Initial commit.

src/main/kotlin/net/thauvin/erik/readingtime/ReadingTime.kt

@@ -0,0 +1,68 @@
+package net.thauvin.erik.readingtime
+
+import org.jsoup.Jsoup
+import java.math.BigDecimal
+import java.math.RoundingMode
+
+/**
+ * Calculates the reading time of the given [text].
+ *
+ * Calculation based on this [Medium's Post](https://blog.medium.com/read-time-and-you-bc2048ab620c)
+ */
+class ReadingTime(
+    var text: String,
+    var wpm: Int = 275,
+    var postfix: String = "min read",
+    var plural: String = "min read",
+    var excludeImages: Boolean = false
+) {
+    companion object {
+        @JvmStatic
+        fun wordCount(words: String): Int {
+            val s = Jsoup.parse(words).text().trim()
+            return if (s.isEmpty()) 0 else s.split("\\s+".toRegex()).size
+        }
+
+        @JvmStatic
+        fun imgCount(html: String): Int {
+            return "<img ".toRegex(RegexOption.IGNORE_CASE).findAll(html).count()
+        }
+    }
+
+    fun calcReadingTimeInSec(): Double {
+        var readingTime = 0.0
+
+        if (!excludeImages)
+            readingTime += calcImgReadingTime()
+
+        readingTime += wordCount(text) / (wpm / 60.0)
+
+        return readingTime
+    }
+
+    fun calcReadingTime(): String {
+        val readingTime = BigDecimal((calcReadingTimeInSec() / 60)).setScale(0, RoundingMode.CEILING)
+        return if (readingTime.compareTo(BigDecimal.ONE) == 1) {
+            "$readingTime $plural".trim()
+        } else {
+            "$readingTime $postfix".trim()
+        }
+    }
+
+    private fun calcImgReadingTime(): Int {
+        var imgTime = 0
+        val imgCount = imgCount(text)
+
+        var offset = 12
+        for (i in 1..imgCount) {
+            if (i > 10) {
+                imgTime += 3
+            } else {
+                imgTime += offset
+                offset--
+            }
+        }
+
+        return imgTime
+    }
+}