/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
 *               2018, 2019, 2020
 *   Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <errno.h>
#include <string.h>

#import "OFProcess.h"
#import "OFString.h"
#import "OFArray.h"
#import "OFDictionary.h"
#import "OFData.h"

#import "OFInitializationFailedException.h"
#import "OFNotOpenException.h"
#import "OFOutOfRangeException.h"
#import "OFReadFailedException.h"
#import "OFWriteFailedException.h"

#include <windows.h>

@interface OFProcess ()
- (of_char16_t *)of_environmentForDictionary: (OFDictionary *)dictionary;
@end

@implementation OFProcess
+ (instancetype)processWithProgram: (OFString *)program
{
	return [[[self alloc] initWithProgram: program] autorelease];
}

+ (instancetype)processWithProgram: (OFString *)program
			 arguments: (OFArray *)arguments
{
	return [[[self alloc] initWithProgram: program
				    arguments: arguments] autorelease];
}

+ (instancetype)processWithProgram: (OFString *)program
		       programName: (OFString *)programName
			 arguments: (OFArray *)arguments
{
	return [[[self alloc] initWithProgram: program
				  programName: programName
				    arguments: arguments] autorelease];
}

+ (instancetype)processWithProgram: (OFString *)program
		       programName: (OFString *)programName
			 arguments: (OFArray *)arguments
		       environment: (OFDictionary *)environment
{
	return [[[self alloc] initWithProgram: program
				  programName: programName
				    arguments: arguments
				  environment: environment] autorelease];
}

- (instancetype)init
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithProgram: (OFString *)program
{
	return [self initWithProgram: program
			 programName: program
			   arguments: nil
			 environment: nil];
}

- (instancetype)initWithProgram: (OFString *)program
		      arguments: (OFArray *)arguments
{
	return [self initWithProgram: program
			 programName: program
			   arguments: arguments
			 environment: nil];
}

- (instancetype)initWithProgram: (OFString *)program
		    programName: (OFString *)programName
		      arguments: (OFArray *)arguments
{
	return [self initWithProgram: program
			 programName: program
			   arguments: arguments
			 environment: nil];
}

- (instancetype)initWithProgram: (OFString *)program
		    programName: (OFString *)programName
		      arguments: (OFArray *)arguments
		    environment: (OFDictionary *)environment
{
	self = [super init];

	@try {
		SECURITY_ATTRIBUTES sa;
		PROCESS_INFORMATION pi;
		STARTUPINFOW si;
		void *pool;
		OFMutableString *argumentsString;
		of_char16_t *argumentsCopy;
		size_t length;

		_process = INVALID_HANDLE_VALUE;
		_readPipe[0] = _writePipe[1] = NULL;

		sa.nLength = sizeof(sa);
		sa.bInheritHandle = TRUE;
		sa.lpSecurityDescriptor = NULL;

		if (!CreatePipe(&_readPipe[0], &_readPipe[1], &sa, 0))
			@throw [OFInitializationFailedException
			    exceptionWithClass: self.class];

		if (!SetHandleInformation(_readPipe[0], HANDLE_FLAG_INHERIT, 0))
			@throw [OFInitializationFailedException
			    exceptionWithClass: self.class];

		if (!CreatePipe(&_writePipe[0], &_writePipe[1], &sa, 0))
			@throw [OFInitializationFailedException
			    exceptionWithClass: self.class];

		if (!SetHandleInformation(_writePipe[1],
		    HANDLE_FLAG_INHERIT, 0))
			@throw [OFInitializationFailedException
			    exceptionWithClass: self.class];

		memset(&pi, 0, sizeof(pi));
		memset(&si, 0, sizeof(si));

		si.cb = sizeof(si);
		si.hStdInput = _writePipe[0];
		si.hStdOutput = _readPipe[1];
		si.hStdError = GetStdHandle(STD_ERROR_HANDLE);
		si.dwFlags |= STARTF_USESTDHANDLES;

		pool = objc_autoreleasePoolPush();

		argumentsString =
		    [OFMutableString stringWithString: programName];
		[argumentsString replaceOccurrencesOfString: @"\\\""
						 withString: @"\\\\\""];
		[argumentsString replaceOccurrencesOfString: @"\""
						 withString: @"\\\""];

		if ([argumentsString containsString: @" "]) {
			[argumentsString prependString: @"\""];
			[argumentsString appendString: @"\""];
		}

		for (OFString *argument in arguments) {
			OFMutableString *tmp =
			    [[argument mutableCopy] autorelease];
			bool containsSpaces = [tmp containsString: @" "];

			[argumentsString appendString: @" "];

			if (containsSpaces)
				[argumentsString appendString: @"\""];

			[tmp replaceOccurrencesOfString: @"\\\""
					     withString: @"\\\\\""];
			[tmp replaceOccurrencesOfString: @"\""
					     withString: @"\\\""];

			[argumentsString appendString: tmp];

			if (containsSpaces)
				[argumentsString appendString: @"\""];
		}

		length = argumentsString.UTF16StringLength;
		argumentsCopy = [self allocMemoryWithSize: sizeof(of_char16_t)
						    count: length + 1];
		memcpy(argumentsCopy, argumentsString.UTF16String,
		    (argumentsString.UTF16StringLength + 1) * 2);
		@try {
			if (!CreateProcessW(program.UTF16String,
			    argumentsCopy, NULL, NULL, TRUE,
			    CREATE_UNICODE_ENVIRONMENT,
			    [self of_environmentForDictionary: environment],
			    NULL, &si, &pi))
				@throw [OFInitializationFailedException
				    exceptionWithClass: self.class];
		} @finally {
			[self freeMemory: argumentsCopy];
		}

		objc_autoreleasePoolPop(pool);

		_process = pi.hProcess;
		CloseHandle(pi.hThread);

		CloseHandle(_readPipe[1]);
		CloseHandle(_writePipe[0]);
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	if (_readPipe[0] != NULL)
		[self close];

	[super dealloc];
}

- (of_char16_t *)of_environmentForDictionary: (OFDictionary *)environment
{
	OFMutableData *env;
	OFEnumerator *keyEnumerator, *objectEnumerator;
	OFString *key, *object;
	const of_char16_t equal = '=';
	const of_char16_t zero[2] = { 0, 0 };

	if (environment == nil)
		return NULL;

	env = [OFMutableData dataWithItemSize: sizeof(of_char16_t)];

	keyEnumerator = [environment keyEnumerator];
	objectEnumerator = [environment objectEnumerator];
	while ((key = [keyEnumerator nextObject]) != nil &&
	    (object = [objectEnumerator nextObject]) != nil) {
		[env addItems: key.UTF16String
			count: key.UTF16StringLength];
		[env addItems: &equal
			count: 1];
		[env addItems: object.UTF16String
			count: object.UTF16StringLength];
		[env addItems: &zero
			count: 1];
	}
	[env addItems: zero
		count: 2];

	return env.mutableItems;
}

- (bool)lowlevelIsAtEndOfStream
{
	if (_readPipe[0] == NULL)
		@throw [OFNotOpenException exceptionWithObject: self];

	return _atEndOfStream;
}

- (size_t)lowlevelReadIntoBuffer: (void *)buffer
			  length: (size_t)length
{
	DWORD ret;

	if (length > UINT32_MAX)
		@throw [OFOutOfRangeException exception];

	if (_readPipe[0] == NULL)
		@throw [OFNotOpenException exceptionWithObject: self];

	if (!ReadFile(_readPipe[0], buffer, (DWORD)length, &ret, NULL)) {
		if (GetLastError() == ERROR_BROKEN_PIPE) {
			_atEndOfStream = true;
			return 0;
		}

		@throw [OFReadFailedException exceptionWithObject: self
						  requestedLength: length
							    errNo: EIO];
	}

	if (ret == 0)
		_atEndOfStream = true;

	return ret;
}

- (size_t)lowlevelWriteBuffer: (const void *)buffer
		       length: (size_t)length
{
	DWORD bytesWritten;

	if (length > UINT32_MAX)
		@throw [OFOutOfRangeException exception];

	if (_writePipe[1] == NULL)
		@throw [OFNotOpenException exceptionWithObject: self];

	if (!WriteFile(_writePipe[1], buffer, (DWORD)length, &bytesWritten,
	    NULL)) {
		int errNo = EIO;

		if (GetLastError() == ERROR_BROKEN_PIPE)
			errNo = EPIPE;

		@throw [OFWriteFailedException exceptionWithObject: self
						   requestedLength: length
						      bytesWritten: 0
							     errNo: errNo];
	}

	return (size_t)bytesWritten;
}

- (void)closeForWriting
{
	if (_writePipe[1] != NULL)
		CloseHandle(_writePipe[1]);

	_writePipe[1] = NULL;
}

- (void)close
{
	if (_readPipe[0] == NULL)
		@throw [OFNotOpenException exceptionWithObject: self];

	[self closeForWriting];
	CloseHandle(_readPipe[0]);

	if (_process != INVALID_HANDLE_VALUE) {
		TerminateProcess(_process, 0);
		CloseHandle(_process);
	}

	_process = INVALID_HANDLE_VALUE;
	_readPipe[0] = NULL;

	[super close];
}

- (int)waitForTermination
{
	if (_readPipe[0] == NULL)
		@throw [OFNotOpenException exceptionWithObject: self];

	if (_process != INVALID_HANDLE_VALUE) {
		DWORD exitCode;

		WaitForSingleObject(_process, INFINITE);

		if (GetExitCodeProcess(_process, &exitCode))
			_status = exitCode;
		else
			_status = GetLastError();

		CloseHandle(_process);
		_process = INVALID_HANDLE_VALUE;
	}

	return _status;
}
@end