/*
 *   Copyright 2024 Vonage
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package com.vonage.client.conversations;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.vonage.client.JsonableBaseObject;
import com.vonage.client.common.HttpMethod;
import java.net.URI;
import java.util.UUID;

/**
 * Callback properties for a {@link Conversation}.
 */
public final class Callback extends JsonableBaseObject {
        private URI url;
        private String eventMask;
        private Params params;
        private HttpMethod method;

        Callback() {}

        Callback(Builder builder) {
                url = builder.url;
                if ((eventMask = builder.eventMask) != null && (eventMask.length() > 200 || eventMask.trim().isEmpty())) {
                        throw new IllegalArgumentException("Event mask must be between 1 and 200 characters");
                }
                if ((method = builder.method) != null && !(method == HttpMethod.POST || method == HttpMethod.GET)) {
                        throw new IllegalArgumentException("Callback HTTP method must be either POST or GET, not "+method);
                }
                params = builder.params;
        }

        /**
         * Event URL for the callback.
         * 
         * @return The callback URL, or {@code null} if unspecified.
         */
        @JsonProperty("url")
        public URI getUrl() {
                return url;
        }

        @JsonProperty("event_mask")
        public String getEventMask() {
                return eventMask;
        }

        /**
         * Additional parameters.
         * 
         * @return The callback parameters, or {@code null} if unspecified.
         */
        @JsonProperty("params")
        public Params getParams() {
                return params;
        }

        /**
         * Method to use for the callback, either {@linkplain HttpMethod#GET} or {@linkplain HttpMethod#POST}.
         * 
         * @return The HTTP method as an enum, or {@code null} if unspecified.
         */
        @JsonProperty("method")
        public HttpMethod getMethod() {
                return method;
        }

        public static class Params extends JsonableBaseObject {
                private UUID applicationId;
                private URI nccoUrl;

                protected Params() {}

                /**
                 * Vonage Application ID.
                 *
                 * @return The application ID, or {@code null} if unspecified.
                 */
                @JsonProperty("applicationId")
                public UUID getApplicationId() {
                        return applicationId;
                }

                /**
                 * Call Control Object URL to use for the callback.
                 *
                 * @return The NCCO URL, or {@code null} if unspecified.
                 */
                @JsonProperty("ncco_url")
                public URI getNccoUrl() {
                        return nccoUrl;
                }
        }

        /**
         * Entry point for constructing an instance of this class.
         *
         * @return A new Builder.
         */
        public static Builder builder() {
                return new Builder();
        }

        /**
         * Builder for creating Callback settings. All parameters are optional.
         */
        public static final class Builder {
                private URI url;
                private String eventMask;
                private HttpMethod method;
                private Params params;

                private Builder() {}

                private Params initParams() {
                        if (params == null) {
                                params = new Params();
                        }
                        return params;
                }

                /**
                 * Event URL for the callback.
                 *
                 * @param url The callback URL as a string.
                 *
                 * @return This builder.
                 */
                public Builder url(String url) {
                        this.url = URI.create(url);
                        return this;
                }

                /**
                 * Callback event mask.
                 *
                 * @param eventMask The event mask as a string.
                 *
                 * @return This builder.
                 */
                public Builder eventMask(String eventMask) {
                        this.eventMask = eventMask;
                        return this;
                }

                /**
                 * HTTP method to use for the callback.
                 * Must be either {@linkplain HttpMethod#GET} or {@linkplain HttpMethod#POST}.
                 *
                 * @param method The HTTP method as an enum, or {@code null} if unspecified.
                 *
                 * @return This builder.
                 */
                public Builder method(HttpMethod method) {
                        this.method = method;
                        return this;
                }

                /**
                 * Vonage Application ID.
                 *
                 * @param applicationId The application ID as a string.
                 *
                 * @return This builder.
                 */
                public Builder applicationId(String applicationId) {
                        initParams().applicationId = UUID.fromString(applicationId);
                        return this;
                }

                /**
                 * Call Control Object URL to use for the callback.
                 *
                 * @param nccoUrl The NCCO URL as a string.
                 *
                 * @return This builder.
                 */
                public Builder nccoUrl(String nccoUrl) {
                        initParams().nccoUrl = URI.create(nccoUrl);
                        return this;
                }

                /**
                 * Builds the {@linkplain Callback}.
                 *
                 * @return An instance of Callback, populated with all fields from this builder.
                 */
                public Callback build() {
                        return new Callback(this);
                }
        }
}