Added "createMarkdownText" and extensions for "CaptionedMediaContent" and "TextContent"

CHANGELOG

@@ -17,3 +17,5 @@
 * Now `ForwardedMessage` contains nullable `from`
 
 ## 0.8.4
+
+* Added `createMarkdownText` and extensions for `CaptionedMediaContent` and `TextContent`

src/main/kotlin/com/github/insanusmokrassar/TelegramBotAPI/utils/CaptionSourcer.kt

@@ -0,0 +1,38 @@
+package com.github.insanusmokrassar.TelegramBotAPI.utils
+
+import com.github.insanusmokrassar.TelegramBotAPI.types.MessageEntity.MessageEntity
+import com.github.insanusmokrassar.TelegramBotAPI.types.message.content.TextContent
+import com.github.insanusmokrassar.TelegramBotAPI.types.message.content.abstracts.CaptionedMediaContent
+
+fun createMarkdownText(
+    text: String,
+    messageEntities: List<MessageEntity>
+): String {
+    val builder = StringBuilder()
+    var offset = 0
+    for (entity in messageEntities) {
+        builder.append(
+            text.substring(offset until entity.offset)
+        )
+        builder.append(
+            entity.asMarkdownSource
+        )
+        offset += entity.length
+    }
+    builder.append(
+        text.substring(offset)
+    )
+    return builder.toString()
+}
+
+fun CaptionedMediaContent.toMarkdownCaption(): String? = caption ?.let {
+    createMarkdownText(
+        it,
+        captionEntities
+    )
+}
+
+fun TextContent.toMarkdownText(): String = createMarkdownText(
+    text,
+    entities
+)