Add a store that reads/writes aliases.

Change-Id: I24afd60eecf5d77e8ecaf23de584243806df8fdd
Reviewed-on: http://gerrit.dmdirc.com/3519
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

src/com/dmdirc/commandparser/aliases/AliasStore.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2006-2014 DMDirc Developers
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.dmdirc.commandparser.aliases;
+
+import java.util.Set;
+
+/**
+ * A store of {@link Alias}es that can read and write them to some kind of persistent media.
+ */
+public interface AliasStore {
+
+    /**
+     * Reads and returns all aliases from within the store.
+     *
+     * @return A set of known aliases, or an empty set if the store is uninitialised.
+     */
+    Set<Alias> readAliases();
+
+    /**
+     * Writes all the given aliases to the store, replacing any existing aliases.
+     *
+     * @param aliases The set of aliases to be written to the store.
+     */
+    void writeAliases(Set<Alias> aliases);
+
+}

src/com/dmdirc/commandparser/aliases/YamlAliasStore.java

@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2006-2014 DMDirc Developers
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.dmdirc.commandparser.aliases;
+
+import com.dmdirc.commandline.CommandLineOptionsModule.Directory;
+import com.dmdirc.commandline.CommandLineOptionsModule.DirectoryType;
+import com.dmdirc.commandparser.CommandType;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import javax.inject.Inject;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.esotericsoftware.yamlbeans.YamlReader;
+import com.esotericsoftware.yamlbeans.YamlWriter;
+
+import static com.dmdirc.util.YamlReaderUtils.asList;
+import static com.dmdirc.util.YamlReaderUtils.asMap;
+import static com.dmdirc.util.YamlReaderUtils.requiredString;
+
+/**
+ * Store that reads and writes aliases from a YAML file on disk.
+ * <p>
+ * Aliases are written as a list of maps:
+ * <pre><code>
+ * ----
+ * - name: quit
+ *   min_arguments: 0
+ *   substitution: exit $1-
+ * </code></pre>
+ */
+public class YamlAliasStore implements AliasStore {
+
+    /** The charset to use when reading and writing files. */
+    private static final String CHARSET = "UTF-8";
+
+    private static final Logger LOG = LoggerFactory.getLogger(YamlAliasStore.class);
+
+    /** The directory to find the aliases file in. */
+    private final String directory;
+
+    @Inject
+    public YamlAliasStore(@Directory(DirectoryType.BASE) final String directory) {
+        this.directory = directory;
+    }
+
+    @Override
+    public Set<Alias> readAliases() {
+        final File file = new File(directory, "aliases.yml");
+        final Set<Alias> aliases = new HashSet<>();
+
+        if (file.exists()) {
+            try (final InputStream stream = new FileInputStream(file);
+                    final InputStreamReader reader = new InputStreamReader(stream, CHARSET)) {
+                final YamlReader yamlReader = new YamlReader(reader);
+                final Object root = yamlReader.read();
+                aliases.addAll(getAliases(asList(root)));
+                yamlReader.close();
+            } catch (IOException | IllegalArgumentException ex) {
+                LOG.warn("Unable to read aliases", ex);
+            }
+        }
+
+        return aliases;
+    }
+
+    @Override
+    public void writeAliases(final Set<Alias> aliases) {
+        final File file = new File(directory, "aliases.yml");
+        final List<Object> list = getAliases(aliases);
+
+        try (final OutputStream stream = new FileOutputStream(file);
+                final OutputStreamWriter writer = new OutputStreamWriter(stream, CHARSET)) {
+            final YamlWriter yamlWriter = new YamlWriter(writer);
+            yamlWriter.write(list);
+            yamlWriter.close();
+        } catch (IOException ex) {
+            LOG.error("Unable to write aliases", ex);
+        }
+    }
+
+    /**
+     * Builds a set of aliases from the given YAML representations.
+     *
+     * @param objects The raw objects read from the YAML file.
+     *
+     * @return A list of corresponding aliases.
+     */
+    private List<Alias> getAliases(final List<Object> objects) {
+        final List<Alias> res = new ArrayList<>(objects.size());
+        for (Object alias : objects) {
+            try {
+                final Map<Object, Object> map = asMap(alias);
+
+                // TODO: Infer command type from the substituted command
+                final CommandType commandType = CommandType.TYPE_GLOBAL;
+                final String name = requiredString(map, "name");
+                final int minArguments = Integer.parseInt(requiredString(map, "min_arguments"));
+                final String substitution = requiredString(map, "substitution");
+
+                res.add(new Alias(commandType, name, minArguments, substitution));
+            } catch (IllegalArgumentException ex) {
+                LOG.info("Unable to read alias", ex);
+            }
+        }
+        return res;
+    }
+
+    /**
+     * Gets a set of maps that can be written to a YAML file.
+     *
+     * @param aliases The aliases to be stored.
+     *
+     * @return A list of corresponding maps.
+     */
+    private List<Object> getAliases(final Set<Alias> aliases) {
+        final List<Object> res = new ArrayList<>(aliases.size());
+        for (Alias alias : aliases) {
+            final Map<Object, Object> map = new HashMap<>();
+            map.put("name", alias.getName());
+            map.put("min_arguments", String.valueOf(alias.getMinArguments()));
+            map.put("substitution", alias.getSubstitution());
+            res.add(map);
+        }
+        return res;
+    }
+
+}