update JSON prettifier style

src/jvmMain/kotlin/com/sunnychung/application/multiplatform/hellohttp/manager/PrettifierManager.kt

@@ -2,6 +2,7 @@ package com.sunnychung.application.multiplatform.hellohttp.manager
 
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import com.sunnychung.application.multiplatform.hellohttp.model.ProtocolApplication
+import com.sunnychung.application.multiplatform.hellohttp.parser.JsonParser
 
 class PrettifierManager {
     private val registrations: MutableSet<PrettifierRegistration> = mutableSetOf()
@@ -17,7 +18,7 @@ class PrettifierManager {
             prettifier = Prettifier(
                 formatName = "JSON (Prettified)",
                 prettify = {
-                    jacksonObjectMapper().readTree(it).toPrettyString()
+                    JsonParser(it).prettify()
                 }
             )
         )

src/jvmMain/kotlin/com/sunnychung/application/multiplatform/hellohttp/parser/JsonParser.kt

@@ -0,0 +1,69 @@
+package com.sunnychung.application.multiplatform.hellohttp.parser
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+
+class JsonParser(jsonBytes: ByteArray) {
+    val tree = jacksonObjectMapper().readTree(jsonBytes)
+
+    constructor(json: String) : this(json.encodeToByteArray())
+
+    fun prettify(): String {
+        return buildString {
+            fun indent(level: Int) {
+                if (level > 0) {
+                    append(" ".repeat(2 * level))
+                }
+            }
+
+            fun StringBuilder.transverse(node: JsonNode, indentLevel: Int) {
+                if (node.isArray) {
+                    append('[')
+                    if (node.size() <= 20 && node.all { it.isValueNode }) {
+                        node.forEachIndexed { i, it ->
+                            if (i > 0) {
+                                append(", ")
+                            }
+                            transverse(it, 0)
+                        }
+                    } else {
+                        append("\n")
+                        node.forEachIndexed { i, it ->
+                            if (i > 0) {
+                                append(",\n")
+                            }
+                            indent(indentLevel + 1)
+                            transverse(it, indentLevel + 1)
+                        }
+                        append("\n")
+                        indent(indentLevel)
+                    }
+                    append(']')
+                } else if (node.isObject) {
+                    if (node.isEmpty) {
+                        append("{}")
+                    } else {
+                        append("{\n")
+                        node.fields().withIndex().forEach { (i, it) ->
+                            if (i > 0) {
+                                append(",\n")
+                            }
+                            indent(indentLevel + 1)
+                            append("\"${it.key}\": ")
+                            transverse(it.value, indentLevel + 1)
+                        }
+                        append("\n")
+                        indent(indentLevel)
+                        append('}')
+                    }
+                } else if (node.isValueNode) {
+                    append(node.toPrettyString())
+                } else {
+                    throw RuntimeException("what is this? -- $node")
+                }
+            }
+
+            transverse(tree, 0)
+        }
+    }
+}