package org.jetbrains.dokka.templates

import org.jetbrains.dokka.DokkaConfiguration
import org.jetbrains.dokka.base.templating.Command
import org.jetbrains.dokka.base.templating.parseJson
import org.jetbrains.dokka.plugability.DokkaContext
import org.jetbrains.dokka.plugability.plugin
import org.jetbrains.dokka.plugability.query
import org.jsoup.Jsoup
import org.jsoup.nodes.Element
import java.io.File
import java.nio.file.Files

class DirectiveBasedHtmlTemplateProcessingStrategy(private val context: DokkaContext) : TemplateProcessingStrategy {

    private val directiveBasedCommandHandlers =
        context.plugin<TemplatingPlugin>().query { directiveBasedCommandHandlers }

    override fun process(input: File, output: File, moduleContext: DokkaConfiguration.DokkaModuleDescription?): Boolean =
        if (input.isFile && input.extension == "html") {
            val document = Jsoup.parse(input, "UTF-8")
            document.outputSettings().indentAmount(0).prettyPrint(false)
            document.select("dokka-template-command").forEach {
                handleCommand(it, parseJson(it.attr("data")), input, output)
            }
            Files.write(output.toPath(), listOf(document.outerHtml()))
            true
        } else false

    fun handleCommand(element: Element, command: Command, input: File, output: File) {
        val handlers = directiveBasedCommandHandlers.filter { it.canHandle(command) }
        if (handlers.isEmpty())
            context.logger.warn("Unknown templating command $command")
        else
            handlers.forEach { it.handleCommand(element, command, input, output) }

    }

    override fun finish(output: File) {
        directiveBasedCommandHandlers.forEach { it.finish(output) }
    }
}