#!/usr/bin/env python3

import math
import sys
import argparse
import svgturtle

parser = argparse.ArgumentParser(description='Generate a hexagonal battery case')
parser.add_argument('--dimension', default=5, type=int, help='Grid dimension')
parser.add_argument('--height', type=float, help='Height of battery')
parser.add_argument('--hole', default='AA', help='Hole diameter (mm or A, AA, AAA)')
parser.add_argument('--kerf', default=.1, type=float, help='Kerf')
parser.add_argument('--corner-length', default=4, help='Length of stretch corner in material thicknesses')
parser.add_argument('--stretch', default=1.05, type=float, help='Reduction factor of stretch material')
parser.add_argument('--horizontal-finger', default=5.0, type=float, help='Width of horizontal fingers')
parser.add_argument('--vertical-finger', default=5.0, type=float, help='Width of vertical fingers')
parser.add_argument('--padding', default=1.5, type=float, help='Padding around holes')
parser.add_argument('--outside-padding', default=4, type=float, help='Extra padding between holes and wall')
parser.add_argument('--thickness', default=3.0, type=float, help='Thickness of material')
parser.add_argument('--lid', default=0.2, type=float, help='How much extra play to give the lid')
parser.add_argument('--verbose', action='store_true', help='Print computed parameter values')
args = parser.parse_args()
assert (args.dimension % 2) == 1

BATTERY = {
    'AAA': [10.5, 44.5],
    'AA':  [14.5, 50.5],
    'C':   [26.2, 50.0],
    'D':   [34.2, 61.5],
}

if args.hole in BATTERY:
    dim = BATTERY[args.hole]
    args.hole = dim[0]
    if args.height == None:
        args.height = dim[1]
else:
    args.hole = float(args.hole)
    assert(args.height != None)

args.kerf2         = args.kerf/2
args.grid          = args.hole+args.padding
args.radius        = args.hole/2
args.corner        = args.corner_length*args.thickness
args.corner_s      = args.corner*args.stretch
args.corner_radius = 3*args.corner_s/math.pi
args.corner_inset  = args.corner_s*math.sqrt(3)/math.pi
args.interior_edge = args.grid*args.dimension*0.5+args.outside_padding
args.exterior_edge = args.interior_edge+2.0*args.thickness
args.interior_leg  = (args.interior_edge-args.horizontal_finger-args.kerf)/2-args.corner_inset
finger_length      = args.interior_edge-2.0*args.corner_inset
args.n_hor_fingers = int(finger_length/args.horizontal_finger/2)
args.exterior_leg  = (finger_length-(2*args.n_hor_fingers-1)*args.horizontal_finger+args.kerf)/2
args.exterior_slot = (args.exterior_edge-args.horizontal_finger+args.kerf)/2
args.n_ver_fingers = int(args.height/args.vertical_finger/2)
args.vertical_finger = args.height/args.n_ver_fingers/2
args.slots         = [args.vertical_finger*2.5-args.thickness*0.5, args.vertical_finger*4.5-args.thickness*0.5]

if args.verbose:
    print(args, file=sys.stderr)

DIMX   = 5.0*args.grid*args.dimension
DIMY   = 3.0*args.grid*args.dimension
PI3    = math.pi/3

HOLES  = ''
SHAPES = ''

def draw_grid(cx, cy):
    global HOLES
    for row in range(-int(args.dimension/2), int((args.dimension+1)/2)):
        cyr = cy+args.grid*row*math.sin(PI3)
        num_col = args.dimension-abs(row)
        cxr = cx-.5*args.grid*(num_col-1.0)
        for col in range(num_col):
            HOLES += '<circle cx="%.2f" cy="%.2f" r="%.2f"/>\n' % (cxr+col*args.grid, cyr, args.radius)

def draw_plane(cx, cy, interior=False):
    global HOLES, SHAPES
    if interior:
        edge = args.interior_edge
    else:
        edge = args.exterior_edge
    turtle       = svgturtle.SvgTurtle(cx, cy)
    turtle.penup()
    turtle.forward(edge)
    turtle.right(120)
    if interior:
        turtle.forward(args.corner_inset)
        turtle.pendown()
        for side in range(5):
            turtle.forward(args.interior_leg)
            turtle.left(90)
            turtle.forward(args.thickness)
            turtle.right(90)
            turtle.forward(args.horizontal_finger+args.kerf)
            turtle.right(90)
            turtle.forward(args.thickness)
            turtle.left(90)
            turtle.forward(args.interior_leg)
            turtle.circle(-args.corner_radius, 60)
        turtle.forward(args.interior_edge-2.0*args.corner_inset)
        turtle.circle(-args.corner_radius, 60)
    else:
        turtle.pendown()
        for side in range(6):
            turtle.forward(args.exterior_edge)
            turtle.right(60)
    SHAPES += '<path d="%s"/>\n' % turtle.to_s()
    if not interior:
        turtle.reset()
        turtle.penup()
        turtle.forward(args.interior_edge)
        turtle.right(120)
        turtle.forward(args.corner_inset)
        for side in range(5):
            for finger in range(args.n_hor_fingers):
                turtle.forward(args.exterior_leg if finger == 0 else args.horizontal_finger+args.kerf)
                turtle.pendown()
                turtle.left(90)
                turtle.forward(args.thickness)
                turtle.right(90)
                turtle.forward(args.horizontal_finger-args.kerf)
                turtle.right(90)
                turtle.forward(args.thickness)
                turtle.right(90)
                turtle.forward(args.horizontal_finger-args.kerf)
                turtle.penup()
                turtle.right(180)
                turtle.forward(args.horizontal_finger-args.kerf)
            turtle.forward(args.exterior_leg)
            turtle.pendown()
            turtle.left(90)
            turtle.forward(args.thickness)
            turtle.right(90)
            turtle.circle(-args.corner_radius-args.thickness, 60)
            turtle.right(90)
            turtle.forward(args.thickness)
            turtle.right(90)
            turtle.circle(args.corner_radius, 60)
            turtle.penup()
            turtle.right(180)
            turtle.circle(-args.corner_radius, 60)
        turtle.forward(args.interior_edge-2*args.corner_inset)
        turtle.pendown()
        turtle.left(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.circle(-args.corner_radius-args.thickness, 60)
        turtle.right(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.circle(args.corner_radius, 60)
        HOLES += '<path d="%s"/>\n' % turtle.to_s()

def draw_side(x0, y0, h, slots):
    global HOLES, SHAPES
    turtle = svgturtle.SvgTurtle(x0, y0+args.thickness)
    for finger in range(args.n_hor_fingers):
        turtle.forward(args.exterior_leg-args.kerf if finger == 0 else args.horizontal_finger-args.kerf)
        turtle.left(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.forward(args.horizontal_finger+args.kerf)
        turtle.right(90)
        turtle.forward(args.thickness)
        turtle.left(90)
    turtle.forward(args.exterior_leg-args.kerf-args.thickness)
    turtle.right(90)
    for finger in range(args.n_ver_fingers):
        turtle.forward(args.vertical_finger-(args.kerf/2 if finger==0 else args.kerf))
        turtle.left(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.forward(args.vertical_finger+args.kerf)
        turtle.right(90)
        if finger < args.n_ver_fingers-1:
            turtle.forward(args.thickness)
            turtle.left(90)
    turtle.forward(args.exterior_edge-args.thickness)
    turtle.right(90)
    for finger in range(args.n_ver_fingers):
        turtle.forward(args.vertical_finger-(args.kerf/2 if finger==0 else args.kerf))
        turtle.left(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.forward(args.vertical_finger+args.kerf)
        turtle.right(90)
        if finger < args.n_ver_fingers-1:
            turtle.forward(args.thickness)
            turtle.left(90)
    SHAPES += '<path d="%s"/>\n' % turtle.to_s()
    for slot in slots:
        x = x0+args.exterior_slot
        y = y0+slot
        w = args.horizontal_finger-args.kerf
        h = args.thickness-args.kerf
        HOLES += '<rect x="%.2f" y="%.2f" width="%.2f" height="%.2f"/>\n' % (x, y, w, h)

def draw_case(x0, y0, h, slots):
    global HOLES, SHAPES
    turtle = svgturtle.SvgTurtle(x0, y0)
    turtle.forward(args.exterior_edge*0.5)
    for side in range(6):
        turtle.right(90)
        turtle.forward(args.height-args.thickness)
        turtle.penup()
        turtle.back(args.height-args.thickness)
        turtle.left(90)
        turtle.forward(2*args.thickness)
        turtle.right(90)
        turtle.pendown()
        turtle.forward(args.height-args.thickness)
        turtle.penup()
        turtle.back(args.height-args.thickness)
        turtle.left(90)
        turtle.pendown()
        if side==5:
            break
        turtle.forward(args.exterior_edge-args.thickness*2)
    turtle.forward(args.exterior_edge*0.5-args.thickness*2)
    turtle.right(90)
    for finger in range(args.n_ver_fingers):
        turtle.forward(args.vertical_finger-(args.kerf/2 if finger==0 else args.kerf))
        turtle.left(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.forward(args.vertical_finger+args.kerf)
        turtle.right(90)
        if finger < args.n_ver_fingers-1:
            turtle.forward(args.thickness)
            turtle.left(90)
    turtle.forward(args.exterior_edge*0.5)
    for side in range(6):
        turtle.right(90)
        turtle.forward(args.height-args.thickness)
        turtle.penup()
        turtle.back(args.height-args.thickness)
        turtle.left(90)
        turtle.pendown()
        if side==5:
            break
        for finger in range(args.n_hor_fingers):
            turtle.forward(args.exterior_leg if finger == 0 else args.horizontal_finger+args.kerf)
            turtle.left(90)
            turtle.forward(args.thickness)
            turtle.right(90)
            turtle.forward(args.horizontal_finger-args.kerf)
            turtle.right(90)
            turtle.forward(args.thickness)
            turtle.left(90)
        turtle.forward(args.exterior_leg)
    turtle.forward(args.exterior_edge*0.5)
    turtle.right(90)
    for finger in range(args.n_ver_fingers):
        turtle.forward(args.vertical_finger-(args.kerf/2 if finger==0 else args.kerf))
        turtle.left(90)
        turtle.forward(args.thickness)
        turtle.right(90)
        turtle.forward(args.vertical_finger+args.kerf)
        turtle.right(90)
        if finger < args.n_ver_fingers-1:
            turtle.forward(args.thickness)
            turtle.left(90)
    SHAPES += '<path d="%s"/>\n' % turtle.to_s()
    for slot in slots:
        for side in range(5):
            x = x0+(side+0.5)*args.exterior_edge+args.thickness+args.exterior_slot
            y = y0+slot
            w = args.horizontal_finger-args.kerf
            h = args.thickness-args.kerf
            HOLES += '<rect x="%.2f" y="%.2f" width="%.2f" height="%.2f"/>\n' % (x, y, w, h)

print('<svg viewBox="0 0 %.2f %.2f" width="%.2fmm" height="%.2fmm" stroke-width="0.1" xmlns="http://www.w3.org/2000/svg">' % (DIMX, DIMY, DIMX, DIMY))
draw_grid(0.65*args.grid*args.dimension, 0.60*args.grid*args.dimension)
draw_plane(0.65*args.grid*args.dimension, 0.60*args.grid*args.dimension, True)
draw_grid(1.90*args.grid*args.dimension, 0.60*args.grid*args.dimension)
draw_plane(1.90*args.grid*args.dimension, 0.60*args.grid*args.dimension, True)
draw_plane(3.15*args.grid*args.dimension, 0.60*args.grid*args.dimension)
draw_case(0.05*args.grid*args.dimension, 1.25*args.grid*args.dimension, args.height, args.slots)
print('<g fill="none" stroke="red">', HOLES, '</g>', '<g fill="none" stroke="black">', SHAPES, '</g>', sep='\n')
print('</svg>')