#!/usr/bin/env python3
"""Generate C++ format constants from the public dictionary format contract."""
import argparse
import json
from pathlib import Path

root = Path(__file__).resolve().parent
spec = json.loads((root / 'format.json').read_text())
rule = spec['quanpin']
expected = '''// Generated by contracts/dictionary/generate.py; edit format.json instead.
#pragma once
#include <cstddef>
#include <string>

namespace metasequoia::dictionary_format
{
inline constexpr int version = VERSION;
inline constexpr std::size_t maximum_numbered_syllables = MAXIMUM;
inline constexpr char initials[] = INITIALS;
inline std::string quanpin_table(std::size_t syllables, char initial)
{
    if (syllables == 0 || initial < 'a' || initial > 'z') return {};
    return std::string(PREFIX) +
           (syllables <= maximum_numbered_syllables ? std::to_string(syllables) : OVERFLOW) +
           "_" + initial;
}
} // namespace metasequoia::dictionary_format
'''.replace('VERSION', str(spec['formatVersion'])).replace('MAXIMUM', str(rule['maximumNumberedSyllables']))
for name, value in [('INITIALS', rule['initials']), ('PREFIX', rule['prefix']), ('OVERFLOW', rule['overflowBucket'])]:
    expected = expected.replace(name, json.dumps(value))
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--check', action='store_true')
args = parser.parse_args()
target = root / 'format.h'
if args.check:
    if not target.exists() or target.read_text() != expected:
        raise SystemExit('Dictionary format header is stale; run contracts/dictionary/generate.py')
else:
    target.write_text(expected)