlotChanged = QtCore.Signal(object)
    sigClicked = QtCore.Signal(object, object)

    def __init__(self, *args, **kargs):
        """
        Forwards all arguments to :func:`setData <pyqtgraph.PlotCurveItem.setData>`.

        Some extra arguments are accepted as well:

        ==============  =======================================================
        **Arguments:**
        parent          The parent GraphicsObject (optional)
        clickable       If True, the item will emit sigClicked when it is
                        clicked on. Defaults to False.
        ==============  =======================================================
        """
        GraphicsObject.__init__(self, kargs.get('parent', None))
        self.clear()

        ## this is disastrous for performance.
        #self.setCacheMode(QtGui.QGraphicsItem.DeviceCoordinateCache)

        self.metaData = {}
        self.opts = {
            'shadowPen': None,
            'fillLevel': None,
            'fillOutline': False,
            'brush': None,
            'stepMode': None,
            'name': None,
            'antialias': getConfigOption('antialias'),
            'connect': 'all',
            'mouseWidth': 8, # width of shape responding to mouse click
            'compositionMode': None,
        }
        if 'pen' not in kargs:
            self.opts['pen'] = fn.mkPen('w')
        self.setClickable(kargs.get('clickable', False))
        self.setData(*args, **kargs)

    def implements(self, interface=None):
        ints = ['plotData']
        if interface is None:
            return ints
        return interface in ints

    def name(self):
        return self.opts.get('name', None)

    def setClickable(self, s, width=None):
        """Sets whether the item responds to mouse clicks.

        The *width* argument specifies the width in pixels orthogonal to the
        curve that will respond to a mouse click.
        """
        self.clickable = s
        if width is not None:
            self.opts['mouseWidth'] = width
            self._mouseShape = None
            self._boundingRect = None

    def setCompositionMode(self, mode):
        """Change the composition mode of the item (see QPainter::CompositionMode
        in the Qt documentation). This is useful when overlaying multiple items.

        ============================================  ============================================================
        **Most common arguments:**
        QtGui.QPainter.CompositionMode_SourceOver     Default; image replaces the background if it
                                                      is opaque. Otherwise, it uses the alpha channel to blend
                                                      the image with the background.
        QtGui.QPainter.CompositionMode_Overlay        The image color is mixed with the background color to
                                                      reflect the lightness or darkness of the background.
        QtGui.QPainter.CompositionMode_Plus           Both the alpha and color of the image and background pixels
                                                      are added together.
        QtGui.QPainter.CompositionMode_Multiply       The output is the image color multiplied by the background.
        ============================================  ============================================================
        """
        self.opts['compositionMode'] = mode
        self.update()

    def getData(self):
        return self.xData, self.yData

    def dataBounds(self, ax, frac=1.0, orthoRange=None):
        ## Need this to run as fast as possible.
        ## check cache first:
        cache = self._boundsCache[ax]
        if cache is not None and cache[0] == (frac, orthoRange):
            return cache[1]

        (x, y) = self.getData()
        if x is None or len(x) == 0:
            return (None, None)

        if ax == 0:
            d = x
            d2 = y
        elif ax == 1:
            d = y
            d2 = x

        ## If an orthogonal range is specified, mask the data now
        if orthoRange is not None:
            mask = (d2 >= orthoRange[0]) * (d2 <= orthoRange[1])
            d = d[mask]
            #d2 = d2[mask]

        if len(d) == 0:
            return (None, None)

        ## Get min/max (or percentiles) of the requested data range
        if frac >= 1.0:
            # include complete data range
            # first try faster nanmin/max function, then cut out infs if needed.
            with warnings.catch_warnings(): 
                # All-NaN data is acceptable; Explicit numpy warning is not needed.
                warnings.simplefilter("ignore")
                b = (np.nanmin(d), np.nanmax(d))
            if any(np.isinf(b)):
                mask = np.isfinite(d)
                d = d[mask]
                if len(d) == 0:
                    return (None, None)
                b = (d.min(), d.max())

        elif frac <= 0.0:
            raise Exception("Value for parameter 'frac' must be > 0. (got %s)" % str(frac))
        else:
            # include a percentile of data range
            mask = np.isfinite(d)
            d = d[mask]
            if len(d) == 0:
                return (None, None)
            b = np.percentile(d, [50 * (1 - frac), 50 * (1 + frac)])

        ## adjust for fill level
        if ax == 1 and self.opts['fillLevel'] not in [None, 'enclosed']:
            b = (min(b[0], self.opts['fillLevel']), max(b[1], self.opts['fillLevel']))

        ## Add pen width only if it is non-cosmetic.
        pen = self.opts['pen']
        spen = self.opts['shadowPen']
        if not pen.isCosmetic():
            b = (b[0] - pen.widthF()*0.7072, b[1] + pen.widthF()*0.7072)
        if spen is not None and not spen.isCosmetic() and spen.style() != QtCore.Qt.NoPen:
            b = (b[0] - spen.widthF()*0.7072, b[1] + spen.widthF()*0.7072)

        self._boundsCache[ax] = [(frac, orthoRange), b]
        return b

    def pixelPadding(self):
        pen = self.opts['pen']
        spen = self.opts['shadowPen']
        w = 0
        if pen.isCosmetic():
            w += pen.widthF()*0.7072
        if spen is not None and spen.isCosmetic() and spen.style() != QtCore.Qt.NoPen:
            w = max(w, spen.widthF()*0.7072)
        if self.clickable:
            w = max(w, self.opts['mouseWidth']//2 + 1)
        return w

    def boundingRect(self):
        if self._boundingRect is None:
            (xmn, xmx) = self.dataBounds(ax=0)
            if xmn is None or xmx is None:
                return QtCore.QRectF()
            (ymn, ymx) = self.dataBounds(ax=1)
            if ymn is None or ymx is None:
                return QtCore.QRectF()

            px = py = 0.0
            pxPad = self.pixelPadding()
            if pxPad > 0:
                # determine length of pixel in local x, y directions
                px, py = self.pixelVectors()
                try:
                    px = 0 if px is None else px.length()
                except OverflowError:
                    px = 0
                try:
                    py = 0 if py is None else py.length()
                except OverflowError:
                    py = 0

                # return bounds expanded by pixel size
                px *= pxPad
                py *= pxPad
            #px += self._maxSpotWidth * 0.5
            #py += self._maxSpotWidth * 0.5
            self._boundingRect = QtCore.QRectF(xmn-px, ymn-py, (2*px)+xmx-xmn, (2*py)+ymx-ymn)

        return self._boundingRect

    def viewTransformChanged(self):
        self.invalidateBounds()
        self.prepareGeometryChange()

    #def boundingRect(self):
        #if self._boundingRect is None:
            #(x, y) = self.getData()
            #if x is None or y is None or len(x) == 0 or len(y) == 0:
                #return QtCore.QRectF()


            #if self.opts['shadowPen'] is not None:
                #lineWidth = (max(self.opts['pen'].width(), self.opts['shadowPen'].width()) + 1)
            #else:
                #lineWidth = (self.opts['pen'].width()+1)


            #pixels = self.pixelVectors()
            #if pixels == (None, None):
                #pixels = [Point(0,0), Point(0,0)]

            #xmin = x.min()
            #xmax = x.max()
            #ymin = y.min()
            #ymax = y.max()

            #if self.opts['fillLevel'] is not None:
                #ymin = min(ymin, self.opts['fillLevel'])
                #ymax = max(ymax, self.opts['fillLevel'])

            #xmin -= pixels[0].x() * lineWidth
            #xmax += pixels[0].x() * lineWidth
            #ymin -= abs(pixels[1].y()) * lineWidth
            #ymax += abs(pixels[1].y()) * lineWidth

            #self._boundingRect = QtCore.QRectF(xmin, ymin, xmax-xmin, ymax-ymin)
        #return self._boundingRect


    def invalidateBounds(self):
        self._boundingRect = None
        self._boundsCache = [None, None]

    def setPen(self, *args, **kargs):
        """Set the pen used to draw the curve."""
        self.opts['pen'] = fn.mkPen(*args, **kargs)
        self.invalidateBounds()
        self.update()

    def setShadowPen(self, *args, **kargs):
        """Set the shadow pen used to draw behind the primary pen.
        This pen must have a larger width than the primary
        pen to be visible.
        """
        self.opts['shadowPen'] = fn.mkPen(*args, **kargs)
        self.invalidateBounds()
        self.update()

    def setBrush(self, *args, **kargs):
        """Set the brush used when filling the area under the curve"""
        self.opts['brush'] = fn.mkBrush(*args, **kargs)
        self.invalidateBounds()
        self.update()

    def setFillLevel(self, level):
        """Set the level filled to when filling under the curve"""
        self.opts['fillLevel'] = level
        self.fillPath = None
        self.invalidateBounds()
        self.update()

    def setData(self, *args, **kargs):
        """
        =============== ========================================================
        **Arguments:**
        x, y            (numpy arrays) Data to show
        pen             Pen to use when drawing. Any single argument accepted by
                        :func:`mkPen <pyqtgraph.mkPen>` is allowed.
        shadowPen       Pen for drawing behind the primary pen. Usually this
                        is used to emphasize the curve by providing a
                        high-contrast border. Any single argument accepted by
                        :func:`mkPen <pyqtgraph.mkPen>` is allowed.
        fillLevel       (float or None) Fill the area 'under' the curve to
                        *fillLevel*
        fillOutline     (bool) If True, an outline surrounding the *fillLevel*
                        area is drawn.
        brush           QBrush to use when filling. Any single argument accepted
                        by :func:`mkBrush <pyqtgraph.mkBrush>` is allowed.
        antialias       (bool) Whether to use antialiasing when drawing. This
                        is disabled by default because it decreases performance.
        stepMode        (str or None) If "center", a step is drawn using the x
                        values as boundaries and the given y values are
                        associated to the mid-points between the boundaries of
                        each step. This is commonly used when drawing
                        histograms. Note that in this case, len(x) == len(y) + 1
                        If "left" or "right", the step is drawn assuming that
                        the y value is associated to the left or right boundary,
                        respectively. In this case len(x) == len(y)
                        If not passed or an empty string or None is passed, the
                        step mode is not enabled.
                        Passing True is a deprecated equivalent to "center".
        connect         Argument specifying how vertexes should be connected
                        by line segments. Default is "all", indicating full
                        connection. "pairs" causes only even-numbered segments
                        to be drawn. "finite" causes segments to be omitted if
                        they are attached to nan or inf values. For any other
                        connectivity, specify an array of boolean values.
        compositionMode See :func:`setCompositionMode
                        <pyqtgraph.PlotCurveItem.setCompositionMode>`.
        =============== ========================================================

        If non-keyword arguments are used, they will be interpreted as
        setData(y) for a single argument and setData(x, y) for two
        arguments.


        """
        self.updateData(*args, **kargs)

    def updateData(self, *args, **kargs):
        profiler = debug.Profiler()

        if 'compositionMode' in kargs:
            self.setCompositionMode(kargs['compositionMode'])

        if len(args) == 1:
            kargs['y'] = args[0]
        elif len(args) == 2:
            kargs['x'] = args[0]
            kargs['y'] = args[1]

        if 'y' not in kargs or kargs['y'] is None:
            kargs['y'] = np.array([])
        if 'x' not in kargs or kargs['x'] is None:
            kargs['x'] = np.arange(len(kargs['y']))

        for k in ['x', 'y']:
            data = kargs[k]
            if isinstance(data, list):
                data = np.array(data)
                kargs[k] = data
            if not isinstance(data, np.ndarray) or data.ndim > 1:
                raise Exception("Plot data must be 1D ndarray.")
            if data.dtype.kind == 'c':
                raise Exception("Can not plot complex data types.")

        profiler("data checks")

        #self.setCacheMode(QtGui.QGraphicsItem.NoCache)  ## Disabling and re-enabling the cache works around a bug in Qt 4.6 causing the cached results to display incorrectly
                                                        ##    Test this bug with test_PlotWidget and zoom in on the animated plot
        self.yData = kargs['y'].view(np.ndarray)
        self.xData = kargs['x'].view(np.ndarray)
        
        self.invalidateBounds()
        self.prepareGeometryChange()
        self.informViewBoundsChanged()

        profiler('copy')

        if 'stepMode' in kargs:
            self.opts['stepMode'] = kargs['stepMode']

        if self.opts['stepMode'] in ("center", True):  ## check against True for backwards compatibility
            if self.opts['stepMode'] is True:
                import warnings
                warnings.warn('stepMode=True is deprecated, use stepMode="center" instead', DeprecationWarning, stacklevel=3)
            if len(self.xData) != len(self.yData)+1:  ## allow difference of 1 for step mode plots
                raise Exception("len(X) must be len(Y)+1 since stepMode=True (got %s and %s)" % (self.xData.shape, self.yData.shape))
        else:
            if self.xData.shape != self.yData.shape:  ## allow difference of 1 for step mode plots
                raise Exception("X and Y arrays must be the same shape--got %s and %s." % (self.xData.shape, self.yData.shape))

        self.path = None
        self.fillPath = None
        self._mouseShape = None
        #self.xDisp = self.yDisp = None

        if 'name' in kargs:
            self.opts['name'] = kargs['name']
        if 'connect' in kargs:
            self.opts['connect'] = kargs['connect']
        if 'pen' in kargs:
            self.setPen(kargs['pen'])
        if 'shadowPen' in kargs and kargs['shadowPen'] is not None:
            self.setShadowPen(kargs['shadowPen'])
        if 'fillLevel' in kargs and kargs['fillLevel'] is not None:
            self.setFillLevel(kargs['fillLevel'])
        if 'fillOutline' in kargs:
            self.opts['fillOutline'] = kargs['fillOutline']
        if 'brush' in kargs and kargs['brush'] is not None:
            self.setBrush(kargs['brush'])
        if 'antialias' in kargs:
            self.opts['antialias'] = kargs['antialias']

        profiler('set')
        self.update()
        profiler('update')
        self.sigPlotChanged.emit(self)
        profiler('emit')

    def generatePath(self, x, y):
        stepMode = self.opts['stepMode']
        if stepMode:
            ## each value in the x/y arrays generates 2 points.
            if stepMode == "right":
                x2 = np.empty((len(x) + 1, 2), dtype=x.dtype)
                x2[:-1] = x[:, np.newaxis]
                x2[-1] = x2[-2]
            elif stepMode == "left":
                x2 = np.empty((len(x) + 1, 2), dtype=x.dtype)
                x2[1:] = x[:, np.newaxis]
                x2[0] = x2[1]
            elif stepMode in ("center", True):  ## support True for back-compat
                x2 = np.empty((len(x),2), dtype=x.dtype)
                x2[:] = x[:, np.newaxis]
            else:
                raise ValueError("Unsupported stepMode %s" % stepMode)
            if self.opts['fillLevel'] is None:
                x = x2.reshape(x2.size)[1:-1]
                y2 = np.empty((len(y),2), dtype=y.dtype)
                y2[:] = y[:,np.newaxis]
                y = y2.reshape(y2.size)
            else:
                ## If we have a fill level, add two extra points at either end
                x = x2.reshape(x2.size)
                y2 = np.empty((len(y)+2,2), dtype=y.dtype)
                y2[1:-1] = y[:,np.newaxis]
                y = y2.reshape(y2.size)[1:-1]
                y[0] = self.opts['fillLevel']
                y[-1] = self.opts['fillLevel']

        path = fn.arrayToQPath(x, y, connect=self.opts['connect'])

        return path


    def getPath(self):
        if self.path is None:
            x,y = self.getData()
            if x is None or len(x) == 0 or y is None or len(y) == 0:
                self.path = QtGui.QPainterPath()
            else:
                self.path = self.generatePath(*self.getData())
            self.fillPath = None
            self._mouseShape = None

        return self.path

    @debug.warnOnException  ## raising an exception here causes crash
    def paint(self, p, opt, widget):
        profiler = debug.Profiler()
        if self.xData is None or len(self.xData) == 0:
            return

        if HAVE_OPENGL and getConfigOption('enableExperimental') and isinstance(widget, QtOpenGL.QGLWidget):
            self.paintGL(p, opt, widget)
            return

        x = None
        y = None
        path = self.getPath()
        profiler('generate path')

        if self._exportOpts is not False:
            aa = self._exportOpts.get('antialias', True)
        else:
            aa = self.opts['antialias']

        p.setRenderHint(p.Antialiasing, aa)

        cmode = self.opts['compositionMode']
        if cmode is not None:
            p.setCompositionMode(cmode)

        if self.opts['brush'] is not None and self.opts['fillLevel'] is not None:
            if self.fillPath is None:
                if x is None:
                    x,y = self.getData()
                p2 = QtGui.QPainterPath(self.path)
                if self.opts['fillLevel'] != 'enclosed':
                    p2.lineTo(x[-1], self.opts['fillLevel'])
                    p2.lineTo(x[0], self.opts['fillLevel'])
                    p2.lineTo(x[0], y[0])
                p2.closeSubpath()
                self.fillPath = p2

            profiler('generate fill path')
            p.fillPath(self.fillPath, self.opts['brush'])
            profiler('draw fill path')

        # Avoid constructing a shadow pen if it's not used.
        if self.opts.get('shadowPen') is not None:
            if isinstance(self.opts.get('shadowPen'), QtGui.QPen):
                sp = self.opts['shadowPen']
            else:
                sp = fn.mkPen(self.opts['shadowPen'])

            if sp.style() != QtCore.Qt.NoPen:
                p.setPen(sp)
                p.drawPath(path)

        if isinstance(self.opts.get('pen'), QtGui.QPen):
            cp = self.opts['pen']
        else:
            cp = fn.mkPen(self.opts['pen'])

        p.setPen(cp)
        if self.opts['fillOutline'] and self.fillPath is not None:
            p.drawPath(self.fillPath)
        else:
            p.drawPath(path)
        profiler('drawPath')

    def paintGL(self, p, opt, widget):
        p.beginNativePainting()
        import OpenGL.GL as gl

        ## set clipping viewport
        view = self.getViewBox()
        if view is not None:
            rect = view.mapRectToItem(self, view.boundingRect())
            #gl.glViewport(int(rect.x()), int(rect.y()), int(rect.width()), int(rect.height()))

            #gl.glTranslate(-rect.x(), -rect.y(), 0)

            gl.glEnable(gl.GL_STENCIL_TEST)
            gl.glColorMask(gl.GL_FALSE, gl.GL_FALSE, gl.GL_FALSE, gl.GL_FALSE) # disable drawing to frame buffer
            gl.glDepthMask(gl.GL_FALSE)  # disable drawing to depth buffer
            gl.glStencilFunc(gl.GL_NEVER, 1, 0xFF)
            gl.glStencilOp(gl.GL_REPLACE, gl.GL_KEEP, gl.GL_KEEP)

            ## draw stencil pattern
            gl.glStencilMask(0xFF)
            gl.glClear(gl.GL_STENCIL_BUFFER_BIT)
            gl.glBegin(gl.GL_TRIANGLES)
            gl.glVertex2f(rect.x(), rect.y())
            gl.glVertex2f(rect.x()+rect.width(), rect.y())
            gl.glVertex2f(rect.x(), rect.y()+rect.height())
            gl.glVertex2f(rect.x()+rect.width(), rect.y()+rect.height())
            gl.glVertex2f(rect.x()+rect.width(), rect.y())
            gl.glVertex2f(rect.x(), rect.y()+rect.height())
            gl.glEnd()

            gl.glColorMask(gl.GL_TRUE, gl.GL_TRUE, gl.GL_TRUE, gl.GL_TRUE)
            gl.glDepthMask(gl.GL_TRUE)
            gl.glStencilMask(0x00)
            gl.glStencilFunc(gl.GL_EQUAL, 1, 0xFF)

        try:
            x, y = self.getData()
            pos = np.empty((len(x), 2))
            pos[:,0] = x
            pos[:,1] = y
            gl.glEnableClientState(gl.GL_VERTEX_ARRAY)
            try:
                gl.glVertexPointerf(pos)
                pen = fn.mkPen(self.opts['pen'])
                color = pen.color()
                gl.glColor4f(color.red()/255., color.green()/255., color.blue()/255., color.alpha()/255.)
                width = pen.width()
                if pen.isCosmetic() and width < 1:
                    width = 1
                gl.glPointSize(width)
                gl.glLineWidth(width)
                gl.glEnable(gl.GL_LINE_SMOOTH)
                gl.glEnable(gl.GL_BLEND)
                gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA)
                gl.glHint(gl.GL_LINE_SMOOTH_HINT, gl.GL_NICEST)
                gl.glDrawArrays(gl.GL_LINE_STRIP, 0, int(pos.size / pos.shape[-1]))
            finally:
                gl.glDisableClientState(gl.GL_VERTEX_ARRAY)
        finally:
            p.endNativePainting()

    def clear(self):
        self.xData = None  ## raw values
        self.yData = None
        self.xDisp = None  ## display values (after log / fft)
        self.yDisp = None
        self.path = None
        self.fillPath = None
        self._mouseShape = None
        self._mouseBounds = None
        self._boundsCache = [None, None]
        #del self.xData, self.yData, self.xDisp, self.yDisp, self.path

    def mouseShape(self):
        """
        Return a QPainterPath representing the clickable shape of the curve

        """
        if self._mouseShape is None:
            view = self.getViewBox()
            if view is None:
                return QtGui.QPainterPath()
            stroker = QtGui.QPainterPathStroker()
            path = self.getPath()
            path = self.mapToItem(view, path)
            stroker.setWidth(self.opts['mouseWidth'])
            mousePath = stroker.createStroke(path)
            self._mouseShape = self.mapFromItem(view, mousePath)
        return self._mouseShape

    def mouseClickEvent(self, ev):
        if not self.clickable or ev.button() != QtCore.Qt.LeftButton:
            return
        if self.mouseShape().contains(ev.pos()):
            ev.accept()
            self.sigClicked.emit(self, ev)



class ROIPlotItem(PlotCurveItem):
    """Plot curve that monitors an ROI and image for changes to automatically replot."""
    def __init__(self, roi, data, img, axes=(0,1), xVals=None, color=None):
        self.roi = roi
        self.roiData = data
        self.roiImg = img
        self.axes = axes
        self.xVals = xVals
        PlotCurveItem.__init__(self, self.getRoiData(), x=self.xVals, color=color)
        #roi.connect(roi, QtCore.SIGNAL('regionChanged'), self.roiChangedEvent)
        roi.sigRegionChanged.connect(self.roiChangedEvent)
        #self.roiChangedEvent()

    def getRoiData(self):
        d = self.roi.getArrayRegion(self.roiData, self.roiImg, axes=self.axes)
        if d is None:
            return
        while d.ndim > 1:
            d = d.mean(axis=1)
        return d

    def roiChangedEvent(self):
        d = self.getRoiData()
        self.updateData(d, self.xVals)
