"""Build /etc/gconf/gconf.xml.defaults from Psion's .schemas files.

On the device gconftool-2 --install-schemas runs at image build time; we do the
same job here so the defaults source is populated before first boot.  Without it
every app that reads a schema default gets NULL -- which is why AisleRiot drew
blank white cards (no /apps/aisleriot/card_options).
"""
import os, re, sys, html, xml.etree.ElementTree as ET

MTIME = "1104537600"          # 2005-01-01, matching the era of the tree

def entries(path):
    """Yield (key, type, ltype, value) for every schema that carries a default."""
    txt = open(path, encoding="utf-8", errors="replace").read()
    for m in re.finditer(r"<schema>(.*?)</schema>", txt, re.S):
        b = m.group(1)
        applyto = re.findall(r"<applyto>(.*?)</applyto>", b, re.S)
        typ = re.search(r"<type>(.*?)</type>", b, re.S)
        lty = re.search(r"<list_type>(.*?)</list_type>", b, re.S)
        dfl = re.search(r"<default>(.*?)</default>", b, re.S)
        if not (applyto and typ and dfl):
            continue
        for key in applyto:
            # .schemas files wrap long defaults across lines; the value itself
            # never contains a newline, so fold the wrapping back to one space.
            val = " ".join(html.unescape(dfl.group(1)).split())
            yield (key.strip(), typ.group(1).strip(),
                   lty.group(1).strip() if lty else None, val)

def render(name, typ, ltype, val):
    if typ == "bool":
        return f'\t<entry name="{name}" mtime="{MTIME}" type="bool" value="{"true" if val.upper()=="TRUE" else "false"}"/>'
    if typ in ("int", "float"):
        return f'\t<entry name="{name}" mtime="{MTIME}" type="{typ}" value="{val}"/>'
    if typ == "string":
        return (f'\t<entry name="{name}" mtime="{MTIME}" type="string">\n'
                f'\t\t<stringvalue>{html.escape(val)}</stringvalue>\n\t</entry>')
    if typ == "list":
        lt = ltype or "string"
        body = ""
        inner = val.strip()
        if inner.startswith("[") and inner.endswith("]"):
            inner = inner[1:-1].strip()
        if inner:
            for item in [i.strip() for i in inner.split(",") if i.strip()]:
                if lt == "string":
                    body += f'\t\t<li type="string"><stringvalue>{html.escape(item)}</stringvalue></li>\n'
                else:
                    body += f'\t\t<li type="{lt}" value="{html.escape(item)}"/>\n'
        return (f'\t<entry name="{name}" mtime="{MTIME}" type="list" ltype="{lt}">\n'
                f'{body}\t</entry>')
    return None

def main(root, schema_files):
    dirs = {}
    for f in schema_files:
        for key, typ, ltype, val in entries(f):
            d, _, name = key.rpartition("/")
            line = render(name, typ, ltype, val)
            if line:
                dirs.setdefault(d.lstrip("/"), []).append(line)
    for d, lines in sorted(dirs.items()):
        out = os.path.join(root, d)
        os.makedirs(out, exist_ok=True)
        with open(os.path.join(out, "%gconf.xml"), "w", encoding="utf-8") as fh:
            fh.write('<?xml version="1.0"?>\n<gconf>\n' + "\n".join(lines) + "\n</gconf>\n")
        print(f"  /{d:44} {len(lines)} keys")
    # every intermediate directory needs a %gconf.xml for the XML backend to walk it
    for d in list(dirs):
        parts = d.split("/")
        for i in range(1, len(parts)):
            p = os.path.join(root, *parts[:i])
            os.makedirs(p, exist_ok=True)
            f = os.path.join(p, "%gconf.xml")
            if not os.path.exists(f):
                open(f, "w").write('<?xml version="1.0"?>\n<gconf>\n</gconf>\n')
    f = os.path.join(root, "%gconf.xml")
    if not os.path.exists(f):
        open(f, "w").write('<?xml version="1.0"?>\n<gconf>\n</gconf>\n')

if __name__ == "__main__":
    main(sys.argv[1], sys.argv[2:])