import sys
from kivy.uix.widget import Widget
from kivy.core.window import Window

from point import Point
from polyomino import Square
from polyomino import Square_element

# painter class
class Painter(Widget):

    def __init__(self,app,**kwargs):

        # list of particles
        self.particles=[]

        # particle under mouse
        self.undermouse=None

        # list of selected particles
        self.selected=[]

        # relative position of mouse when moving
        self.offset=Point(0,0)

        # app is used to share information between widgets
        self.app=app

        # modifiers
        self.modifiers=[]

        # init Widget
        super(Painter,self).__init__(**kwargs)

        # init keyboard
        self.keyboard = Window.request_keyboard(None,self,"text")
        self.keyboard.bind(on_key_down=self.on_key_down,on_key_up=self.on_key_up)

    
    def reset(self):
        self.particles=[]
        self.undermouse=None
        self.draw()


    # draw all particles
    def draw(self):
        self.canvas.clear()
        with self.canvas:
            for particle in self.particles:
                particle.draw()


    # respond to keyboard
    def on_key_down(self, keyboard, keycode, text, modifiers):
        # check that command_prompt is not focused
        if not self.app.command_prompt.insert:
            if keycode[1]=="shift":
                if not 's' in self.modifiers:
                    self.modifiers.append('s')
                    self.modifiers.sort()

    def on_key_up(self, keyboard, keycode):
        if keycode[1]=="shift":
            if 's' in self.modifiers:
                # remove
                self.modifiers[self.modifiers.index('s')]=self.modifiers[len(self.modifiers)-1]
                self.modifiers=self.modifiers[:len(self.modifiers)-1]
                self.modifiers.sort()


    # respond to mouse down
    def on_touch_down(self,touch):
        # only respond to touch in drawing area
        if self.collide_point(*touch.pos):

            # create new cross
            if touch.button=="right":
                new=Square(touch.x/Square_element.size,touch.y/Square_element.size)
                if not self.check_interaction_any(new,Point(0,0)):
                    # add to list
                    self.particles.append(new)

                    # unselect all particles
                    for sel in self.selected:
                        sel.selected=False
                    self.selected=[]

                    self.draw()

            # select particle
            if touch.button=="left":
                # find particle under touch
                self.undermouse=self.find_particle(Point(touch.x/Square_element.size,touch.y/Square_element.size))

                # record relative position of click with respect to reference
                if self.undermouse!=None:
                    self.offset=Point(touch.x/Square_element.size,touch.y/Square_element.size)-self.undermouse.squares[0].pos

                # no modifiers
                if self.modifiers==[]:
                    if self.undermouse==None or not self.undermouse in self.selected:
                        # unselect all particles
                        for sel in self.selected:
                            sel.selected=False
                        self.selected=[]


                # shift-click
                elif self.modifiers==['s']:
                    if self.undermouse!=None:
                        if self.undermouse not in self.selected:
                            self.selected.append(self.undermouse)
                            self.undermouse.selected=True
                        else:
                            # remove
                            self.selected[self.selected.index(self.undermouse)]=self.selected[len(self.selected)-1]
                            self.selected=self.selected[:len(self.selected)-1]
                            self.undermouse.selected=False

                self.draw()


    # respond to drag
    def on_touch_move(self,touch):
        # only respond to touch in drawing area
        if self.collide_point(*touch.pos):
            # only move on left click
            if touch.button=="left" and self.modifiers==[] and self.undermouse!=None:
                # change in position
                delta=self.check_move(Point(touch.x/Square_element.size,touch.y/Square_element.size)-(self.offset+self.undermouse.squares[0].pos),self.undermouse)
                self.undermouse.move(delta)
                # multiple particles
                # TODO: group moves
                #else:
                #    self.group_move(touch)

                # redraw
                self.draw()

    ## move all selected particles
    #def group_move(self,touch):
    #    # save position of undermouse (to use it after it has been reset)
    #    relative_position=self.undermouse.pos

    #    # determine order in which to move
    #    # direction of motion
    #    direction=Point(touch.x/Square_element.size,touch.y/Square_element.size)-self.undermouse.pos
    #    # sort according to scalar product with direction
    #    self.selected.sort(key=(lambda particle: direction.dot(particle.pos-self.undermouse.pos)),reverse=True)

    #    # move
    #    for particle in self.selected:
    #        particle.pos=self.check_move(Point(touch.x/Square_element.size-relative_position.x+particle.pos.x,touch.y/Square_element.size-relative_position.y+particle.pos.y),particle)
    #    
    #    ## new position of undermouse
    #    #self.undermouse.pos=self.check_move(Point(touch.x/Square_element.size,touch.y/Square_element.size),self.undermouse)
    #    ## move other particles by the same amount as undermouse
    #    #for particle in self.selected:
    #    #    if particle!=self.undermouse:
    #    #        particle.pos=self.check_move(Point(self.undermouse.pos.x-relative_position.x+particle.pos.x,self.undermouse.pos.y-relative_position.y+particle.pos.y),particle)
    #    #
    #    #for particle in self.selected:
    #    #    particle.pos=self.check_move(Point(touch.x/Square_element.size-relative_position.x+particle.pos.x,touch.y/Square_element.size-relative_position.y+particle.pos.y),particle)


    # find the particle at position pos
    def find_particle(self,pos):
        for particle in self.particles:
            if particle.in_support(pos):
                return particle
        # none found
        return None

    # check whether a position intersects with any of the particles
    def check_interaction_any(self,candidate,offset):
        for particle in self.particles:
            # do not check interaction if candidate=particle
            if candidate!=particle and particle.check_interaction(candidate,offset):
                return True
        return False

    # check that a particle can move by delta, and return the closest allowed relative motion
    def check_move(self,delta,particle):
        # whether newpos is acceptable
        accept_newpos=True
        for other in self.particles:
            # do not compare a particle to itself
            if other!=particle:
                # move would make particle overlap with other
                if other.check_interaction(particle,delta):
                    accept_newpos=False
                    # check if particle already touches other
                    if other.check_touch(particle):
                        # move along other while remaining stuck
                        # TODO: this assumes other is a square
                        newdelta=other.squares[0].move_along(delta,particle.squares[0].pos)
                    else:
                        newdelta=other.squares[0].move_on_line_to_stick(particle.squares[0].pos,delta)
                    if not self.check_interaction_any(particle,newdelta):
                        return newdelta
        if accept_newpos:
            return delta
        else:
            # cannot move particle at all, try again
            return self.check_move(newdelta,particle)


    # write configuration to file
    def write(self,file):
        ff=open(file,"w")
        for particle in self.particles:
            ff.write("{:05.2f},{:05.2f};{:3.1f},{:3.1f},{:3.1f}\n".format(particle.pos.x,particle.pos.y,particle.color[0],particle.color[1],particle.color[2]))
        ff.close()

    # read configuration from file
    def read(self,file):
        self.reset()
        try:
            ff=open(file,"r")
        except:
            self.app.command_prompt.message="error: could not read file '"+file+"' (this should not happen and is probably a bug)"
            return

        # counter
        i=0

        try:
            lines=ff.readlines()
        except:
            self.app.command_prompt.message="error: could not read the contents of file '"+file+"'"
            return

        for line in lines:
            i+=1

            # remove newline
            line=line[:len(line)-1]

            # ignore comments
            if '#' in line:
                line=line[:line.find('#')]
            # ignore empty lines
            if len(line)==0:
                continue

            entries=line.split(";")
            # skip line if improperly formatted
            if len(entries)>2:
                print("warning: ignoring line "+str(i)+" in file '"+file+"': more than two ';' spearated entries in '"+line+"'",file=sys.stderr)
                continue

            # position
            pos_str=entries[0].split(",")
            # skip line if improperly formatted
            if len(pos_str)!=2:
                print("warning: ignoring line "+str(i)+" in file '"+file+"': position '"+entries[0]+"' does not have two components",file=sys.stderr)
                continue
            try:
                pos=Point(float(pos_str[0]),float(pos_str[1]))
            except:
                print("warning: ignoring line "+str(i)+" in file '"+file+"': position '"+entries[0]+"' cannot be read",file=sys.stderr)
                continue
                

            # color
            color=(0,0,1)
            if len(entries)==2:
                color_str=entries[1].split(",")
                # skip line if improperly formatted
                if len(color_str)!=3:
                    print("warning: ignoring line "+str(i)+" in file '"+file+"': color '"+entries[1]+"' does not have three components",file=sys.stderr)
                    continue
                try:
                    color=(float(color_str[0]),float(color_str[1]),float(color_str[2]))
                except:
                    print("warning: ignoring line "+str(i)+" in file '"+file+"': color '"+entries[1]+"' cannot be read",file=sys.stderr)
                    continue

            if self.check_interaction_any(pos,None):
                # add to list
                self.particles.append(Cross(pos.x,pos.y,color=color))
            else:
                print("warning: ignoring line "+str(i)+" in file '"+file+"': particle overlaps with existing particles",file=sys.stderr)
            
        ff.close()
        self.draw()