#include <unistd.h>
#include <malloc.h>
#include <spawn.h>
#include <signal.h>
#include <dlfcn.h>
#include <limits.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "Spawner.h"

typedef JNIEXPORT void * (JNICALL * JVM_GetThreadInterruptEvent)();
typedef JNIEXPORT char * (JNICALL * JVM_NativePath)(const char *);

void ThrowByName(JNIEnv *env, const char *name, const char *msg);
void * GetJVMProc(char * vmlib, char * procName);

static void * hVM = NULL; /* Java Virtual Machine handler. */

JNIEXPORT jint JNICALL Java_org_eclipse_cdt_utils_spawner_Spawner_exec0
  (JNIEnv * env, jobject proc, jobjectArray cmdArray, jobjectArray envp, jstring dir, jintArray channels)
{
	int fd_map[3]; /* File descriptors.  */
	int fd_ret[3]; /* File descriptors that we return to Java.  */
	int fd[2];     /* Pipe open structure.  */
	int i;
	int nParms = 0;/* Number of parameters.  */
	int nEnvs  = 0;/* Number of environment variables.  */
	char ** pParms = NULL; /* Parameters.  */
	char ** pEnvs  = NULL; /* Environment variables.  */
	char * pCommand = NULL; /* Command to execute.  */
	char cwd[PATH_MAX + 1]; /* Current working directory.  */
	pid_t pid;       /* Process ID.  */
	struct inheritance inherit;
   
	if ((cmdArray == NULL) || ((nParms = (*env)->GetArrayLength(env, cmdArray)) == 0))
		ThrowByName(env, "java/lang/IOException", "No command line specified");

	for (i = 0; i < 3; ++i) {
		if (EOK != pipe(fd)) 
			ThrowByName(env, "java/io/IOException", "Cannot create pipe for spawner");
		if (0 == i) {
			fd_map[i] = fd[0];
			fd_ret[i] = fd[1];
		} else {
			fd_map[i] = fd[1];
			fd_ret[i] = fd[0];
		}
	}

	if (nParms > 0) {
		pParms = malloc(sizeof(char *) * (nParms + 1));
		for (i = 0; i < nParms; ++i) {
			jobject item = (*env)->GetObjectArrayElement(env, cmdArray, i);
			const char *str = (*env)->GetStringUTFChars(env, item, 0);	
			if (i == 0)
				pCommand = strdup(str);
			pParms[i] = strdup(str);
			(*env)->ReleaseStringUTFChars(env, item, str);
		}
		pParms[i] = NULL;
	}

	nEnvs = (*env) -> GetArrayLength(env, envp);
	if (nEnvs > 0) {
		pEnvs = malloc(sizeof(char *) * (nEnvs + 1));
		for (i = 0; i < nEnvs; ++i) {
			jobject item = (*env)->GetObjectArrayElement(env, envp, i);
			const char *str = (*env)->GetStringUTFChars(env, item, 0);	
			pEnvs[i] = strdup(str);
			(*env)->ReleaseStringUTFChars(env, item, str);
		}
		pEnvs[i] = NULL;
	}

	if (dir != 0) {
		char *item = (char *)(*env)->GetStringUTFChars(env, dir, 0);
		getcwd(cwd, sizeof(cwd));
		chdir(item);
		(*env)->ReleaseStringUTFChars(env, dir, item);	
	}
 
	/* Nothing for now.  */
	memset(&inherit, 0, sizeof(inherit));
	inherit.flags = SPAWN_SETGROUP;
	inherit.pgroup = SPAWN_NEWPGROUP;
 
	pid = spawnp(pCommand, 3, fd_map, &inherit, pParms, pEnvs);

	if (dir != 0) /* Restore working directory.  */
		chdir(cwd);
 
	for (i = 0; i < 3; ++i) {
		close(fd_map[i]);
	}
   
	if (-1 == pid) { /* Failed - close pipes.  */ 
		for (i = 0; i < 3; ++i) {
			close(fd_ret[i]);
		}
	} else { /* Success - return pipes to Java.  */
		(*env) -> SetIntArrayRegion(env, channels, 0, 3, fd_ret);
	}

	/* Free Parameters.  */
	if (pParms != NULL) {
		int j;
		for (j = 0; pParms[j] != NULL; j++) {
			if (pParms[j] != NULL) {
				free(pParms[j]);
			}
		}
		free(pParms);
	}

	/* Free Environment variables.  */
	if (pEnvs != NULL) {
		int j;
		for (j = 0; pEnvs[j] != NULL; j++) {
			if (pEnvs[j] != NULL) {
				free(pEnvs[j]);
			}
		}
		free(pEnvs);
	}

	/* Free Command to execute.  */
	if (pCommand != NULL) {
		free(pCommand);
	}

	return pid;
 
}

JNIEXPORT jint JNICALL Java_org_eclipse_cdt_utils_spawner_Spawner_exec1
  (JNIEnv * env, jobject proc, jobjectArray cmdArray, jobjectArray envp, jstring dir)
{
   int i;
   int nParms = 0;// Number of parameters
   int nEnvs  = 0;// Number of environment variables
   char ** pParms = NULL; // Parameters
   char ** pEnvs  = NULL; // Environment variables
   char * pCommand = NULL; // Command to execute
   char * pwd   = 0; // Process working directory
   char cwd[PATH_MAX + 1]; // Current working directory
   pid_t pid;       // Process ID
   struct inheritance inherit;
   
   if ((cmdArray == 0) || ((nParms = (*env) -> GetArrayLength(env, cmdArray)) == 0))
	ThrowByName(env, "java/lang/NullPointerException", "No command line specified");
   
   if(nParms > 0)
     {
     pParms = malloc(sizeof(char *) * (nParms + 1));
     for(i = 0; i < nParms; ++i)
	{
	jobject item = (*env) -> GetObjectArrayElement(env, cmdArray, i);
	const char *  str = (*env) -> GetStringUTFChars(env, item, 0);	
	if(i == 0)
	   pCommand = strdup(str);
	pParms[i] = strdup(str);
        (*env) -> ReleaseStringUTFChars(env, item, str);
	}
     pParms[i] = NULL;
     }
   nEnvs = (*env) -> GetArrayLength(env, envp);
   if(nEnvs > 0)
     {
     pEnvs = malloc(sizeof(char *) * (nEnvs + 1));
     for(i = 0; i < nEnvs; ++i)
	{
	jobject item = (*env) -> GetObjectArrayElement(env, envp, i);
	const char *  str = (*env) -> GetStringUTFChars(env, item, 0);	
	pEnvs[i] = strdup(str);
        (*env) -> ReleaseStringUTFChars(env, item, str);
	}
     pEnvs[i] = NULL;
     }

   if (dir != 0) 
     {
     char * item;
     pwd = strdup(item = (char *)(*env) -> GetStringUTFChars(env, dir, 0));
     getcwd(cwd, sizeof(cwd));
     chdir(pwd);
     (*env) -> ReleaseStringUTFChars(env, dir, item);	
     }
   
   // Nothing for now
   memset(&inherit, 0, sizeof(inherit));
   inherit.flags = SPAWN_SETGROUP;
   inherit.pgroup = SPAWN_NEWPGROUP;

   
   pid = spawnp(pCommand, 0, NULL, &inherit, pParms, pEnvs);

   
   if(dir != 0) // Restore working directory
     chdir(cwd);
   
   return pid;
   
}

/*
 * Class:     com_qnx_tools_utils_spawner_Spawner
 * Method:    raise
 * Signature: (II)I
 */
JNIEXPORT jint JNICALL Java_org_eclipse_cdt_utils_spawner_Spawner_raise
  (JNIEnv * env, jobject proc, jint pid, jint sig)
{
	return kill(pid, sig);
}

/*
 * Class:     com_qnx_tools_utils_spawner_Spawner
 * Method:    waitFor
 * Signature: (I)I
 */
JNIEXPORT jint JNICALL Java_org_eclipse_cdt_utils_spawner_Spawner_waitFor
  (JNIEnv * env, jobject proc, jint pid)
{
	int ret;
	int val = -1;

	ret = waitpid(pid, &stat_loc, WEXITED);
	if (ret == -1 && errno == EINTR) {
		// Throw an exception here.
	}
	if (WIFEXITED(stat_loc)) {
		val = WEXITSTATUS(stat_loc);
	}
	return val;
}


// Utilities

void ThrowByName(JNIEnv *env, const char *name, const char *msg)
{
	jclass cls = (*env)->FindClass(env, name);

	if (cls != 0) /* Otherwise an exception has already been thrown */
		(*env)->ThrowNew(env, cls, msg);

	/* It's a good practice to clean up the local references. */
	(*env)->DeleteLocalRef(env, cls);
}



void * GetJVMProc(char * vmlib, char * procName)
{
   if(NULL == vmlib)
     vmlib = "libj9vm14.so";
   if((NULL == hVM) || (NULL == procName))
     {
     if(NULL == (hVM = dlopen(vmlib, 0)))
	return NULL;
     }
   return dlsym(hVM, procName);
}
