package net.pterodactylus.sone.web.pages

import freenet.support.api.Bucket
import net.pterodactylus.sone.text.TextFilter
import net.pterodactylus.sone.utils.emptyToNull
import net.pterodactylus.sone.utils.headers
import net.pterodactylus.sone.utils.isPOST
import net.pterodactylus.sone.utils.parameters
import net.pterodactylus.sone.utils.use
import net.pterodactylus.sone.web.WebInterface
import net.pterodactylus.sone.web.page.FreenetRequest
import net.pterodactylus.util.template.Template
import net.pterodactylus.util.template.TemplateContext
import java.awt.image.BufferedImage
import java.io.ByteArrayInputStream
import java.io.ByteArrayOutputStream
import javax.imageio.ImageIO

/**
 * Page implementation that lets the user upload an image.
 */
class UploadImagePage(template: Template, webInterface: WebInterface):
		SoneTemplatePage("uploadImage.html", template, "Page.UploadImage.Title", webInterface, true) {

	override fun handleRequest(freenetRequest: FreenetRequest, templateContext: TemplateContext) {
		if (freenetRequest.isPOST) {
			val parentAlbum = freenetRequest.parameters["parent"]!!.let(webInterface.core::getAlbum) ?: throw RedirectException("noPermission.html")
			if (parentAlbum.sone != getCurrentSone(freenetRequest.toadletContext)) {
				throw RedirectException("noPermission.html")
			}
			val title = freenetRequest.parameters["title", 200].emptyToNull ?: throw RedirectException("emptyImageTitle.html")

			val uploadedFile = freenetRequest.httpRequest.getUploadedFile("image")
			val bytes = uploadedFile.data.use { it.toByteArray() }
			val bufferedImage = bytes.toImage()
			if (bufferedImage == null) {
				templateContext["messages"] = webInterface.l10n.getString("Page.UploadImage.Error.InvalidImage")
				return
			}

			val temporaryImage = webInterface.core.createTemporaryImage(bytes.mimeType, bytes)
			webInterface.core.createImage(getCurrentSone(freenetRequest.toadletContext), parentAlbum, temporaryImage).modify().apply {
				setWidth(bufferedImage.width)
				setHeight(bufferedImage.height)
				setTitle(title)
				setDescription(TextFilter.filter(freenetRequest.headers["Host"], freenetRequest.parameters["description", 4000]))
			}.update()
			throw RedirectException("imageBrowser.html?album=${parentAlbum.id}")
		}
	}

	private fun Bucket.toByteArray(): ByteArray = ByteArrayOutputStream(size().toInt()).use { outputStream ->
		inputStream.copyTo(outputStream)
		outputStream.toByteArray()
	}

	private fun ByteArray.toImage(): BufferedImage? = ByteArrayInputStream(this).use {
		ImageIO.read(it)
	}

	private val ByteArray.mimeType get() = ByteArrayInputStream(this).use {
		ImageIO.createImageInputStream(it).use {
			ImageIO.getImageReaders(it).asSequence()
					.firstOrNull()?.originatingProvider?.mimeTypes?.firstOrNull()
					?: UNKNOWN_MIME_TYPE
		}
	}

}

private const val UNKNOWN_MIME_TYPE = "application/octet-stream"