package com.bitcointxoko.gudariwallet.api

import androidx.compose.runtime.Immutable
import kotlinx.serialization.KSerializer
import kotlinx.serialization.SerialName
import kotlinx.serialization.Serializable
import kotlinx.serialization.descriptors.SerialDescriptor
import kotlinx.serialization.descriptors.buildClassSerialDescriptor
import kotlinx.serialization.encoding.Decoder
import kotlinx.serialization.encoding.Encoder
import kotlinx.serialization.json.JsonDecoder
import kotlinx.serialization.json.JsonElement
import kotlinx.serialization.json.JsonEncoder
import kotlinx.serialization.json.JsonNull
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.JsonPrimitive
import kotlinx.serialization.json.jsonObject
import kotlinx.serialization.json.jsonPrimitive

// ── Wallet ────────────────────────────────────────────────────────────────────
@Serializable
data class WalletResponse(
    val id: String = "",
    val name: String = "",
    val balance: Long = 0L      // millisatoshis
)

// ── Create invoice ────────────────────────────────────────────────────────────
@Serializable
data class CreateInvoiceRequest(
    val out: Boolean,
    val amount: Long,       // satoshis
    val memo: String
)

@Serializable
data class CreateInvoiceResponse(
    @SerialName("payment_hash")    val paymentHash: String  = "",
    @SerialName("payment_request") val paymentRequest: String = "",
    @SerialName("expiry")          val expiry: String?      = null
)

// ── Pay invoice ───────────────────────────────────────────────────────────────
@Serializable
data class PayInvoiceRequest(
    val out: Boolean,
    val bolt11: String
)

@Serializable
data class PayInvoiceResponse(
    @SerialName("payment_hash") val paymentHash: String = "",
    @SerialName("checking_id")  val checkingId: String  = ""
)

// ── Check payment ─────────────────────────────────────────────────────────────
@Serializable
data class PaymentStatusResponse(
    val paid: Boolean = false,
    val details: PaymentDetails? = null
)

@Serializable
data class PaymentDetails(
    val amount: Long?  = null,
    val fee: Long?     = null,
    val memo: String?  = null
)

// ── Decode BOLT-11 ────────────────────────────────────────────────────────────
@Serializable
data class DecodeInvoiceRequest(
    val data: String
)

@Serializable
data class DecodeInvoiceResponse(
    @SerialName("payment_hash") val paymentHash: String?            = null,
    @SerialName("amount_msat")  val amountMsat: Long?               = null,
    @SerialName("description")  val description: String?            = null,
    @SerialName("payee")        val payee: String?                  = null,
    @SerialName("route_hints")  val routeHints: List<List<RouteHintHop>>? = null
)

@Serializable
data class RouteHintHop(
    @SerialName("public_key")        val publicKey: String        = "",
    @SerialName("short_channel_id")  val shortChannelId: String?  = null,
    @SerialName("base_fee")          val baseFeeMsat: Long        = 0,
    @SerialName("ppm_fee")           val ppmFee: Long             = 0,
    @SerialName("cltv_expiry_delta") val cltvExpiryDelta: Int     = 0
)

// ── LNURL scan ────────────────────────────────────────────────────────────────
@Serializable
data class LnurlScanResponse(
    val tag: String? = null,
    // ── payRequest fields ─────────────────────────────────────────────────────
    val callback: String?                       = null,
    @SerialName("minSendable")    val minSendable: Long?           = null,
    @SerialName("maxSendable")    val maxSendable: Long?           = null,
    val metadata: String?                       = null,
    @SerialName("commentAllowed") val commentAllowed: Int?         = null,
    @SerialName("allowsNostr")    val allowsNostr: Boolean?        = null,
    @SerialName("nostrPubkey")    val nostrPubkey: String?         = null,
    val bolt11: String?                         = null,
    @SerialName("amount_msat")    val amountMsat: Long?            = null,
    val disposable: Boolean?                    = null,  // LUD-06: null means treat as true (do not cache)
    // ── withdrawRequest fields ────────────────────────────────────────────────
    val k1: String?                             = null,
    @SerialName("defaultDescription") val defaultDescription: String? = null,
    @SerialName("minWithdrawable")    val minWithdrawable: Long?   = null,
    @SerialName("maxWithdrawable")    val maxWithdrawable: Long?   = null,
    @SerialName("balanceCheck")       val balanceCheck: String?    = null,
    @SerialName("currentBalance")     val currentBalance: Long?    = null,
    // ── Error fields ──────────────────────────────────────────────────────────
    val status: String?                         = null,  // "OK" or "ERROR"
    val reason: String?                         = null   // error message when status == "ERROR"
)

// ── LNURL-pay callback response (LUD-06) ─────────────────────────────────────
@Serializable
data class LnurlCallbackResponse(
    val pr: String = "",
    val routes: List<JsonElement>? = null,
    @SerialName("successAction") val successAction: SuccessAction? = null,
    val status: String? = null,
    val reason: String? = null
)

// ── LNURL pay ─────────────────────────────────────────────────────────────────
@Serializable
data class LnurlPayRes(
    val tag: String?                              = null,
    val callback: String?                         = null,
    @SerialName("minSendable")    val minSendable: Long?    = null,
    @SerialName("maxSendable")    val maxSendable: Long?    = null,
    val metadata: String?                         = null,
    @SerialName("commentAllowed") val commentAllowed: Int?  = null,
    @SerialName("allowsNostr")    val allowsNostr: Boolean? = null,
    @SerialName("nostrPubkey")    val nostrPubkey: String?  = null
)

@Serializable
data class PayLnurlRequest(
    val res: LnurlPayRes,
    val lnurl: String,
    val amount: Long,
    val comment: String? = null
)

@Serializable
data class PayLnurlResponse(
    @SerialName("payment_hash") val paymentHash: String = "",
    @SerialName("checking_id")  val checkingId: String  = ""
)

@Serializable
data class WithdrawCallbackResponse(
    val status: String  = "",
    val reason: String? = null
)

// ── LNURLp pay link (lightning address) ──────────────────────────────────────
@Serializable
data class LnurlpLink(
    val id: String       = "",
    val wallet: String   = "",
    val username: String?    = null,
    val description: String? = null,
    @Serializable(with = LongAsDoubleSerializer::class) val min: Long = 0L,
    @Serializable(with = LongAsDoubleSerializer::class) val max: Long = 0L
)

// ── Payment history ───────────────────────────────────────────────────────────
@Immutable
@Serializable
data class PaymentRecord(
    @SerialName("payment_hash") val paymentHash: String = "",
    @SerialName("checking_id")  val checkingId: String  = "",
    @SerialName("amount")       val amountMsat: Long     = 0L,
    @SerialName("fee")          val feeMsat: Long        = 0L,
    @SerialName("memo")         val memo: String?        = null,
    @SerialName("time")         val time: String         = "",
    @SerialName("status")       val status: String       = "",
    @SerialName("bolt11")       val bolt11: String?      = null,
    @SerialName("pending")      val pending: Boolean     = false,
    @SerialName("preimage")     val preimage: String?    = null,
    @SerialName("extra")        val extra: PaymentExtra? = null,
    // Not from the API — populated only when loaded from Room via toDomain()
    val createdAt: Long? = null,
    val pubkey: String?  = null,
    val alias: String?   = null
) {
    val amountSat: Long     get() = kotlin.math.abs(amountMsat) / 1000L
    val feeSat: Long        get() = kotlin.math.abs(feeMsat)    / 1000L
    val isOutgoing: Boolean get() = amountMsat < 0

    companion object {
        fun fromPayment(
            paymentHash: String,
            amountSats: Long,
            feeSats: Long?,
            bolt11: String?,
            memo: String?,
            pubkey: String?,
            alias: String?,
        ): PaymentRecord = PaymentRecord(
            paymentHash = paymentHash,
            checkingId  = paymentHash,
            amountMsat  = -(amountSats * 1_000L),
            feeMsat     = (feeSats ?: 0L) * 1_000L,
            memo        = memo,
            time        = (System.currentTimeMillis() / 1_000L).toString(),
            status      = "complete",
            bolt11      = bolt11,
            pending     = false,
            preimage    = null,
            extra       = null,
            pubkey      = pubkey,
            alias       = alias,
        )
    }
}

@Immutable
@Serializable
data class PaymentExtra(
    @SerialName("tag")            val tag: String?            = null,
    @Serializable(with = FlexibleStringSerializer::class)
    val comment: String?        = null,
    @SerialName("success_action") @Serializable(with = SuccessActionSerializer::class)
    val successAction: SuccessAction? = null,
    @SerialName("wallet_id")      val walletId: String?       = null,
    @SerialName("destination")    val destination: String?    = null,
    @SerialName("expires_at")     val expiresAt: String?      = null
)

@Immutable
@Serializable(with = SuccessActionSerializer::class)
data class SuccessAction(
    @SerialName("tag")         val tag: String?,
    @SerialName("message")     val message: String?,
    @SerialName("url")         val url: String?,
    @SerialName("description") val description: String?
)

/**
 * LNbits returns `success_action` as either:
 *   - a JSON object  {"tag":"message","message":"Thanks!"}
 *   - a plain string "Thanks!"
 *   - null
 *
 * kotlinx.serialization's default deserializer throws when it sees a
 * string where it expects {. This serializer handles all three cases.
 *
 * Applied via @Serializable(with = SuccessActionSerializer::class) on
 * the SuccessAction class and on PaymentExtra.successAction.
 */
object SuccessActionSerializer : KSerializer<SuccessAction?> {

    override val descriptor: SerialDescriptor =
        buildClassSerialDescriptor("SuccessAction")

    override fun serialize(encoder: Encoder, value: SuccessAction?) {
        val jsonEncoder = encoder as JsonEncoder
        if (value == null) {
            jsonEncoder.encodeJsonElement(JsonNull)
        } else {
            jsonEncoder.encodeJsonElement(
                JsonObject(
                    mapOf(
                        "tag"         to JsonPrimitive(value.tag),
                        "message"     to JsonPrimitive(value.message),
                        "url"         to JsonPrimitive(value.url),
                        "description" to JsonPrimitive(value.description)
                    )
                )
            )
        }
    }

    override fun deserialize(decoder: Decoder): SuccessAction? {
        val jsonDecoder = decoder as JsonDecoder
        return when (val element = jsonDecoder.decodeJsonElement()) {
            is JsonNull      -> null
            is JsonPrimitive -> {
                // Plain string — treat as a message-type success action
                val text = element.jsonPrimitive.content
                if (text.isBlank()) null
                else SuccessAction(tag = "message", message = text, url = null, description = null)
            }
            is JsonObject    -> {
                SuccessAction(
                    tag         = element.jsonObject["tag"]?.jsonPrimitive?.content,
                    message     = element.jsonObject["message"]?.jsonPrimitive?.content,
                    url         = element.jsonObject["url"]?.jsonPrimitive?.content,
                    description = element.jsonObject["description"]?.jsonPrimitive?.content
                )
            }
            else             -> null
        }
    }
}

@Serializable
data class PaymentDetailResponse(
    val paid: Boolean,
    val details: PaymentRecord?
)

// ── WebSocket payment message ─────────────────────────────────────────────────
@Serializable
data class WsPaymentMessage(
    @SerialName("wallet_balance") val walletBalance: Long?   = null,
    val payment: WsPayment?                                  = null
)

@Serializable
data class WsPayment(
    @SerialName("payment_hash") val paymentHash: String  = "",
    @SerialName("checking_id")  val checkingId: String   = "",
    @SerialName("amount")       val amount: Long         = 0L,
    @SerialName("fee")          val fee: Long            = 0L,
    @SerialName("memo")         val memo: String?        = null,
    @SerialName("time")         val time: String         = "",
    @SerialName("status")       val status: String       = "",
    @SerialName("bolt11")       val bolt11: String?      = null,
    @SerialName("pending")      val pending: Boolean     = false,
    @SerialName("preimage")     val preimage: String?    = null,
    @SerialName("extra")        val extra: PaymentExtra? = null
)

// ── Fiat rate ─────────────────────────────────────────────────────────────────
@Serializable
data class FiatRateResponse(
    val rate: Double   = 0.0,  // sat to fiat rate
    val price: Double  = 0.0   // BTC price in the requested fiat currency
)

// ── History sync ──────────────────────────────────────────────────────────────
@Serializable
data class PaginatedPaymentsResponse(
    @SerialName("data")  val data: List<PaymentRecord> = emptyList(),
    @SerialName("total") val total: Int                = 0
)

// ── NWC Provider models ───────────────────────────────────────────────────────
@Serializable
data class NwcKey(
    val pubkey: String      = "",
    val wallet: String      = "",
    val description: String = "",
    val expires_at: Long    = 0L,
    val permissions: String = "",
    val created_at: Long    = 0L,
    val last_used: Long     = 0L
)

@Serializable
data class NwcBudget(
    val id: Int              = 0,
    val pubkey: String       = "",
    val budget_msats: Long   = 0L,
    val refresh_window: Int  = 0,
    val created_at: Long     = 0L,
    val used_budget_msats: Long = 0L
)

@Serializable
data class NwcGetResponse(
    val data: NwcKey            = NwcKey(),
    val budgets: List<NwcBudget> = emptyList()
)

// Request models — no defaults needed (you control the fields, never deserializing)
@Serializable
data class NwcNewBudget(
    val budget_msats: Long,
    val refresh_window: Int,
    val created_at: Long = System.currentTimeMillis() / 1000L
)

@Serializable
data class NwcRegistrationRequest(
    val permissions: List<String>,
    val description: String,
    val expires_at: Long,
    val budgets: List<NwcNewBudget> = emptyList()
)

/**
 * Deserializes a JSON number that may arrive as either an integer (1)
 * or a float (1.0) into a Long, truncating any fractional part.
 */
object LongAsDoubleSerializer : KSerializer<Long> {
    override val descriptor = buildClassSerialDescriptor("LongAsDouble")

    override fun serialize(encoder: Encoder, value: Long) = encoder.encodeLong(value)

    override fun deserialize(decoder: Decoder): Long {
        val jsonDecoder = decoder as JsonDecoder
        return when (val element = jsonDecoder.decodeJsonElement()) {
            is JsonPrimitive -> element.content.toDouble().toLong()
            else -> 0L
        }
    }
}