import Image, ImageDraw, ImageChops
from GifImagePlugin import getheader, getdata

# Get the entire text of a file.
# @param  filename name of the file
# @return  entire text of a file.
def getFileText( filename ):
    file = open( filename, 'r' )
    fileText = file.read()
    file.close()
    return fileText

# Get the all the lines of text of a text.
# @param  text text
# @return  the lines of text of a text
def getTextLines( text ):
    return text.replace( '\r', '\n' ).split( '\n' )

# Get the double value of the word after the first letter.
# @param  word string with value starting after the first letter
# @return  double value of the word after the first letter
def getDoubleAfterFirstLetter( word ):
    return float( word[ 1 : ] )

# Get the double value of the word after the first occurence of the letter in the split line.
def getDoubleForLetter( letter, splitLine ):
    return getDoubleAfterFirstLetter( splitLine[ indexOfStartingWithSecond( letter, splitLine ) ] )

# Get index of the first occurence of the given letter in the split line, starting with the second word.  Return - 1 if letter is not found
def indexOfStartingWithSecond( letter, splitLine ):
    for wordIndex in range( 1, len( splitLine ) ):
        word = splitLine[ wordIndex ]
        firstLetter = word[ 0 ]
        if firstLetter == letter:
            return wordIndex
    return - 1

# straightforward delta encoding taken from gifmaker.py
def makedelta(fp, sequence):
    """Convert list of image frames to a GIF animation file"""
    previous = None
    for im in sequence:
        if not previous:
            # global header
            for s in getheader(im) + getdata(im):
                fp.write(s)
        else:
            # delta frame
            delta = ImageChops.subtract_modulo(im, previous)
            bbox = delta.getbbox()
            if not bbox:
                bbox = (0,0, 1,1)
            # compress difference
            for s in getdata(im.crop(bbox), offset = bbox[:2]):
                fp.write(s)
        previous = im.copy()
    fp.write(";")



class vec3:
    "A three dimensional vector class."
    def __init__( self ):
        self.x = 0.0
        self.y = 0.0
        self.z = 0.0


class g2gif:
    def __init__(self,filename, outfile):
        self.last_pos = vec3()
        self.last_pos.z = 999
        self.do_move = 1
        fileText = getFileText( filename )
        textLines = getTextLines( fileText )
        self.images = []
        self.image = None
        for line in textLines:
            self.parseLine( line )
        self.images.append(self.image)
        # write GIF animation
        fp = open(outfile, "wb")
        makedelta(fp, self.images)
        fp.close()


    def parseLine(self, line):
        splitLine = line.split( ' ' )
        if len( splitLine ) < 1:
            return 0
        firstWord = splitLine[ 0 ]
        if firstWord == 'G1':
            self.linearMove( splitLine )
        if firstWord == 'M101':
            self.do_move = 1

    # Set the feedrate to the gcode split line.
    def setFeedrate( self, splitLine ):
        indexOfF = indexOfStartingWithSecond( "F", splitLine )
        if indexOfF > 0:
            self.feedrateMinute = getDoubleAfterFirstLetter( splitLine[ indexOfF ] )

    # Set a point to the gcode split line.
    def setPointComponent( self, point, splitLine ):
        point.x = getDoubleForLetter( "X", splitLine )
        point.y = getDoubleForLetter( "Y", splitLine )
        indexOfZ = indexOfStartingWithSecond( "Z", splitLine )
        if indexOfZ > 0:
            point.z = getDoubleAfterFirstLetter( splitLine[ indexOfZ ] )

    def scale(self, x, y):
        return x * 5 + 150, -y * 5 + 100

    def linearMove( self, splitLine ):
        location = vec3()
        self.setFeedrate( splitLine )
        self.setPointComponent( location, splitLine )
        if location.z != self.last_pos.z:
            if self.image:
                for i in range(10):
                    self.images.append(self.image)
            self.image = Image.new('P', (300, 200), 255)
            palette = []
            for red in range(8):
                for green in range(8):
                    for blue in range(4):
                        palette.extend((red * 255 / 7, green * 255 / 7, blue * 255 / 3))
            self.image.putpalette(palette)
            self.segment = 0
        else:
            if self.do_move:
                draw = ImageDraw.Draw(self.image)
                draw.line((self.scale(self.last_pos.x, self.last_pos.y),
                           self.scale(location.x, location.y)), fill = 192)
                self.segment = self.segment + 1
            else:
                draw = ImageDraw.Draw(self.image)
                draw.line((self.scale(self.last_pos.x, self.last_pos.y),
                           self.scale(location.x, location.y)), fill = self.segment)
        self.last_pos = location
        self.do_move = 0