#!/usr/bin/env python3

import os
import sys
import datetime


if len(sys.argv) <= 1:
    print("Expected argument: string list. Strings to be put in PROGMEM, along with an index table.")
    sys.exit(-1)

if len(sys.argv) <= 2:
    print("Expected argument: destination. The path to be appended with '.h' for the destination file.")
    sys.exit(-1)

stringFile = sys.argv[1]
destPath = sys.argv[2]

if destPath.endswith(".h"):
    destPath = destPath.replace(".h", "")
if destPath.endswith(".cpp"):
    destPath = destPath.replace(".cpp", "")

destFname = os.path.basename(destPath)

print("str2pgmspace: processing '{}' into '{}.[h,c]'".format(stringFile, destPath))

if not os.path.exists( stringFile ):
    print("File does not exist...")
    exit(-1)

fileDir = os.path.dirname(stringFile) + "/"

idtf = None
blob = bytearray()
indexes = []

with open(stringFile, "r") as flist:
    lcounter = 1

    l = flist.readline()
    if(l.endswith('\n')):
        l = l[:-1]

    while l != "" :
        tokens = l.split()
        if len(tokens) == 2:
            if tokens[0] == "__IDENTIFIER":
                idtf = tokens[1]
                l = flist.readline()
                lcounter += 1
                continue

        if(not l.startswith("#")):
            indexes.append(len(blob))
            idx = 0
            while idx < len(l):
                if(l[idx] == "¬"[0] and idx+2 < len(l)):
                    # char byte in hex incoming
                    hex = ""
                    hex += l[idx+1]
                    hex += l[idx+2]
                    blob += bytes.fromhex(hex)
                    idx += 2
                else:
                    blob += bytes([ord(l[idx])])

                idx += 1
            blob.append(0); # add null terminator to every string


        l = flist.readline()
        if(l.endswith('\n')):
            l = l[:-1]

idtf = "_progmem_str" if not idtf else idtf

outh = open(destPath+".h", "w")
outc = open(destPath+".c", "w")

# add initial cruft
outh.write("#pragma once\n\n#include <avr/pgmspace.h>\n\n")
outh.write("// '{}.h': generated by str2pgmspace from '{}' at {}\n".format(destPath, stringFile, datetime.datetime.now()))
outc.write('#include "./{}.h"\n\n'.format(destFname))


# add constants and interface
outh.write("static const int {}_COUNT = {};\n".format(idtf.upper(), len(indexes)))
outh.write("static const int {}_BLOB_SZ = {};\n".format(idtf.upper(), len(blob)))
outh.write("extern const unsigned short {}_offsets[];\n".format(idtf))
outh.write("extern const char {}_blob[];\n".format(idtf))
outh.write("\n#define {}_GET_OFFSET(I) pgm_read_word(&({}_offsets[(I)]]))\n".format(idtf.upper(), idtf))
outh.write("\n#define {}_GET(I) ( ((const char*) &{}_blob) + {}_GET_OFFSET(I) )\n".format(idtf.upper(), idtf, idtf.upper()))


# write blob to c file now
outc.write("const char {}_blob[] PROGMEM = \n".format(idtf))
allbytes = blob
sz = len(allbytes)
chunks = sz // 16

if (sz % 16):
    chunks += 1

for i in range(chunks):
    end = (i+1)*32
    end = end if end <= len(allbytes) else len(allbytes)
    chunk = allbytes[i*16:end]

    outc.write('"')
    for j in range(len(chunk)):
        outc.write('\\x{:02x}'.format(chunk[j]));
    outc.write('"\n')

outc.write(";\n\n")


# write indices to c file now
outc.write("const unsigned short {}_offsets[] PROGMEM = {}\n    ".format(idtf, "{"))
idxcnt = 1
for i in range(len(indexes)):

    outc.write(str(indexes[i]))
    if(i < len(indexes) - 1):
        outc.write(", ")
    if idxcnt%32 == 0:
        outc.write('\n    ')
    idxcnt += 1

outc.write("};\n\n")


print("str2pgmspace done!")