import io.ktor.client.*
import io.ktor.client.engine.cio.*
import io.ktor.client.request.*
import io.ktor.client.statement.*
import kotlinx.serialization.*
import kotlinx.serialization.descriptors.PolymorphicKind
import kotlinx.serialization.descriptors.SerialDescriptor
import kotlinx.serialization.descriptors.buildSerialDescriptor
import kotlinx.serialization.encoding.Decoder
import kotlinx.serialization.json.*
import java.io.File

@Serializable
data class NpcListData(
    val displayName: String,
    val id: NpcId,
    val tag: String? = null,
)

@Serializable
data class ListData<T>(
    val data: List<T>
)


val json = Json { ignoreUnknownKeys = true }
val ListDataPattern = "new Listview\\((.*)\\);\n".toRegex()
val NpcLocationDataPattern = "g_mapperData = (.*);\n".toRegex()
val client = HttpClient(CIO)

suspend fun getNpcList(zoneId: Int): List<NpcListData> {
    return getNpcList("https://www.wowhead.com/npcs/react-a:1?filter=6;$zoneId;0") +
            getNpcList("https://www.wowhead.com/npcs/react-a:0?filter=6;$zoneId;0") +
            getNpcList("https://www.wowhead.com/npcs/react-a:-1?filter=6;$zoneId;0")
}

suspend fun getNpcList(url: String): List<NpcListData> {
    val string =
        client.get(url).bodyAsText()
    val match = ListDataPattern.find(string)!!
    val jsonData = match.groupValues[1]
    val data = json.decodeFromString<ListData<NpcListData>>(jsonData).data
    if (data.size == 1000) {
        println("Warning: Encountered NPC limit for url $url")
    }
    return data
}

@Serializable
@JvmInline
value class ZoneId(val int: Int)

@Serializable
@JvmInline
value class MapId(val int: Int)

@Serializable
@JvmInline
value class NpcId(val int: Int)

@Serializable
data class MapCoordinates(
    val count: Int,
    val coords: List<List<Float>>,
    val uiMapId: MapId? = null,
    val uiMapName: String? = null,
)

@OptIn(InternalSerializationApi::class, ExperimentalSerializationApi::class)
object NpcZoneMapSerializer : DeserializationStrategy<Map<ZoneId, List<MapCoordinates>>> {
    override val descriptor: SerialDescriptor
        get() = buildSerialDescriptor("NpcZoneMapSerializer", PolymorphicKind.SEALED)

    override fun deserialize(decoder: Decoder): Map<ZoneId, List<MapCoordinates>> {
        val d = decoder as JsonDecoder
        val el = d.decodeJsonElement()
        el as JsonObject

        return el.mapNotNull { (t, u) ->
            if (u is JsonArray)
                ZoneId(t.toInt()) to d.json.decodeFromJsonElement<List<MapCoordinates>>(u)
            else null
        }.toMap()
    }
}

suspend fun getNpcData(id: NpcId, name: String): Map<ZoneId, List<MapCoordinates>> {
    val string = client.get("https://www.wowhead.com/npc=${id.int}/${name.replace(" ", "-").lowercase()}").bodyAsText()
    val match = NpcLocationDataPattern.find(string)!!
    val jsonData = match.groupValues[1]
    try {
        return json.decodeFromString(NpcZoneMapSerializer, jsonData)
    } finally {
        File("crash.html").writeText(string)
    }
}

@Serializable
data class CompleteNpcData(
    val metadata: NpcListData,
    val locations: Map<ZoneId, List<MapCoordinates>>,
)

@Serializable
data class AllNpcData(
    val npcData: Map<NpcId, CompleteNpcData>
)

suspend fun main() {
    val zoneIdsToScrape = listOf(13646)
    val npcsPerZone = zoneIdsToScrape.associateWith { getNpcList(it) }
    val indexedNpcIds = npcsPerZone.flatMap { it.value }.associateBy { it.id }
    val npcData = indexedNpcIds.values.associate { it.id to CompleteNpcData(it, getNpcData(it.id, it.displayName)) }
    File("database.json").writeText(json.encodeToString(npcData))
}