package com.bitcointxoko.gudariwallet.util

import android.app.Notification
import android.app.NotificationChannel
import android.app.NotificationManager
import android.app.PendingIntent
import android.content.Context
import android.content.Intent
import androidx.core.app.NotificationCompat
import androidx.core.app.NotificationManagerCompat
import com.bitcointxoko.gudariwallet.MainActivity
import com.bitcointxoko.gudariwallet.R

object NotificationHelper {

    // ── Intent extra key — read by MainActivity ───────────────────────────────
    const val EXTRA_PAYMENT_HASH = "extra_payment_hash"

    // ── Channel setup ─────────────────────────────────────────────────────────

    fun createChannels(context: Context) {
        val nm = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

        nm.createNotificationChannel(
            NotificationChannel(
                NotificationConstants.CHANNEL_PAYMENTS,
                context.getString(R.string.notif_channel_payments_name),
                NotificationManager.IMPORTANCE_HIGH
            ).apply {
                description = context.getString(R.string.notif_channel_payments_desc)
                enableVibration(true)
                enableLights(true)
            }
        )

        nm.createNotificationChannel(
            NotificationChannel(
                NotificationConstants.CHANNEL_SERVICE_STATUS,
                context.getString(R.string.notif_channel_service_name),
                NotificationManager.IMPORTANCE_LOW
            ).apply {
                description = context.getString(R.string.notif_channel_service_desc)
                setShowBadge(false)
                enableVibration(false)
                setSound(null, null)
            }
        )

        nm.createNotificationChannel(
            NotificationChannel(
                NotificationConstants.CHANNEL_SYNC,
                context.getString(R.string.notif_channel_sync_name),
                NotificationManager.IMPORTANCE_DEFAULT
            ).apply {
                description = context.getString(R.string.notif_channel_sync_desc)
                enableVibration(false)
                setSound(null, null)
            }
        )
    }

    // ── User-facing notifications ─────────────────────────────────────────────

    /**
     * Posts a high-priority notification for an incoming payment.
     * Tapping opens MainActivity and navigates directly to the payment detail
     * screen for [paymentHash].
     */
    fun notifyPaymentReceived(context: Context, amountSats: Long, memo: String?, paymentHash: String) {
        val title = context.getString(R.string.notif_payment_received_title, amountSats)
        val text  = if (!memo.isNullOrBlank()) memo
        else context.getString(R.string.notif_payment_received_no_memo)

        val notification = NotificationCompat.Builder(context, NotificationConstants.CHANNEL_PAYMENTS)
            .setSmallIcon(R.drawable.ic_notification)
            .setContentTitle(title)
            .setContentText(text)
            .setAutoCancel(true)
            .setContentIntent(mainActivityPendingIntent(context, paymentHash))
            // BigTextStyle shows the full memo when the notification is expanded,
            // in case it is long enough to be truncated in the compact view.
            .setStyle(
                NotificationCompat.BigTextStyle()
                    .bigText(text)
                    .setSummaryText(context.getString(R.string.notif_payment_received_summary, amountSats))
            )
            .build()

        notify(context, NotificationConstants.NOTIF_ID_PAYMENT_RECEIVED, notification)
    }

    /**
     * Posts a default-priority notification for a successfully sent payment.
     * Tapping opens MainActivity and navigates directly to the payment detail
     * screen for [paymentHash].
     */
    fun notifyPaymentSent(context: Context, amountSats: Long, paymentHash: String) {
        val title = context.getString(R.string.notif_payment_sent_title)
        val text  = context.getString(R.string.notif_payment_sent_text, amountSats)
        notify(
            context,
            NotificationConstants.NOTIF_ID_PAYMENT_SENT,
            buildPaymentNotification(context, title, text, paymentHash)
        )
    }

    /**
     * Posts a notification when the one-time historical payment sync completes.
     * No tap destination needed — the user is already in the app or will land
     * on the main screen via the default MainActivity launch.
     */
    fun notifySyncComplete(context: Context, paymentCount: Int) {
        val title = context.getString(R.string.notif_sync_complete_title)
        val text  = context.getString(R.string.notif_sync_complete_text, paymentCount)
        notify(
            context,
            NotificationConstants.NOTIF_ID_SYNC_COMPLETE,
            NotificationCompat.Builder(context, NotificationConstants.CHANNEL_SYNC)
                .setSmallIcon(R.drawable.ic_notification)
                .setContentTitle(title)
                .setContentText(text)
                .setAutoCancel(true)
                .build()
        )
    }

    // ── Foreground service notification ───────────────────────────────────────

    fun buildServiceNotification(context: Context): Notification {
        return NotificationCompat.Builder(context, NotificationConstants.CHANNEL_SERVICE_STATUS)
            .setSmallIcon(R.drawable.ic_notification)
            .setContentTitle(context.getString(R.string.notif_service_title))
            .setContentText(context.getString(R.string.notif_service_text))
            .setOngoing(true)
            .setSilent(true)
            .setShowWhen(false)
            .setForegroundServiceBehavior(NotificationCompat.FOREGROUND_SERVICE_IMMEDIATE)
            // Service notification taps open the app with no specific destination
            .setContentIntent(mainActivityPendingIntent(context, paymentHash = null))
            .build()
    }

    // ── Dismiss ───────────────────────────────────────────────────────────────

    fun cancel(context: Context, notificationId: Int) {
        NotificationManagerCompat.from(context).cancel(notificationId)
    }

    // ── Private helpers ───────────────────────────────────────────────────────

    private fun buildPaymentNotification(
        context    : Context,
        title      : String,
        text       : String,
        paymentHash: String
    ): Notification {
        return NotificationCompat.Builder(context, NotificationConstants.CHANNEL_PAYMENTS)
            .setSmallIcon(R.drawable.ic_notification)
            .setContentTitle(title)
            .setContentText(text)
            .setAutoCancel(true)
            .setContentIntent(mainActivityPendingIntent(context, paymentHash))
            .build()
    }

    /**
     * Builds a PendingIntent that opens MainActivity.
     *
     * If [paymentHash] is non-null, it is attached as [EXTRA_PAYMENT_HASH].
     * MainActivity reads this in onCreate / onNewIntent and navigates to the
     * payment detail screen.
     *
     * FLAG_UPDATE_CURRENT ensures that if a second notification arrives before
     * the first is tapped, the hash is updated to the latest payment.
     * Each notification ID gets its own requestCode so they don't overwrite
     * each other's extras.
     */
    private fun mainActivityPendingIntent(context: Context, paymentHash: String?): PendingIntent {
        val intent = Intent(context, MainActivity::class.java).apply {
            flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or Intent.FLAG_ACTIVITY_CLEAR_TOP
            if (paymentHash != null) {
                putExtra(EXTRA_PAYMENT_HASH, paymentHash)
            }
        }
        // Use the hash's hashCode as requestCode so each unique payment gets
        // its own PendingIntent — prevents one notification's tap from
        // overwriting another's extras.
        val requestCode = paymentHash?.hashCode() ?: 0
        return PendingIntent.getActivity(
            context,
            requestCode,
            intent,
            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
        )
    }

    private fun notify(context: Context, id: Int, notification: Notification) {
        runCatching {
            NotificationManagerCompat.from(context).notify(id, notification)
        }
    }
}