/*************************************************************************/
/*  editor_file_system.h                                                 */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
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/*************************************************************************/

#ifndef EDITOR_FILE_SYSTEM_H
#define EDITOR_FILE_SYSTEM_H

#include "core/io/dir_access.h"
#include "core/os/thread.h"
#include "core/os/thread_safe.h"
#include "core/templates/safe_refcount.h"
#include "core/templates/set.h"
#include "core/templates/thread_work_pool.h"
#include "scene/main/node.h"

class FileAccess;

struct EditorProgressBG;
class EditorFileSystemDirectory : public Object {
	GDCLASS(EditorFileSystemDirectory, Object);

	String name;
	uint64_t modified_time;
	bool verified; //used for checking changes

	EditorFileSystemDirectory *parent;
	Vector<EditorFileSystemDirectory *> subdirs;

	struct FileInfo {
		String file;
		StringName type;
		ResourceUID::ID uid = ResourceUID::INVALID_ID;
		uint64_t modified_time = 0;
		uint64_t import_modified_time = 0;
		bool import_valid = false;
		String import_group_file;
		Vector<String> deps;
		bool verified = false; //used for checking changes
		String script_class_name;
		String script_class_extends;
		String script_class_icon_path;
	};

	struct FileInfoSort {
		bool operator()(const FileInfo *p_a, const FileInfo *p_b) const {
			return p_a->file < p_b->file;
		}
	};

	void sort_files();

	Vector<FileInfo *> files;

	static void _bind_methods();

	friend class EditorFileSystem;

public:
	String get_name();
	String get_path() const;

	int get_subdir_count() const;
	EditorFileSystemDirectory *get_subdir(int p_idx);
	int get_file_count() const;
	String get_file(int p_idx) const;
	String get_file_path(int p_idx) const;
	StringName get_file_type(int p_idx) const;
	Vector<String> get_file_deps(int p_idx) const;
	bool get_file_import_is_valid(int p_idx) const;
	uint64_t get_file_modified_time(int p_idx) const;
	String get_file_script_class_name(int p_idx) const; //used for scripts
	String get_file_script_class_extends(int p_idx) const; //used for scripts
	String get_file_script_class_icon_path(int p_idx) const; //used for scripts

	EditorFileSystemDirectory *get_parent();

	int find_file_index(const String &p_file) const;
	int find_dir_index(const String &p_dir) const;

	void force_update();

	EditorFileSystemDirectory();
	~EditorFileSystemDirectory();
};

class EditorFileSystem : public Node {
	GDCLASS(EditorFileSystem, Node);

	_THREAD_SAFE_CLASS_

	struct ItemAction {
		enum Action {
			ACTION_NONE,
			ACTION_DIR_ADD,
			ACTION_DIR_REMOVE,
			ACTION_FILE_ADD,
			ACTION_FILE_REMOVE,
			ACTION_FILE_TEST_REIMPORT,
			ACTION_FILE_RELOAD
		};

		Action action = ACTION_NONE;
		EditorFileSystemDirectory *dir = nullptr;
		String file;
		EditorFileSystemDirectory *new_dir = nullptr;
		EditorFileSystemDirectory::FileInfo *new_file = nullptr;
	};

	bool use_threads;
	Thread thread;
	static void _thread_func(void *_userdata);

	EditorFileSystemDirectory *new_filesystem;

	bool abort_scan;
	bool scanning;
	bool importing;
	bool first_scan;
	bool scan_changes_pending;
	float scan_total;
	String filesystem_settings_version_for_import;
	bool revalidate_import_files;

	void _scan_filesystem();

	Set<String> late_update_files;

	void _save_late_updated_files();

	EditorFileSystemDirectory *filesystem;

	static EditorFileSystem *singleton;

	/* Used for reading the filesystem cache file */
	struct FileCache {
		String type;
		ResourceUID::ID uid = ResourceUID::INVALID_ID;
		uint64_t modification_time = 0;
		uint64_t import_modification_time = 0;
		Vector<String> deps;
		bool import_valid = false;
		String import_group_file;
		String script_class_name;
		String script_class_extends;
		String script_class_icon_path;
	};

	HashMap<String, FileCache> file_cache;

	struct ScanProgress {
		float low = 0;
		float hi = 0;
		mutable EditorProgressBG *progress = nullptr;
		void update(int p_current, int p_total) const;
		ScanProgress get_sub(int p_current, int p_total) const;
	};

	void _save_filesystem_cache();
	void _save_filesystem_cache(EditorFileSystemDirectory *p_dir, FileAccess *p_file);

	bool _find_file(const String &p_file, EditorFileSystemDirectory **r_d, int &r_file_pos) const;

	void _scan_fs_changes(EditorFileSystemDirectory *p_dir, const ScanProgress &p_progress);

	void _delete_internal_files(String p_file);

	Set<String> textfile_extensions;
	Set<String> valid_extensions;
	Set<String> import_extensions;

	void _scan_new_dir(EditorFileSystemDirectory *p_dir, DirAccess *da, const ScanProgress &p_progress);

	Thread thread_sources;
	bool scanning_changes;
	bool scanning_changes_done;

	static void _thread_func_sources(void *_userdata);

	List<String> sources_changed;
	List<ItemAction> scan_actions;

	bool _update_scan_actions();

	void _update_extensions();

	void _reimport_file(const String &p_file, const Map<StringName, Variant> *p_custom_options = nullptr, const String &p_custom_importer = String());
	Error _reimport_group(const String &p_group_file, const Vector<String> &p_files);

	bool _test_for_reimport(const String &p_path, bool p_only_imported_files);

	bool reimport_on_missing_imported_files;

	Vector<String> _get_dependencies(const String &p_path);

	struct ImportFile {
		String path;
		String importer;
		bool threaded = false;
		int order = 0;
		bool operator<(const ImportFile &p_if) const {
			return order == p_if.order ? (importer < p_if.importer) : (order < p_if.order);
		}
	};

	void _scan_script_classes(EditorFileSystemDirectory *p_dir);
	SafeFlag update_script_classes_queued;
	void _queue_update_script_classes();

	String _get_global_script_class(const String &p_type, const String &p_path, String *r_extends, String *r_icon_path) const;

	static Error _resource_import(const String &p_path);

	bool using_fat32_or_exfat; // Workaround for projects in FAT32 or exFAT filesystem (pendrives, most of the time)

	void _find_group_files(EditorFileSystemDirectory *efd, Map<String, Vector<String>> &group_files, Set<String> &groups_to_reimport);

	void _move_group_files(EditorFileSystemDirectory *efd, const String &p_group_file, const String &p_new_location);

	Set<String> group_file_cache;

	ThreadWorkPool import_threads;

	struct ImportThreadData {
		const ImportFile *reimport_files;
		int reimport_from;
		int max_index = 0;
	};

	void _reimport_thread(uint32_t p_index, ImportThreadData *p_import_data);

	static ResourceUID::ID _resource_saver_get_resource_id_for_path(const String &p_path, bool p_generate);

	bool _scan_extensions();

protected:
	void _notification(int p_what);
	static void _bind_methods();

public:
	static EditorFileSystem *get_singleton() { return singleton; }

	EditorFileSystemDirectory *get_filesystem();
	bool is_scanning() const;
	bool is_importing() const { return importing; }
	float get_scanning_progress() const;
	void scan();
	void scan_changes();
	void update_file(const String &p_file);

	EditorFileSystemDirectory *get_filesystem_path(const String &p_path);
	String get_file_type(const String &p_file) const;
	EditorFileSystemDirectory *find_file(const String &p_file, int *r_index) const;

	void reimport_files(const Vector<String> &p_files);

	void reimport_file_with_custom_parameters(const String &p_file, const String &p_importer, const Map<StringName, Variant> &p_custom_params);

	void update_script_classes();

	bool is_group_file(const String &p_path) const;
	void move_group_file(const String &p_path, const String &p_new_path);

	static bool _should_skip_directory(const String &p_path);

	EditorFileSystem();
	~EditorFileSystem();
};

#endif // EDITOR_FILE_SYSTEM_H