from .Exporter import Exporter
from pyqtgraph.parametertree import Parameter
from pyqtgraph.Qt import QtGui, QtCore, QtSvg
import pyqtgraph as pg
import re
import xml.dom.minidom as xml
import numpy as np


__all__ = ['SVGExporter']

class SVGExporter(Exporter):
    Name = "Scalable Vector Graphics (SVG)"
    allowCopy=True
    
    def __init__(self, item):
        Exporter.__init__(self, item)
        #tr = self.getTargetRect()
        self.params = Parameter(name='params', type='group', children=[
            #{'name': 'width', 'type': 'float', 'value': tr.width(), 'limits': (0, None)},
            #{'name': 'height', 'type': 'float', 'value': tr.height(), 'limits': (0, None)},
            #{'name': 'viewbox clipping', 'type': 'bool', 'value': True},
            #{'name': 'normalize coordinates', 'type': 'bool', 'value': True},
            #{'name': 'normalize line width', 'type': 'bool', 'value': True},
        ])
        #self.params.param('width').sigValueChanged.connect(self.widthChanged)
        #self.params.param('height').sigValueChanged.connect(self.heightChanged)

    def widthChanged(self):
        sr = self.getSourceRect()
        ar = sr.height() / sr.width()
        self.params.param('height').setValue(self.params['width'] * ar, blockSignal=self.heightChanged)
        
    def heightChanged(self):
        sr = self.getSourceRect()
        ar = sr.width() / sr.height()
        self.params.param('width').setValue(self.params['height'] * ar, blockSignal=self.widthChanged)
        
    def parameters(self):
        return self.params
    
    def export(self, fileName=None, toBytes=False, copy=False):
        if toBytes is False and copy is False and fileName is None:
            self.fileSaveDialog(filter="Scalable Vector Graphics (*.svg)")
            return
        #self.svg = QtSvg.QSvgGenerator()
        #self.svg.setFileName(fileName)
        #dpi = QtGui.QDesktopWidget().physicalDpiX()
        ### not really sure why this works, but it seems to be important:
        #self.svg.setSize(QtCore.QSize(self.params['width']*dpi/90., self.params['height']*dpi/90.))
        #self.svg.setResolution(dpi)
        ##self.svg.setViewBox()
        #targetRect = QtCore.QRect(0, 0, self.params['width'], self.params['height'])
        #sourceRect = self.getSourceRect()
        
        #painter = QtGui.QPainter(self.svg)
        #try:
            #self.setExportMode(True)
            #self.render(painter, QtCore.QRectF(targetRect), sourceRect)
        #finally:
            #self.setExportMode(False)
        #painter.end()

        ## Workaround to set pen widths correctly
        #data = open(fileName).readlines()
        #for i in range(len(data)):
            #line = data[i]
            #m = re.match(r'(<g .*)stroke-width="1"(.*transform="matrix\(([^\)]+)\)".*)', line)
            #if m is not None:
                ##print "Matched group:", line
                #g = m.groups()
                #matrix = list(map(float, g[2].split(',')))
                ##print "matrix:", matrix
                #scale = max(abs(matrix[0]), abs(matrix[3]))
                #if scale == 0 or scale == 1.0:
                    #continue
                #data[i] = g[0] + ' stroke-width="%0.2g" ' % (1.0/scale) + g[1] + '\n'
                ##print "old line:", line
                ##print "new line:", data[i]
        #open(fileName, 'w').write(''.join(data))
        
        ## Qt's SVG generator is not complete. (notably, it lacks clipping)
        ## Instead, we will use Qt to generate SVG for each item independently,
        ## then manually reconstruct the entire document.
        xml = generateSvg(self.item)
        
        if toBytes:
            return xml.encode('UTF-8')
        elif copy:
            md = QtCore.QMimeData()
            md.setData('image/svg+xml', QtCore.QByteArray(xml.encode('UTF-8')))
            QtGui.QApplication.clipboard().setMimeData(md)
        else:
            with open(fileName, 'w') as fh:
                fh.write(xml.encode('UTF-8'))


xmlHeader = """\
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"  version="1.2" baseProfile="tiny">
<title>pyqtgraph SVG export</title>
<desc>Generated with Qt and pyqtgraph</desc>
<defs>
</defs>
"""

def generateSvg(item):
    global xmlHeader
    try:
        node = _generateItemSvg(item)
    finally:
        ## reset export mode for all items in the tree
        if isinstance(item, QtGui.QGraphicsScene):
            items = item.items()
        else:
            items = [item]
            for i in items:
                items.extend(i.childItems())