package org.shedlang.compiler.config;

import org.junit.jupiter.api.Test;
import org.shedlang.compiler.config.json.Json5ObjectWithSource;
import org.shedlang.compiler.sources.SourceTexts;

import java.util.OptionalLong;

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.zwobble.precisely.AssertThat.assertThat;
import static org.zwobble.precisely.Matchers.*;

public class GcConfigTests {
    @Test
    public void whenNameIsUnrecognisedThenErrorIsThrown() {
        var source = """
            {
                name: "huh",
            }
            """;

        var error = assertThrows(
            IllegalArgumentException.class,
            () -> parseGcConfig(source)
        );

        assertThat(error.getMessage(), equalTo("Unrecognised GC name: \"huh\""));
    }

    @Test
    public void canParseConfigForBump() {
        var source = """
            {
                "name": "bump",
            }
            """;

        var config = parseGcConfig(source);

        assertThat(config, instanceOf(GcBumpConfig.class));
    }

    @Test
    public void canParseMinimalConfigForMarkAndSweep() {
        var source = """
            {
                name: "mark-and-sweep",
            }
            """;

        var config = parseGcConfig(source);

        assertThat(config, instanceOf(GcMarkAndSweepConfig.class));
    }

    @Test
    public void additionalFieldsCanBeUsedBySpecificGcConfig() {
        var source = """
            {
                name: "mark-and-sweep",
                collectInterval: 10000,
            }
            """;

        var config = parseGcConfig(source);

        assertThat(config, instanceOf(
            GcMarkAndSweepConfig.class,
            has("collectInterval", x -> x.collectInterval(), equalTo(OptionalLong.of(10000L)))
        ));
    }

    private GcConfig parseGcConfig(String text) {
        var sourceText = SourceTexts.string(text);
        return GcConfig.fromJson5(Json5ObjectWithSource.parse(sourceText));
    }
}