#include "mapreduce.h"

// execute executables using execvp
void execute(char **argv, int nProcesses){
	pid_t  pid;

	int i;
	for (i = 0; i < nProcesses; i++){
		pid = fork();
		if (pid < 0) {
			printf("ERROR: forking child process failed\n");
			exit(1);
		} else if (pid == 0) {
			char *processID = (char *) malloc(sizeof(char) * 5); // memory leak
			sprintf(processID, "%d", i+1);
			argv[1] = processID;
			if (execvp(*argv, argv) < 0) {
				printf("ERROR: exec failed\n");
				exit(1);
			}
		}
     }
}

int main(int argc, char *argv[]) {
	
	if(argc < 4) {
		printf("Less number of arguments.\n");
		printf("./mapreduce #mappers #reducers inputFile\n");
		exit(0);
	}

	int nMappers 	= strtol(argv[1], NULL, 10);
	int nReducers 	= strtol(argv[2], NULL, 10);

	if(nMappers < nReducers){
		printf("ERROR: Number of mappers should be greater than or equal to number of reducers...\n");
		exit(0);
	}

	if(nMappers == 0 || nReducers == 0){
		printf("ERROR: Mapper and Reducer count should be grater than zero...\n");
		exit(0);
	}
	char *inputFile = argv[3];
	bookeepingCode();

	int status;
	pid_t pid = fork();
	if(pid == 0){
		//send chunks of data to the mappers in RR fashion
		printf("TEST\n");
		sendChunkData(inputFile, nMappers);
		exit(0);
	}
	sleep(1);

	// spawn mappers
	char *mapperArgv[] = {"./mapper", NULL, NULL};
	execute(mapperArgv, nMappers);

	// wait for all children to complete execution
    while (wait(&status) > 0);

    // shuffle sends the word.txt files generated by mapper 
    // to reducer based on a hash function
	pid = fork();
	if(pid == 0){
		shuffle(nMappers, nReducers);
		exit(0);
	}
	sleep(1);

	// spawn reducers
	char *reducerArgv[] = {"./reducer", NULL, NULL};
	execute(reducerArgv, nReducers);

	// wait for all children to complete execution
    while (wait(&status) > 0);

	closeQueue();
	return 0;
}