#include "session.hpp"

#include <QDebug>
#include <QFile>
#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>

namespace ZShell {

ChatSession::ChatSession(const QString& id, QObject* parent)
: QObject(parent), m_id(id) {
}

void ChatSession::setTitle(const QString& value) {
	if (m_title == value)
		return;
	m_title = value;
	Q_EMIT titleChanged();
}

void ChatSession::setUpdatedAt(qint64 value) {
	if (m_updatedAt == value)
		return;
	m_updatedAt = value;
	Q_EMIT updatedAtChanged();
}

void ChatSession::setCount(int value) {
	if (m_messageCount == value)
		return;
	m_messageCount = value;
	Q_EMIT messageCountChanged();
}

void ChatSession::setMeta(
	const QString& title,
	qint64 createdAt,
	qint64 updatedAt,
	int messageCount) {
	m_title = title;
	m_createdAt = createdAt;
	m_updatedAt = updatedAt;
	m_messageCount = messageCount;
}

void ChatSession::ensureLoaded() {
	if (m_loaded || m_path.isEmpty())
		return;
	m_loaded = true;
	loadMessages();
}

void ChatSession::loadMessages() {
	QFile file(m_path);
	if (file.open(QIODevice::ReadOnly)) {
		const QJsonDocument doc = QJsonDocument::fromJson(file.readAll());
		file.close();
		if (doc.isObject()) {
			const QJsonObject obj = doc.object();
			m_title = obj["title"].toString(m_title);
			m_createdAt = obj["createdAt"].toVariant().toLongLong() || m_createdAt;
			m_updatedAt = obj["updatedAt"].toVariant().toLongLong() || m_updatedAt;
			for (const QJsonValue& value : obj["messages"].toArray()) {
				const QJsonObject msg = value.toObject();
				const QString content = msg["content"].toString();
				const QString reasoning = msg["reasoning"].toString();
				if (content.isEmpty() && reasoning.isEmpty())
					continue;
				auto* message = new ChatMessage(
					msg["role"].toString() == "user" ? ChatMessage::Role::User
													  : ChatMessage::Role::Assistant,
					content,
					msg["timestamp"].toVariant().toLongLong(),
					this);
				message->setReasoning(reasoning);
				message->setElapsedMs(
					msg["reasoningElapsedMs"].toVariant().toLongLong(),
					msg["contentElapsedMs"].toVariant().toLongLong());
				m_messages.append(message);
			}
		}
	} else {
		qWarning() << "ChatSession: failed to load" << m_path << ":"
		           << file.errorString();
	}
	setCount(int(m_messages.size()));
	Q_EMIT titleChanged();
	Q_EMIT messagesChanged();
}

ChatMessage* ChatSession::appendMessage(
	ChatMessage::Role role, const QString& content, qint64 timestamp) {
	ensureLoaded();
	auto* message = new ChatMessage(role, content, timestamp, this);
	m_messages.append(message);
	setCount(int(m_messages.size()));
	Q_EMIT messagesChanged();
	return message;
}

void ChatSession::removeMessage(ChatMessage* message) {
	if (!message || !m_messages.removeOne(message))
		return;
	delete message;
	setCount(int(m_messages.size()));
	Q_EMIT messagesChanged();
}

void ChatSession::clearMessages() {
	ensureLoaded();
	if (m_messages.isEmpty())
		return;
	qDeleteAll(m_messages);
	m_messages.clear();
	setCount(0);
	Q_EMIT messagesChanged();
}

QJsonObject ChatSession::document() {
	ensureLoaded();
	QJsonArray arr;
	for (const auto* message : m_messages) {
		QJsonObject messageObj;
		messageObj[QStringLiteral("role")] =
			message->role() == ChatMessage::Role::User
				? QStringLiteral("user")
				: QStringLiteral("assistant");
		messageObj[QStringLiteral("content")] = message->content();
		if (!message->reasoning().isEmpty())
			messageObj[QStringLiteral("reasoning")] = message->reasoning();
		const qint64 reasoningMs = message->reasoningElapsedMs();
		if (reasoningMs > 0)
			messageObj[QStringLiteral("reasoningElapsedMs")] = reasoningMs;
		const qint64 contentMs = message->contentElapsedMs();
		if (contentMs > 0)
			messageObj[QStringLiteral("contentElapsedMs")] = contentMs;
		messageObj[QStringLiteral("timestamp")] = message->timestamp();
		arr.append(messageObj);
	}
	QJsonObject doc;
	doc[QStringLiteral("id")] = m_id;
	doc[QStringLiteral("title")] = m_title;
	doc[QStringLiteral("createdAt")] = m_createdAt;
	doc[QStringLiteral("updatedAt")] = m_updatedAt;
	doc[QStringLiteral("messages")] = arr;
	return doc;
}

} // namespace ZShell