Find matching records in 2 text files with Binary Search Tree

matching-records-bst.kt

package matching_logs

import java.io.File

data class BinarySearchTree(
        private val data: String,
        internal var left: BinarySearchTree? = null,
        internal var right: BinarySearchTree? = null
) {
    private fun compare(s1: String, s2: String): Int {
        val name1 = s1.extractJustClassName()
        val name2 = s2.extractJustClassName()
        return name1.compareTo(name2)
    }

    fun insert(newData: String) {
        val insertData = newData.removeEndingColon()

        if (compare(insertData, this.data) >= 0) {
            if (right != null) {
                right!!.insert(insertData)
            } else {
                val leaf = BinarySearchTree(insertData)
                this.right = leaf
            }
        } else {
            if (left != null) {
                left!!.insert(insertData)
            } else {
                val leaf = BinarySearchTree(insertData)
                this.left = leaf
            }
        }
    }

    fun search(theData: String): Boolean {
        val searchData = theData.removeEndingColon()

        if (searchData == this.data) return true
        return if (compare(searchData, this.data) > 0) {
            if (right != null) {
                right!!.search(searchData)
            } else {
                false
            }
        } else {
            if (left != null) {
                left!!.search(searchData)
            } else {
                false
            }
        }
    }
}

private fun String.extractJustClassName() = substring(this.lastIndexOf("."))

private fun String.removeEndingColon(): String {
    return if (this.endsWith(":")) {
        this.substring(0, this.length - 1)
    } else {
        this
    }
}

fun main() {
    val mappingReader = File("/Users/ericn/tmp/algo/kotlin/src/matching_logs/mapping.txt").bufferedReader()
    val mappingTree = BinarySearchTree("com.myawesomeapp.ghafaewafe") // hopefully the tree will be balance
    mappingReader.lines().forEach {
        if (it.startsWith("com.myawesomeapp") && !it.contains("$") && !it.contains("_")) {
            val arrowIndex = it.indexOf("->")
            mappingTree.insert(it.substring(0, arrowIndex - 1))
        }
    }

    val usageReader = File("/Users/ericn/tmp/algo/kotlin/src/matching_logs/usage.txt").bufferedReader()
    val unusedClasses = mutableListOf<String>()
    val usedClasses = mutableListOf<String>()
    usageReader.lines().forEach {
        if (it.startsWith("com.myawesomeapp") && !it.contains("$") && !it.contains("_") && !it.endsWith(".R") && !it.endsWith(".R:") && !it.endsWith("Binding") && !it.endsWith("BuildConfig") && !it.contains("Test")) {
            if (mappingTree.search(it)) {
                usedClasses.add(it)
            } else {
                unusedClasses.add(it)
            }
        }
    }
}