14 files changed, 173 insertions, 112 deletions

diff --git a/src/main/java/org/pacien/pandoc/filter/plantuml/Filter.java b/src/main/java/org/pacien/pandoc/filter/plantuml/Filter.java
deleted file mode 100644
index 66abc2d..0000000
--- a/src/main/java/org/pacien/pandoc/filter/plantuml/Filter.java
+++ /dev/null
@@ -1,84 +0,0 @@
-package org.pacien.pandoc.filter.plantuml;
-
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.node.ArrayNode;
-import com.fasterxml.jackson.databind.node.ObjectNode;
-import com.fasterxml.jackson.databind.node.TextNode;
-import net.sourceforge.plantuml.FileFormat;
-import net.sourceforge.plantuml.FileFormatOption;
-import net.sourceforge.plantuml.SourceStringReader;
-
-import java.io.*;
-import java.util.Iterator;
-import java.util.stream.Collectors;
-
-final public class Filter {
-
-  private static final String BEGIN_TAG = "\\begin{tikzpicture}[yscale=-1]";
-  private static final String LINE_SEP = "\n";
-  private static final String TYPE_KEY = "t";
-  private static final String CONTENT_KEY = "c";
-  private static final String CODE_BLOCK_TYPE = "CodeBlock";
-  private static final String RAW_BLOCK_TYPE = "RawBlock";
-  private static final String PLANTUML_TYPE = "puml";
-  private static final String LATEX_TYPE = "latex";
-  private static final int META_INDEX = 0;
-  private static final int META_PROP_INDEX = 1;
-  private static final int META_PROP_TYPE_INDEX = 0;
-  private static final int CONTENT_INDEX = 1;
-
-  private static String plantumlToLatex(String puml) throws IOException {
-    try (ByteArrayOutputStream s = new ByteArrayOutputStream()) {
-      new SourceStringReader(puml).generateImage(s, new FileFormatOption(FileFormat.LATEX_NO_PREAMBLE));
-      try (BufferedReader r = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(s.toByteArray())))) {
-        return BEGIN_TAG + LINE_SEP + r.lines().filter(l -> !l.equals(BEGIN_TAG)).collect(Collectors.joining(LINE_SEP));
-      }
-    }
-  }
-
-  private static void renderPlantumlNode(ObjectNode n) throws IOException {
-    String puml = n.get(CONTENT_KEY).get(CONTENT_INDEX).asText();
-    String tikz = plantumlToLatex(puml);
-
-    n.set(TYPE_KEY, TextNode.valueOf(RAW_BLOCK_TYPE));
-    ((ArrayNode) n.get(CONTENT_KEY)).removeAll()
-    .add(TextNode.valueOf(LATEX_TYPE))
-    .add(TextNode.valueOf(tikz));
-  }
-
-  private static boolean isPlantumlNode(JsonNode n) {
-    return n.path(TYPE_KEY).asText().equals(CODE_BLOCK_TYPE) &&
-           n.path(CONTENT_KEY).path(META_INDEX).path(META_PROP_INDEX).path(META_PROP_TYPE_INDEX).asText().equals(PLANTUML_TYPE);
-  }
-
-  private static void walk(JsonNode n) throws IOException {
-    if (isPlantumlNode(n))
-      renderPlantumlNode((ObjectNode) n);
-    else if (n.isContainerNode())
-      for (Iterator<JsonNode> i = n.elements(); i.hasNext(); ) walk(i.next());
-  }
-
-  public static void filter(InputStream i, OutputStream o) throws IOException {
-    ObjectMapper m = new ObjectMapper();
-    JsonNode t = m.readTree(i);
-    if (t != null) {
-      walk(t);
-      m.writeValue(o, t);
-    }
-  }
-
-  public static void main(String args[]) {
-    try {
-      filter(System.in, System.out);
-    } catch (IOException e) {
-      e.printStackTrace();
-      System.exit(1);
-    }
-  }
-
-  private Filter() {
-    // static class
-  }
-
-}
diff --git a/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Filter.kt b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Filter.kt
new file mode 100644
index 0000000..82a78b5
--- /dev/null
+++ b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Filter.kt
@@ -0,0 +1,57 @@
+package org.pacien.pandoc.filter.plantuml
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.node.ArrayNode
+import com.fasterxml.jackson.databind.node.ObjectNode
+import com.fasterxml.jackson.databind.node.TextNode
+import java.io.InputStream
+import java.io.OutputStream
+
+object Filter {
+  private val mapper = ObjectMapper()
+
+  private inline fun <T> T.conditionally(condition: Boolean, block: (T) -> T): T =
+    if (condition) block(this) else this
+
+  private inline fun <T, A> T.withNonNull(value: A?, block: (T, A) -> T): T =
+    if (value != null) block(this, value) else this
+
+  private fun JsonNode.isCodeBlock() = type() == "CodeBlock"
+  private fun JsonNode.isPlantUmlBlock() = isCodeBlock() && "puml" in classNames()
+
+  private fun Latex.resizeBox(attrs: Map<String, String>) =
+    resizeBox(attrs["width"] ?: "!", attrs["height"] ?: "!")
+
+  private fun Latex.setOptions(classes: List<String>, attrs: Map<String, String>) =
+    this
+      .conditionally("width" in attrs || "height" in attrs) { it -> it.resizeBox(attrs) }
+      .conditionally("centered" in classes, Latex::centering)
+      .withNonNull(attrs["caption"], Latex::caption)
+      .withNonNull(attrs["label"], Latex::label)
+      .conditionally("caption" in attrs || "label" in attrs, Latex::figure)
+
+  private fun arrayNodeOf(type: String, content: String): ArrayNode =
+    mapper.createArrayNode()
+      .add(TextNode.valueOf(type))
+      .add(TextNode.valueOf(content))
+
+  private fun renderPlantumlNode(node: ObjectNode) {
+    val puml = node.content()
+    val tikz = PlantUml.renderTikz(puml)
+    val block = tikz.setOptions(node.classNames(), node.attributeMap())
+    node.setBlock("RawBlock", arrayNodeOf("latex", block.raw()))
+  }
+
+  private fun walk(node: JsonNode): Unit = when {
+    node.isPlantUmlBlock() -> renderPlantumlNode(node as ObjectNode)
+    else -> node.forEach(Filter::walk)
+  }
+
+  fun filter(input: InputStream, output: OutputStream) {
+    mapper.readTree(input)?.let { tree ->
+      walk(tree)
+      mapper.writeValue(output, tree)
+    }
+  }
+}
diff --git a/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Latex.kt b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Latex.kt
new file mode 100644
index 0000000..48ce087
--- /dev/null
+++ b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Latex.kt
@@ -0,0 +1,16 @@
+package org.pacien.pandoc.filter.plantuml
+
+fun Sequence<String>.toLatex() = Latex(this)
+
+class Latex(private val body: Sequence<String>) {
+  fun raw() = body.filterNot(String::isEmpty).joinToString("\n")
+
+  private fun surround(prefix: String, suffix: String) =
+    Latex(sequenceOf(prefix) + body + sequenceOf(suffix))
+
+  fun resizeBox(width: String, height: String) = surround("\\resizebox{$width}{$height}{", "}")
+  fun centering() = surround("\\centering", "")
+  fun label(label: String) = surround("", "\\label{$label}")
+  fun caption(caption: String) = surround("", "\\caption{$caption}")
+  fun figure() = surround("\\begin{figure}[h]", "\\end{figure}")
+}
diff --git a/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Main.kt b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Main.kt
new file mode 100644
index 0000000..1ebe8f9
--- /dev/null
+++ b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/Main.kt
@@ -0,0 +1,5 @@
+package org.pacien.pandoc.filter.plantuml
+
+fun main(args: Array<String>) {
+  Filter.filter(System.`in`, System.out)
+}
diff --git a/src/main/kotlin/org/pacien/pandoc/filter/plantuml/PandocNode.kt b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/PandocNode.kt
new file mode 100644
index 0000000..8b3ddde
--- /dev/null
+++ b/src/main/kotlin/org/pacien/pandoc/filter/plantuml/PandocNode.kt
@@ -0,0 +1,30 @@
+package org.pacien.pandoc.filter.plantuml
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.node.ObjectNode
+import com.fasterxml.jackson.databind.node.TextNode
+
+// Structure of a content node:
+// {