package filesystem

import org.junit.jupiter.api.*
import java.nio.file.FileSystemException
import java.nio.file.Files
import java.nio.file.Path
import java.util.concurrent.TimeUnit
import kotlin.test.Test
import kotlin.test.assertEquals

class FSCreatorTest {
    private val creator = FSCreator()

    @BeforeEach
    fun `before each`() {
        assertDoesNotThrow("should create _tmp directory") {
            Files.createDirectory(Path.of("_tmp"))
        }
    }

    @AfterEach
    fun `after each`() {
        assertDoesNotThrow("should delete _tmp directory") {
            deleteRecursive(Path.of("_tmp"))
        }
    }

    @Test
    fun `create entries`() {
        val readme = FSFile("README", "Hello World!")
        val gomod = FSFile("go.mod", "module example.com/hello-world\n\ngo1.21.5")
        val maingo = FSFile("main.go", "package main\n\nimport \"example.com/hello-world/utils\"\n\n" +
            "func main() {\n\tprintln(\"Hello World!\")\n}")
        val helloworldgo = FSFile("hello-world.go", "package utils\n\nfunc PrintHelloWorld() {\n" +
            "\tprintln(\"Hello World!\")\n}")
        assertDoesNotThrow("should create entries") {
            creator.create(FSFolder("folder", listOf(
                readme,
                gomod,
                maingo,
                FSFolder("utils", listOf(
                    helloworldgo
                ))
            )), "_tmp")
        }
        // If objects don't exist, these functions will throw anyway, so don't explicitly check for existence.
        // Similarly, don't explicitly check if an object is a directory.
        assertEquals(readme.content, Files.readString(Path.of("_tmp/folder", readme.name)))
        assertEquals(gomod.content, Files.readString(Path.of("_tmp/folder", gomod.name)))
        assertEquals(maingo.content, Files.readString(Path.of("_tmp/folder", maingo.name)))
        assertEquals(helloworldgo.content, Files.readString(Path.of("_tmp/folder/utils", helloworldgo.name)))
    }

    @Test
    fun `create existing entries`() {
        assertDoesNotThrow("creation one") {
            creator.create(FSFolder("folder", listOf(
                FSFolder("sub-folder", listOf(
                    FSFile("hi", "hi")
                )),
                FSFolder("another-folder", listOf()),
                FSFile("1.txt", "One!"),
                FSFile("2.txt", "Two!")
            )), "_tmp")
        }
        assertDoesNotThrow("creation two") {
            creator.create(FSFolder("folder", listOf(
                FSFolder("another-folder", listOf(
                    FSFolder("secrets", listOf(
                        FSFile("secret", "P4ssW0rd")
                    ))
                )),
                FSFile("1.txt", "One is a good number"),
                FSFile("3.txt", "Three!")
            )), "_tmp")
        }
        assertEquals("hi", Files.readString(Path.of("_tmp/folder/sub-folder/hi")))
        assertEquals("P4ssW0rd", Files.readString(Path.of("_tmp/folder/another-folder/secrets/secret")))
        assertEquals("One is a good number", Files.readString(Path.of("_tmp/folder/1.txt")))
        assertEquals("Two!", Files.readString(Path.of("_tmp/folder/2.txt")))
        assertEquals("Three!", Files.readString(Path.of("_tmp/folder/3.txt")))
    }

    @Test
    @Timeout(500, unit = TimeUnit.MILLISECONDS) // in case implementation starts trying to handle recursion
    fun `create throws on recursive folder`() {
        val files = mutableListOf<FSEntry>()
        val folder = FSFolder("folder", files)
        files.add(folder)
        assertThrows<FileSystemException> {
            creator.create(folder, "_tmp")
        }
    }
}

fun deleteRecursive(path: Path) {
    if (Files.isDirectory(path)) {
        for (child in Files.list(path)) {
            deleteRecursive(child)
        }
    }
    Files.delete(path)
}