package com.tt.honeyDue.notifications

import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.os.Build
import androidx.core.app.NotificationManagerCompat

/**
 * Android NotificationChannels that map to the iOS UNNotificationCategory
 * identifiers defined in `iosApp/iosApp/PushNotifications/NotificationCategories.swift`.
 *
 * iOS uses categories + per-notification actions. Android uses channels for
 * importance grouping. Channels here mirror the four high-level iOS tones:
 *
 *   task_reminder    — default importance (upcoming/due-soon reminders)
 *   task_overdue     — high importance (user is late, needs attention)
 *   residence_invite — default importance (social-style invite, not urgent)
 *   subscription     — low importance (billing/status changes, passive info)
 *
 * User-visible names and descriptions match the keys in
 * `composeApp/src/commonMain/composeResources/values/strings.xml`
 * (`notif_channel_*_name`, `notif_channel_*_description`).
 */
object NotificationChannels {

    const val TASK_REMINDER: String = "task_reminder"
    const val TASK_OVERDUE: String = "task_overdue"
    const val RESIDENCE_INVITE: String = "residence_invite"
    const val SUBSCRIPTION: String = "subscription"

    // English fallback strings. These are duplicated in composeResources
    // strings.xml under the matching notif_channel_* keys so localised builds
    // can override them. Services without access to Compose resources fall
    // back to these values.
    private const val NAME_TASK_REMINDER = "Task Reminders"
    private const val NAME_TASK_OVERDUE = "Overdue Tasks"
    private const val NAME_RESIDENCE_INVITE = "Residence Invites"
    private const val NAME_SUBSCRIPTION = "Subscription Updates"

    private const val DESC_TASK_REMINDER = "Upcoming and due-soon task reminders"
    private const val DESC_TASK_OVERDUE = "Alerts when a task is past its due date"
    private const val DESC_RESIDENCE_INVITE = "Invitations to join a shared residence"
    private const val DESC_SUBSCRIPTION = "Subscription status and billing updates"

    /**
     * Create all four channels if they don't already exist. Safe to call
     * repeatedly — `NotificationManagerCompat.createNotificationChannel` is
     * a no-op when a channel with the same id already exists.
     */
    fun ensureChannels(context: Context) {
        // Channels only exist on O+; on older versions this is a no-op and the
        // NotificationCompat layer ignores channel ids.
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return

        val compat = NotificationManagerCompat.from(context)
        val channels = listOf(
            NotificationChannel(
                TASK_REMINDER,
                NAME_TASK_REMINDER,
                NotificationManager.IMPORTANCE_DEFAULT
            ).apply { description = DESC_TASK_REMINDER },
            NotificationChannel(
                TASK_OVERDUE,
                NAME_TASK_OVERDUE,
                NotificationManager.IMPORTANCE_HIGH
            ).apply { description = DESC_TASK_OVERDUE },
            NotificationChannel(
                RESIDENCE_INVITE,
                NAME_RESIDENCE_INVITE,
                NotificationManager.IMPORTANCE_DEFAULT
            ).apply { description = DESC_RESIDENCE_INVITE },
            NotificationChannel(
                SUBSCRIPTION,
                NAME_SUBSCRIPTION,
                NotificationManager.IMPORTANCE_LOW
            ).apply { description = DESC_SUBSCRIPTION }
        )
        channels.forEach { compat.createNotificationChannel(it) }
    }

    /**
     * Map a [NotificationPayload.type] string to a channel id. Unknown types
     * fall back to [TASK_REMINDER] (default importance, safe default).
     */
    fun channelIdForType(type: String): String = when (type) {
        TASK_OVERDUE -> TASK_OVERDUE
        RESIDENCE_INVITE -> RESIDENCE_INVITE
        SUBSCRIPTION -> SUBSCRIPTION
        TASK_REMINDER -> TASK_REMINDER
        else -> TASK_REMINDER
    }
}