/*
 * Copyright 2008-2026 Async-IO.org
 *
 * 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 org.atmosphere.integrationtests.ai;

import org.atmosphere.ai.StreamingSessions;
import org.atmosphere.ai.llm.ChatCompletionRequest;
import org.atmosphere.cpr.AtmosphereHandler;
import org.atmosphere.cpr.AtmosphereResource;
import org.atmosphere.cpr.AtmosphereResourceEvent;
import org.atmosphere.cpr.RawMessage;

import java.io.IOException;

/**
 * Test handler for classroom broadcast scenarios.
 * Each instance represents one room with a distinct persona and streaming text prefix.
 * Registered at explicit paths (/ai/classroom/math, /ai/classroom/code) so
 * each room gets its own broadcaster — proving room isolation.
 */
public class ClassroomTestHandler implements AtmosphereHandler {

    private final String roomName;
    private final FakeLlmClient llmClient;

    public ClassroomTestHandler(String roomName) {
        this.roomName = roomName;
        this.llmClient = FakeLlmClient.slow(
                roomName + "-model", 30,
                "[" + roomName.toUpperCase() + "]",
                " This", " is", " the", " " + roomName,
                " room", " response."
        );
    }

    @Override
    public void onRequest(AtmosphereResource resource) throws IOException {
        resource.suspend();

        var reader = resource.getRequest().getReader();
        var prompt = reader.readLine();
        if (prompt != null && !prompt.trim().isEmpty()) {
            var trimmed = prompt.trim();
            Thread.ofVirtual().name("classroom-" + roomName).start(() -> {
                var session = StreamingSessions.start(resource.getBroadcaster());
                session.sendMetadata("room", roomName);
                llmClient.streamChatCompletion(
                        ChatCompletionRequest.of(roomName + "-model", trimmed),
                        session
                );
            });
        }
    }

    @Override
    public void onStateChange(AtmosphereResourceEvent event) throws IOException {
        if (event.isCancelled() || event.isResumedOnTimeout()) {
            return;
        }
        var message = event.getMessage();
        if (message instanceof RawMessage raw) {
            var inner = raw.message();
            if (inner instanceof String json) {
                event.getResource().getResponse().write(json);
                event.getResource().getResponse().flushBuffer();
            }
        }
    }

    @Override
    public void destroy() {
    }
}
