File Fundamentals

import java.io.File
import java.nio.file.Path
import java.nio.file.Paths
import java.nio.file.Files
import java.nio.file.attribute.FileTime
import java.time.Instant

const val DEMO_DIR = "/tmp/kotlin-tutorial-file-fundamentals"

fun main() {
    // Bersihkan dir demo jika ada dari run sebelumnya
    File(DEMO_DIR).deleteRecursively()
    File(DEMO_DIR).mkdirs()

    println("=== 1. java.io.File: representasi file teks ===")
    val fileA = File("data/contoh.txt")
    println("path = ${fileA.path}")
    println("parent = ${fileA.parent}")
    println("name = ${fileA.name}")
    println("extension = ${fileA.extension}")
    println("nameWithoutExtension = ${fileA.nameWithoutExtension}")

    println()
    println("=== 2. java.nio.file.Path: representasi modern ===")
    val pathA: Path = Paths.get("data/contoh.txt")
    println("toString = $pathA")
    println("fileName = ${pathA.fileName}")
    println("parent = ${pathA.parent}")
    println("root = ${pathA.root}")

    println()
    println("=== 3. Membuat file demo di direktori tetap ===")
    val fileDemo = File("$DEMO_DIR/catatan.txt")
    fileDemo.writeText("baris pertama")
    println("fileDemo.path (relatif terhadap dir demo) = ${File(fileDemo.parentFile.name, fileDemo.name).path}")
    println("fileDemo.absolutePath = <tmp>/${fileDemo.parentFile.name}/${fileDemo.name}")

    println()
    println("=== 4. Properti umum: exists, isDirectory, isFile, length ===")
    println("exists = ${fileDemo.exists()}")
    println("isDirectory = ${fileDemo.isDirectory}")
    println("isFile = ${fileDemo.isFile}")
    println("length (bytes) = ${fileDemo.length()}")

    println()
    println("=== 5. lastModified: waktu modifikasi terakhir (di-set eksplisit) ===")
    val waktuTetap = Instant.parse("2026-01-15T08:30:00Z").toEpochMilli()
    fileDemo.setLastModified(waktuTetap)
    val lastMod = FileTime.from(Instant.ofEpochMilli(fileDemo.lastModified()))
    println("lastModified (FileTime) = ${lastMod.toString().substringBefore('.')}")

    println()
    println("=== 6. Direktori vs File ===")
    val dirDemo = File(DEMO_DIR)
    println("dirDemo.isDirectory = ${dirDemo.isDirectory}")
    println("fileDemo.isDirectory = ${fileDemo.isDirectory}")
    println("dirDemo.name = ${dirDemo.name}")

    println()
    println("=== 7. File vs Path: kapan memakai yang mana ===")
    val dariFile: Path = fileDemo.toPath()  // konversi File -> Path
    val dariPath: File = pathA.toFile()     // konversi Path -> File
    println("File.toPath().fileName = ${dariFile.fileName}")
    println("Path.toFile().name = ${dariPath.name}")
    println("Path.toFile().exists (file 'data/contoh.txt' belum dibuat) = ${dariPath.exists()}")

    println()
    println("=== 8. Bersih-bersih ===")
    fileDemo.delete()
    println("fileDemo.exists setelah delete = ${fileDemo.exists()}")
    dirDemo.delete()
    println("dirDemo.exists setelah delete = ${dirDemo.exists()}")
}

=== 1. java.io.File: representasi file teks ===
path = data/contoh.txt
parent = data
name = contoh.txt
extension = txt
nameWithoutExtension = contoh

=== 2. java.nio.file.Path: representasi modern ===
toString = data/contoh.txt
fileName = contoh.txt
parent = data
root = null

=== 3. Membuat file demo di direktori tetap ===
fileDemo.path (relatif terhadap dir demo) = kotlin-tutorial-file-fundamentals/catatan.txt
fileDemo.absolutePath = <tmp>/kotlin-tutorial-file-fundamentals/catatan.txt

=== 4. Properti umum: exists, isDirectory, isFile, length ===
exists = true
isDirectory = false
isFile = true
length (bytes) = 13

=== 5. lastModified: waktu modifikasi terakhir (di-set eksplisit) ===
lastModified (FileTime) = 2026-01-15T08:30:00Z

=== 6. Direktori vs File ===
dirDemo.isDirectory = true
fileDemo.isDirectory = false
dirDemo.name = kotlin-tutorial-file-fundamentals

=== 7. File vs Path: kapan memakai yang mana ===
File.toPath().fileName = catatan.txt
Path.toFile().name = contoh.txt
Path.toFile().exists (file 'data/contoh.txt' belum dibuat) = false

=== 8. Bersih-bersih ===
fileDemo.exists setelah delete = false
dirDemo.exists setelah delete = false