// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.tools;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assumptions.assumeTrue;

import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.text.DecimalFormat;
import java.util.Locale;
import java.util.stream.Stream;

import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.RegisterExtension;
import org.openstreetmap.josm.testutils.JOSMTestRules;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;

/**
 * Unit tests of {@link JosmDecimalFormatSymbolsProvider}.
 */
class JosmDecimalFormatSymbolsProviderTest {

    /**
     * Setup rule.
     */
    @RegisterExtension
    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
    public JOSMTestRules test = new JOSMTestRules();

    @BeforeAll
    static void beforeAll() throws IOException {
        if (Utils.getJavaVersion() >= 9) {
            assertEquals("SPI,JRE,CLDR", System.getProperty("java.locale.providers"), "This test must be launched with -Djava.locale.providers=SPI,JRE,CLDR");
            try (InputStream in = I18n.class.getResourceAsStream("/META-INF/services/java.text.spi.DecimalFormatSymbolsProvider")) {
                assertEquals("org.openstreetmap.josm.tools.JosmDecimalFormatSymbolsProvider", new String(Utils.readBytesFromStream(in), StandardCharsets.UTF_8).trim());
            }
        }
    }

    @Test
    void testGroupingSeparator() {
        System.out.println(Locale.getDefault());
        assumeTrue(Utils.getJavaVersion() >= 9);

        assertTrue(I18n.getAvailableTranslations().count() > 10);
        I18n.getAvailableTranslations().forEach(this::checkGroupingSymbol);
        Stream.of("", "AU", "IE", "US", "UK").map(country -> new Locale("en", country, "")).forEach(this::checkGroupingSymbol);
        Stream.of("", "AT", "CH", "DE").map(country -> new Locale("de", country, "")).forEach(this::checkGroupingSymbol);
    }

    private void checkGroupingSymbol(Locale locale) {
        assertEquals("123\u202F456", DecimalFormat.getInstance(locale).format(123_456), locale.toString());
    }

    /**
     * Test {@link JosmDecimalFormatSymbolsProvider#parseDouble}.
     */
    @Test
    void testParseDouble() {
        final Locale defLocale = Locale.getDefault();
        try {
            Locale.setDefault(Locale.ENGLISH);
            assertEquals(0.3, JosmDecimalFormatSymbolsProvider.parseDouble("0.3"), 1e-7);
            assertEquals(0.3, JosmDecimalFormatSymbolsProvider.parseDouble("0,3"), 1e-7);
            Locale.setDefault(Locale.FRENCH);
            assertEquals(0.3, JosmDecimalFormatSymbolsProvider.parseDouble("0.3"), 1e-7);
            assertEquals(0.3, JosmDecimalFormatSymbolsProvider.parseDouble("0,3"), 1e-7);
        } finally {
            Locale.setDefault(defLocale);
        }
    }
}