package com.sptmobile.link

import android.app.NotificationChannel
import android.app.NotificationManager
import android.app.PendingIntent
import android.content.Context
import androidx.core.app.NotificationCompat

// [impl->REQ-INBOUND-NOTIFS]
/**
 * Android half of inbound notifications (DESIGN.md §Interlaced view
 * mechanics): every sending endpoint gets its OWN notification channel,
 * created on its first message — per-endpoint channels are the ruling, so
 * the user mutes a chatty agent in system settings without silencing the
 * rest. One drained entry = one notification; the id keys on msg-id so a
 * re-notify of the same message replaces rather than stacks.
 *
 * Without POST_NOTIFICATIONS (asked at app launch) `notify` is a system-side
 * no-op — the message still lands in host history, so it is late-surfaced in
 * the endpoint view, never lost.
 */
class InboundNotifier(private val context: Context) {
    private val manager = context.getSystemService(NotificationManager::class.java)

    fun notify(entries: List<SpoolEntry>) {
        for (entry in entries) {
            manager.createNotificationChannel(
                NotificationChannel(
                    CHANNEL_PREFIX + entry.from,
                    entry.from,
                    NotificationManager.IMPORTANCE_DEFAULT,
                )
            )
            manager.notify(
                TAG,
                (entry.msg_id ?: "${entry.from}@${entry.ts_ms}").hashCode(),
                NotificationCompat.Builder(context, CHANNEL_PREFIX + entry.from)
                    .setSmallIcon(android.R.drawable.stat_notify_chat)
                    .setContentTitle(entry.from)
                    .setContentText(entry.body)
                    .setStyle(NotificationCompat.BigTextStyle().bigText(entry.body))
                    .setWhen(entry.ts_ms)
                    .setShowWhen(true)
                    .setAutoCancel(true)
                    .setContentIntent(tapIntent(entry.from))
                    .build(),
            )
        }
    }

    /**
     * Tap deep-links into the SENDING endpoint's view: the launch intent
     * carries [EXTRA_OPEN_ENDPOINT] and MainActivity (singleTop) routes it.
     * Request code keys on the endpoint so per-endpoint intents don't
     * clobber each other; UPDATE_CURRENT keeps a reused one fresh.
     */
    private fun tapIntent(endpoint: String): PendingIntent? =
        context.packageManager.getLaunchIntentForPackage(context.packageName)?.let {
            it.putExtra(EXTRA_OPEN_ENDPOINT, endpoint)
            PendingIntent.getActivity(
                context,
                endpoint.hashCode(),
                it,
                PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT,
            )
        }

    companion object {
        private const val TAG = "inbound"
        private const val CHANNEL_PREFIX = "inbound_"

        /** Intent extra: endpoint id whose view a notification tap opens. */
        const val EXTRA_OPEN_ENDPOINT = "com.sptmobile.OPEN_ENDPOINT"
    }
}