package com.mobify.astro;

import android.app.Activity;
import android.content.pm.PackageManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;

import java.util.HashMap;
import java.util.Map;

public class PermissionsManager {

    Activity activity;
    Map<Integer, PermissionsCallback> permissionsCallbacks = new HashMap<>();

    public interface PermissionsCallback {
        void onPermissionUpdated(boolean isPermissionGiven);
    }

    public PermissionsManager(Activity activity) {
        this.activity = activity;
    }

    private void returnPermissionsResult(boolean isPermissionGiven, final int requestCode) {
        PermissionsCallback permissionCallBack = this.permissionsCallbacks.get(requestCode);

        if (permissionCallBack != null) {
            // When permission is either granted or denied, invoke callBack
            permissionCallBack.onPermissionUpdated(isPermissionGiven);
            permissionsCallbacks.remove(requestCode);
        }
    }

    public boolean handleRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (permissionsCallbacks.containsKey(requestCode)) {
            boolean isPermissionGiven = (grantResults.length == permissions.length) && isAllPermissionsGranted(grantResults);
            returnPermissionsResult(isPermissionGiven, requestCode);
            return true;
        }
        // return false if request code is invalid
        return false;
    }

    // Checks if all permissions are granted
    private boolean isAllPermissionsGranted(int[] grantResults) {
        for (Integer grantResult: grantResults) {
            if (grantResult != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }

    // Checks if app has all permissions
    private boolean hasPermissions(String[] permissions) {
        for (String permission: permissions) {
            if (ContextCompat.checkSelfPermission(activity, permission) != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }

    public void permissionRequest(final int requestCode, String[] permissions, final PermissionsManager.PermissionsCallback callback) {
        permissionsCallbacks.put(requestCode, callback);

        // Check if the permissions being asked are already granted
        if (hasPermissions(permissions)) {
            returnPermissionsResult(true, requestCode);
        } else {
            // Request permissions - AstroActivity.onRequestPermissionsResult will be invoked upon
            ActivityCompat.requestPermissions(activity, permissions, requestCode);
        }
    }
}