/*
 * Copyright (C) 2019 Weber Yann
 * 
 * This file is part of PyFCGI.
 * 
 * PyFCGI is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 * 
 * PyFCGI 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with PyFCGI.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __CONF_H___
#define __CONF_H___

#include <fcgiapp.h>
#include <fcgi_stdio.h> /* fcgi library; put it first*/

#define PY_SSIZE_T_CLEAN
#include <Python.h>
#include "structmember.h"

#include <unistd.h>
#include <getopt.h>
#include <limits.h>
#include <semaphore.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "config.h"
/**@file conf.h 
 * @brief PyFCGI configuration handling headers
 * @ingroup conf_internal */

/**@defgroup conf_internal PyFCGI configuration handling
 * @brief Informations about PyFCGI configuration handling
 */

/**@defgroup conf_glob PYFCGI global (for all process) configurations
 * @see struct_pyfcgi_conf_s
 * @ingroup conf_internal */

/**@brief Friendly name for @ref pyfcgi_conf_s
 * @see struct pyfcgi_conf_s
 * @ingroup conf_internal */
typedef struct pyfcgi_conf_s pyfcgi_conf_t;
typedef struct pyfcgi_conf_logger_s pyfcgi_conf_logger_t;
typedef struct pyfcgi_context_s pyfcgi_context_t;
typedef struct pyfcgi_semdata_s pyfcgi_semdata_t;
typedef struct pyfcgi_shmdata_s pyfcgi_shmdata_t;

/**@brief Configuration globals, inherited from parent process to childs
 * @ingroup conf_internal
 * @see pyfcgi_conf_s
 */
pyfcgi_conf_t PyFCGI_conf;

/* Include other PyFCGI stuff */
#include "logger.h"
#include "pyutils.h"
#include "ipc.h"
#include "monitor.h"

/**@defgroup ret_status Function & process return status
 * @brief Constants
 * @ingroup proc_intern
 */
/**@ingroup ret_status */
#define EXIT_PYERR 4
/**@ingroup ret_status */
#define PYFCGI_TIMEOUT 8
/**@ingroup ret_status */
#define PYFCGI_ERR 16
/**@ingroup ret_status */
#define PYFCGI_WORKER_FAIL 32
/**@ingroup ret_status */
#define PYFCGI_MASTER_FAIL 64
/**@ingroup ret_status */
#define PYFCGI_FATAL 128

/**@brief Backlog argument for socket creation */
#define PYFCGI_SOCK_BACKLOG 100

/**@brief Program name */
#define PYFCGI_NAME "pyfcgi"

/**@brief Short options specifications */
#define PYFCGI_SHORT_OPT "C:l:e:E:Aw:W:m:ft:L:SPs:vVh"

/**@brief Long options specifications */
#define PYFCGI_LONG_OPT { \
	{"config", required_argument, 0, 'C'},\
	{"listen", required_argument, 0, 'l'},\
	{"pymodule", required_argument, 0, 'e'},\
	{"pyapp", required_argument, 0, 'E'},\
	{"alt-io", no_argument, 0, 'A'},\
	{"min-worker", required_argument, 0, 'w'},\
	{"max-worker", required_argument, 0, 'W'},\
	{"max-request", required_argument, 0, 'm'},\
	{"fast-spawn", no_argument, 0, 'f'},\
	{"timeout", required_argument, 0, 't'},\
	{"log", required_argument, 0, 'L'},\
	{"syslog", no_argument, 0, 'S'},\
	{"pid-file", required_argument, 0, 'P'},\
	{"socket-server", required_argument, 0, 's'},\
	{"verbose", no_argument, 0, 'v'},\
	{"version", no_argument, 0, 'V'},\
	{"help", no_argument, 0, 'h' },\
	{0, 0, 0, 0}\
}

/**@brief Data for help generation
 *
 * For each options {HELP_TEXT, ARGS_PLACEOLDER} are specified PLACEOLDER
 * is NULL for flags*/
#define PYFCGI_OPT_HELP {\
	{"Load options from configuration file", "CONFIG"},\
	{"Listen socket path (a path for UNIX socket or a 'IPV4:PORT' string)", "SOCK_PATH"},\
	{"Search application function in given python module", "MODULE_NAME"},\
	{"Python application entrypoint function name", "FUNC_NAME"},\
	{"Use stdout to communicate with web server instead of entrypoint return as specified in PEP 333", NULL},\
	{"Minimum worker in the pool", "INT"},\
	{"Maximum worker in the pool", "INT"},\
	{"Request count after wich the worker is restarted (if 0 never restart)", "INT"},\
	{"If not given there is at least 1s between 2 child creation, else childs may be spawned in small burst", NULL},\
	{"Request timeout (before worker restarts)", "SECONDS"},\
	{"Add a logfile using syntax : 'LOGFILE[;FILT][;FMT]'", "LOGGER_SPEC"},\
	{"Use syslog for logging", NULL},\
	{"Create a PID file", "FILENAME"},\
	{"Indicate a socket (for example 'udp://localhost:8765' ) to listen on, replying stats & status", "SOCKET"},\
	{"Send all loglines on stderr", NULL},\
	{"Print PyFCGI and Python version and exit", NULL},\
	{"Display this help and exit", NULL},\
}

#define PYFCGI_HELP_TEXT "\n\
Logger specification format 'LOGFILE[;FILT][;FMT]' with :\n\
\t- LOGFILE the log file name\n\
\t- FILT a number (in decimal or hexadicimal 0xXX) indicating wich\n\
\t  facility/level to log\n\
\t- FMT the logline format in a special markup format using fields between { }\n\
\t  supported fields are :\n\
\t\t- {datetime} {datetime:SIZE} {datetime:SIZE:FMT} defines a format and a \n\
\t\t  constant length for a datetime field. Default : {datetime:25:%F %T%z}\n\
\t\t- {level} the loglevel \n\
\t\t- {facility} the log facility\n\
\t\t- {pid} the process PID\n\
\t\t- {ident} the defined ident (set by process)\n\
\t\t- {msg} the log message (can only appear once)\n\
You can escape { and } by using {{ and }} and all field names can by\n\
abbreviated to one character.\n\n\
Socket URL specification format : PROT://HOST[:PORT] with PROT on of \n\
\t- tcp for tcp sockets and HOST a valid INET address\n\
\t- udp for udp sockets and HOST a valid INET address\n\
\t- unix for file sockets and HOST a valid path\n\
"

#define PYENTRY_DEFAULT_FUN "application"

/**@brief Stores a semaphore name and pointer */
struct pyfcgi_semdata_s
{
	/**@brief Semaphore names. Set by master process */
	char name[NAME_MAX - 4];
	/**@brief Semaphore pointer. */
	sem_t *sem;
};

/**@brief Stores an SHM name and pointer */
struct pyfcgi_shmdata_s
{
	/**@brief SHM name. Set by master process */
	char name[NAME_MAX];
	/**@brief SHM file descriptor */
	int fd;
	/**@brief SHM size */
	size_t len;

	/**@brief SHM pointer */
	void *ptr;
};


/**@brief Stores contextual informations about current process */
struct pyfcgi_context_s {

	/**@brief Timestamp of master process starts */
	time_t uptime;

	/**@brief Stores current process PID */
	pid_t pid;
	/**@brief Stores parent process PID */
	pid_t ppid;

	/**@brief Returned by FCGX_OpenSocket for responder process */
	int fcgi_socket;

	/**@brief Request information (local to each worker) */
	FCGX_Request fcgi_request;

	/**@brief Stores the watchdog timer */
	timer_t wd_timer;
	/**@brief Security timer sending a sigkill */
	timer_t wd_timerkill;
	/**@brief Watchdog delay */
	struct timespec wd_delay;
	/**@brief SIGKILL watchdog delay */
	struct timespec wd_killdelay;
	/**@brief Watchdog sig restorer */
	struct sigaction wd_oldsig;
	/**@brief watchdog flag */
	short wd;

	/**@brief array of worker pids (pool handler context) */
	pid_t *wrk_pids;
	/**@brief workers count */
	unsigned int n_wrk;

	/**@brief Stores IPC flag used in init */
	pyfcgi_ipc_flag_t ipc_flag;

	/**@brief Stores python_path (not dupped by python) */
	wchar_t python_path[PATH_MAX];
	/**@brief Stores venv_path for python home (not dupped by python) */
	wchar_t venv_path[PATH_MAX];
	/**@brief Stores a part of the environ (containing wsgi.* keys) */
	PyObject *wsgi_dict;
};

/**@brief Structure containing configuration
 * @ingroup conf_internal
 * The structure is used for the global @ref PyFCGI_conf variable.
 * @see pyfcgi_conf_s
 */
struct pyfcgi_conf_s
{
	/** @brief Stores pidfile path */
	char *pidfile;

	/**@brief Stores the socket path argument
	 * @ingroup conf_glob
	 * Can be a file path for a UNIX socket or IPv4:PORT string */
	char *sock_path;
	/**@brief Entrypoint module name
	 * @ingroup conf_glob */
	char *py_entrymod;
	/**@brief Entrypoint function name
	 * @ingroup conf_glob */
	char *py_entryfun;
	/**@brief If 0 use stdout to communicate with webserver, else
	 * PyFCGI will expect PEP333 compliant entrypoint */
	short pep333;
	/**@brief Minimum count worker in pool
	 * @ingroup conf_glob */
	int min_wrk;
	/**@brief Maximum count workers in pool
	 * @ingroup conf_glob */
	int max_wrk;
	/**@brief Maximum request before a worker restarts (0 for no restart)
	 * @ingroup conf_glob */
	int max_reqs;

	//Pool handling conf
	/**@brief Idle timeout : starts GC workers after Xs idle */
	time_t worker_gc_timeout;
	/**@brief Fast spawn : if 1 spawn more childs faster
	 *
	 * When not activated there is at least 1s between 2 child creation,
	 * else child are created in small burst ( ~2 childs burst)
	 */
	short worker_fast_spawn;


	//watchdogs config
	/**@brief Worker timeout in seconds (if 0 no timeout)*/
	time_t worker_timeout;
	/**@brief Pool timeout in seconds (if 0 no timeout)*/
	time_t pool_timeout;

	// logger config
	/**@brief 0 is silent 1 means logs to stderr */
	short verbosity;
	/**@brief Logger configuration
	 * @ingroup conf_glob */
	pyfcgi_conf_logger_t logs;

	/**@brief Context informations */
	pyfcgi_context_t context;

	/**@brief Semaphores informations
	 *
	 * - sems[0] is the worker state indicator : when a worker is idle the
	 * sem is incremented
	 * - sems[1] is the request counter sem : when a request is handled
	 * this sem is incremented
	 * - sems[2] is the stats/status SHM semaphore
	 */
	pyfcgi_semdata_t sems[PYFCGI_NSEM];
	/**@brief Shared memory informations */
	pyfcgi_shmdata_t shm;

	/**@brief Stores a copy of the specified socket URL to listen to. */
	char *mon_socket;
	/**@brief If 1 force ipv4 */
	short ipv4;
	/**@brief If 1 force ipv6 */
	short ipv6;
};


/**@brief Print usage on FD 2 (stdout) */
void usage();

/**@brief Print pyfcgi & python version on given fd */
void print_version(int);

/**@brief Init conf with default values */
void default_conf();

/**@brief Parse arguments and store them in conf
 * @return 0 if no error */
int parse_args(int argc, char *argv[]);

/**@brief Check Python entrypoint import
 *
 * Forks into a childprocess that will start python and import the entrypoint.
 * The child process exit status indicate if the import was successfull or not
 * @return 0 if no errors 1 if import fails
 */
int check_entrypoint_import();

/**@brief Parse a logger declaration option

 * Expected format is : LOGFILE[;FILTER][;FMT]
 * @param logspec The logspec option value
 * @return 0 if no error else 1
 */
int parse_optlog(const char* logspec);

/**@defgroup pyfcgi_watchdog PyFCGI watchdogs
 * @brief Child process watchdogs mecanism
 *
 * @ingroup proc_intern
 */

/**@brief Initialize the watchdog
 * @ingroup pyfcgi_watchdog
 * @param wd_sig_cleaner pointer on a signal handler (or NULL to
 * use @ref pyfcgi_wd_default_sighandler
 * @param delay a pointer on the watchdog timeout
 * @return 0 if no error else -1
 */
int pyfcgi_wd_init(void (*wd_sig_cleaner)(int), const struct timespec *delay);
/**@brief (Re)starts watchdog timer
 * @ingroup pyfcgi_watchdog
 *@return 0 if no error else -1 */
int pyfcgi_wd_arm();
/**@brief Temporarly disables watchdog
 * @ingroup pyfcgi_watchdog
 *@return 0 if no error else -1 */
int pyfcgi_wd_pause();
/**@brief Stop and delete a watchdog
 * @ingroup pyfcgi_watchdog
 * @return 0 if no error else -1*/
int pyfcgi_wd_stop();

/**@brief Watchdog default signal handler
 * @ingroup pyfcgi_watchdog
 * @param signum signal number*/
void pyfcgi_wd_default_sighandler(int signum);

/**@brief Return a string representing a status
 * @param status Status
 * @return a char* that should be freed
 */
char *status2str(int status);

void pyfcgi_sighandler_drop(int signum);

#endif