import io.papermc.paperweight.util.*
import org.gradle.api.tasks.testing.logging.TestExceptionFormat
import org.gradle.api.tasks.testing.logging.TestLogEvent
import java.io.IOException
import java.net.URI
import java.nio.file.FileVisitResult
import java.nio.file.Files
import java.nio.file.SimpleFileVisitor
import kotlin.io.path.*
import java.nio.file.Path
import kotlin.random.Random

plugins {
    id("io.papermc.paperweight.core") version "2.0.0-beta.4" apply false
}

subprojects {
    apply(plugin = "java-library")
    apply(plugin = "maven-publish")

    extensions.configure<JavaPluginExtension> {
        toolchain {
            languageVersion = JavaLanguageVersion.of(21)
        }
    }

    dependencies {
        "testRuntimeOnly"("org.junit.platform:junit-platform-launcher")
    }

    tasks.withType<AbstractArchiveTask>().configureEach {
        isPreserveFileTimestamps = false
        isReproducibleFileOrder = true
    }
}

val paperMavenPublicUrl = "https://repo.papermc.io/repository/maven-public/"

subprojects {
    tasks.withType<JavaCompile> {
        options.encoding = Charsets.UTF_8.name()
        options.release = 21
        options.isFork = true
    }
    tasks.withType<Javadoc> {
        options.encoding = Charsets.UTF_8.name()
    }
    tasks.withType<ProcessResources> {
        filteringCharset = Charsets.UTF_8.name()
    }
    tasks.withType<Test> {
        testLogging {
            showStackTraces = true
            exceptionFormat = TestExceptionFormat.FULL
            events(TestLogEvent.STANDARD_OUT)
        }
    }

    repositories {
        mavenCentral()
        maven(paperMavenPublicUrl)
    }

    extensions.configure<PublishingExtension> {
        repositories {
            maven("https://repo.papermc.io/repository/maven-snapshots/") {
                name = "paperSnapshots"
                credentials(PasswordCredentials::class)
            }
        }
    }
}

tasks.register("printMinecraftVersion") {
    val mcVersion = providers.gradleProperty("mcVersion")
    doLast {
        println(mcVersion.get().trim())
    }
}

tasks.register("printPaperVersion") {
    val paperVersion = provider { project.version }
    doLast {
        println(paperVersion.get())
    }
}

tasks.register("gibWork") {
    val issue = providers.gradleProperty("updateTaskListIssue").get()
    val patchesFolder = layout.projectDirectory.dir("paper-server/patches/").convertToPath()
    val storage = layout.cache.resolve("last-updating-folder").also { it.parent.createDirectories() }

    doLast {
        val html = URI(issue).toURL().readText()

        val beginMarker = "```[tasklist]"
        val start = html.indexOf(beginMarker)
        val end = html.indexOf("```", start + beginMarker.length)
        val taskList = html.substring(start + beginMarker.length, end)

        // Extract all incomplete tasks and select a random one
        val incompleteTasks = taskList.split("\\n").filter { it.startsWith("- [ ]") }.map { it.replace("- [ ] ", "") }
        if (incompleteTasks.isEmpty()) {
            error("No incomplete tasks found in the task list.")
        }

        val next = incompleteTasks[Random.nextInt(incompleteTasks.size)]

        println("checking out $next...")
        val dir = patchesFolder.resolve("unapplied").resolve(next)
        if (!dir.exists()) {
            error("Unapplied patch folder $next does not exist, did someone else already check it out and forgot to mark it?")
        }
        dir.listDirectoryEntries("*.patch").forEach { patch ->
            patch.copyTo(patchesFolder.resolve("sources").resolve(next).resolve(patch.fileName).also { it.createDirectories() }, overwrite = true)
            patch.deleteIfExists()
        }
        if (dir.listDirectoryEntries().isEmpty()) {
            dir.deleteIfExists()
        }

        storage.writeText(next)
        println("please tick the box in the issue: $issue")
        println("if you don't finish it, uncheck the task again after you commited")
    }
}

tasks.register("showWork") {
    val patchDir = layout.projectDirectory.dir("paper-server/patches/unapplied/").convertToPath()

    doLast {
        Files.walkFileTree(patchDir, object : SimpleFileVisitor<Path>() {
            override fun postVisitDirectory(dir: Path?, exc: IOException?): FileVisitResult {
                dir?.takeIf { it.listDirectoryEntries("*.patch").isNotEmpty() }?.let {
                    println("- [ ] ${patchDir.relativize(it).pathString.replace("\\", "/")}")
                }
                return FileVisitResult.CONTINUE
            }
        })
    }
}

tasks.register("checkWork") {
    notCompatibleWithConfigurationCache("This task is interactive")
    fun expandUserHome(path: String): Path {
        return Path.of(path.replaceFirst("^~".toRegex(), System.getProperty("user.home")))
    }

    val input = layout.cache.resolve("last-updating-folder").readText().trim()
    val patchFolder = layout.projectDirectory.file("paper-server/patches/sources").convertToPath().resolve(input)
    val sourceFolder = layout.projectDirectory.file("paper-server/src/vanilla/java/").convertToPath().resolve(input)
    val targetFolder = expandUserHome(
        providers.gradleProperty("cleanPaperRepo").orNull
            ?: error("cleanPaperRepo is required, define it in gradle.properties")
    ).resolve(input)

    fun copy(back: Boolean = false) {
        patchFolder.listDirectoryEntries().forEach {
            val relative = patchFolder.relativize(it).toString().replace(".patch", "")
            val source = sourceFolder.resolve(relative)
            val target = targetFolder.resolve(relative)
            if (target.isDirectory()) { return@forEach }
            if (back) {
                target.copyTo(source, overwrite = true)
            } else {
                source.copyTo(target, overwrite = true)
            }
        }
    }

    doLast {
        copy()
        val files = patchFolder.listDirectoryEntries().map { it.fileName.toString().replace(".patch", "") }
        println("Copied $files from $sourceFolder to $targetFolder")
        println("Make the files compile, then press enter to copy them back!")
        System.`in`.read()
        copy(back = true)
        println("copied back!")
    }
}

// see gradle.properties
/*
if (providers.gradleProperty("updatingMinecraft").getOrElse("false").toBoolean()) {
    tasks.collectAtsFromPatches {
        val dir = layout.projectDirectory.dir("patches/unapplied/server")
        if (dir.path.isDirectory()) {
            extraPatchDir = dir
        }
    }
    tasks.withType<io.papermc.paperweight.tasks.RebuildGitPatches>().configureEach {
        filterPatches = false
    }
    tasks.register("continueServerUpdate", RebasePatches::class) {
        description = "Moves the next X patches from unapplied to applied, and applies them. X being the number of patches that apply cleanly, plus the terminal failure if any."
        projectDir = project.projectDir
        appliedPatches = file("patches/server")
        unappliedPatches = file("patches/unapplied/server")
        applyTaskName = "applyServerPatches"
        patchedDir = "Paper-Server"
    }
}

@UntrackedTask(because = "Does not make sense to track state")
abstract class RebasePatches : BaseTask() {
    @get:Internal
    abstract val projectDir: DirectoryProperty

    @get:InputFiles
    abstract val appliedPatches: DirectoryProperty

    @get:InputFiles
    abstract val unappliedPatches: DirectoryProperty

    @get:Input
    abstract val applyTaskName: Property<String>

    @get:Input
    abstract val patchedDir: Property<String>

    private fun unapplied(): List<Path> =
        unappliedPatches.path.listDirectoryEntries("*.patch").sortedBy { it.name }

    private fun appliedLoc(patch: Path): Path = appliedPatches.path.resolve(unappliedPatches.path.relativize(patch))

    companion object {
        val regex = Pattern.compile("Patch failed at ([0-9]{4}) (.*)")
        val continuationRegex = Pattern.compile("^\\s{1}.+\$")
        const val subjectPrefix = "Subject: [PATCH] "
    }

    @TaskAction
    fun run() {
        val patchedDirPath = projectDir.path.resolve(patchedDir.get())
        if (patchedDirPath.isDirectory()) {
            val status = Git(patchedDirPath)("status").getText()
            if (status.contains("You are in the middle of an am session.")) {
                throw PaperweightException("Cannot continue update when $patchedDirPath is in the middle of an am session.")
            }
        }

        val unapplied = unapplied()
        for (patch in unapplied) {
            patch.copyTo(appliedLoc(patch))
        }

        val out = ByteArrayOutputStream()
        val proc = ProcessBuilder()
            .directory(projectDir.path)
            .command("./gradlew", applyTaskName.get())
            .redirectErrorStream(true)
            .start()

        val f = redirect(proc.inputStream, out)

        val exit = proc.waitFor()
        f.get()

        if (exit != 0) {
            val outStr = String(out.toByteArray())
            val matcher = regex.matcher(outStr)
            if (!matcher.find()) error("Could not determine failure point")
            val failedSubjectFragment = matcher.group(2)
            val failed = unapplied.single { p ->
                p.useLines { lines ->
                    val collect = mutableListOf<String>()
                    for (line in lines) {
                        if (line.startsWith(subjectPrefix)) {
                            collect += line
                        } else if (collect.size == 1) {
                            if (continuationRegex.matcher(line).matches()) {
                                collect += line
                            } else {
                                break
                            }
                        }
                    }
                    val subjectLine = collect.joinToString("").substringAfter(subjectPrefix)
                    subjectLine.startsWith(failedSubjectFragment)
                }
            }

            // delete successful & failure point from unapplied patches dir
            for (path in unapplied) {
                path.deleteIfExists()
                if (path == failed) {
                    break
                }
            }

            // delete failed from patches dir
            var started = false
            for (path in unapplied) {
                if (path == failed) {
                    started = true
                    continue
                }
                if (started) {
                    appliedLoc(path).deleteIfExists()
                }
            }

            // Delete the build file before resetting the AM session in case it has compilation errors
            patchedDirPath.resolve("build.gradle.kts").deleteIfExists()
            // Apply again to reset the am session (so it ends on the failed patch, to allow us to rebuild after fixing it)
            val apply2 = ProcessBuilder()
                .directory(projectDir.path)
                .command("./gradlew", applyTaskName.get())
                .redirectErrorStream(true)
                .start()

            val f1 = redirect(apply2.inputStream, System.out)
            apply2.waitFor()
            f1.get()

            logger.lifecycle(outStr)
            logger.lifecycle("Patch failed at $failed; See Git output above.")
        } else {
            unapplied.forEach { it.deleteIfExists() }
            logger.lifecycle("All patches applied!")
        }

        val git = Git(projectDir.path)
        git("add", appliedPatches.path.toString() + "/*").runSilently()
        git("add", unappliedPatches.path.toString() + "/*").runSilently()
    }
}
 */