introduce new data store

src/main/java/de/marhali/easyi18n/DataStore.java

@@ -0,0 +1,103 @@
+package de.marhali.easyi18n;
+
+import com.intellij.openapi.project.Project;
+
+import de.marhali.easyi18n.io.IOStrategy;
+import de.marhali.easyi18n.io.json.JsonIOStrategy;
+import de.marhali.easyi18n.model.SettingsState;
+import de.marhali.easyi18n.model.TranslationData;
+import de.marhali.easyi18n.service.SettingsService;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.function.Consumer;
+
+/**
+ * Responsible for loading, saving and updating translation files.
+ * Provides access to the cached translation data which is used in the whole project.
+ * @author marhali
+ */
+public class DataStore {
+
+    private static final Set<IOStrategy> STRATEGIES = new LinkedHashSet<>(Arrays.asList(
+       new JsonIOStrategy()
+    ));
+
+    private final Project project;
+
+    private @NotNull TranslationData data;
+
+    protected DataStore(Project project) {
+        this.project = project;
+        this.data = new TranslationData(true, true); // Initialize with hard-coded configuration
+    }
+
+    public @NotNull TranslationData getData() {
+        return data;
+    }
+
+    /**
+     * Loads the translation data into cache and overwrites any previous cached data.
+     * If the configuration does not fit an empty translation instance will be populated.
+     * @param successResult Consumer will inform if operation was successful
+     */
+    public void loadFromPersistenceLayer(@NotNull Consumer<Boolean> successResult) {
+        SettingsState state = SettingsService.getInstance(this.project).getState();
+        String localesPath = state.getLocalesPath();
+
+        if(localesPath == null || localesPath.isEmpty()) { // Populate empty instance
+            this.data = new TranslationData(state.isSortKeys(), state.isNestedKeys());
+            return;
+        }
+
+        IOStrategy strategy = this.determineStrategy(state, localesPath);
+
+        strategy.read(this.project, localesPath, state, (data) -> {
+            this.data = data == null
+                    ? new TranslationData(state.isSortKeys(), state.isNestedKeys())
+                    : data;
+
+            successResult.accept(data != null);
+        });
+    }
+
+    /**
+     * Saves the cached translation data to the underlying io system.
+     * @param successResult Consumer will inform if operation was successful
+     */
+    public void saveToPersistenceLayer(@NotNull Consumer<Boolean> successResult) {
+        SettingsState state = SettingsService.getInstance(this.project).getState();
+        String localesPath = state.getLocalesPath();
+
+        if(localesPath == null || localesPath.isEmpty()) { // Cannot save without valid path
+            successResult.accept(false);
+            return;
+        }
+
+        IOStrategy strategy = this.determineStrategy(state, localesPath);
+
+        strategy.write(this.project, localesPath, state, this.data, successResult);
+    }
+
+    /**
+     * Chooses the right strategy for the opened project. An exception might be thrown on
+     * runtime if the project configuration (e.g. locale files does not fit in any strategy).
+     * @param state Plugin configuration
+     * @param localesPath Locales directory
+     * @return matching {@link IOStrategy}
+     */
+    public @NotNull IOStrategy determineStrategy(@NotNull SettingsState state, @NotNull String localesPath) {
+        for(IOStrategy strategy : STRATEGIES) {
+            if(strategy.canUse(this.project, localesPath, state)) {
+                return strategy;
+            }
+        }
+
+        throw new IllegalArgumentException("Could not determine i18n strategy. " +
+                "At least one locale file must be defined. " +
+                "For examples please visit https://github.com/marhali/easy-i18n");
+    }
+}