// GRUPO: 18
// DATA DO PRAZO DE ENTREGA: 10/12/2004
// NUMERO DO TRABALHO: 02
// NOME FICHEIRO: CheckLink_18.c
// SUMARIO DO PROGRAMA:
// Este programa permite verificar o estado da ligacao a um determinado 
// servidor http. Analisa se o link e valido e tenta efectuar a ligacao em 
// intervalos de tempo aleatorios.
//-----------------------------------------


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <time.h>

#define MAXSTR 255
#define PORT 80

typedef struct serv{
	char httpd[100], httpstatus[20];
	int checkstatus, tested, valid, stoped;
	pthread_t threadP,threadF;
	pthread_cond_t cond;
	pthread_mutex_t mutex;
} *servers;

servers httpserver[100];
int timeout=0, periodo=0;
FILE *conffile;
int grace=0, thrd1=0, thrd2=0, thrd3=0;

// Funcao connect_server ---

int connect_server(char *server){ 
	int sockfd, rc, count;
	char msg[256], buffer[8192];
	struct hostent *he;
	struct sockaddr_in server_addr;

	he = gethostbyname(server);
	if (he == NULL)
		return -1;
	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0)
		return -1;
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(PORT);
	server_addr.sin_addr = *((struct in_addr *)he->h_addr);
	memset(&(server_addr.sin_zero), '\0', 8);
	rc = connect(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
	if (rc < 0){ 
		close(sockfd);
		return -1;
	}
	sprintf(msg, "GET / HTTP/1.0\nHost: %s\n\n", server);
	rc = send(sockfd, msg, strlen(msg), 0);
	if (rc < 0){
		close (sockfd);
		return -1;
	}
	do{
		count = recv(sockfd, buffer, sizeof(buffer), 0);
	} while (count > 0);
	close(sockfd);
	return 0;
}

// ---

// Funcao validate_link --- 

int validate_link(char link[100]){
	int i=0, j=0, x=0, z=0, test=0;
	char caracteres[70]; 
	strcpy(caracteres,"1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-.");
	x = strlen(link);
	z = strlen(caracteres);
	for (i=0;i < x;i++){
		for (j=0;j < z;j++){
			if (link[i] == caracteres[j])
				test=1;
		}
		
		if (test == 0)
			return (1);
		
		test=0;
	}
	
	if (strstr(link,".."))
		return (1);
	
	return (0);	
}

// ---

// load_content2men ---

void load_content2mem(){
	int i=0;
	char *fileline;

	fileline = (char *)malloc(sizeof(char *)*20);
	
	conffile=fopen("checkLink.conf","r");
	if (conffile == NULL){
		printf("# Ficheiro de configuracao nao encontrado!\n");
		exit(1);
	}
	else{
		while (fgets(fileline,MAXSTR,conffile) != NULL) {			
			if ((strcmp(fileline,"") != 0) || (strcmp(fileline,"\n") != 0)){
				httpserver[i]=(servers)malloc(sizeof(struct serv));		
				strcpy(httpserver[i]->httpd,strtok(fileline,"\n"));
				httpserver[i]->checkstatus = 0;
				httpserver[i]->tested = 0;
				httpserver[i]->stoped = 0;
				
				if (validate_link(httpserver[i]->httpd) == 0){
					httpserver[i]->valid = 0;
					strcpy(httpserver[i]->httpstatus,"not tested");
				}
				else {
					httpserver[i]->valid = 1;
					strcpy(httpserver[i]->httpstatus,"invalid link");
					printf("# Link invalido encontrado: %s\n",httpserver[i]->httpd);
					printf("# O link foi adicionado mas nao ira ser testado!\n");
				}
			}
			i++;
		} 
		
		if (i > 1)
			printf("# %d Links adicionados a lista\n",i);
		else if (i = 1)
			printf("# %d Link adicionado a lista\n",i);
		else
			printf("# Ficheiro de configuracao vazio\n");
	}
	fclose(conffile);
	free(fileline);
}

// ---

// Funcao add_new_server ---

void check_conffile(){
	int i=0,test=0;
	char *fileline;
	
	while(1){
		fileline = (char *)malloc(sizeof(char *)*20);
			
		conffile=fopen("checkLink.conf","r");
		if (conffile != NULL){
			while (fgets(fileline,MAXSTR,conffile) != NULL) {
				strcmp(fileline,strtok(fileline,"\n"));
				while (httpserver[i] != NULL){
					if (strcmp(fileline,httpserver[i]->httpd)==0){
						test = 1;
					}
					i++;
				}
			
				if (test == 0){
					httpserver[i]=(servers)malloc(sizeof(struct serv));
					strcpy(httpserver[i]->httpd,fileline);
					httpserver[i]->checkstatus = 0;
					httpserver[i]->tested = 0;
					httpserver[i]->stoped = 0;
					
					if (validate_link(httpserver[i]->httpd) == 0){
						httpserver[i]->valid = 0;
						strcpy(httpserver[i]->httpstatus,"not tested");
						printf("# --\n");
						printf("# Novo Link adicionado: %s\n",fileline);
					}
					else {
						httpserver[i]->valid = 1;
						strcpy(httpserver[i]->httpstatus,"invalid link");
						printf("# --\n");
						printf("# Link invalido encontrado: %s\n",httpserver[i]->httpd);
						printf("# O link foi adicionado mas nao ira ser testado!\n");
					}
				}
			
				i=0;
				test=0;
				sleep(1);
			}
		}
		fclose(conffile);
		free(fileline);
		
		if (grace !=0){
			thrd1 = 1;
			pthread_exit();
		}
	}
}

// ---

// Funcao print_test_results --

void print_report(){
	int i=0, pos=0, neg=0, time=0, ntested=0, inv=0, aux=0;
	float media;
	while (httpserver[i] != NULL){
		
		aux = strlen(httpserver[i]->httpd);
		
		if (aux < 12)
			printf("# %s \t\t\t [ %s ]\n",httpserver[i]->httpd,httpserver[i]->httpstatus);
		else
			printf("# %s \t\t [ %s ]\n",httpserver[i]->httpd,httpserver[i]->httpstatus);
				
		if (!(strcmp(httpserver[i]->httpstatus,"ok")))
			++pos;
		else if (!(strcmp(httpserver[i]->httpstatus,"failed")))
			++neg;
		else if (!(strcmp(httpserver[i]->httpstatus,"timeout")))
			++time;
		else if (!(strcmp(httpserver[i]->httpstatus,"not tested")))
			++ntested;
		else
			++inv;
		
		i++;
	}
	media = ((float)pos/((float)i-(float)inv))*100;
	aux = i-inv;
	printf("# %.2f positive checked links. Cheked links: %d (total %d);\n",media,aux,i); 
}

// ---

// Funcao cicle_print_report

void cicle_print_report(){
	while (1){
		if (grace !=0){
			thrd2 = 1;
			pthread_exit();
		}
		sleep(5);
		printf("# --\n");
		print_report();
		
		if (grace !=0){
			thrd2 = 1;
			pthread_exit();
		}
	}
}

// ---

// Funcao linktester ---

void linktester(int indice){
	int result;
	
	result = connect_server(httpserver[indice]->httpd);
	
	pthread_mutex_lock(&httpserver[indice]->mutex);
	if (result < 0)
		strcpy(httpserver[indice]->httpstatus,"failed");
	else
		strcpy(httpserver[indice]->httpstatus,"ok");
	
	httpserver[indice]->tested = 1;
	pthread_mutex_unlock(&httpserver[indice]->mutex);
	pthread_cond_signal(&httpserver[indice]->cond);
}
 
// ---

// Funcao test_link ---

void test_link(int indice){
	int secs, test=0, j=0, i=0, sleeptime=0;
	
	struct timespec ts;
	struct timeval tv;
			
	pthread_mutex_init(&httpserver[indice]->mutex, NULL);
	pthread_cond_init(&httpserver[indice]->cond, NULL);
	
	while (1){
		
		pthread_mutex_lock(&httpserver[indice]->mutex);
		
		pthread_create(&httpserver[indice]->threadF, NULL, (void *)&linktester, indice);
		
		secs = gettimeofday(&tv,NULL);
		ts.tv_sec = tv.tv_sec + timeout;
		ts.tv_nsec = tv.tv_usec*1000;
		
		pthread_cond_timedwait(&httpserver[indice]->cond,&httpserver[indice]->mutex,&ts);
		
		if (httpserver[indice]->tested == 0){
			strcpy(httpserver[indice]->httpstatus,"timeout");
			pthread_kill(&httpserver[indice]->threadF,9);
		}
				
		httpserver[indice]->tested=0;
	
		pthread_mutex_unlock(&httpserver[indice]->mutex);
		
		j=0+(int) (16.0*rand()/(RAND_MAX+1.0));
		i=0+(int) (2.0*rand()/(RAND_MAX+1.0));
		
		if (i==0){
			sleeptime = periodo - j;
			if (sleeptime < 0)
				sleeptime = 0;
		}
		else{
			sleeptime = periodo + j;
		}
		
		if (grace !=0){
			httpserver[indice]->stoped = 1;
			pthread_exit();
		}
		
		sleep(sleeptime);
	}
}

// --

// Funcao create_test_threads ---
void create_test_threads(){
	int i=0;
	while (1){
		while(httpserver[i] != NULL){
			if ((httpserver[i]->checkstatus == 0) && (httpserver[i]->valid == 0)){
				httpserver[i]->checkstatus = 1;
				pthread_create(&httpserver[i]->threadP, NULL, (void *)&test_link, i);
			}
			i++;
		}
		i=0;
		
		if (grace !=0){
			thrd3 = 1;
			pthread_exit();
		}
		
		sleep(1);
	}
}

// ---

// Funcao catch_pressed_keys ---

void catch_pressed_keys(){
	int i=0, test=0;
	while(1){
		switch (getchar()){
			case 'a': {
				printf("# --\n");
				printf("# user aborted, exiting -- last report\n");
				printf("# --\n");
				print_report();
				printf("\n");
				free(*httpserver);
				exit(1);
				break; 
			}
			case 'g':{
				grace = 1;
				printf("# --\n");
				printf("# starting exit procedure\n");
				while (1){
					if ((thrd1 == 1) && (thrd2 == 1)){
						while(1){
							while(httpserver[i] != NULL){
								if (httpserver[i]->stoped == 0){
									test = 1;
								}
								i++;
							}
							if (test == 0){
								printf("# -- last report --\n");
								print_report();
								printf("\n");
								free(*httpserver);
								exit(1);
							}
							test = 0;
							i=0;
						}
					}
				}
				break;
			}
			default: { printf("# tecla invalida!\n"); break; } 
		}
	}
}

// ---

// main ---

main(int argc, char *argv[]){
	pthread_t threadA, threadB, threadC;
	char itemA = 'A', itemB = 'B', itemC = 'C';
	
	if ((argv[1] == NULL) || (argv[2] == NULL))
		printf("# Argumentos iniciais sao necessarios\n");
	else {
		timeout = atoi(argv[1]);
		periodo = atoi(argv[2]);
		if ((timeout == 0) || (periodo == 0)){
			if ((strcmp(argv[1],"0")!=0) || (strcmp(argv[2],"0")!=0)){
				printf("# Argumentos iniciais invalidos\n");
				exit(1);
			}
		}
		
		if ((timeout < 0) || (periodo < 0)){
			printf("# Argumentos iniciais invalidos\n");
			exit(1);
		}
		
		system("clear");
	
		printf("# -- timeout: %d / periodo: %d --\n",timeout,periodo);
	
		load_content2mem();
	
		pthread_create(&threadA, NULL, (void *)&check_conffile, (void *)&itemA);
		pthread_create(&threadB, NULL, (void *)&create_test_threads, (void *)&itemB);
		pthread_create(&threadC, NULL, (void *)&cicle_print_report, (void *)&itemC);
		
		catch_pressed_keys();		
	}
	return 0;
}

// ---