#! /usr/bin/python3
# ===================================================================
# ===================================================================

from numpy import *

import user_interface as ui
import draw_xy_axes as ax
import coordinate_conversion as cc
from graphics import *

from parallel_lines    import parallel_lines
from line_intersection import intersection_point

# ------------------------------------------------------------------
# ---- test data (an array of arrays which are tests)
# ---- each test is an array contains two tuples and a
# ---- test description string
# ---- each tuple is a line segment used for the test
# ---- each line segment contains a start X,Y coordinate and
# ----   an end X,Y coordinate
# ----
# ---- test line segment #1
# ---- [0] line segment #1 start X coord
# ---- [1] line segment #1 start Y coord
# ---- [2] line segment #1 end   X coord
# ---- [3] line segment #1 end   Y coord
# ----
# ---- test line segment #2
# ---- [0] line segment #2 start X coord
# ---- [1] line segment #2 start Y coord
# ---- [2] line segment #2 end   X coord
# ---- [3] line segment #2 end   Y coord
# ----
# ---- test description (a string)
# ------------------------------------------------------------------

accuracy = 0.0001

tests = [
        [ (-100.0,200.0,100.0,200.0),
          (-50.0,-50.0,250.0,350.0), 'test #1' ],

        [ (50.0,300.0,350.0,300.0),
          (0.0,-50.0,300.0,350.0), 'test #2' ],

        [ (-200.0,-200.0,-200.0,100.0),
          (-40.0,-100.0,200.0,-200.0), 'test #3' ],

        [ (-325.0,300.0,-325.0,200.0),
          (-350.0,300.0,-350.0,200.0), 'test #4 - vertical parallel lines' ],

        [ (-200.0,325.0,0.0,325.0),
          (-200.0,350.0,0.0,350.0), 'test #5 - horizontal parallel lines' ],

        [ (-200.0,150.0,-150.0,250.0),
          (-225.0,150.0,-175.0,250.0), 'test 6 - same slope parallel lines' ],

        [ (-300.0,-300.0,-300.0,100.0),
          (-350.0,-200.0,-50.0,-300.0), 'test #7' ],

        [ (250.0,0.0,350.0,0.0),
          (300.0,-100.0,300,100.0), 'test #8' ],
        ]


# -------------------------------------------------------------------
# ---- draw line segment
# -------------------------------------------------------------------

def draw_line_segment(win,x1,y1,x2,y2,color='black'):
    draw_line(win,x1,y1,x2,y2,color)
    draw_point(win,x1,y1,'black')
    draw_point(win,x2,y2,'yellow')


# -------------------------------------------------------------------
# ---- draw line
# -------------------------------------------------------------------

def draw_line(win,x1,y1,x2,y2,color='black'):
    wx1,wy1 = cc.center_to_win_coords(x1,y1,win.width,win.height)
    wx2,wy2 = cc.center_to_win_coords(x2,y2,win.width,win.height)
    l = Line(Point(wx1,wy1),Point(wx2,wy2))
    l.setWidth(2)
    l.setFill(color)
    l.draw(win)


# -------------------------------------------------------------------
# ---- draw point (small circle)
# -------------------------------------------------------------------

def draw_point(win,x,y,color='red'):
    wx,wy = cc.center_to_win_coords(x,y,win.width,win.height)
    c = Circle(Point(wx,wy),4)
    c.setFill(color)
    c.draw(win)

# -------------------------------------------------------------------
# ---- basic drawing test
# -------------------------------------------------------------------

def basic_drawing_test(win):
   # ---- draw point
    draw_point(win,100,100,'red')
    # ---- draw line
    draw_line_segment(win,-100,-100,-45,50)

# -------------------------------------------------------------------
# ---- data type and value
# -------------------------------------------------------------------

def point_data_type(p):
    print('----POINT----------------------------------')
    print(type(p))
    print(p)
    print(f'p[0] = {type(p[0])}  {p[0]}')
    print(f'p[1] = {type(p[1])}  {p[1]}')

# -------------------------------------------------------------------
# ---- main
# -------------------------------------------------------------------

if __name__ == '__main__':

    win_width  = 801
    win_height = 801

    # ---- create window

    win = GraphWin("Intersection Point", win_width, win_height)
    win.setBackground("white")

    # ---- draw axes

    ax.draw_xy_axes(win,True)

    # ---- basic drawing test
    ##basic_drawing_test(win)

    # ---- example tests

    for t in tests:

        print()
        print(f'---- {t[2]} ---------------')

        draw_line_segment(win,t[0][0],t[0][1], t[0][2],t[0][3])
        draw_line_segment(win,t[1][0],t[1][1], t[1][2],t[1][3])

        if parallel_lines(t[0],t[1]):
            print('parallel lines')
            continue

        p1 = array([t[0][0],t[0][1]])
        p2 = array([t[0][2],t[0][3]])
        p3 = array([t[1][0],t[1][1]])
        p4 = array([t[1][2],t[1][3]])
   
        xy = intersection_point(p1,p2,p3,p4)

        print(f'intersection = {xy[0]},{xy[1]}')

        draw_point(win,xy[0],xy[1],'green')

    # ---- end program

    ui.pause()
    win.close()
    print()