from tkinter import *
from R2Graph import *
import math

def main():
    points = []
    mouseButtons = []
    objectIDs = []
    triangleComputed = False
    
    bisectors = []
    inCenter = R2Point(0., 0.)
    inRadius = 0.
    
    scaleX = 40.; scaleY = 40.
    root = Tk()
    root.title("Triangle")
    root.geometry("800x600")
    panel = Frame(root)
    drawButton = Button(panel, text="Draw")
    clearButton = Button(panel, text="Clear")
    drawArea = Canvas(root, bg="white")
    panel.pack(side=TOP, fill=X)
    drawButton.pack(side=LEFT, padx=4, pady=4)    
    clearButton.pack(side=LEFT, padx=4, pady=4)
    drawArea.pack(side=TOP, fill=BOTH, expand=True, padx=4, pady=4)
    root.update()
    
    def map(t):
        w = drawArea.winfo_width()
        h = drawArea.winfo_height()
        centerX = w/2.
        centerY = h/2.
        x = centerX + t.x*scaleX
        y = centerY - t.y*scaleY
        return (x, y)
        
    def invmap(p):
        w = drawArea.winfo_width()
        h = drawArea.winfo_height()
        centerX = w/2.
        centerY = h/2.
        x = (p[0] - centerX)/scaleX
        y = (centerY - p[1])/scaleY
        return R2Point(x, y)
        
    def xMin():
        w = drawArea.winfo_width()
        return (-(w/scaleX)/2.)
    def xMax():
        return (-xMin())
    def yMin():
        w = drawArea.winfo_height()
        return (-(w/scaleY)/2.)
    def yMax():
        return (-yMin())
        
    def drawGrid():
        ix0 = int(xMin())
        ix1 = int(xMax())
        x = ix0
        while x <= ix1:
            if x != 0:
                p0 = map(R2Point(x, yMin()))
                p1 = map(R2Point(x, yMax()))
                drawArea.create_line(p0, p1, fill="lightGray", width=1)
            x += 1

        iy0 = int(yMin())
        iy1 = int(yMax())
        y = iy0
        while y <= iy1:
            if y != 0:
                p0 = map(R2Point(xMin(), y))
                p1 = map(R2Point(xMax(), y))
                drawArea.create_line(p0, p1, fill="lightGray", width=1)
            y += 1
            
        # Draw x-axis
        drawArea.create_line(
            map(R2Point(xMin(), 0.)), map(R2Point(xMax(), 0.)),
            fill="black", width=2
        )    
        # Draw y-axis
        drawArea.create_line(
            map(R2Point(0., yMin())), map(R2Point(0., yMax())),
            fill="black", width=2
        )
        
    def onMouseRelease(e):
        # print("Mouse release event:", e)
        p = (e.x, e.y)
        t = invmap(p)
        points.append(t)
        mouseButtons.append(e.num)
        drawPoint(t, e.num)
        
    def drawPoint(t, mouseButton = 1):
        vx = R2Vector(0.2, 0.)
        vy = R2Vector(0., 0.2)
        color = "red"
        if mouseButton == 2:
            color = "green"
        elif mouseButton == 3:
            color = "magenta"
        lineID = drawArea.create_line(
            map(t - vx), map(t + vx), fill=color, width=3
        )
        objectIDs.append(lineID)    
        lineID = drawArea.create_line(
            map(t - vy), map(t + vy), fill=color, width=3
        )    
        objectIDs.append(lineID)
        
    def drawPoints():
        for i in range(len(points)):
            drawPoint(points[i], mouseButtons[i])
        
    def onDraw():
        if not triangleComputed and len(points) >= 3:
            computeTriangle()
            drawTriangle()
            
    def computeTriangle():
        nonlocal triangleComputed, bisectors, inCenter, inRadius 
        if len(points) < 3:
            triangleComputed = False
            return
        (inCenter, inRadius, bisectors) = computeInscribedCircle(points)              
        triangleComputed = True
        
    def drawTriangle():
        if len(points) < 3 or not triangleComputed:
            return

        # Draw a triangle
        path = [
            map(points[0]), map(points[1]), map(points[2]), map(points[0])
        ]  
        lineID = drawArea.create_line(path, fill="blue", width=3)
        objectIDs.append(lineID)

        # Draw bisectors
        for i in range(3):
            lineID = drawArea.create_line(
                map(points[i]), map(bisectors[i]),
                fill="green", width=2
            )
            objectIDs.append(lineID)

        # Draw an inscribed circle
        rx = inCenter + R2Vector(inRadius, 0.)
        ry = inCenter + R2Vector(0., inRadius)
        leftTop = map(inCenter - rx + ry)
        bottomRight = map(inCenter + rx - ry)
        lineID = drawArea.create_oval(
            leftTop, bottomRight,
            fill=None, outline="red", width=2
        )
        objectIDs.append(lineID)
        
        # Draw a circle center
        pixelCenter = map(inCenter)
        lineID = drawArea.create_oval(
            pixelCenter[0] - 4, pixelCenter[1] - 4,
            pixelCenter[0] + 4, pixelCenter[1] + 4,
            fill="red", outline="black", width=1
        )
        objectIDs.append(lineID)
        
    def clearPicture():
        for i in objectIDs:
            drawArea.delete(i)
        objectIDs.clear()
            
    def onClear():
        nonlocal triangleComputed
        clearPicture()
        points.clear()
        mouseButtons.clear()
        triangleComputed = False
        
    def onConfigure(e):
        drawArea.delete("all")
        drawGrid()
        drawPoints()        
        if triangleComputed:
            drawTriangle()    

    drawButton.configure(command = onDraw)
    clearButton.configure(command = onClear)
    drawArea.bind("<ButtonRelease-1>", onMouseRelease)
    drawArea.bind("<ButtonRelease-2>", onMouseRelease)
    drawArea.bind("<ButtonRelease-3>", onMouseRelease)
    drawArea.bind("<Configure>", onConfigure)
    
    drawGrid()
    # plotFunction(func)
    
    root.mainloop()
    
def computeInscribedCircle(points):
    assert(len(points) >= 3)
    bisectors = []
    for i in range(3):
        inext = i + 1
        if inext == 3:
            inext = 0
        iprev = i - 1
        if iprev == (-1):
            iprev = 2
        vnext = points[inext] - points[i]
        vnext.normalize()
        vprev = points[iprev] - points[i]
        vprev.normalize()
        vbis = vnext + vprev 
        (_, bis) = intersectLines(
            points[i], vbis,
            points[inext], points[iprev] - points[inext]
        )
        bisectors.append(bis)
            
    (_, center) = intersectLines(
        points[0], bisectors[0] - points[0],
        points[1], bisectors[1] - points[1]
    )
    radius = center.distanceToLine(
        points[0], points[1] - points[0]
    )         
    return (center, radius, bisectors)       
    
if __name__ == "__main__":
    main()