import sys
import math
from openscad import *

layer_info={}

# Google Sky process mapping layer , datatype, start, height, color
layer_info[0x4114]=[-0.25,0.25,"brown"] # Diffusion
layer_info[0x4214]=[0,0.1,"lightblue"]  # Poly-Silicon
layer_info[0x422c]=[0,0.25,"green"]     # Contact
layer_info[0x4314]=[0.25,0.25,"gray"]   # Metal

# GDS File is public domain from https://github.com/google/skywater-pdk-libs-sky130_fd_sc_hd/blob/main/cells/a2111o/

gdsfile="sky130_fd_sc_hd__a2111o_1.gds"
topcell="sky130_fd_sc_hd__a2111o_1"

currentview = []
cells = {}

fh=open(gdsfile,"rb")
layer=0
datatype=0
element=-1
coords=[]
sys_scale=1
strname=""
while True:
    l=int.from_bytes(fh.read(2), byteorder='big')
    rtyp=int.from_bytes(fh.read(1), byteorder='big')
    dtyp=int.from_bytes(fh.read(1), byteorder='big')
    data = []
    if dtyp == 0: # nothing
        pass
    elif dtyp == 1: # bitarray
            ba = fh.read(l-4)
    elif dtyp == 2: # uint16
        for i in range((l-4)>>1):
            data.append(int.from_bytes(fh.read(2), byteorder='big', signed = True) )
    elif dtyp == 3: # uint32
        for i in range((l-4)>>2):
            data.append(int.from_bytes(fh.read(4), byteorder='big', signed = True) )
    elif dtyp == 5: # double
        for i in range((l-4)>>3):
            ba=fh.read(8)
            d=0.0
            for j in range(7):
                d/=256.0;
                d+=ba[7-j];
            d/=256;
            d = d*math.pow(16, (ba[0]&0x7f)-64)
            data.append(d)

    elif dtyp == 6: # string
            ba = fh.read(l-4)
            if ba[-1] == 0:
                ba=ba[:-1]                
            data.append(ba.decode("utf-8"))
    else:
        print("Unknown data type %d"%(dtyp))

    if rtyp == 0: #0 HEADER  
        pass 
    elif rtyp == 1: #1 BGNLIB  
        pass 
    elif rtyp == 2: #2 LIBNAME 
        pass
    elif rtyp == 3: #3 UNITS   
        sys_scale=data[0]
        pass
    elif rtyp == 4: #4 ENDLIB  
        break
    elif rtyp == 5:#5 BGNSTR  
        currentview = []
        pass
    elif rtyp == 6: #6 STRNAME 
        strname=data[0]
        print("strname %s"%(data[0]))
    elif rtyp == 7: #7 ENDSTR  
        cells[strname]=currentview
        pass
    elif rtyp == 8:#8 BOUNDARY
        element=0
    elif rtyp == 9:#9 PATH    
        element=3
    elif rtyp == 10:#10 SREF    
        element=1
        pass
    elif rtyp == 11: #11 AREF    
        element=2
        pass
    elif rtyp == 12:#12 TEXT    
        pass
    elif rtyp == 13:#13 LAYER   
        layer=data[0]
    elif rtyp == 14:#14 DATATYPE
        datatype=data[0]
    elif rtyp == 15: #15 WIDTH   
        width=data[0]
    elif rtyp == 16: #16 XY      
        coords=[]
        for i in range(len(data)>>1):
            coords.append([data[2*i+0]*sys_scale, data[2*i+1]*sys_scale])
    elif rtyp == 18: #18 SNAME   
        sname=data[0]
    elif rtyp == 17: #17 ENDEL   
        if element == 0: # Boundary
            coords.pop()
            layer_dt = (layer<<8)|datatype
            if layer_dt in layer_info:
                print("bnd info for %04X"%(layer<<8|datatype))
                info = layer_info[layer_dt]
                bnd = linear_extrude(polygon(coords), info[1]).up(info[0]).color(info[2])
                print(bnd)
                currentview.append(bnd)
            else:
                pass
#                print("No Mapping for Layer %d"%(layer))
        elif element == 1: # SREF
            print("coords is")
            print(coords)
            print(sname)
            if sname in cells:
                subcell = union(cells[sname])
                currentview.append(subcell.translate([coords[0][0],coords[0][1],0]))
                print("found")
            else:
                print("not found")
            pass
        elif element == 2: # AREF
            pass
        elif element == 3: # PATH
            print("missing path")
            layer_dt = (layer<<8)|datatype
            print("path info for %04X"%(layer<<8|datatype))
            if layer_dt in layer_info:
                info = layer_info[(layer<<8|datatype)]
        element=-1
    elif rtyp == 22: #22 TEXTTYPE
        pass
    elif rtyp == 23:#23 PRSNTTON
        pass
    elif rtyp == 25:#25 STRING  
        pass
    elif rtyp == 26: #26 STRANS  
        pass
    elif rtyp == 27: #27 MAG     
        pass
    elif rtyp == 28:#28 ANGLE   
        pass
    elif rtyp == 43:#43 PROPATTR
        pass
    elif rtyp == 44: #44 PRPVALUE
        pass
    else:
        print("Unknown record type %d"%(rtyp))
if topcell in cells:        
    output(union(cells[topcell]))
else:
    print("topcell not found")