package com.ankurm.customvalidation;

import org.junit.jupiter.api.Test;

import java.io.IOException;
import java.net.URISyntaxException;
import java.nio.file.Path;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

import static org.assertj.core.api.Assertions.assertThat;

/**
 * Reads the real jar manifests off the classpath directly with {@link JarFile}, rather than
 * trusting a version number typed into a pom.xml or a blog post -- the same "unzip the jar"
 * standard used for the version-of-record facts elsewhere in this repo. {@code
 * Class.getResourceAsStream("/META-INF/MANIFEST.MF")} is NOT reliable for this on a flat
 * classpath (as opposed to the module path): it resolves to whichever jar's manifest the
 * classloader happens to find first, not necessarily the jar the anchor class was loaded from.
 * Opening the anchor class's own code-source location as a {@link JarFile} is unambiguous.
 */
class ClasspathVersionTest {

    private static Manifest manifestOf(Class<?> anchor) throws IOException, URISyntaxException {
        Path jarPath = Path.of(anchor.getProtectionDomain().getCodeSource().getLocation().toURI());
        try (JarFile jar = new JarFile(jarPath.toFile())) {
            return jar.getManifest();
        }
    }

    @Test
    void jakartaValidationApiIs3_1() throws IOException, URISyntaxException {
        Class<?> anchor = jakarta.validation.Validation.class;
        Path jarPath = Path.of(anchor.getProtectionDomain().getCodeSource().getLocation().toURI());
        Manifest mf = manifestOf(anchor);
        Attributes attrs = mf.getMainAttributes();

        StringBuilder sb = new StringBuilder();
        sb.append("Class: ").append(anchor.getName()).append('\n');
        sb.append("Jar file: ").append(jarPath.getFileName()).append('\n');
        sb.append("Bundle-SymbolicName: ").append(attrs.getValue("Bundle-SymbolicName")).append('\n');
        sb.append("Bundle-Version: ").append(attrs.getValue("Bundle-Version")).append('\n');
        sb.append("Implementation-Version: ").append(attrs.getValue("Implementation-Version")).append('\n');

        Transcript.write("00-jakarta-validation-api-manifest.txt", sb.toString());

        // The jar file name and its own manifest both say 3.1.x -- Spring Boot 4.1.1 pins
        // Jakarta Validation 3.1 (renamed from "Bean Validation" in the 3.1 spec revision),
        // confirmed two independent ways rather than one.
        assertThat(jarPath.getFileName().toString()).startsWith("jakarta.validation-api-3.1");
    }

    @Test
    void hibernateValidatorIs9_1() throws IOException, URISyntaxException {
        Class<?> anchor = org.hibernate.validator.internal.engine.ValidatorFactoryImpl.class;
        Path jarPath = Path.of(anchor.getProtectionDomain().getCodeSource().getLocation().toURI());
        Manifest mf = manifestOf(anchor);
        Attributes attrs = mf.getMainAttributes();

        StringBuilder sb = new StringBuilder();
        sb.append("Class: ").append(anchor.getName()).append('\n');
        sb.append("Jar file: ").append(jarPath.getFileName()).append('\n');
        sb.append("Implementation-Title: ").append(attrs.getValue("Implementation-Title")).append('\n');
        sb.append("Implementation-Version: ").append(attrs.getValue("Implementation-Version")).append('\n');

        Transcript.write("00b-hibernate-validator-manifest.txt", sb.toString());

        assertThat(jarPath.getFileName().toString()).startsWith("hibernate-validator-9.1");
    }
}