/**
 * WinPR: Windows Portable Runtime
 * WinPR Logger
 *
 * Copyright © 2015 Thincast Technologies GmbH
 * Copyright © 2015 David FORT <contact@hardening-consulting.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <winpr/config.h>

#include "JournaldAppender.h"

#include <unistd.h>
#include <syslog.h>
#include <systemd/sd-journal.h>

#include <winpr/crt.h>
#include <winpr/environment.h>

typedef struct
{
	wLogAppender common;
	char* identifier;
	FILE* stream;
} wLogJournaldAppender;

static BOOL WLog_JournaldAppender_Open(wLog* log, wLogAppender* appender)
{
	int fd = 0;
	wLogJournaldAppender* journaldAppender = nullptr;

	if (!log || !appender)
		return FALSE;

	journaldAppender = (wLogJournaldAppender*)appender;
	if (journaldAppender->stream)
		return TRUE;

	fd = sd_journal_stream_fd(journaldAppender->identifier, LOG_INFO, 1);
	if (fd < 0)
		return FALSE;

	journaldAppender->stream = fdopen(fd, "w");
	if (!journaldAppender->stream)
	{
		close(fd);
		return FALSE;
	}

	setbuffer(journaldAppender->stream, nullptr, 0);
	return TRUE;
}

static BOOL WLog_JournaldAppender_Close(wLog* log, wLogAppender* appender)
{
	wLogJournaldAppender* journaldAppender = (wLogJournaldAppender*)appender;
	if (!log || !appender)
		return FALSE;

	if (journaldAppender->stream)
		(void)fclose(journaldAppender->stream);

	free(journaldAppender->identifier);

	journaldAppender->stream = nullptr;
	journaldAppender->identifier = nullptr;
	return TRUE;
}

static BOOL WLog_JournaldAppender_WriteMessage(wLog* log, wLogAppender* appender,
                                               const wLogMessage* cmessage)
{
	if (!log || !appender || !cmessage)
		return FALSE;

	wLogJournaldAppender* journaldAppender = (wLogJournaldAppender*)appender;

	const char* formatStr = nullptr;
	switch (cmessage->Level)
	{
		case WLOG_TRACE:
		case WLOG_DEBUG:
			formatStr = "<7>%s%s\n";
			break;
		case WLOG_INFO:
			formatStr = "<6>%s%s\n";
			break;
		case WLOG_WARN:
			formatStr = "<4>%s%s\n";
			break;
		case WLOG_ERROR:
			formatStr = "<3>%s%s\n";
			break;
		case WLOG_FATAL:
			formatStr = "<2>%s%s\n";
			break;
		case WLOG_OFF:
			return TRUE;
		default:
			(void)fprintf(stderr, "%s: unknown level %" PRIu32 "\n", __func__, cmessage->Level);
			return FALSE;
	}

	char prefix[WLOG_MAX_PREFIX_SIZE] = WINPR_C_ARRAY_INIT;
	WLog_Layout_GetMessagePrefix(log, appender->Layout, cmessage, prefix, sizeof(prefix));

	if (cmessage->Level != WLOG_OFF)
	{
		WINPR_PRAGMA_DIAG_PUSH
		WINPR_PRAGMA_DIAG_IGNORED_FORMAT_NONLITERAL(void)
		fprintf(journaldAppender->stream, formatStr, prefix, cmessage->TextString);
		WINPR_PRAGMA_DIAG_POP
	}
	return TRUE;
}

static BOOL WLog_JournaldAppender_WriteDataMessage(wLog* log, wLogAppender* appender,
                                                   const wLogMessage* message)
{
	if (!log || !appender || !message)
		return FALSE;

	(void)fprintf(stderr, "[TODO: %s] data messages not implemented! Ignoring.\n", __func__);
	return TRUE;
}

static BOOL WLog_JournaldAppender_WriteImageMessage(wLog* log, wLogAppender* appender,
                                                    const wLogMessage* message)
{
	if (!log || !appender || !message)
		return FALSE;

	(void)fprintf(stderr, "[TODO: %s] image messages not implemented! Ignoring.\n", __func__);
	return TRUE;
}

static BOOL WLog_JournaldAppender_Set(wLogAppender* appender, const char* setting, void* value)
{
	wLogJournaldAppender* journaldAppender = (wLogJournaldAppender*)appender;

	/* Just check the value string is not empty */
	if (!value || (strnlen(value, 2) == 0))
		return FALSE;

	if (strcmp("identifier", setting) != 0)
		return FALSE;

	/* If the stream is already open the identifier can't be changed */
	if (journaldAppender->stream)
		return FALSE;

	if (journaldAppender->identifier)
		free(journaldAppender->identifier);

	return ((journaldAppender->identifier = _strdup((const char*)value)) != nullptr);
}

static void WLog_JournaldAppender_Free(wLogAppender* appender)
{
	wLogJournaldAppender* journaldAppender = nullptr;
	if (appender)
	{
		journaldAppender = (wLogJournaldAppender*)appender;
		if (journaldAppender->stream)
			(void)fclose(journaldAppender->stream);
		free(journaldAppender->identifier);
		free(journaldAppender);
	}
}

wLogAppender* WLog_JournaldAppender_New(wLog* log)
{
	LPCSTR name = "WLOG_JOURNALD_ID";

	wLogJournaldAppender* appender = (wLogJournaldAppender*)calloc(1, sizeof(wLogJournaldAppender));
	if (!appender)
		return nullptr;

	appender->common.Type = WLOG_APPENDER_JOURNALD;
	appender->common.Open = WLog_JournaldAppender_Open;
	appender->common.Close = WLog_JournaldAppender_Close;
	appender->common.WriteMessage = WLog_JournaldAppender_WriteMessage;
	appender->common.WriteDataMessage = WLog_JournaldAppender_WriteDataMessage;
	appender->common.WriteImageMessage = WLog_JournaldAppender_WriteImageMessage;
	appender->common.Set = WLog_JournaldAppender_Set;
	appender->common.Free = WLog_JournaldAppender_Free;

	const DWORD nSize = GetEnvironmentVariableA(name, nullptr, 0);
	if (nSize)
	{
		appender->identifier = (LPSTR)malloc(nSize);
		if (!appender->identifier)
			goto error_open;

		if (GetEnvironmentVariableA(name, appender->identifier, nSize) != nSize - 1)
			goto error_open;

		if (!WLog_JournaldAppender_Open(log, (wLogAppender*)appender))
			goto error_open;
	}

	return (wLogAppender*)appender;

error_open:
	free(appender->identifier);
	free(appender);
	return nullptr;
}