package com.timesafari.dailynotification;

import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.provider.Settings;
import android.util.Log;

/**
 * Manages notification channels and ensures they are properly configured
 * for reliable notification delivery.
 * 
 * Handles channel creation, importance checking, and provides deep links
 * to channel settings when notifications are blocked.
 * 
 * @author Matthew Raymer
 * @version 1.0
 */
public class ChannelManager {
    private static final String TAG = "ChannelManager";
    private static final String DEFAULT_CHANNEL_ID = "timesafari.daily";
    private static final String DEFAULT_CHANNEL_NAME = "Daily Notifications";
    private static final String DEFAULT_CHANNEL_DESCRIPTION = "Daily notifications from TimeSafari";
    
    private final Context context;
    private final NotificationManager notificationManager;
    
    public ChannelManager(Context context) {
        this.context = context;
        this.notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    }
    
    /**
     * Ensures the default notification channel exists and is properly configured.
     * Creates the channel if it doesn't exist.
     * 
     * @return true if channel is ready for notifications, false if blocked
     */
    public boolean ensureChannelExists() {
        try {
            Log.d(TAG, "Ensuring notification channel exists");
            
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
                
                if (channel == null) {
                    Log.d(TAG, "Creating notification channel");
                    createDefaultChannel();
                    return true;
                } else {
                    Log.d(TAG, "Channel exists with importance: " + channel.getImportance());
                    return channel.getImportance() != NotificationManager.IMPORTANCE_NONE;
                }
            } else {
                // Pre-Oreo: channels don't exist, always ready
                Log.d(TAG, "Pre-Oreo device, channels not applicable");
                return true;
            }
        } catch (Exception e) {
            Log.e(TAG, "Error ensuring channel exists", e);
            return false;
        }
    }
    
    /**
     * Checks if the notification channel is enabled and can deliver notifications.
     * 
     * @return true if channel is enabled, false if blocked
     */
    public boolean isChannelEnabled() {
        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
                if (channel == null) {
                    Log.w(TAG, "Channel does not exist");
                    return false;
                }
                
                int importance = channel.getImportance();
                Log.d(TAG, "Channel importance: " + importance);
                return importance != NotificationManager.IMPORTANCE_NONE;
            } else {
                // Pre-Oreo: always enabled
                return true;
            }
        } catch (Exception e) {
            Log.e(TAG, "Error checking channel status", e);
            return false;
        }
    }
    
    /**
     * Gets the current channel importance level.
     * 
     * @return importance level, or -1 if channel doesn't exist
     */
    public int getChannelImportance() {
        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
                if (channel != null) {
                    return channel.getImportance();
                }
            }
            return -1;
        } catch (Exception e) {
            Log.e(TAG, "Error getting channel importance", e);
            return -1;
        }
    }
    
    /**
     * Opens the notification channel settings for the user to enable notifications.
     * 
     * @return true if settings intent was launched, false otherwise
     */
    public boolean openChannelSettings() {
        try {
            Log.d(TAG, "Opening channel settings");
            
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                Intent intent = new Intent(Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS)
                        .putExtra(Settings.EXTRA_APP_PACKAGE, context.getPackageName())
                        .putExtra(Settings.EXTRA_CHANNEL_ID, DEFAULT_CHANNEL_ID)
                        .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                
                context.startActivity(intent);
                Log.d(TAG, "Channel settings opened");
                return true;
            } else {
                Log.d(TAG, "Channel settings not available on pre-Oreo");
                return false;
            }
        } catch (Exception e) {
            Log.e(TAG, "Error opening channel settings", e);
            return false;
        }
    }
    
    /**
     * Creates the default notification channel with high importance.
     */
    private void createDefaultChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                    DEFAULT_CHANNEL_ID,
                    DEFAULT_CHANNEL_NAME,
                    NotificationManager.IMPORTANCE_HIGH
            );
            channel.setDescription(DEFAULT_CHANNEL_DESCRIPTION);
            channel.enableLights(true);
            channel.enableVibration(true);
            channel.setShowBadge(true);
            
            notificationManager.createNotificationChannel(channel);
            Log.d(TAG, "Default channel created with HIGH importance");
        }
    }
    
    /**
     * Gets the default channel ID for use in notifications.
     * 
     * @return the default channel ID
     */
    public String getDefaultChannelId() {
        return DEFAULT_CHANNEL_ID;
    }
    
    /**
     * Logs the current channel status for debugging.
     */
    public void logChannelStatus() {
        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
                if (channel != null) {
                    Log.i(TAG, "Channel Status - ID: " + channel.getId() + 
                              ", Importance: " + channel.getImportance() + 
                              ", Enabled: " + (channel.getImportance() != NotificationManager.IMPORTANCE_NONE));
                } else {
                    Log.w(TAG, "Channel does not exist");
                }
            } else {
                Log.i(TAG, "Pre-Oreo device, channels not applicable");
            }
        } catch (Exception e) {
            Log.e(TAG, "Error logging channel status", e);
        }
    }
}