package com.hyperling.apps.infinitetimer;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.provider.Settings;
import android.util.Log;

public class Alert {
    private static final String TAG = "Alert";
    public static final String ACTION_TIMER = "com.hyperling.apps.infinitetimer.ACTION_TIMER";
    
    /**
     * Sets a persistent alarm that triggers the TimerReceiver.
     * Uses setExactAndAllowWhileIdle to bypass Android Doze mode.
     */
    public static void start(Context context, long intervalMs) {
        Intent intent = new Intent(context, TimerReceiver.class);
        intent.setAction(ACTION_TIMER);

        // FLAG_IMMUTABLE required for Android 12+ (API 31+)
        int flags = PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_CANCEL_CURRENT;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            flags |= PendingIntent.FLAG_IMMUTABLE;
        }

        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, flags);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);

        if (alarmManager != null) {
            long triggerTime = System.currentTimeMillis() + intervalMs;
            // Exact alarm ensures it triggers even in Doze mode
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, triggerTime, pendingIntent);
            } else {
                alarmManager.setExact(AlarmManager.RTC_WAKEUP, triggerTime, pendingIntent);
            }
            Log.d(TAG, "Alarm set for " + intervalMs + "ms at " + triggerTime);
        } else {
            Log.e(TAG, "Could not get AlarmManager service");
        }
    }

    /**
     * Cancels the timer. If the app is killed, alarms are dropped automatically.
     */
    public static void stop(Context context) {
        Intent intent = new Intent(context, TimerReceiver.class);
        int flags = PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_CANCEL_CURRENT;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            flags |= PendingIntent.FLAG_IMMUTABLE;
        }

        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, flags);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        
        if (alarmManager != null) {
            alarmManager.cancel(pendingIntent);
            Log.d(TAG, "Alarm cancelled");
        }
    }

    /**
     * Checks/Requests permission for exact alarms on Android 12+
     */
    public static boolean isExactAlarmAllowed(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
            return am != null && am.canScheduleExactAlarms();
        }
        return true; // Android 11 and below allow exact alarms by default
    }

    /**
     * Helper to request exact alarm permission if missing
     */
    public static void requestExactAlarmPermission(android.app.Activity activity) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S && !isExactAlarmAllowed(activity)) {
            Intent intent = new Intent(Settings.ACTION_REQUEST_SCHEDULE_EXACT_ALARM);
            activity.startActivity(intent);
        }
    }
}