From 69bc6c2ae35883286d9c2b8cc77d5fa0a8c37351 Mon Sep 17 00:00:00 2001
From: pacien
Date: Thu, 26 Jul 2018 11:34:06 +0200
Subject: Kotlin rewrite, adding diagram options

---
 .../org/pacien/pandoc/filter/plantuml/Filter.kt    | 57 ++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 src/main/kotlin/org/pacien/pandoc/filter/plantuml/Filter.kt

(limited to 'src/main/kotlin/org/pacien/pandoc/filter/plantuml/Filter.kt')

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)
+    }
+  }
+}
-- 
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