#pragma once

#include "session.hpp"

#include <QAbstractListModel>
#include <QHash>
#include <QList>
#include <QSet>
#include <QSqlDatabase>
#include <QString>
#include <QtQml>

namespace ZShell::llm {

class LlmClient;

class ChatStore : public QAbstractListModel {
	Q_OBJECT
	QML_ELEMENT
	QML_UNCREATABLE("Chat sessions are owned by the LlmClient singleton")

	public:
	explicit ChatStore(LlmClient* client, QObject* parent = nullptr);
	~ChatStore() override;

	[[nodiscard]] int rowCount(
		const QModelIndex& parent = QModelIndex()) const override;
	[[nodiscard]] QVariant data(
		const QModelIndex& index, int role = Qt::DisplayRole) const override;
	[[nodiscard]] QHash<int, QByteArray> roleNames() const override;

	[[nodiscard]] LlmClient* client() const { return m_client; }

	[[nodiscard]] int rowOf(const ChatSession* session) const;

	Q_INVOKABLE ZShell::llm::ChatSession* draft();
	Q_INVOKABLE void remove(ZShell::llm::ChatSession* chat);
	Q_INVOKABLE void clear();

	void commitDraft(ZShell::llm::ChatSession* session);

	void persist(ZShell::llm::ChatSession* session);
	void saveFlags(ZShell::llm::ChatSession* session);
	void loadMessagesInto(ZShell::llm::ChatSession* session);

	void requestClear(ZShell::llm::ChatSession* session);
	void applyPendingClear(ZShell::llm::ChatSession* session);

	void reposition(ZShell::llm::ChatSession* session);

	Q_SIGNALS:
	void sessionRemoved(ZShell::llm::ChatSession* session);

	private:
	void openDb();
	void load();
	[[nodiscard]] int sortedRow(const ChatSession* session) const;
	[[nodiscard]] static bool firstAfter(
		const ChatSession* a, const ChatSession* b);
	void insertRow(ChatSession* session);
	void moveRow(int from, int to);
	void removeRow(ChatSession* session);
	[[nodiscard]] bool saveSession(ChatSession* session);
	[[nodiscard]] bool writeSessionRow(ChatSession* session);
	[[nodiscard]] QSqlDatabase db() const;

	LlmClient* m_client;
	QList<ChatSession*> m_sessions;
	ChatSession* m_draft = nullptr;
	QString m_connectionName;
	QString m_dbPath;
	QSet<ChatSession*> m_pendingPersists;
	QSet<ChatSession*> m_pendingClears;
	bool m_loading = false;
};

} // namespace ZShell::llm