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.max
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.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.ClientChatLineReceivedEvent
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 ImagePreview : FirmamentFeature {
    override val identifier: String
        get() = "image-preview"

    object TConfig : ManagedConfig(identifier) {
        val enabled by toggle("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 screenPercentage by integer("percentage", 10, 100) { 50 }
        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://[^. ]+\\.[^ ]+(\\.(png|gif|jpe?g))(\\?[^ ]*)?( |$)".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
            }
        }
    }

    @OptIn(ExperimentalCoroutinesApi::class)
    override fun onLoad() {
        ClientChatLineReceivedEvent.subscribe {
            it.replaceWith = it.text.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)))
                        )
                    )
                    tryCacheUrl(url)
                    index = range.last + 1
                }
                s
            }
        }

        ScreenRenderPostEvent.subscribe {
            if (!TConfig.enabled) 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
            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()
        }
    }
}