/**
 * Copyright 2017, Digi International Inc.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
package com.digi.xbee.api.models;

/**
 * This class represents an Access Point for the Wi-Fi protocol. It contains 
 * SSID, the encryption type and the link quality between the Wi-Fi module and 
 * the access point.
 * 
 * <p>This class is used within the XBee Java Library to list the access points 
 * and connect to a specific one in the Wi-Fi protocol.</p>
 * 
 * @since 1.2.0
 */
public class AccessPoint {

        // Constants.
        private static final String ERROR_CHANNEL = "Channel cannot be negative.";
        private static final String ERROR_SIGNAL_QUALITY = "Signal quality must be between 0 and 100.";
        
        // Variables.
        private final String ssid;
        
        private final WiFiEncryptionType encryptionType;
        
        private int channel;
        private int signalQuality;
        
        /**
         * Class constructor. Instantiates a new object of type 
         * {@code AccessPoint} with the given parameters.
         * 
         * @param ssid The SSID of the access point.
         * @param encryptionType The encryption type configured in the access 
         *                       point.
         * 
         * @throws IllegalArgumentException if {@code ssid.length < 0}.
         * @throws NullPointerException if {@code ssid == null} or 
         *                              if {@code encryptionType == null}.
         * 
         * @see #AccessPoint(String, WiFiEncryptionType, int, int)
         * @see com.digi.xbee.api.models.WiFiEncryptionType
         */
        public AccessPoint(String ssid, WiFiEncryptionType encryptionType) {
                this(ssid, encryptionType, 0, 0);
        }
        
        /**
         * Class constructor. Instantiates a new object of type 
         * {@code AccessPoint} with the given parameters.
         * 
         * @param ssid The SSID of the access point.
         * @param encryptionType The encryption type configured in the access 
         *                       point.
         * @param channel Operating channel of the access point.
         * @param signalQuality Signal quality with the access point in %.
         * 
         * @throws IllegalArgumentException if {@code ssid.length < 0} or 
         *                                  if {@code channel < 0} or 
         *                                  if {@code signalQuality < 0} or 
         *                                  if {@code signalQuality > 100}.
         * @throws NullPointerException if {@code ssid == null} or
         *                              if {@code encryptionType == null}.
         * 
         * @see #AccessPoint(String, WiFiEncryptionType)
         * @see com.digi.xbee.api.models.WiFiEncryptionType
         */
        public AccessPoint(String ssid, WiFiEncryptionType encryptionType, int channel,
                        int signalQuality) {
                if (ssid == null)
                        throw new NullPointerException("SSID cannot be null.");
                if (encryptionType == null)
                        throw new NullPointerException("Encryption type cannot be null.");
                
                if (ssid.length() == 0)
                        throw new IllegalArgumentException("SSID cannot be empty.");
                if (channel < 0)
                        throw new IllegalArgumentException(ERROR_CHANNEL);
                if (signalQuality < 0 || signalQuality > 100)
                        throw new IllegalArgumentException(ERROR_SIGNAL_QUALITY);
                
                this.ssid = ssid;
                this.encryptionType = encryptionType;
                this.channel = channel;
                this.signalQuality = signalQuality;
        }
        
        /**
         * Returns the SSID of the access point.
         * 
         * @return The SSID of the access point.
         */
        public String getSSID() {
                return ssid;
        }
        
        /**
         * Returns the encryption type of the access point.
         * 
         * @return The encryption type of the access point.
         * 
         * @see com.digi.xbee.api.models.WiFiEncryptionType
         */
        public WiFiEncryptionType getEncryptionType() {
                return encryptionType;
        }
        
        /**
         * Returns the operating channel of the access point.
         * 
         * @return The operating channel of the access point.
         * 
         * @see #setChannel(int)
         */
        public int getChannel() {
                return channel;
        }
        
        /**
         * Sets the new channel of the access point.
         * 
         * @param channel The new channel of the access point.
         * 
         * @see #getChannel()
         */
        public void setChannel(int channel) {
                if (channel < 0)
                        throw new IllegalArgumentException(ERROR_CHANNEL);
                
                this.channel = channel;
        }
        
        /**
         * Returns the signal quality with the access point in %.
         * 
         * @return The signal quality with the access point in %.
         * 
         * @see #setSignalQuality(int)
         */
        public int getSignalQuality() {
                return signalQuality;
        }
        
        /**
         * Sets the new signal quality with the access point.
         * 
         * @param signalQuality The new signal quality with the access point.
         * 
         * @see #getSignalQuality()
         */
        public void setSignalQuality(int signalQuality) {
                if (signalQuality < 0 || signalQuality > 100)
                        throw new IllegalArgumentException(ERROR_SIGNAL_QUALITY);
                
                this.signalQuality = signalQuality;
        }
        
        /*
         * (non-Javadoc)
         * @see java.lang.Object#toString()
         */
        @Override
        public String toString() {
                StringBuilder message = new StringBuilder();
                message.append(ssid);
                message.append(" (");
                message.append(encryptionType.name());
                message.append(") - CH: ");
                message.append(channel);
                message.append(" - Signal: ");
                message.append(signalQuality);
                message.append("%");
                
                return message.toString();
        }
}