#!/usr/bin/env python3
"""Embed spry CLI template files as Vala const strings (mkconst-style)."""
import os
import re
import sys


def const_name(filename):
    base = filename
    for ext in ('.vala', '.html', '.build', '.md'):
        if base.endswith(ext):
            base = base[: -len(ext)]
            break
    base = re.sub(r'([a-z0-9])([A-Z])', r'\1_\2', base)
    base = re.sub(r'[^A-Za-z0-9]', '_', base)
    return base.upper()


def vala_literal(text):
    text = text.replace('\\', '\\\\').replace('"', '\\"')
    text = text.replace('\r', '\\r').replace('\t', '\\t').replace('\n', '\\n')
    return '"%s"' % text


def main():
    if len(sys.argv) < 3:
        sys.stderr.write('usage: mkconst.py OUTPUT TEMPLATE...\n')
        return 1
    output, templates = sys.argv[1], sys.argv[2:]
    with open(output, 'w', encoding='utf-8') as out:
        out.write('// Generated by tools/spry/mkconst.py - do not edit.\n')
        out.write('namespace Spry.Cli {\n\n')
        out.write('    public class Templates : GLib.Object {\n')
        for path in templates:
            with open(path, 'r', encoding='utf-8') as handle:
                text = handle.read()
            out.write('\n        public const string %s = %s;\n'
                      % (const_name(os.path.basename(path)), vala_literal(text)))
        out.write('    }\n}\n')
    return 0


if __name__ == '__main__':
    sys.exit(main())