import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/** Regenerates localized country names while preserving the maintained dialing codes. */
public final class GenerateCountryCallingCodeLocales {
    private static final Pattern ITEM = Pattern.compile(
            "\\{\\\"code\\\":\\\"([^\\\"]+)\\\",\\\"name\\\":\\\"[^\\\"]*\\\",\\\"dial_code\\\":\\\"([^\\\"]+)\\\"}");

    private record Country(String code, String dialCode) {}

    public static void main(String[] args) throws IOException {
        Path assets = Path.of("app", "src", "main", "assets");
        String source = Files.readString(assets.resolve("country_calling_codes.json"), StandardCharsets.UTF_8);
        Matcher matcher = ITEM.matcher(source);
        List<Country> countries = new ArrayList<>();
        while (matcher.find()) {
            countries.add(new Country(matcher.group(1), matcher.group(2)));
        }
        if (countries.isEmpty()) {
            throw new IllegalStateException("No country records found in the source JSON");
        }

        write(assets.resolve("country_calling_codes_en.json"), countries, Locale.ENGLISH);
        write(assets.resolve("country_calling_codes_ar.json"), countries, Locale.forLanguageTag("ar"));
    }

    private static void write(Path output, List<Country> countries, Locale locale) throws IOException {
        StringBuilder json = new StringBuilder("[\n");
        for (int index = 0; index < countries.size(); index++) {
            Country country = countries.get(index);
            String name = new Locale.Builder().setRegion(country.code()).build().getDisplayCountry(locale);
            json.append("  {\"code\":\"").append(country.code())
                    .append("\",\"name\":\"").append(escape(name))
                    .append("\",\"dial_code\":\"").append(country.dialCode()).append("\"}");
            json.append(index + 1 == countries.size() ? "\n" : ",\n");
        }
        json.append("]\n");
        Files.writeString(output, json, StandardCharsets.UTF_8);
    }

    private static String escape(String value) {
        return value.replace("\\", "\\\\").replace("\"", "\\\"");
    }
}