[JGIT PATCH 05/22] Added ProjectSeeker class.

[Florian Koeberle <florianskarten@web.de>]

Signed-off-by: Florian Koeberle <florianskarten@web.de>
---
 .../src/org/spearce/jgit/lib/Project.java          |    5 +-
 .../src/org/spearce/jgit/lib/ProjectSeeker.java    |  118 ++++++++++++++++++++
 2 files changed, 122 insertions(+), 1 deletions(-)
 create mode 100644 org.spearce.jgit/src/org/spearce/jgit/lib/ProjectSeeker.java

diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/Project.java b/org.spearce.jgit/src/org/spearce/jgit/lib/Project.java
index 6e72486..f6b6a17 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/Project.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/Project.java
@@ -19,7 +19,10 @@ package org.spearce.jgit.lib;
 import java.io.File;
 
 /**
- * Represents a project controlled by git. Use {@link ProjectFactory} in order to create an object of this class.
+ * Represents a project controlled by git. Use {@link ProjectFactory} in order to create an object of this class. If you
+ * don't want to create a new repository, but need a new {@link Project}
+ * instance then use {@link ProjectSeeker}.
+ * 
  * @author Florian Köberle
  *
  */
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/ProjectSeeker.java b/org.spearce.jgit/src/org/spearce/jgit/lib/ProjectSeeker.java
new file mode 100644
index 0000000..3aa5284
--- /dev/null
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/ProjectSeeker.java
@@ -0,0 +1,118 @@
+/*
+ *  Copyright (C) 2008 Florian Köberle
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public
+ *  License, version 2, as published by the Free Software Foundation.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
+ */
+package org.spearce.jgit.lib;
+
+import java.io.File;
+import java.io.IOException;
+import static org.spearce.jgit.lib.GitPathConstants.OBJECTS_DIRECTORY_NAME;
+import static org.spearce.jgit.lib.GitPathConstants.REPOSITORY_DIRECTORY_NAME;
+import static org.spearce.jgit.lib.GitPathConstants.REFS_DIRECTORY_NAME;
+import static org.spearce.jgit.lib.GitPathConstants.HEAD_FILE_NAME;
+
+/**
+ * Use this class to create instances of {@link Project}.
+ * 
+ * @author Florian Köberle
+ * 
+ */
+public class ProjectSeeker {
+
+	/**
+	 * Find the git repository for the current working directory.
+	 * 
+	 * @return a {@link Repository}.
+	 * @throws IOException
+	 *             if the system property user.dir isn't set or if it is
+	 *             invalid.
+	 */
+	public Project findProject() throws IOException {
+		final String workingDirectoryPath = System.getProperty("user.dir");
+		if (workingDirectoryPath == null) {
+			throw new IOException("unable to get working directory");
+		}
+		final File workingDirectoryFile = new File(workingDirectoryPath);
+		if (!workingDirectoryFile.exists()) {
+			throw new IOException("Working directory path is invalid");
+		}
+		return findProject(workingDirectoryFile);
+	}
+
+	/**
+	 * Checks if a path is a valid git repository. Works similar like the method
+	 * is_git_directory from the original setup.c file.
+	 * 
+	 * @param directory
+	 *            the path which should be checked.
+	 * @return true if the path is a valid git repository.
+	 */
+	private boolean isRepository(File directory) {
+		if (!directory.isDirectory()) {
+			return false;
+		}
+
+		final File objectDirectory = new File(directory, OBJECTS_DIRECTORY_NAME);
+		if (!objectDirectory.isDirectory()) {
+			return false;
+		}
+
+		final File refsDirectory = new File(directory, REFS_DIRECTORY_NAME);
+		if (!refsDirectory.isDirectory()) {
+			return false;
+		}
+
+		final File head = new File(directory, HEAD_FILE_NAME);
+		if (!hasValidateHeadRef(head)) {
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Checks for example if a path is a valid HEAD file. Should do the same
+	 * like validate_headref from path.c.
+	 * 
+	 * @param path
+	 *            is the path of the HEAD file.
+	 * @return true if it has a valid head reference.
+	 */
+	private static final boolean hasValidateHeadRef(File path) {
+		return true; // TODO stub. view int validate_headref(const char
+		// *path) at path.c
+	}
+
+	private Project findProject(File directory) throws IOException {
+		File currentDirectory = directory.getAbsoluteFile();
+		while (true) {
+			final File commonGitDirectory = new File(directory,
+					REPOSITORY_DIRECTORY_NAME);
+			if (isRepository(commonGitDirectory)) {
+				return new Project(currentDirectory, new Repository(
+						commonGitDirectory));
+			}
+
+			if (isRepository(currentDirectory)) {
+				return new Project(null, new Repository(currentDirectory));
+			}
+			currentDirectory = currentDirectory.getParentFile();
+			if (currentDirectory == null) {
+				throw new IOException("Can't find git repository");
+			}
+		}
+
+	}
+}
-- 
1.5.2.5