/*
 * SPDX-FileCopyrightText: 2023 Linnea Gräf <nea@nea.moe>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

package moe.nea.firmament.features.chat

import io.ktor.client.request.*
import io.ktor.client.statement.*
import io.ktor.utils.io.jvm.javaio.*
import java.net.URL
import java.util.*
import moe.nea.jarvis.api.Point
import kotlinx.coroutines.Deferred
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.async
import kotlin.math.min
import net.minecraft.client.gui.screen.ChatScreen
import net.minecraft.client.texture.NativeImage
import net.minecraft.client.texture.NativeImageBackedTexture
import net.minecraft.text.ClickEvent
import net.minecraft.text.HoverEvent
import net.minecraft.text.Style
import net.minecraft.text.Text
import net.minecraft.util.Formatting
import net.minecraft.util.Identifier
import moe.nea.firmament.Firmament
import moe.nea.firmament.events.ModifyChatEvent
import moe.nea.firmament.events.ScreenRenderPostEvent
import moe.nea.firmament.features.FirmamentFeature
import moe.nea.firmament.gui.config.ManagedConfig
import moe.nea.firmament.util.MC
import moe.nea.firmament.util.transformEachRecursively
import moe.nea.firmament.util.unformattedString

object ChatLinks : FirmamentFeature {
    override val identifier: String
        get() = "chat-links"

    object TConfig : ManagedConfig(identifier) {
        val enableLinks by toggle("links-enabled") { true }
        val imageEnabled by toggle("image-enabled") { true }
        val allowAllHosts by toggle("allow-all-hosts") { false }
        val allowedHosts by string("allowed-hosts") { "cdn.discordapp.com,media.discordapp.com,media.discordapp.net,i.imgur.com" }
        val actualAllowedHosts get() = allowedHosts.split(",").map { it.trim() }
        val position by position("position", 16 * 20, 9 * 20) { Point(0.0, 0.0) }
    }

    private fun isHostAllowed(host: String) =
        TConfig.allowAllHosts || TConfig.actualAllowedHosts.any { it.equals(host, ignoreCase = true) }

    private fun isUrlAllowed(url: String) = isHostAllowed(url.removePrefix("https://").substringBefore("/"))

    override val config get() = TConfig
    val urlRegex = "https://[^. ]+\\.[^ ]+(\\.?( |$))".toRegex()

    data class Image(
        val texture: Identifier,
        val width: Int,
        val height: Int,
    )

    val imageCache: MutableMap<String, Deferred<Image?>> =
        Collections.synchronizedMap(mutableMapOf<String, Deferred<Image?>>())

    private fun tryCacheUrl(url: String) {
        if (!isUrlAllowed(url)) {
            return
        }
        if (url in imageCache) {
            return
        }
        imageCache[url] = Firmament.coroutineScope.async {
            try {
                val response = Firmament.httpClient.get(URL(url))
                if (response.status.value == 200) {
                    val inputStream = response.bodyAsChannel().toInputStream(Firmament.globalJob)
                    val image = NativeImage.read(inputStream)
                    val texture = MC.textureManager.registerDynamicTexture(
                        "dynamic_image_preview",
                        NativeImageBackedTexture(image)
                    )
                    Image(texture, image.width, image.height)
                } else
                    null
            } catch (exc: Exception) {
                exc.printStackTrace()
                null
            }
        }
    }

    val imageExtensions = listOf("jpg", "png", "gif", "jpeg")
    fun isImageUrl(url: String): Boolean {
        return (url.substringAfterLast('.').lowercase() in imageExtensions)
    }

    @OptIn(ExperimentalCoroutinesApi::class)
    override fun onLoad() {
        ModifyChatEvent.subscribe {
            if (TConfig.enableLinks)
                it.replaceWith = it.replaceWith.transformEachRecursively { child ->
                    val text = child.string
                    if ("://" !in text) return@transformEachRecursively child
                    val s = Text.empty().setStyle(child.style)
                    var index = 0
                    while (index < text.length) {
                        val nextMatch = urlRegex.find(text, index)
                        if (nextMatch == null) {
                            s.append(Text.literal(text.substring(index, text.length)))
                            break
                        }
                        val range = nextMatch.groups[0]!!.range
                        val url = nextMatch.groupValues[0]
                        s.append(Text.literal(text.substring(index, range.first)))
                        s.append(
                            Text.literal(url).setStyle(
                                Style.EMPTY.withUnderline(true).withColor(
                                    Formatting.AQUA
                                ).withHoverEvent(HoverEvent(HoverEvent.Action.SHOW_TEXT, Text.literal(url)))
                                    .withClickEvent(ClickEvent(ClickEvent.Action.OPEN_URL, url))
                            )
                        )
                        if (isImageUrl(url))
                            tryCacheUrl(url)
                        index = range.last + 1
                    }
                    s
                }
        }

        ScreenRenderPostEvent.subscribe {
            if (!TConfig.imageEnabled) return@subscribe
            if (it.screen !is ChatScreen) return@subscribe
            val hoveredComponent =
                MC.inGameHud.chatHud.getTextStyleAt(it.mouseX.toDouble(), it.mouseY.toDouble()) ?: return@subscribe
            val hoverEvent = hoveredComponent.hoverEvent ?: return@subscribe
            val value = hoverEvent.getValue(HoverEvent.Action.SHOW_TEXT) ?: return@subscribe
            val url = urlRegex.matchEntire(value.unformattedString)?.groupValues?.get(0) ?: return@subscribe
            if (!isImageUrl(url)) return@subscribe
            val imageFuture = imageCache[url] ?: return@subscribe
            if (!imageFuture.isCompleted) return@subscribe
            val image = imageFuture.getCompleted() ?: return@subscribe
            it.drawContext.matrices.push()
            val pos = TConfig.position
            pos.applyTransformations(it.drawContext.matrices)
            val scale = min(1F, min((9 * 20F) / image.height, (16 * 20F) / image.width))
            it.drawContext.matrices.scale(scale, scale, 1F)
            it.drawContext.drawTexture(
                image.texture,
                0,
                0,
                1F,
                1F,
                image.width,
                image.height,
                image.width,
                image.height,
            )
            it.drawContext.matrices.pop()
        }
    }
}