package org.argeo.osgi.a2;
   
   import java.io.FileOutputStream;
   import java.io.IOException;
   import java.io.InputStream;
   import java.net.URL;
   import java.nio.file.FileVisitResult;
   import java.nio.file.Files;
   import java.nio.file.Path;
  import java.nio.file.SimpleFileVisitor;
  import java.nio.file.attribute.BasicFileAttributes;
  import java.util.Collections;
  import java.util.Map;
  import java.util.SortedMap;
  import java.util.TreeMap;
  import java.util.jar.JarInputStream;
  import java.util.jar.JarOutputStream;
  import java.util.jar.Manifest;
  import java.util.zip.ZipEntry;
  
  import org.osgi.framework.Bundle;
  import org.osgi.framework.BundleContext;
  import org.osgi.framework.BundleException;
  import org.osgi.framework.Constants;
  import org.osgi.framework.Version;
  
  /** Where components are retrieved from. */
  public abstract class AbstractProvisioningSource implements ProvisioningSource {
  	protected final Map<String, A2Contribution> contributions = Collections.synchronizedSortedMap(new TreeMap<>());
  
  	public Iterable<A2Contribution> listContributions(Object filter) {
  		return contributions.values();
  	}
  
  	@Override
  	public Bundle install(BundleContext bc, A2Module module) {
  		try {
  			Path tempJar = null;
  			if (module.getLocator() instanceof Path && Files.isDirectory((Path) module.getLocator()))
  				tempJar = toTempJar((Path) module.getLocator());
  			Bundle bundle;
  			try (InputStream in = newInputStream(tempJar != null ? tempJar : module.getLocator())) {
  				bundle = bc.installBundle(module.getBranch().getCoordinates(), in);
  			}
  			if (tempJar != null)
  				Files.deleteIfExists(tempJar);
  			return bundle;
  		} catch (BundleException | IOException e) {
  			throw new A2Exception("Cannot install module " + module, e);
  		}
  	}
  
  	@Override
  	public void update(Bundle bundle, A2Module module) {
  		try {
  			Path tempJar = null;
  			if (module.getLocator() instanceof Path && Files.isDirectory((Path) module.getLocator()))
  				tempJar = toTempJar((Path) module.getLocator());
  			try (InputStream in = newInputStream(tempJar != null ? tempJar : module.getLocator())) {
  				bundle.update(in);
  			}
  			if (tempJar != null)
  				Files.deleteIfExists(tempJar);
  		} catch (BundleException | IOException e) {
  			throw new A2Exception("Cannot update module " + module, e);
  		}
  	}
  
  	@Override
  	public A2Branch findBranch(String componentId, Version version) {
  		A2Component component = findComponent(componentId);
  		if (component == null)
  			return null;
  		String branchId = version.getMajor() + "." + version.getMinor();
  		if (!component.branches.containsKey(branchId))
  			return null;
  		return component.branches.get(branchId);
  	}
  
  	protected A2Contribution getOrAddContribution(String contributionId) {
  		if (contributions.containsKey(contributionId))
  			return contributions.get(contributionId);
  		else {
  			A2Contribution contribution = new A2Contribution(this, contributionId);
  			contributions.put(contributionId, contribution);
  			return contribution;
  		}
  	}
  
  	protected void asTree(String prefix, StringBuffer buf) {
  		if (prefix == null)
  			prefix = "";
  		for (String contributionId : contributions.keySet()) {
  			buf.append(prefix);
  			buf.append(contributionId);
  			buf.append('\n');
  			A2Contribution contribution = contributions.get(contributionId);
  			contribution.asTree(prefix + " ", buf);
  		}
 	}
 
 	protected void asTree() {
 		StringBuffer buf = new StringBuffer();
 		asTree("", buf);
 		System.out.println(buf);
 	}
 
 	protected A2Component findComponent(String componentId) {
 		SortedMap<A2Contribution, A2Component> res = new TreeMap<>();
 		for (A2Contribution contribution : contributions.values()) {
 			components: for (String componentIdKey : contribution.components.keySet()) {
 				if (componentId.equals(componentIdKey)) {
 					res.put(contribution, contribution.components.get(componentIdKey));
 					break components;
 				}
 			}
 		}
 		if (res.size() == 0)
 			return null;
 		// TODO explicit contribution priorities
 		return res.get(res.lastKey());
 
 	}
 
 	protected String readVersionFromModule(Path modulePath) {
 		Manifest manifest;
 		if (Files.isDirectory(modulePath)) {
 			manifest = findManifest(modulePath);
 		} else {
 			try (JarInputStream in = new JarInputStream(newInputStream(modulePath))) {
 				manifest = in.getManifest();
 			} catch (IOException e) {
 				throw new A2Exception("Cannot read manifest from " + modulePath, e);
 			}
 		}
 		String versionStr = manifest.getMainAttributes().getValue(Constants.BUNDLE_VERSION);
 		return versionStr;
 	}
 
 	protected String readSymbolicNameFromModule(Path modulePath) {
 		Manifest manifest;
 		if (Files.isDirectory(modulePath)) {
 			manifest = findManifest(modulePath);
 		} else {
 			try (JarInputStream in = new JarInputStream(newInputStream(modulePath))) {
 				manifest = in.getManifest();
 			} catch (IOException e) {
 				throw new A2Exception("Cannot read manifest from " + modulePath, e);
 			}
 		}
 		String symbolicName = manifest.getMainAttributes().getValue(Constants.BUNDLE_SYMBOLICNAME);
 		int semiColIndex = symbolicName.indexOf(';');
 		if (semiColIndex >= 0)
 			symbolicName = symbolicName.substring(0, semiColIndex);
 		return symbolicName;
 	}
 
 	private static Manifest findManifest(Path currentPath) {
 		Path metaInfPath = currentPath.resolve("META-INF");
 		if (Files.exists(metaInfPath) && Files.isDirectory(metaInfPath)) {
 			Path manifestPath = metaInfPath.resolve("MANIFEST.MF");
 			try {
 				try (InputStream in = Files.newInputStream(manifestPath)) {
 					Manifest manifest = new Manifest(in);
 					return manifest;
 				}
 			} catch (IOException e) {
 				throw new A2Exception("Cannot read manifest from " + manifestPath, e);
 			}
 		} else {
 			Path parentPath = currentPath.getParent();
 			if (parentPath == null)
 				throw new A2Exception("MANIFEST.MF file not found.");
 			return findManifest(currentPath.getParent());
 		}
 	}
 
 	private static Path toTempJar(Path dir) {
 		try {
 			Manifest manifest = findManifest(dir);
 			Path jarPath = Files.createTempFile("a2Source", ".jar");
 			try (JarOutputStream zos = new JarOutputStream(new FileOutputStream(jarPath.toFile()), manifest)) {
 				Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {
 					public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
 						Path relPath = dir.relativize(file);
 						// skip MANIFEST from folder
 						if (relPath.toString().contentEquals("META-INF/MANIFEST.MF"))
 							return FileVisitResult.CONTINUE;
 						zos.putNextEntry(new ZipEntry(relPath.toString()));
 						Files.copy(file, zos);
 						zos.closeEntry();
 						return FileVisitResult.CONTINUE;
 					}
 				});
 			}
 			return jarPath;
 		} catch (IOException e) {
 			throw new A2Exception("Cannot install OSGi bundle from " + dir, e);
 		}
 
 	}
 
 	private InputStream newInputStream(Object locator) throws IOException {
 		if (locator instanceof Path) {
 			return Files.newInputStream((Path) locator);
 		} else if (locator instanceof URL) {
 			return ((URL) locator).openStream();
 		} else {
 			throw new IllegalArgumentException("Unsupported module locator type " + locator.getClass());
 		}
 	}
 }