#pragma once

#include "tickingservice.hpp"

#include <optional>

#include <qabstractitemmodel.h>
#include <qhash.h>
#include <qobject.h>
#include <qqmlintegration.h>
#include <qtmetamacros.h>
#include <qtypes.h>
#include <sys/types.h>

template <typename T> class QFutureWatcher;

namespace ZShell::services {

class ProcessModel : public QAbstractListModel {
	Q_OBJECT
	Q_PROPERTY(int count READ count NOTIFY countChanged)

	public:
	enum Roles : quint16 {
		PidRole = Qt::UserRole + 1,
		PpidRole,
		CommandRole,
		CommandLineRole,
		StateRole,
		SleepingRole,
		CpuUsageRole,
		MemoryUsageRole,
		ElapsedRole,
		UidRole,
		UserRole,
		IoReadBytesRole,
		IoWriteBytesRole,
		IconNameRole,
	};
	Q_ENUM(Roles)

	explicit ProcessModel(QObject* parent = nullptr);

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

	[[nodiscard]] int count() const;

	void refresh();
	bool killProcess(qint64 pid, int signal = 15) const;
	void setDesktopEntryIcons(
		QHash<QString, QString> execPathToIcon,
		QHash<QString, QString> execNameToIcon);

	[[nodiscard]] QString searchText() const;
	void setSearchText(const QString& text);

	[[nodiscard]] bool currentUserOnly() const;
	void setCurrentUserOnly(bool enabled);

	[[nodiscard]] int sortField() const;
	void setSortField(int field);

	[[nodiscard]] bool sortAscending() const;
	void setSortAscending(bool ascending);

	signals:
	void countChanged();
	void searchTextChanged();
	void currentUserOnlyChanged();
	void sortFieldChanged();
	void sortAscendingChanged();

	private:
	struct RawStat {
		pid_t pid = 0;
		pid_t ppid = 0;
		QString comm;
		char state = '?';
		quint64 utime = 0;
		quint64 stime = 0;
		quint64 starttime = 0;
	};

	struct ProcessEntry {
		pid_t pid = 0;
		pid_t ppid = 0;
		QString command;
		QString commandLine;
		char state = '?';
		double cpuPercent = 0.0;
		quint64 rssKb = 0;
		double elapsedSecs = 0.0;
		uid_t uid = 0;
		QString username;
		QString iconName;
		quint64 ioReadBytes = 0;
		quint64 ioWriteBytes = 0;
		int searchScore = -1;

		quint64 lastUtime = 0;
		quint64 lastStime = 0;
		quint64 starttime = 0;
	};

	struct StatusInfo {
		quint64 rssKb = 0;
		uid_t uid = 0;
	};

	struct IoInfo {
		quint64 readBytes = 0;
		quint64 writeBytes = 0;
	};

	struct ScanResult {
		QVector<ProcessEntry> entries;
		QHash<uid_t, QString> newUidNames;
		quint64 iconVersion = 0;
	};

	static std::optional<RawStat> readStat(pid_t pid);
	static QString readCommandLine(pid_t pid, const QString& fallbackComm);
	static StatusInfo readStatus(pid_t pid);
	static IoInfo readIo(pid_t pid);
	static std::optional<double> readUptimeSeconds();
	static QString resolveUsername(uid_t uid, QHash<uid_t, QString>& cache);
	static QString resolveProcessExe(pid_t pid);

	static ScanResult scanProcesses(
		double uptime,
		double deltaSecs,
		QHash<pid_t, int> prevPidToAll,
		QVector<ProcessEntry> prevAll,
		QHash<uid_t, QString> uidCache,
		long clockTicksPerSec,
		QHash<QString, QString> execPathToIcon,
		QHash<QString, QString> execNameToIcon,
		QStringList pathDirs,
		bool desktopEntryIconsChanged,
		quint64 iconVersion);

	void doRefresh();
	void onScanFinished();
	void applyView();
	void converge(const QVector<ProcessEntry>& desired);
	[[nodiscard]] int compareEntries(
		const ProcessEntry& a, const ProcessEntry& b) const;
	[[nodiscard]] static bool isSleeping(const ProcessEntry& e);

	QVector<ProcessEntry> mAll;
	QHash<pid_t, int> mPidToAll;

	QVector<ProcessEntry> mProcesses;
	QHash<uid_t, QString> mUidToName;

	double mLastUptimeSecs = -1.0;
	long mClockTicksPerSec = 100;

	QFutureWatcher<ScanResult>* mWatcher = nullptr;
	bool mRefreshPending = false;
	double mPendingUptime = -1.0;

	QString m_searchText;
	bool m_currentUserOnly = true;
	uid_t m_currentUid = 0;
	int m_sortField = 0;
	bool m_sortAscending = true;

	QHash<QString, QString> mExecPathToIcon;
	QHash<QString, QString> mExecNameToIcon;

	quint64 m_iconVersion = 0;
	quint64 m_scannedIconVersion = 0;
};

class Processes : public TickingService {
	Q_OBJECT
	QML_ELEMENT
	QML_SINGLETON

	public:
	enum SortField : int {
		Unsorted = 0,
		Pid,
		Ppid,
		Command,
		CommandLine,
		State,
		Sleeping,
		CpuUsage,
		MemoryUsage,
		Elapsed,
		Uid,
		User,
		IoReadBytes,
		IoWriteBytes
	};
	Q_ENUM(SortField)

	private:
	Q_PROPERTY(QAbstractItemModel* list READ list CONSTANT)
	Q_PROPERTY(int count READ count NOTIFY countChanged)
	Q_PROPERTY(
		SortField sortField READ sortField WRITE setSortField NOTIFY
			sortFieldChanged)
	Q_PROPERTY(
		bool sortAscending READ sortAscending WRITE setSortAscending NOTIFY
			sortAscendingChanged)
	Q_PROPERTY(
		QString searchText READ searchText WRITE setSearchText NOTIFY
			searchTextChanged)
	Q_PROPERTY(
		bool currentUserOnly READ currentUserOnly WRITE setCurrentUserOnly
			NOTIFY currentUserOnlyChanged)

	public:
	explicit Processes(QObject* parent = nullptr);

	[[nodiscard]] QAbstractItemModel* list() const;

	[[nodiscard]] int count() const;

	[[nodiscard]] SortField sortField() const;
	void setSortField(SortField field);

	[[nodiscard]] bool sortAscending() const;
	void setSortAscending(bool ascending);

	[[nodiscard]] QString searchText() const;
	void setSearchText(const QString& text);

	[[nodiscard]] bool currentUserOnly() const;
	void setCurrentUserOnly(bool enabled);

	Q_INVOKABLE void sortBy(SortField field);
	Q_INVOKABLE void refresh();
	Q_INVOKABLE bool killProcess(qint64 pid, int signal = 15) const;
	Q_INVOKABLE void setDesktopEntries(const QVariantList& entries);


	signals:
	void countChanged();
	void sortFieldChanged();
	void sortAscendingChanged();
	void searchTextChanged();
	void currentUserOnlyChanged();

	protected:
	void tick() override;

	private:
	ProcessModel* m_model;
};

} // namespace ZShell::services