/*
 *   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.*;
import com.vonage.client.JsonableBaseObject;
import com.vonage.client.users.User;
import java.time.Instant;
import java.util.Objects;

/**
 * Events are actions that occur within a conversation.
 */
@JsonTypeInfo(
                use = JsonTypeInfo.Id.NAME,
                include = JsonTypeInfo.As.EXISTING_PROPERTY,
                property = "type",
                visible = true,
                defaultImpl = GenericEvent.class
)
@JsonSubTypes({
                @JsonSubTypes.Type(value = EventDeleteEvent.class, name = "event:delete"),
                @JsonSubTypes.Type(value = ConversationUpdatedEvent.class, name = "conversation:updated"),
                @JsonSubTypes.Type(value = MessageSeenEvent.class, name = "message:seen"),
                @JsonSubTypes.Type(value = MessageSubmittedEvent.class, name = "message:submitted"),
                @JsonSubTypes.Type(value = MessageDeliveredEvent.class, name = "message:delivered"),
                @JsonSubTypes.Type(value = MessageUndeliverableEvent.class, name = "message:undeliverable"),
                @JsonSubTypes.Type(value = MessageRejectedEvent.class, name = "message:rejected"),
                @JsonSubTypes.Type(value = AudioPlayEvent.class, name = "audio:play"),
                @JsonSubTypes.Type(value = AudioPlayStopEvent.class, name = "audio:play:stop"),
                @JsonSubTypes.Type(value = AudioPlayDoneEvent.class, name = "audio:play:done"),
                @JsonSubTypes.Type(value = AudioSayEvent.class, name = "audio:say"),
                @JsonSubTypes.Type(value = AudioSayStopEvent.class, name = "audio:say:stop"),
                @JsonSubTypes.Type(value = AudioSayDoneEvent.class, name = "audio:say:done"),
                @JsonSubTypes.Type(value = AudioRecordEvent.class, name = "audio:record"),
                @JsonSubTypes.Type(value = AudioRecordStopEvent.class, name = "audio:record:stop"),
                @JsonSubTypes.Type(value = AudioMuteOnEvent.class, name = "audio:mute:on"),
                @JsonSubTypes.Type(value = AudioMuteOffEvent.class, name = "audio:mute:off"),
                @JsonSubTypes.Type(value = AudioEarmuffOnEvent.class, name = "audio:earmuff:on"),
                @JsonSubTypes.Type(value = AudioEarmuffOffEvent.class, name = "audio:earmuff:off"),
                @JsonSubTypes.Type(value = EphemeralEvent.class, name = "ephemeral"),
                @JsonSubTypes.Type(value = CustomEvent.class, name = "custom")
})
public abstract class Event extends JsonableBaseObject {
        @JsonIgnore String conversationId;
        @JsonProperty("type") EventType type;
        @JsonProperty("id") Integer id;
        @JsonProperty("from") String from;
        @JsonProperty("timestamp") Instant timestamp;
        @JsonProperty("_embedded") Embedded _embedded;

        private static class Embedded extends JsonableBaseObject {
                @JsonProperty("from_user") User fromUser;
                @JsonProperty("from_member") BaseMember fromMember;
        }

        protected Event() {
        }

        Event(Builder<?, ?> builder) {
                type = Objects.requireNonNull(builder.type, "Event type is required.");
                from = ConversationsClient.validateMemberId(builder.from);
        }

        /**
         * Event id. This is a progressive integer.
         * 
         * @return The event ID as an integer, or {@code null} if unknown.
         */
        public Integer getId() {
                return id;
        }

        /**
         * Type of event.
         * 
         * @return The event type as an enum.
         */
        public EventType getType() {
                return type;
        }

        /**
         * Member ID this event was sent from.
         * 
         * @return The member ID, or {@code null} if unspecified.
         */
        public String getFrom() {
                return from;
        }

        /**
         * Time of creation.
         * 
         * @return The event timestamp, or {@code null} if unknown.
         */
        public Instant getTimestamp() {
                return timestamp;
        }

        /**
         * Details about the user that initiated the event.
         * 
         * @return The embedded {@code from_user} object, or {@code null} if absent.
         */
        @JsonIgnore
        public User getFromUser() {
                return _embedded != null ? _embedded.fromUser : null;
        }

        /**
         * Member that initiated the event. Only the {@code id} field will be present.
         * 
         * @return The embedded {@code from_member} object, or {@code null} if absent.
         */
        @JsonIgnore
        public BaseMember getFromMember() {
                return _embedded != null ? _embedded.fromMember : null;
        }

        /**
         * Builder for constructing an event request's parameters.
         *
         * @param <E> The event type.
         * @param <B> The builder type.
         */
        @SuppressWarnings("unchecked")
        public abstract static class Builder<E extends Event, B extends Builder<? extends E, ? extends B>> {
                private final EventType type;
                private String from;

                /**
                 * Construct a new builder for a given event type.
                 *
                 * @param type The event type as an enum.
                 */
                protected Builder(EventType type) {
                        this.type = type;
                }

                /**
                 * Member ID this event was sent from.
                 *
                 * @param from The member ID, or {@code null} if unspecified.
                 *
                 * @return This builder.
                 */
                public B from(String from) {
                        this.from = from;
                        return (B) this;
                }

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