/*
 * Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 3.0 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * version 3.0 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3.0 along with this program. If not, see
 * <https://www.gnu.org/licenses/>.
 */

#ifndef __STDC_LIMIT_MACROS
# define __STDC_LIMIT_MACROS
#endif
#ifndef __STDC_CONSTANT_MACROS
# define __STDC_CONSTANT_MACROS
#endif

#include "objfw-defs.h"

#ifdef OF_HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#import "OFStream.h"
#import "OFKernelEventObserver.h"
#import "OFString.h"

#ifdef OF_WINDOWS
# include <windows.h>
#endif

OF_ASSUME_NONNULL_BEGIN

@class OFArray OF_GENERIC(ObjectType);
@class OFDictionary OF_GENERIC(KeyType, ObjectType);

/**
 * @class OFSubprocess OFSubprocess.h ObjFW/OFSubprocess.h
 *
 * @brief A class for stream-like communication with a newly created subprocess.
 */
OF_SUBCLASSING_RESTRICTED
@interface OFSubprocess: OFStream
#ifndef OF_WINDOWS
    <OFReadyForReadingObserving, OFReadyForWritingObserving>
#endif
{
#ifndef OF_WINDOWS
	pid_t _pid;
	int _readPipe[2], _writePipe[2];
#else
	HANDLE _handle, _readPipe[2], _writePipe[2];
#endif
	int _status;
	bool _atEndOfStream;
}

/**
 * @brief Creates a new OFSubprocess with the specified program and invokes the
 *	  program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @return A new, autoreleased OFSubprocess.
 */
+ (instancetype)subprocessWithProgram: (OFString *)program;

/**
 * @brief Creates a new OFSubprocess with the specified program and arguments
 *	  and invokes the program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @param arguments The arguments to pass to the program, or `nil`
 * @return A new, autoreleased OFSubprocess.
 */
+ (instancetype)
    subprocessWithProgram: (OFString *)program
		arguments: (nullable OFArray OF_GENERIC(OFString *) *)arguments;

/**
 * @brief Creates a new OFSubprocess with the specified program, program name
 *	  and arguments and invokes the program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @param programName The program name for the program to invoke (argv[0]).
 *		      Usually, this is equal to program.
 * @param arguments The arguments to pass to the program, or `nil`
 * @return A new, autoreleased OFSubprocess.
 */
+ (instancetype)
    subprocessWithProgram: (OFString *)program
	      programName: (OFString *)programName
		arguments: (nullable OFArray OF_GENERIC(OFString *) *)arguments;

/**
 * @brief Creates a new OFSubprocess with the specified program, program name,
 *	  arguments and environment and invokes the program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @param programName The program name for the program to invoke (argv[0]).
 *		      Usually, this is equal to program.
 * @param arguments The arguments to pass to the program, or `nil`
 * @param environment The environment to pass to the program, or `nil`. If it
 *		      is not `nil`, the passed dictionary will be used to
 *		      override the environment. If you want to add to the
 *		      existing environment, you need to get the existing
 *		      environment first, copy it, modify it and then pass it.
 * @return A new, autoreleased OFSubprocess.
 */
+ (instancetype)
    subprocessWithProgram: (OFString *)program
	      programName: (OFString *)programName
		arguments: (nullable OFArray OF_GENERIC(OFString *) *)arguments
	      environment: (nullable OFDictionary
			       OF_GENERIC(OFString *, OFString *) *)environment;

- (instancetype)init OF_UNAVAILABLE;

/**
 * @brief Initializes an already allocated OFSubprocess with the specified
 *	  program and invokes the program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @return An initialized OFSubprocess.
 */
- (instancetype)initWithProgram: (OFString *)program;

/**
 * @brief Initializes an already allocated OFSubprocess with the specified
 *	  program and arguments and invokes the program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @param arguments The arguments to pass to the program, or `nil`
 * @return An initialized OFSubprocess.
 */
- (instancetype)
    initWithProgram: (OFString *)program
	  arguments: (nullable OFArray OF_GENERIC(OFString *) *)arguments;

/**
 * @brief Initializes an already allocated OFSubprocess with the specified
 *	  program, program name and arguments and invokes the program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @param programName The program name for the program to invoke (argv[0]).
 *		      Usually, this is equal to program.
 * @param arguments The arguments to pass to the program, or `nil`
 * @return An initialized OFSubprocess.
 */
- (instancetype)
    initWithProgram: (OFString *)program
	programName: (OFString *)programName
	  arguments: (nullable OFArray OF_GENERIC(OFString *) *)arguments;

/**
 * @brief Initializes an already allocated OFSubprocess with the specified
 *	  program, program name, arguments and environment and invokes the
 *	  program.
 *
 * @param program The program to execute. If it does not start with a slash, the
 *		  search path specified in PATH is used.
 * @param programName The program name for the program to invoke (argv[0]).
 *		      Usually, this is equal to program.
 * @param arguments The arguments to pass to the program, or `nil`
 * @param environment The environment to pass to the program, or `nil`. If it
 *		      is not `nil`, the passed dictionary will be used to
 *		      override the environment. If you want to add to the
 *		      existing environment, you need to get the existing
 *		      environment first, copy it, modify it and then pass it.
 * @return An initialized OFSubprocess.
 */
- (instancetype)
    initWithProgram: (OFString *)program
	programName: (OFString *)programName
	  arguments: (nullable OFArray OF_GENERIC(OFString *) *)arguments
	environment: (nullable OFDictionary
			 OF_GENERIC(OFString *, OFString *) *)environment
    OF_DESIGNATED_INITIALIZER;

/**
 * @brief Closes the write direction of the subprocess.
 *
 * This method needs to be called for some programs before data can be read,
 * since some programs don't start processing before the write direction is
 * closed.
 *
 * @throw OFNotOpenException The subprocess was already closed
 */
- (void)closeForWriting;

/**
 * @brief Waits for the subprocess to terminate and returns the exit status.
 *
 * If the subprocess has already exited, this returns the exit status
 * immediately.
 *
 * @return The status code of the subprocess
 * @throw OFNotOpenException The subprocess was already closed
 */
- (int)waitForTermination;
@end

OF_ASSUME_NONNULL_END