Add CLI

1 files changed, 90 insertions, 0 deletions

diff --git a/src/main/java/org/zwobble/couscous/cli/CouscousCli.java b/src/main/java/org/zwobble/couscous/cli/CouscousCli.java
new file mode 100644
index 0000000..561b3f5
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/cli/CouscousCli.java
@@ -0,0 +1,90 @@
+package org.zwobble.couscous.cli;
+
+import org.apache.commons.cli.*;
+import org.zwobble.couscous.Backend;
+import org.zwobble.couscous.ast.ClassNode;
+import org.zwobble.couscous.backends.python.PythonBackend;
+import org.zwobble.couscous.frontends.java.JavaFrontend;
+
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.util.List;
+
+import static java.util.Arrays.asList;
+import static org.zwobble.couscous.util.ExtraLists.eagerFlatMap;
+import static org.zwobble.couscous.util.ExtraLists.eagerMap;
+import static org.zwobble.couscous.util.ExtraLists.list;
+
+public class CouscousCli {
+    public static final String SOURCEPATH = "sourcepath";
+    public static final String BACKEND = "backend";
+    public static final String OUTPUT = "output";
+
+    public static void main(String[] rawArguments) throws Exception {
+        CommandLine arguments = parseArguments(rawArguments);
+
+        JavaFrontend frontend = new JavaFrontend();
+        List<ClassNode> classNodes = eagerFlatMap(
+            arguments.getArgList(),
+            path -> {
+                try {
+                    return frontend.readSourceDirectory(
+                        eagerMap(sourcePath(arguments), sourcePath -> path(sourcePath)),
+                        path(path));
+                } catch (IOException exception) {
+                    throw new RuntimeException(exception);
+                }
+            });
+
+        Backend backend = backend(
+            arguments.getOptionValue(BACKEND),
+            arguments.getOptionValue(OUTPUT));
+        backend.compile(classNodes);
+    }
+
+    private static List<String> sourcePath(CommandLine arguments) {
+        if (arguments.hasOption(SOURCEPATH)) {
+            return asList(arguments.getOptionValues(SOURCEPATH));
+        } else {
+            return list();
+        }
+    }
+
+    private static Backend backend(String backend, String output) {
+        switch (backend) {
+            case "python":
+                return new PythonBackend(path(output), "_couscous");
+            default:
+                throw new RuntimeException("Unrecognised backend: " + backend);
+        }
+    }
+
+    private static Path path(String output) {
+        return FileSystems.getDefault().getPath(output);
+    }
+
+    private static CommandLine parseArguments(String[] rawArguments) throws ParseException {
+        Options options = new Options();
+        options.addOption(requiredOption(BACKEND));
+        options.addOption(requiredOption(OUTPUT));
+        options.addOption(multipleOption(SOURCEPATH));
+
+        return new DefaultParser().parse(options, rawArguments);
+    }
+
+    private static Option requiredOption(String name) {
+        return Option.builder()
+            .longOpt(name)
+            .required()
+            .hasArg()
+            .build();
+    }
+
+    private static Option multipleOption(String name) {
+        return Option.builder()
+            .longOpt(name)
+            .hasArgs()
+            .build();
+    }
+}