import rhinoscriptsyntax as rs
import random as ran

# stair values
s_width = 2.0                   # s_width = stair total width
pod_l = 1.5                     # pod_l = depth of landing
tt = 0.28                        # length of steps
th = 0.17                       # initial rise setting
thick = 0.25                    # maximum acceptable rise

def make_curved_podeststair(curve, th=th, tt=tt, steps=40, thick=thick, s_width=s_width, pod_l=pod_l, DC=24, P=24, An=0):
    pts = [[0,0,0]]
    if(th<0 and An==0):
        An=0.3
        steps=steps-1
    for i in range(1,steps+1):
        if(not(i%DC)):      #DC: Direction Change
            pts.append([pts[-1][0],pts[-1][1],pts[-1][2]+th])
            pts.append((pts[-1][0]+tt,pts[-1][1],pts[-1][2]))
            pts.append([pts[-1][0]+pod_l,pts[-1][1],pts[-1][2]])
            pts.append(pts[-1])
            pts.append((pts[-1][0]+tt,pts[-1][1],pts[-1][2]))
            th=-th
        elif(i==1):         #An: Erstes Podest
            if An>0:
                pts.append([pts[-1][0]+An,pts[-1][1],pts[-1][2]])
            pts.append([pts[-1][0],pts[-1][1],pts[-1][2]+th])
            pts.append([pts[-1][0]+tt,pts[-1][1],pts[-1][2]])
        elif(i==steps):      #An: Letztes Podest
            pts.append([pts[-1][0],pts[-1][1],pts[-1][2]+th])
            pts.append([pts[-1][0]+tt,pts[-1][1],pts[-1][2]])
        elif(not(i%P)):     #P: Podest
            pts.append([pts[-1][0],pts[-1][1],pts[-1][2]+th])
            pts.append((pts[-1][0]+tt,pts[-1][1],pts[-1][2]))
            pts.append((pts[-1][0]+pod_l,pts[-1][1],pts[-1][2]))
            pts.append((pts[-1][0]+tt,pts[-1][1],pts[-1][2]))
        else:               #Regular steps
            pts.append([pts[-1][0],pts[-1][1],pts[-1][2]+th])
            pts.append([pts[-1][0]+tt,pts[-1][1],pts[-1][2]])
    if th<0:                #stair ends going down
        pts.append([pts[-1][0],pts[-1][1],pts[-1][2]+th])
    return_list = []
    for i in range(-1,-len(pts),-2):
        return_list.append((pts[i][0], pts[i][1], pts[i][2]-thick))
    pts.extend(return_list)
    if (An>0):
        pts.append([pts[1][0]-tt, pts[1][1], pts[1][2]-thick])
    pts.append([pts[0][0], pts[0][1], pts[0][2]-thick])
    pts.append(pts[0])
    s_outline = rs.AddPolyline(pts)
    path = rs.AddLine(pts[0],[pts[0][0], pts[0][1]+s_width/2, pts[0][2]])
    shadow = rs.AddLine(pts[0],[return_list[0][0], return_list[0][1], pts[0][2]]) 
    s_surf = rs.AddPlanarSrf(s_outline)
    rs.Command("_Flow selID {} _Enter selID {} selID {} _Enter".format(s_surf[0], shadow, curve), False)
    profile = rs.FirstObject()
    stair = rs.OffsetSurface(profile, s_width/2, both_sides=True, create_solid=True)
    rs.DeleteObjects([s_surf[0], shadow, path, s_outline, profile])
    return(stair)


rs.DeleteObjects(rs.AllObjects())

curve =rs.AddSpiral([0,0,0],[0,0,1], 0, turns=9, radius0=36, radius1=3)
len_c= rs.CurveLength(curve)
An=0
P=21
mods = (len_c+An) / (P*tt+pod_l + tt)
steps = int(mods*P)+1

make_curved_podeststair(curve, steps=steps, pod_l=pod_l, DC=steps+1, P=P, An=An)
i = 1
len_fromstart = An+P*tt+pod_l/2
while (len_fromstart <= len_c):
    point = rs.CurveArcLengthPoint(curve, len_fromstart)
    m_l=rs.AddLine(point, [point[0],point[1],i*P*th-thick])
    rs.AddPipe(m_l,0,0.2)
    i = i+1
    len_fromstart +=  P*tt+pod_l + tt