// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com>
// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)

#pragma once

#include "types.h"

#include <cstdio>
#include <ctime>
#include <memory>
#include <optional>
#include <string>
#include <sys/stat.h>
#include <vector>

class Error;

#ifdef _WIN32
#define FS_OSPATH_SEPARATOR_CHARACTER '\\'
#define FS_OSPATH_SEPARATOR_STR "\\"
#else
#define FS_OSPATH_SEPARATOR_CHARACTER '/'
#define FS_OSPATH_SEPARATOR_STR "/"
#endif

enum FILESYSTEM_FILE_ATTRIBUTES
{
  FILESYSTEM_FILE_ATTRIBUTE_DIRECTORY = 1,
  FILESYSTEM_FILE_ATTRIBUTE_READ_ONLY = 2,
  FILESYSTEM_FILE_ATTRIBUTE_COMPRESSED = 4,
};

enum FILESYSTEM_FIND_FLAGS
{
  FILESYSTEM_FIND_RECURSIVE = (1 << 0),
  FILESYSTEM_FIND_RELATIVE_PATHS = (1 << 1),
  FILESYSTEM_FIND_HIDDEN_FILES = (1 << 2),
  FILESYSTEM_FIND_FOLDERS = (1 << 3),
  FILESYSTEM_FIND_FILES = (1 << 4),
  FILESYSTEM_FIND_KEEP_ARRAY = (1 << 5),
};

struct FILESYSTEM_STAT_DATA
{
  std::time_t CreationTime; // actually inode change time on linux
  std::time_t ModificationTime;
  s64 Size;
  u32 Attributes;
};

struct FILESYSTEM_FIND_DATA
{
  std::time_t CreationTime; // actually inode change time on linux
  std::time_t ModificationTime;
  std::string FileName;
  s64 Size;
  u32 Attributes;
};

namespace FileSystem {
using FindResultsArray = std::vector<FILESYSTEM_FIND_DATA>;

/// Returns the display name of a filename. Usually this is the same as the path.
std::string GetDisplayNameFromPath(const std::string_view& path);

/// Returns a list of "root directories" (i.e. root/home directories on Linux, drive letters on Windows).
std::vector<std::string> GetRootDirectoryList();

/// Search for files
bool FindFiles(const char* path, const char* pattern, u32 flags, FindResultsArray* results);

/// Stat file
bool StatFile(const char* path, struct stat* st);
bool StatFile(std::FILE* fp, struct stat* st);
bool StatFile(const char* path, FILESYSTEM_STAT_DATA* pStatData);
bool StatFile(std::FILE* fp, FILESYSTEM_STAT_DATA* pStatData);
s64 GetPathFileSize(const char* path);

/// File exists?
bool FileExists(const char* path);

/// Directory exists?
bool DirectoryExists(const char* path);

/// Directory does not contain any files?
bool DirectoryIsEmpty(const char* path);

/// Delete file
bool DeleteFile(const char* path);

/// Rename file
bool RenamePath(const char* OldPath, const char* NewPath);

/// Deleter functor for managed file pointers
struct FileDeleter
{
  ALWAYS_INLINE void operator()(std::FILE* fp)
  {
    if (fp)
      std::fclose(fp);
  }
};

/// open files
using ManagedCFilePtr = std::unique_ptr<std::FILE, FileDeleter>;
ManagedCFilePtr OpenManagedCFile(const char* filename, const char* mode, Error* error = nullptr);
std::FILE* OpenCFile(const char* filename, const char* mode, Error* error = nullptr);
int FSeek64(std::FILE* fp, s64 offset, int whence);
s64 FTell64(std::FILE* fp);
s64 FSize64(std::FILE* fp);

int OpenFDFile(const char* filename, int flags, int mode, Error* error = nullptr);

/// Sharing modes for OpenSharedCFile().
enum class FileShareMode
{
  DenyReadWrite, /// Exclusive access.
  DenyWrite,     /// Other processes can read from this file.
  DenyRead,      /// Other processes can write to this file.
  DenyNone,      /// Other processes can read and write to this file.
};

/// Opens a file in shareable mode (where other processes can access it concurrently).
/// Only has an effect on Windows systems.
ManagedCFilePtr OpenManagedSharedCFile(const char* filename, const char* mode, FileShareMode share_mode,
                                       Error* error = nullptr);
std::FILE* OpenSharedCFile(const char* filename, const char* mode, FileShareMode share_mode, Error* error = nullptr);

/// Abstracts a POSIX file lock.
#ifndef _WIN32
class POSIXLock
{
public:
  POSIXLock(int fd);
  POSIXLock(std::FILE* fp);
  ~POSIXLock();

private:
  int m_fd;
};
#endif

std::optional<std::vector<u8>> ReadBinaryFile(const char* filename, Error* error = nullptr);
std::optional<std::vector<u8>> ReadBinaryFile(std::FILE* fp);
std::optional<std::string> ReadFileToString(const char* filename, Error* error = nullptr);
std::optional<std::string> ReadFileToString(std::FILE* fp);
bool WriteBinaryFile(const char* filename, const void* data, size_t data_length);
bool WriteStringToFile(const char* filename, const std::string_view& sv);

/// creates a directory in the local filesystem
/// if the directory already exists, the return value will be true.
/// if Recursive is specified, all parent directories will be created
/// if they do not exist.
bool CreateDirectory(const char* path, bool recursive);

/// Creates a directory if it doesn't already exist.
/// Returns false if it does not exist and creation failed.
bool EnsureDirectoryExists(const char* path, bool recursive);

/// Removes a directory.
bool DeleteDirectory(const char* path);

/// Recursively removes a directory and all subdirectories/files.
bool RecursiveDeleteDirectory(const char* path);

/// Copies one file to another, optionally replacing it if it already exists.
bool CopyFilePath(const char* source, const char* destination, bool replace);

/// Returns the path to the current executable.
std::string GetProgramPath();

/// Retrieves the current working directory.
std::string GetWorkingDirectory();

/// Sets the current working directory. Returns true if successful.
bool SetWorkingDirectory(const char* path);

/// Enables/disables NTFS compression on a file or directory.
/// Does not apply the compression flag recursively if called for a directory.
/// Does nothing and returns false on non-Windows platforms.
bool SetPathCompression(const char* path, bool enable);

}; // namespace FileSystem