init

p1/Repository.java

@@ -0,0 +1,146 @@
+import java.util.*;
+import java.text.SimpleDateFormat;
+
+public class Repository {
+
+    private String name;
+    private LinkedList<Commit> commits;
+
+    public Repository(String name) {
+        if (name.isEmpty() || name == null) {
+            throw new IllegalArgumentException("Repository must have a name!");
+        }
+        this.name = name;
+        this.commits = new LinkedList<>();
+    }
+
+    public String getRepoHead() {
+        return commits.peek().id;
+    }
+
+    public int getRepoSize() {
+        return commits.size();
+    }
+
+    public String toString() {
+        return name + " -  Current head: " + commits.peek().toString();
+    }
+
+    public boolean contains(String targetId) {
+        for (Commit commit : commits) {
+            if (commit.id == targetId) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public String getHistory(int n) {
+        String output = "";
+        for (int i = 0; i < commits.size() - 1; i++) {
+            output += commits.get(i).toString() + "\n";
+        }
+        return output;
+    }
+
+    public String commit(String message) {
+        commits.add(new Commit(message));
+        return commits.peek().id;
+    }
+
+    public boolean drop(String targetId) {
+        for (int n = 0; n < commits.size() - 1; n ++) {
+            if (commits.get(n).id == targetId) {
+                commits.remove(n);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void synchronize(Repository other) {
+        
+    }
+    /**
+     * DO NOT MODIFY
+     * A class that represents a single commit in the repository.
+     * Commits are characterized by an identifier, a commit message,
+     * and the time that the commit was made. A commit also stores
+     * a reference to the immediately previous commit if it exists.
+     *
+     * Staff Note: You may notice that the comments in this 
+     * class openly mention the fields of the class. This is fine 
+     * because the fields of the Commit class are public. In general, 
+     * be careful about revealing implementation details!
+     */
+    public class Commit {
+
+        private static int currentCommitID;
+
+        /**
+         * The time, in milliseconds, at which this commit was created.
+         */
+        public final long timeStamp;
+
+        /**
+         * A unique identifier for this commit.
+         */
+        public final String id;
+
+        /**
+         * A message describing the changes made in this commit.
+         */
+        public final String message;
+
+        /**
+         * A reference to the previous commit, if it exists. Otherwise, null.
+         */
+        public Commit past;
+
+        /**
+         * Constructs a commit object. The unique identifier and timestamp
+         * are automatically generated.
+         * @param message A message describing the changes made in this commit.
+         * @param past A reference to the commit made immediately before this
+         *             commit.
+         */
+        public Commit(String message, Commit past) {
+            this.id = "" + currentCommitID++;
+            this.message = message;
+            this.timeStamp = System.currentTimeMillis();
+            this.past = past;
+        }
+
+        /**
+         * Constructs a commit object with no previous commit. The unique
+         * identifier and timestamp are automatically generated.
+         * @param message A message describing the changes made in this commit.
+         */
+        public Commit(String message) {
+            this(message, null);
+        }
+
+        /**
+         * Returns a string representation of this commit. The string
+         * representation consists of this commit's unique identifier,
+         * timestamp, and message, in the following form:
+         *      "[identifier] at [timestamp]: [message]"
+         * @return The string representation of this collection.
+         */
+        @Override
+        public String toString() {
+            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd 'at' HH:mm:ss z");
+            Date date = new Date(timeStamp);
+
+            return id + " at " + formatter.format(date) + ": " + message;
+        }
+
+        /**
+        * Resets the IDs of the commit nodes such that they reset to 0.
+        * Primarily for testing purposes.
+        */
+        public static void resetIds() {
+            Commit.currentCommitID = 0;
+        }
+    }
+}