/* -*- mode: C; coding: euc-japan -*- */
/* $OpenXM: OpenXM/src/oxc/sm_ext.c,v 1.12 2016/04/02 15:01:46 ohara Exp $ */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <signal.h>
#include <ox_toolkit.h>
#include "sm.h"

static int  sm_control_spawn();
static int  sm_control_terminate();
static int  sm_control_kill();
static int  sm_control_reset_pid();

static void pid_extend();
static int  pid_lookup(pid_t pid);
static int  pid_registered(pid_t pid);
static void pid_register(pid_t pid);
static void pid_delete(pid_t pid);
static int  pid_reset(pid_t pid);
static int  pid_kill(pid_t pid);
static void pid_kill_all();

#define IS_CMO_INT32(c)       ((c) && ((c)->tag == CMO_INT32))
#define IS_CMO_STRING(c)      ((c) && ((c)->tag == CMO_STRING))
#define IS_CMO_LIST(c)        ((c) && ((c)->tag == CMO_LIST))
#define IS_CMO_LIST_LEN(c,n)  (IS_CMO_LIST(c) && (list_length((c)) >= (n)))

/* ultra loose data base. */
static struct { int (*func_ptr)(); char *key; } tbl_lfunc[] = {
    {lf_oxc_open, "spawn"}, 
    {lf_oxc_open, "oxc_open"}, 
    {NULL, NULL}
};

static struct { int (*func_ptr)(); int key; } tbl_smcmd[] = {
    {sm_control_spawn,     SM_control_spawn_server},
    {sm_control_terminate, SM_control_terminate_server},
    {sm_executeFunction, SM_executeFunction}, 
    {sm_mathcap,         SM_mathcap},
    {sm_set_mathcap,     SM_setMathCap},
    {sm_popCMO,          SM_popCMO},
    {sm_pops,            SM_pops},
    {sm_control_reset_pid, SM_control_reset_connection_server},
    {sm_control_kill, SM_control_kill},
    {NULL, 0}
};

extern OXFILE *stack_oxfp;

int (*sm_search_f(int code))()
{
    int i;
    for (i=0; tbl_smcmd[i].key != 0; i++) {
        if (code == tbl_smcmd[i].key) {
            return tbl_smcmd[i].func_ptr;
        }
    }
    return NULL;
}

static int (*lookup_localfunction(char *name))()
{
    int i;
    for (i=0; tbl_lfunc[i].key != NULL; i++) {
        if (strcmp(name, tbl_lfunc[i].key) == 0) {
            return tbl_lfunc[i].func_ptr;
        }
    }
    return NULL;
}

/* 
Normally local functions push a return value to the stack.
but, if error occurs, then these return non-positive numbers and
the sm_executeFunction push an error object.
*/
int sm_executeFunction()
{
    int (*func)();
    int retcode = 0;
    cmo *ob = pop();
    if (ob->tag == CMO_STRING) {
        func = lookup_localfunction(((cmo_string *)ob)->s);
        if (func != NULL) {
            if ((retcode = func()) > 0) {
                return 0;
            }
        }
    }
    push_error(retcode, ob);
    return 0;
}

/* getargs() set number of popped objects to argc. */
static int getargs(cmo ***args)
{
    cmo **argv;
    int i;
    int argc = -1;
    cmo_int32 *m = (cmo_int32 *)pop();

    if (m->tag != CMO_INT32 || (argc = m->i) < 0) {
        ox_printf("oxc: invalid arguments\n");
    }else {
        argv = (cmo **)malloc(sizeof(cmo *)*argc);
        for(i=0; i<argc; i++) {
            argv[i] = pop();
        }
        *args = argv;
    }
    return argc;
}

#define MAX_PROCESS 1024

/* Process Table */
static pid_t *pids = NULL;
static int pid_ptr = 0;
static int pid_size = 0;

static void pids_extend()
{
    int size2 = pid_size + MAX_PROCESS;
    pid_t *pids2 = (pid_t *)malloc(sizeof(pid_t)*size2);
    if (pids != NULL) {
        memcpy(pids2, pids, sizeof(pid_t)*pid_size);
        free(pids);
    }
    pid_size = size2;
    pids = pids2;
}

static int pid_lookup(pid_t pid)
{
    int i;
    for(i=0; i<pid_ptr; i++) {
        if (pids[i] == pid) {
            return i;
        }
    }
    return -1;
}

static int pid_registered(pid_t pid)
{
    return pid_lookup(pid)+1;
}

static void pid_register(pid_t pid)
{
    if (pid_ptr >= pid_size) {
        pids_extend();
    }
    pids[pid_ptr++] = pid;
}

static void pid_delete(pid_t pid)
{
    int i = pid_lookup(pid);
    if (i >= 0 && i != --pid_ptr) {
        pids[i] = pids[pid_ptr];
    }
}

static int pid_reset(pid_t pid)
{
    if (pid_registered(pid)) {
        kill(pid, SIGUSR1);
        return 1;
    }
    return 0;
}

static int pid_kill(pid_t pid)
{
    if (pid_registered(pid)) {
        kill(pid, SIGKILL);
        pid_delete(pid);
        return 1;
    }
    return 0;
}

/* Killing all child processes */
static void pid_kill_all()
{
    while(pid_ptr > 0) {
        kill(pids[--pid_ptr], SIGKILL);
    }
}

cmo_error2 *type_checker(cmo *ob, int type)
{
/*  cmo_error2 *err_ob; */
    if (ob->tag != type) {
        /* push and return an error object */
    }
    return NULL;
}

int lf_oxc_open()
{
    cmo_int32 *argc = (cmo_int32 *)pop();
	if (argc->tag == CMO_INT32 && argc->i == 1) {
		return sm_control_spawn();
	}
	push_error(-1, (cmo *)argc);
	return -1;
}

int sm_control_spawn_typecheck(cmo_list *args, int *portp, char **s)
{
    cmo_int32 *port;
    cmo_string *name;

    if( IS_CMO_LIST_LEN(args,2) ) {
        name = (cmo_string *)list_nth(args, 1);
        args = (cmo_list *)list_first_cmo(args);
        if( IS_CMO_STRING(name) && IS_CMO_LIST_LEN(args,1) ) {
            port   = (cmo_int32 *)list_first_cmo(args);
            if( IS_CMO_INT32(port) && name->s && which(name->s, getenv("PATH")) != NULL) {
                *portp = port->i;
                *s     = name->s;
                return 1;
            }
        }
    }
    return 0;
}

static int sm_control_spawn()
{
    int port;
    char *s;
    pid_t pid;
    cmo *args = pop();

    if (sm_control_spawn_typecheck((cmo_list *)args, &port, &s)) {
        pid = lf_oxc_open_main(s, (short)port);
        if (pid > 0) {
            push((cmo *)new_cmo_int32(pid));
            pid_register(pid);
            ox_printf("oxc: spawns %s\n", s);
            return pid;
        }
    }
    push_error(-1, (cmo *)args);
    return 0;
}

int sm_mathcap()
{
    push((cmo *)oxf_cmo_mathcap(stack_oxfp));
    return 0;
}

int sm_set_mathcap()
{
    cmo_mathcap *m = (cmo_mathcap *)pop();
    if (m->tag == CMO_MATHCAP) {
        oxf_mathcap_update(stack_oxfp, m);
    }else {
        push_error(-1, (cmo *)m);
        /* an error object must be pushed */
    }
    return 0;
}

static int sm_control_kill()
{
    pid_kill_all();
    return 0;
}

static int sm_control_terminate()
{
    cmo_int32 *m = (cmo_int32 *)pop();
    pid_t pid = m->i;
    if (m->tag != CMO_INT32 || !pid_kill(pid)) {
        push_error(-1, (cmo *)m);
    }
    return 0;
}

static int sm_control_reset_pid()
{
    cmo_int32 *m = (cmo_int32 *)pop();
    pid_t pid = m->i;
    if (m->tag != CMO_INT32 || !pid_reset(pid)) {
        push_error(-1, (cmo *)m);
        return 0;
    }
    /* ... */
    return 0;
}