package org.the_jk.cleversync

import com.google.common.truth.Truth.assertThat
import org.junit.Assert
import org.junit.Assume
import org.junit.Test
import org.the_jk.cleversync.io.Directory
import org.the_jk.cleversync.io.Link
import org.the_jk.cleversync.io.ModifiableLink
import org.the_jk.cleversync.io.ModifiableTree
import java.io.IOException

abstract class TreeAbstractTest {
    protected lateinit var tree: ModifiableTree

    @Test
    open fun empty() {
        val content = tree.list()
        assertThat(content.directories).isEmpty()
        assertThat(content.files).isEmpty()
        assertThat(content.links).isEmpty()
    }

    @Test
    open fun emptyLive() {
        val liveContent = tree.liveList()
        onMain {
            val content = liveContent.safeValue()
            assertThat(content?.directories).isEmpty()
            assertThat(content?.files).isEmpty()
            assertThat(content?.links).isEmpty()
        }
    }

    @Test
    open fun createDirectory() {
        val foo = tree.createDirectory("foo")
        assertThat(foo.name).isEqualTo("foo")
        val fooContent = foo.list()
        assertThat(fooContent.directories).isEmpty()
        assertThat(fooContent.files).isEmpty()
        assertThat(fooContent.links).isEmpty()
        val content = tree.list()
        assertThat(content.directories).contains(foo)
        assertThat(content.files).isEmpty()
        assertThat(content.links).isEmpty()
    }

    @Test
    open fun createDirectoryAlreadyExists() {
        tree.createDirectory("foo")
        tree.createFile("bar").write().use { it.write(0) }
        if (supportSymlinks()) {
            tree.createLink("fum", "does-not-exist")
        }
        Assert.assertThrows(IOException::class.java) {
            tree.createDirectory("foo")
        }
        Assert.assertThrows(IOException::class.java) {
            tree.createDirectory("bar")
        }
        if (supportSymlinks()) {
            Assert.assertThrows(IOException::class.java) {
                tree.createDirectory("fum")
            }
        }
    }

    @Test(timeout = 10000)
    open fun observeCreateDirectory() {
        val content = tree.liveList()
        // Only accessed on main thread
        var dir: Directory? = null
        onMain {
            content.observeForever {
                if (it.directories.size == 1) dir = it.directories[0]
            }
        }
        tree.createDirectory("foo")
        onMain {
            while (dir == null) {
                idle()
            }
            assertThat(dir?.name).isEqualTo("foo")
        }
    }

    @Test
    open fun createFile() {
        val foo = tree.createFile("foo")
        // Files are not created until you write to them.
        assertThat(tree.list().files).isEmpty()
        foo.write().use { os ->
            os.write(byteArrayOf(1, 2, 3, 4))
        }
        assertThat(tree.list().files).contains(foo)
        assertThat(foo.size).isEqualTo(4.toULong())
        foo.read().use {
            assertThat(it.readBytes()).isEqualTo(byteArrayOf(1, 2, 3, 4))
        }
    }

    @Test
    open fun createFileAlreadyExists() {
        tree.createDirectory("foo")
        tree.createFile("bar").write().use { it.write(0) }
        if (supportSymlinks()) {
            tree.createLink("fum", "does-not-exist")
        }
        Assert.assertThrows(IOException::class.java) {
            tree.createFile("foo")
        }
        Assert.assertThrows(IOException::class.java) {
            tree.createFile("bar")
        }
        if (supportSymlinks()) {
            Assert.assertThrows(IOException::class.java) {
                tree.createFile("fum")
            }
        }
    }

    @Test
    open fun overwriteFile() {
        val foo = tree.createFile("foo")
        foo.write().use { os ->
            os.write(byteArrayOf(1, 2, 3, 4))
        }
        foo.write().use { os ->
            os.write(127)
            os.write(byteArrayOf(1))
            os.write(byteArrayOf(2), 0, 0)
        }
        assertThat(foo.size).isEqualTo(2.toULong())
        assertThat(tree.list().files).hasSize(1)
        foo.read().use {
            assertThat(it.readBytes()).isEqualTo(byteArrayOf(127, 1))
        }
    }

    @Test
    open fun removeDir() {
        tree.createDirectory("foo")
        assertThat(tree.removeDirectory("foo")).isTrue()
        assertThat(tree.list().directories).isEmpty()
    }

    @Test(timeout = 10000)
    open fun removeDirLive() {
        tree.createDirectory("foo")
        val content = tree.liveList()
        // Only accessed on main
        var done = false
        onMain {
            content.observeForever {
                if (it.directories.isEmpty()) done = true
            }
        }
        assertThat(tree.removeDirectory("foo")).isTrue()
        onMain {
            while (!done) {
                idle()
            }
        }
    }

    @Test
    open fun createLink() {
        Assume.assumeTrue(supportSymlinks())

        val dir = tree.createDirectory("dir")
        val file = tree.createFile("file")
        val link = tree.createLink("link", dir.name)
        var target = link.resolve()
        when (target) {
            is Link.DirectoryTarget -> {
                assertThat(target.directory).isEqualTo(dir)
                assertThat(target.path).isEqualTo("dir")
            }
            is Link.FileTarget -> Assert.fail()
            is Link.NoTarget -> Assert.fail()
        }
        assertThat(tree.openDir("link")?.name).isAnyOf("dir", "link")

        link.target(file)
        target = link.resolve()
        when (target) {
            is Link.DirectoryTarget -> Assert.fail()
            is Link.FileTarget -> Assert.fail()
            is Link.NoTarget -> assertThat(target.path).isEqualTo("file")
        }
        file.write().use { it.write(1) }
        target = link.resolve()
        when (target) {
            is Link.DirectoryTarget -> Assert.fail()
            is Link.FileTarget -> {
                assertThat(target.file).isEqualTo(file)
                assertThat(target.path).isEqualTo("file")
            }
            is Link.NoTarget -> Assert.fail()
        }

        assertThat(tree.openFile("link")?.name).isAnyOf("file", "link")
    }

    @Test
    open fun createLinkAlreadyExists() {
        Assume.assumeTrue(supportSymlinks())

        tree.createDirectory("foo")
        tree.createFile("bar").write().use { it.write(0) }
        tree.createLink("fum", "does-not-exist")
        Assert.assertThrows(IOException::class.java) {
            tree.createLink("foo", "test")
        }
        Assert.assertThrows(IOException::class.java) {
            tree.createLink("bar", "test")
        }
        Assert.assertThrows(IOException::class.java) {
            tree.createLink("fum", "test")
        }
    }

    @Test
    open fun createLinkSubdir() {
        Assume.assumeTrue(supportSymlinks())

        val foo = tree.createDirectory("foo")
        val bar = foo.createDirectory("bar")
        val link1 = tree.createLink("link1", "foo/bar")
        val link2 = tree.createLink("link2", bar)
        assertThat(link1.resolve()).isEqualTo(link2.resolve())
        when (val target = link1.resolve()) {
            is Link.DirectoryTarget -> {
                assertThat(target.directory).isEqualTo(bar)
                assertThat(target.path).isEqualTo("foo/bar")
            }
            else -> Assert.fail()
        }
        val link3 = foo.createLink("link3", "../link1")
        when (val target = link3.resolve()) {
            is Link.DirectoryTarget -> {
                assertThat(target.directory).isEqualTo(bar)
                assertThat(target.path).isEqualTo("../link1")
            }
            else -> Assert.fail()
        }
    }

    @Test(timeout = 10000)
    open fun createLiveLink() {
        Assume.assumeTrue(supportSymlinks())

        val content = tree.liveList()
        // Only accessed on main
        var link: Link? = null
        onMain {
            content.observeForever {
                if (it.links.size == 1) link = it.links[0]
            }
        }
        val dir = tree.createDirectory("dir")
        tree.createLink("link", "dir")
        onMain {
            while (link == null) {
                idle()
            }
            assertThat((link?.resolve() as Link.DirectoryTarget).directory).isEqualTo(
                dir
            )
        }
    }

    @Test
    open fun sameDir() {
        val dir1 = tree.createDirectory("dir")
        val dir2 = tree.openDir("dir")
        assertThat(dir1).isEqualTo(dir2)
        assertThat(dir1.hashCode()).isEqualTo(dir2.hashCode())
        assertThat(dir1.toString()).isEqualTo(dir2.toString())
    }

    @Test
    open fun sameFile() {
        val file1 = tree.createFile("file")
        file1.write().use { it.write(127) }
        val file2 = tree.openFile("file")
        assertThat(file1).isEqualTo(file2)
        assertThat(file1.hashCode()).isEqualTo(file2.hashCode())
        assertThat(file1.toString()).isEqualTo(file2.toString())
    }

    @Test
    open fun sameLink() {
        Assume.assumeTrue(supportSymlinks())

        val link1 = tree.createLink("link", "foo")
        val link2 = tree.openLink("link")
        assertThat(link1).isEqualTo(link2)
        assertThat(link1.hashCode()).isEqualTo(link2.hashCode())
        assertThat(link1.toString()).isEqualTo(link2.toString())
    }

    @Test
    open fun removeDirWithContent() {
        val foo = tree.createDirectory("foo")
        foo.createDirectory("dir")
        foo.createFile("file").write().use { it.write(byteArrayOf(1, 2, 3, 4)) }
        if (supportSymlinks()) {
            foo.createLink("link", "file")
        }
        assertThat(tree.list().directories).hasSize(1)
        assertThat(tree.removeDirectory("foo")).isTrue()
        assertThat(tree.list().directories).isEmpty()
    }

    @Test
    open fun removeWrongType() {
        tree.createDirectory("dir")
        assertThat(tree.removeFile("dir")).isFalse()
        assertThat(tree.removeLink("dir")).isFalse()
        tree.createFile("file").write().use { it.write(byteArrayOf(1, 2, 3, 4)) }
        assertThat(tree.removeDirectory("file")).isFalse()
        assertThat(tree.removeLink("file")).isFalse()
        if (supportSymlinks()) {
            tree.createLink("link", "doesn't exist")
            assertThat(tree.removeDirectory("link")).isFalse()
            assertThat(tree.removeFile("link")).isFalse()
        }
        val content = tree.list()
        assertThat(content.directories).hasSize(1)
        assertThat(content.files).hasSize(1)
        if (supportSymlinks()) {
            assertThat(content.links).hasSize(1)
        }
    }

    @Test
    open fun removeFile() {
        tree.createFile("file").write().use { it.write(byteArrayOf(1, 2, 3, 4)) }
        assertThat(tree.list().files).hasSize(1)
        assertThat(tree.removeFile("file")).isTrue()
        assertThat(tree.list().files).isEmpty()
    }

    @Test
    open fun removeLink() {
        Assume.assumeTrue(supportSymlinks())

        val dir = tree.createDirectory("dir")
        val file = tree.createFile("file")
        file.write().use { it.write(127) }
        tree.createLink("link1", dir)
        tree.createLink("link2", file)
        assertThat(tree.list().links).hasSize(2)
        assertThat(tree.removeLink("link1")).isTrue()
        assertThat(tree.removeLink("link2")).isTrue()
        assertThat(tree.list().links).isEmpty()
    }

    @Test
    open fun changeLink() {
        Assume.assumeTrue(supportSymlinks())

        val dir = tree.createDirectory("dir")
        val file = tree.createFile("file")
        file.write().use { it.write(127) }
        val link = tree.createLink("link", "doesn't exist")
        assertThat(link.resolve() is Link.NoTarget).isTrue()
        link.target(file)
        assertThat((link.resolve() as Link.FileTarget).file).isEqualTo(file)
        link.target(dir)
        assertThat((link.resolve() as Link.DirectoryTarget).directory).isEqualTo(dir)
        link.target("bad")
        assertThat(link.resolve() is Link.NoTarget).isTrue()
    }

    @Test
    open fun changeModifiableLink() {
        Assume.assumeTrue(supportSymlinks())

        val dir = tree.createDirectory("dir")
        val file = tree.createFile("file")
        file.write().use { it.write(127) }
        val link = tree.createLink("link", "doesn't exist")
        assertThat(link.modifiableResolve() is ModifiableLink.NoTarget).isTrue()
        link.target(file)
        assertThat((link.modifiableResolve() as ModifiableLink.ModifiableFileTarget).file).isEqualTo(file)
        link.target(dir)
        assertThat((link.modifiableResolve() as ModifiableLink.ModifiableDirectoryTarget).directory).isEqualTo(dir)
        link.target("bad")
        assertThat(link.modifiableResolve() is ModifiableLink.NoTarget).isTrue()
    }

    @Test
    open fun recursiveLink() {
        Assume.assumeTrue(supportSymlinks())

        val link = tree.createLink("link", "link")
        assertThat(link.resolve() is Link.NoTarget).isTrue()
    }

    @Test
    open fun names() {
        assertThat(tree.createDirectory("dir").name).isEqualTo("dir")
        assertThat(tree.createFile("file").name).isEqualTo("file")
        if (supportSymlinks()) {
            assertThat(tree.createLink("link", "file").name).isEqualTo("link")
        }
    }

    @Test
    open fun openNonExistent() {
        assertThat(tree.openDir("dir")).isNull()
        assertThat(tree.openFile("file")).isNull()
        assertThat(tree.openLink("link")).isNull()
    }

    @Test
    open fun lastModified() {
        val file = tree.createFile("foo")
        file.write().use { it.write(1) }
        val old = file.lastModified
        file.write().use { it.write(2); it.flush() }
        val new = file.lastModified
        assertThat(old.isBefore(new) || old == new).isTrue()
    }

    @Test
    open fun unicodeFilename() {
        val file = tree.createFile("r\u00E4ksm\u00f6rg\u00E4s")
        file.write().use { it.write("Delicious".toByteArray()) }
        val dir = tree.createDirectory("\uD83D\uDCA9")

        val content = tree.list()
        assertThat(content.directories).hasSize(1)
        assertThat(content.directories[0].name).isEqualTo(dir.name)
        assertThat(content.files).hasSize(1)
        assertThat(content.files[0].name).isEqualTo(file.name)
    }

    @Test
    open fun openDirInDir() {
        val foo = tree.createDirectory("foo")
        val bar = foo.createDirectory("bar")
        val fooBar = tree.openDir("foo/bar")
        assertThat(fooBar).isEqualTo(bar)
    }

    @Test
    open fun openFileInDir() {
        val foo = tree.createDirectory("foo")
        val bar = foo.createFile("bar")
        bar.write().use { it.write(1) }
        val fooBar = tree.openFile("foo/bar")
        assertThat(fooBar).isEqualTo(bar)
    }

    @Test
    open fun createDirInDir() {
        val foo = tree.createDirectory("foo")
        val fooBar = tree.createDirectory("foo/bar")
        val bar = foo.openDir("bar")
        assertThat(bar).isEqualTo(fooBar)
    }

    @Test
    open fun createFileInDir() {
        val foo = tree.createDirectory("foo")
        val fooBar = tree.createFile("foo/bar")
        fooBar.write().use { it.write(1) }
        val bar = foo.openFile("bar")
        assertThat(bar).isEqualTo(fooBar)
    }

    @Test
    open fun removeDirInDir() {
        val foo = tree.createDirectory("foo")
        foo.createDirectory("bar")
        assertThat(tree.removeDirectory("foo/bar")).isTrue()
        assertThat(foo.list().directories).isEmpty()
    }

    @Test
    open fun removeFileInDir() {
        val foo = tree.createDirectory("foo")
        val bar = foo.createFile("bar")
        bar.write().use { it.write(1) }
        assertThat(tree.removeFile("foo/bar")).isTrue()
        assertThat(foo.list().files).isEmpty()
    }

    protected abstract fun supportSymlinks(): Boolean

    protected abstract fun idle()

    protected open fun onMain(block: () -> Unit) {
        block.invoke()
    }
}