4 files changed, 154 insertions, 7 deletions
diff --git a/src/main/java/io/trygvis/queue/JdbcQueueService.java b/src/main/java/io/trygvis/queue/JdbcQueueService.java
new file mode 100644
index 0000000..793333d
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/JdbcQueueService.java
@@ -0,0 +1,91 @@
+package io.trygvis.queue;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+
+public class JdbcQueueService {
+
+    private Logger log = LoggerFactory.getLogger(getClass());
+
+    private JdbcQueueService(Connection c) throws SQLException {
+        if (c.getAutoCommit()) {
+            throw new SQLException("The connection cannot be in auto-commit mode.");
+        }
+
+        DatabaseMetaData metaData = c.getMetaData();
+        String productName = metaData.getDatabaseProductName();
+        String productVersion = metaData.getDatabaseProductVersion();
+
+        log.info("productName = " + productName);
+        log.info("productVersion = " + productVersion);
+    }
+
+    public void consume(Connection c, Queue queue, QueueService.TaskEffect effect) throws SQLException {
+        TaskDao taskDao = createTaskDao(c);
+
+        List<Task> tasks = taskDao.findByNameAndCompletedIsNull(queue.name);
+        log.trace("Got {} tasks.", tasks.size());
+
+        for (Task task : tasks) {
+            log.trace("Executing task {}", task.id());
+            try {
+                List<Task> newTasks = effect.consume(task);
+                log.trace("Executed task {}, newTasks: ", task.id(), newTasks.size());
+
+                Date now = new Date();
+
+                task = task.registerComplete(now);
+
+                for (Task newTask : newTasks) {
+                    taskDao.insert(task.id(), newTask.queue, now, newTask.arguments);
+                }
+
+                taskDao.update(task);
+            } catch (Throwable e) {
+                log.error("Unable to execute task, id=" + task.id(), e);
+            }
+            c.commit();
+        }
+    }
+
+    public Queue getQueue(Connection c, String name, int interval, boolean autoCreate) throws SQLException {
+        QueueDao queueDao = createQueueDao(c);
+
+        Queue q = queueDao.findByName(name);
+
+        if (q == null) {
+            if (!autoCreate) {
+                throw new SQLException("No such queue: '" + name + "'.");
+            }
+
+            q = new Queue(name, interval);
+            queueDao.insert(q);
+        }
+
+        return q;
+    }
+
+    public void schedule(Connection c, Queue queue, Date scheduled, List<String> arguments) throws SQLException {
+        TaskDao taskDao = createTaskDao(c);
+
+        taskDao.insert(queue.name, scheduled, arguments);
+    }
+
+    public static JdbcQueueService createQueueService(Connection c) throws SQLException {
+        return new JdbcQueueService(c);
+    }
+
+    public QueueDao createQueueDao(Connection c) {
+        return new QueueDao(c);
+    }
+
+    public TaskDao createTaskDao(Connection c) {
+        return new TaskDao(c);
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/QueueService.java b/src/main/java/io/trygvis/queue/QueueService.java
new file mode 100644
index 0000000..2111013
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/QueueService.java
@@ -0,0 +1,17 @@
+package io.trygvis.queue;
+
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+
+public interface QueueService {
+    void consume(Queue queue, TaskEffect effect) throws SQLException;
+
+    Queue getQueue(String name, int interval, boolean autoCreate) throws SQLException;
+
+    void schedule(Queue queue, Date scheduled, List<String> arguments) throws SQLException;
+
+    public static interface TaskEffect {
+        List<Task> consume(Task task) throws Exception;
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/Task.java b/src/main/java/io/trygvis/queue/Task.java
index 2b1103b..1af40d7 100755
--- a/src/main/java/io/trygvis/queue/Task.java
+++ b/src/main/java/io/trygvis/queue/Task.java
@@ -3,9 +3,11 @@ package io.trygvis.queue;
 import java.util.Date;
 import java.util.List;
 
+import static java.util.Arrays.asList;
+
 public class Task {
 
-    public final long id;
+    private final long id;
 
     public final Long parent;
 
@@ -54,7 +56,42 @@ public class Task {
                 '}';
     }
 
+    public long id() {
+        if (id == 0) {
+            throw new RuntimeException("This task has not been persisted yet.");
+        }
+
+        return id;
+    }
+
     public boolean isDone() {
         return completed != null;
     }
+
+    public static Task newTask(String name, Date scheduled, String... arguments) {
+        return new Task(0, 0l, name, scheduled, null, 0, null, asList(arguments));
+    }
+
+    public static Task newTask(String name, Date scheduled, List<String> arguments) {
+        return new Task(0, 0l, name, scheduled, null, 0, null, arguments);
+    }
+
+    public static List<String> stringToArguments(String arguments) {
+        return asList(arguments.split(","));
+    }
+
+    public static String argumentsToString(List<String> arguments) {
+        StringBuilder builder = new StringBuilder();
+        for (int i = 0, argumentsLength = arguments.size(); i < argumentsLength; i++) {
+            String argument = arguments.get(i);
+            if (argument.contains(",")) {
+                throw new RuntimeException("The argument string can't contain a comma.");
+            }
+            if (i > 0) {
+                builder.append(',');
+            }
+            builder.append(argument);
+        }
+        return builder.toString();
+    }
 }
diff --git a/src/main/java/io/trygvis/queue/TaskDao.java b/src/main/java/io/trygvis/queue/TaskDao.java
index 5459933..3aa2ac2 100644
--- a/src/main/java/io/trygvis/queue/TaskDao.java
+++ b/src/main/java/io/trygvis/queue/TaskDao.java
@@ -11,7 +11,8 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
-import static java.util.Arrays.asList;
+import static io.trygvis.queue.Task.argumentsToString;
+import static io.trygvis.queue.Task.stringToArguments;
 
 public class TaskDao {
 
@@ -23,11 +24,11 @@ public class TaskDao {
         this.connection = connection;
     }
 
-    public long insert(String queue, Date scheduled, String arguments) throws SQLException {
+    public long insert(String queue, Date scheduled, List<String> arguments) throws SQLException {
         return insert(null, queue, scheduled, arguments);
     }
 
-    public long insert(Long parent, String queue, Date scheduled, String arguments) throws SQLException {
+    public long insert(Long parent, String queue, Date scheduled, List<String> arguments) throws SQLException {
         String sql = "INSERT INTO task(id, parent, run_count, queue, scheduled, arguments) " +
                 "VALUES(nextval('task_seq'), ?, 0, ?, ?, ?)";
         try (PreparedStatement stmt = connection.prepareStatement(sql)) {
@@ -39,7 +40,7 @@ public class TaskDao {
             }
             stmt.setString(i++, queue);
             stmt.setTimestamp(i++, new Timestamp(scheduled.getTime()));
-            stmt.setString(i, arguments);
+            stmt.setString(i, argumentsToString(arguments));
             stmt.executeUpdate();
         }
         try (PreparedStatement stmt = connection.prepareStatement("SELECT currval('task_seq')")) {
@@ -51,6 +52,7 @@ public class TaskDao {
 
     public Task findById(long id) throws SQLException {
         try (PreparedStatement stmt = connection.prepareStatement("SELECT " + fields + " FROM task WHERE id=?")) {
+            stmt.setLong(1, id);
             ResultSet rs = stmt.executeQuery();
             return rs.next() ? mapRow(rs) : null;
         }
@@ -76,7 +78,7 @@ public class TaskDao {
             setTimestamp(stmt, i++, task.lastRun);
             stmt.setInt(i++, task.runCount);
             setTimestamp(stmt, i++, task.completed);
-            stmt.setLong(i, task.id);
+            stmt.setLong(i, task.id());
             stmt.executeUpdate();
         }
     }
@@ -99,6 +101,6 @@ public class TaskDao {
                 rs.getTimestamp(5),
                 rs.getInt(6),
                 rs.getTimestamp(7),
-                arguments != null ? asList(arguments.split(" ")) : Collections.<String>emptyList());
+                arguments != null ? stringToArguments(arguments) : Collections.<String>emptyList());
     }
 }