package org.jetbrains.dokka

import org.jetbrains.dokka.Model.Module
import org.jetbrains.dokka.Utilities.pretty
import org.jetbrains.dokka.links.DRI
import org.jetbrains.dokka.pages.MarkdownToContentConverter
import org.jetbrains.dokka.pages.PageNode
import org.jetbrains.dokka.renderers.FileWriter
import org.jetbrains.dokka.renderers.HtmlRenderer
import org.jetbrains.dokka.resolvers.DefaultLocationProvider
import org.jetbrains.dokka.transformers.DefaultDocumentationToPageTransformer
import org.jetbrains.kotlin.cli.common.messages.CompilerMessageLocation
import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
import org.jetbrains.kotlin.cli.common.messages.MessageCollector
import org.jetbrains.kotlin.cli.common.messages.MessageRenderer
import org.jetbrains.kotlin.utils.PathUtil
import java.io.File

class DokkaGenerator(
    private val configuration: DokkaConfiguration,
    private val logger: DokkaLogger
) {
    fun generate(): Unit {
        configuration.passesConfigurations.map { pass ->
            AnalysisEnvironment(DokkaMessageCollector(logger), pass.analysisPlatform).run {
                if (analysisPlatform == Platform.jvm) {
                    addClasspath(PathUtil.getJdkClassesRootsFromCurrentJre())
                }
                for (element in pass.classpath) {
                    addClasspath(File(element))
                }

                addSources(pass.sourceRoots.map { it.path })

                loadLanguageVersionSettings(pass.languageVersion, pass.apiVersion)

                val environment = createCoreEnvironment()
                val (facade, _) = createResolutionFacade(environment)

                val markdownConverter = MarkdownToContentConverter(facade, logger)

                val module = environment.getSourceFiles().asSequence()
                    .map { it.packageFqName }
                    .distinct()
                    .mapNotNull { facade.resolveSession.getPackageFragment(it) }
                    .map { DokkaDescriptorVisitor.visitPackageFragmentDescriptor(it, DRI.topLevel) }
                    .toList()
                    .let { Module(it) }
                    .also { println("${pass.analysisPlatform}:\n${it.pretty()}\n\n") }

                DefaultDocumentationToPageTransformer(markdownConverter, logger).transform(pass, module)
            }
        }
            .merge()
            .also {
                HtmlRenderer(
                    FileWriter(configuration.outputDir, ""),
                    DefaultLocationProvider(it, configuration, ".${configuration.format}")
                ).render(it)
            }
    }
}

private fun Iterable<PageNode>.merge(): PageNode = first() // TODO: implement

private class DokkaMessageCollector(private val logger: DokkaLogger) : MessageCollector {
    override fun clear() {
        seenErrors = false
    }

    private var seenErrors = false

    override fun report(severity: CompilerMessageSeverity, message: String, location: CompilerMessageLocation?) {
        if (severity == CompilerMessageSeverity.ERROR) {
            seenErrors = true
        }
        logger.error(MessageRenderer.PLAIN_FULL_PATHS.render(severity, message, location))
    }

    override fun hasErrors() = seenErrors
}