import argparse
import os
import re

parser = argparse.ArgumentParser(description="Embed a JS file as a C string header")
parser.add_argument("--input", required=True, help="Path to input JS file")
parser.add_argument("--output", required=True, help="Path to output .h file")
parser.add_argument("--name", help="C identifier name (default: derived from filename)")
args = parser.parse_args()

if args.name:
    name = args.name
else:
    stem = os.path.splitext(os.path.basename(args.input))[0]
    name = re.sub(r"[^a-zA-Z0-9]", "_", stem).upper() + "_JS"

with open(args.input, "r", encoding="utf-8") as f:
    source = f.read()

def escape_line(s):
    s = s.replace("\\", "\\\\")
    s = s.replace('"', '\\"')
    s = s.replace("\r", "\\r")
    s = s.replace("\t", "\\t")
    return s

lines = source.split("\n")
if lines and lines[-1] == "":
    lines = lines[:-1]

out = [
    "#pragma once",
    "#include <stddef.h>",
    "",
    f"static const char {name}[] =",
]

if not lines:
    out[-1] += ' "";'
else:
    for i, line in enumerate(lines):
        suffix = ";" if i == len(lines) - 1 else ""
        out.append(f'  "{escape_line(line)}\\n"{suffix}')

out += [
    "",
    f"static const size_t {name}_SIZE = sizeof({name}) - 1;",
    "",
]

os.makedirs(os.path.dirname(args.output), exist_ok=True)
with open(args.output, "w", encoding="utf-8") as f:
    f.write("\n".join(out))