function copyMessage(message, includeReasoning = true) {
    const copy = { role: message.role, content: message.content };
    if (includeReasoning && message.reasoning) copy.reasoning = message.reasoning;
    return copy;
}

function create(systemPrompt, messages = []) {
    const conversation = {
        systemPrompt,
        messages: messages.map(message => copyMessage(message)),

        add(source) {
            if (Array.isArray(source?.messages)) {
                for (const message of source.messages) conversation.messages.push(copyMessage(message, false));
                return conversation;
            }

            conversation.messages.push(copyMessage(source));
            return conversation;
        }
    };
    return conversation;
}

function start(systemPrompt = null) {
    return create(systemPrompt);
}

function from(blob, fallbackSystemPrompt = null) {
    const systemPrompt = blob.systemPrompt === undefined ? fallbackSystemPrompt : blob.systemPrompt;
    return create(systemPrompt, blob.messages || []);
}

module.exports = { start, from };