@file:OptIn(ExperimentalTime::class, ExperimentalSerializationApi::class)

package demo.timebug

import com.mongodb.kotlin.client.coroutine.MongoClient
import com.mongodb.kotlin.client.model.Filters.eq
import kotlin.time.Clock
import kotlin.time.ExperimentalTime
import kotlin.time.Instant
import kotlinx.coroutines.runBlocking
import kotlinx.serialization.ExperimentalSerializationApi
import kotlinx.serialization.KSerializer
import kotlinx.serialization.Serializable
import kotlinx.serialization.SerializationException
import kotlinx.serialization.descriptors.PrimitiveKind
import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
import kotlinx.serialization.descriptors.SerialDescriptor
import kotlinx.serialization.encoding.Decoder
import kotlinx.serialization.encoding.Encoder
import org.bson.BsonDateTime
import org.bson.BsonDocument
import org.bson.codecs.kotlinx.BsonDecoder
import org.bson.codecs.kotlinx.BsonEncoder

@Serializable
private data class Person(
    val name: String,
    @Serializable(with = InstantAsBsonDateTime::class)
    val birthday: Instant,
)

// example from https://www.mongodb.com/docs/drivers/kotlin/coroutine/current/fundamentals/data-formats/serialization/#custom-serializer-example
object InstantAsBsonDateTime : KSerializer<Instant> {
    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("InstantAsBsonDateTime", PrimitiveKind.LONG)
    override fun serialize(encoder: Encoder, value: Instant) {
        when (encoder) {
            is BsonEncoder -> encoder.encodeBsonValue(BsonDateTime(value.toEpochMilliseconds()))
            else -> throw SerializationException("Instant is not supported by ${encoder::class}")
        }
    }
    override fun deserialize(decoder: Decoder): Instant {
        return when (decoder) {
            is BsonDecoder -> Instant.fromEpochMilliseconds(decoder.decodeBsonValue().asDateTime().value)
            else -> throw SerializationException("Instant is not supported by ${decoder::class}")
        }
    }
}

fun main(): Unit = runBlocking {
    val database = MongoClient.create().getDatabase("test")
    val collection = database.getCollection<Person>("persons")
    val rawCollection = database.getCollection<BsonDocument>("persons")

    collection.drop()

    val now = Clock.System.now()

    collection.insertOne(Person("John Doe", now))
    rawCollection.find().collect { println(it) } // prints: {"_id": {"$oid": "6888badb86a11b04656ce4d1"}, "name": "John Doe", "birthday": {"$date": "2025-07-29T12:13:15.217Z"}}

    collection.find(Person::birthday eq now).collect { println(it) } // throws: Exception in thread "main" org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for CodecCacheKey{clazz=class kotlin.time.Instant, types=null}.
}