#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <getopt.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include "ipc.h"
#include "pa1.h"
#include "common.h"

#define MAX_NUM_OF_PROCESSES 10

static const char * const log_opened_fmt =
	"Pipe (input %5d, output %5d) was opened\n";

static const char * const log_closed_fmt =
	"Pipe %5d in process %5d was closed\n";

static const char * const log_read_fmt =
	"Pipe (input %5d, output %5d) in process %5d read %5d bytes\n";

static const char * const log_write_fmt =
	"Pipe (input %5d, output %5d) in process %5d write %5d bytes\n";

typedef struct{
	int in;
	int out;
} Pipe;

typedef struct{
	int numOfChildren;
	local_id id;
	Pipe *pipes[MAX_NUM_OF_PROCESSES + 1][MAX_NUM_OF_PROCESSES + 1];
} IO;

int send(void * self, local_id dst, const Message * msg){
	IO *inout = (IO*)self;
	int fd = inout -> pipes[inout -> id][dst] -> out;
	if (write(fd, msg, msg->s_header.s_payload_len + sizeof(MessageHeader)) == -1)
		return errno;
	else return 0;
}

int send_multicast(void * self, const Message * msg){
	IO *inout = (IO*)self;
	for (int i = 0; i < inout -> numOfChildren + 1; i++){
		if (i != inout -> id){ 
			int fd = inout -> pipes[inout -> id][i] -> out;
			int sum;
			switch(sum = write(fd, msg, msg -> s_header.s_payload_len + sizeof(MessageHeader))){
				case -1: return errno;
				default: 
					printf(log_write_fmt, inout -> pipes[inout -> id][i] -> in, inout -> pipes[inout -> id][i] -> out, inout -> id, sum);
					break;
			}
		}
	}
	return 0;
}

int receive(void * self, local_id from, Message * msg){
	IO *inout = (IO*)self;
	int fd = inout -> pipes[from][inout -> id] -> in;
	int sum, sum1;
	if ((sum = read(fd, &msg -> s_header, sizeof(MessageHeader))) == -1) return errno;
	printf(log_read_fmt, inout -> pipes[from][inout -> id] -> in, inout -> pipes[from][inout -> id] -> out, inout -> id, sum);
	if (msg -> s_header.s_payload_len > 0) {
		sum1 = read(fd, msg->s_payload, msg->s_header.s_payload_len);
		printf(log_read_fmt, inout -> pipes[from][inout -> id] -> in, inout -> pipes[from][inout -> id] -> out, inout -> id, sum1);
	}
	return 0;
}

//wrong, must be released with fcntl(2)
int receive_any(void * self, Message * msg){
	IO *inout = (IO*)self;
	while(1){
		for (int i = 0; i < inout -> numOfChildren + 1; i++){
			if (i != inout -> id - 1){
				int fd = inout -> pipes[i][inout -> id] -> in;
				int cur = lseek(fd, 0, SEEK_CUR);
				int end = lseek(fd, 0, SEEK_END);
				lseek(fd, cur, SEEK_SET);
				if (end > cur) {
					if (read(fd, msg, msg->s_header.s_payload_len) == -1)
						return errno;
					else return 0;					
				}
			}
		}
	}
}

int main(int argc, char *argv[]){
	
	// create an IO structure
	IO *inout = (IO*)malloc(sizeof(IO));
	
	// number of child processes from command line to numOfChildren variable
	int opt;	
	while ( (opt = getopt(argc,argv,"p:")) != -1){
		switch (opt){
		case 'p': inout -> numOfChildren = atoi(optarg); break;
		default:
			free(inout); 
			return -1;		
        	}
	}

	inout -> id = PARENT_ID;
	
	// create or open logs for writing
	FILE *pipesLog = fopen(pipes_log, "w+");
	FILE *eventsLog = fopen(events_log, "w+");
	
	// create pipes and fill the inout.pipes  
	for (int i = 0; i < inout -> numOfChildren + 1; i++){
		for (int j = 0; j < inout -> numOfChildren + 1; j++){
			if  (i != j){
				Pipe *pipeMem = (Pipe*)malloc(sizeof(Pipe));
				int pipefd[2];
				pipe(pipefd);
				pipeMem -> in = pipefd[0];
				pipeMem -> out = pipefd[1];
				inout -> pipes[i][j] = pipeMem;
				fprintf(pipesLog, log_opened_fmt, pipefd[0], pipefd[1]);
				fflush(pipesLog);
				printf(log_opened_fmt, pipefd[0], pipefd[1]);
			}
		}	
	}	
	
	Message *msgReceive = (Message*)malloc(sizeof(Message));
	
	// create children
	for (int id = 1; id < inout -> numOfChildren + 1; id++){
		switch(fork()){
			case -1:
				perror("fork");
				exit(1);
			case 0:
				fprintf(eventsLog, log_started_fmt, id, getpid(), getppid());
				fflush(eventsLog);
				printf(log_started_fmt, id, getpid(), getppid());
				
				inout -> id = id;
				
				// close unused pipes
				for (int i = 0; i < inout -> numOfChildren + 1; i++){
					for (int j = 0; j < inout -> numOfChildren + 1; j++){					
						if (i != j){
							if (i != inout -> id && j != inout -> id){
								close(inout -> pipes[i][j] -> in);
								fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
								fflush(pipesLog);
								printf(log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
								close(inout -> pipes[i][j] -> out);
								fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
								fflush(pipesLog);
								printf(log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
							}
							if (i == inout -> id){
								close(inout -> pipes[i][j] -> in);
								fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
								fflush(pipesLog);
								printf(log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
							}
							if (j == inout -> id){
								close(inout -> pipes[i][j] -> out);
								fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
								fflush(pipesLog);
								printf(log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
							}
							
						}
					
					}
				}
				
				// fill the STARTED message
				Message *msg = (Message*)malloc(sizeof(Message));
				sprintf(msg -> s_payload, log_started_fmt, id, getpid(), getppid());
				msg -> s_header.s_magic = MESSAGE_MAGIC;
				msg -> s_header.s_payload_len = strlen(msg -> s_payload)+1;
				msg -> s_header.s_type = STARTED;
				msg -> s_header.s_local_time = time(NULL);

				// send STARTED message to other processes
				send_multicast(inout, msg);

				// receive STARTED message from other processes
				for (int i = 1; i < inout -> numOfChildren + 1; i++){
					if (i != inout -> id){					
						do{
							receive(inout, i, msgReceive);
						} while (msgReceive -> s_header.s_type != STARTED);
					}
				}

				// logs
				fprintf(eventsLog, log_received_all_started_fmt, inout -> id);
				fflush(eventsLog);
				printf(log_received_all_started_fmt, inout -> id);

				// fill the DONE message
				sprintf(msg -> s_payload, log_done_fmt, inout -> id);
				msg -> s_header.s_magic = MESSAGE_MAGIC;
				msg -> s_header.s_payload_len = strlen(msg -> s_payload)+1;
				msg -> s_header.s_type = DONE;
				msg -> s_header.s_local_time = time(NULL);
				//msg -> s_header = *head;

				// send STARTED message to other processes
				send_multicast(inout, msg);

				// receive STARTED message from other processes
				for (int i = 1; i < inout -> numOfChildren + 1; i++){
					if (i != inout -> id){					
						do{
							receive(inout, i, msgReceive);
						} while (msgReceive -> s_header.s_type != DONE);
					}
				}

				// logs
				fprintf(eventsLog, log_received_all_done_fmt, inout -> id);
				fflush(eventsLog);
				printf(log_received_all_done_fmt, inout -> id);

				// close all other pipes 
				for (int i = 0; i < inout -> numOfChildren + 1; i++){
					for (int j = 0; j < inout -> numOfChildren + 1; j++){					
						if (i != j){
							if (i == inout -> id){
 								close(inout -> pipes[i][j] -> out);
								fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
								fflush(pipesLog);
								printf(log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
							}
							if (j == inout -> id){
 								close(inout -> pipes[i][j] -> in);
								fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
								fflush(pipesLog);
								printf(log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
								
							}
						}
					}
				}
				
				for (int i = 0; i < inout -> numOfChildren + 1; i++){
					for (int j = 0; j < inout -> numOfChildren + 1; j++){					
						if (i != j) free(inout -> pipes[i][j]);
 					}						
				}
				free(msg);
				fprintf(eventsLog, log_done_fmt, inout -> id);
				fflush(eventsLog);
				printf(log_done_fmt, inout -> id);
				return 0;
			default:
				break;				
		}
	}
	
	for (int i = 0; i < inout -> numOfChildren + 1; i++){
		for (int j = 0; j < inout -> numOfChildren + 1; j++){					
			if (i != j){
				if (i != PARENT_ID && j != PARENT_ID){
 					close(inout -> pipes[i][j] -> in);
					fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
					fflush(pipesLog);
					printf(log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
					close(inout -> pipes[i][j] -> out);
					fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
					fflush(pipesLog);
					printf(log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
				}
				if (i == PARENT_ID){
					close(inout -> pipes[i][j] -> in);
					fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
					fflush(pipesLog);
					printf(log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
				}
				if (j == PARENT_ID){
					close(inout -> pipes[i][j] -> out);
					fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
					fflush(pipesLog);
					printf(log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
				}
			}
		}
	}
	
	for (int i = 1; i < inout -> numOfChildren + 1; i++){
		if (i != inout -> id){		
			do{
				receive(inout, i, msgReceive);
			} while (msgReceive -> s_header.s_type != STARTED);
		}
	}
	fprintf(eventsLog, log_received_all_started_fmt, inout -> id);
	fflush(eventsLog);
	printf(log_received_all_started_fmt, inout -> id);
	for (int i = 1; i < inout -> numOfChildren + 1; i++){
		if (i != inout -> id){
			do{
				receive(inout, i, msgReceive);
			} while (msgReceive -> s_header.s_type != DONE);
		}
	}
	fprintf(eventsLog, log_received_all_done_fmt, inout -> id);
	fflush(eventsLog);
	printf(log_received_all_done_fmt, inout -> id);
	for (int i = 0; i < inout -> numOfChildren + 1; i++){
		for (int j = 0; j < inout -> numOfChildren + 1; j++){					
			if (i != j){
				if (i == PARENT_ID){
 					close(inout -> pipes[i][j] -> out);
					fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
					fflush(pipesLog);
					printf(log_closed_fmt, inout -> pipes[i][j] -> out, inout -> id);
				}
				if (j == PARENT_ID){
 					close(inout -> pipes[i][j] -> in);
					fprintf(pipesLog, log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
					fflush(pipesLog);
					printf(log_closed_fmt, inout -> pipes[i][j] -> in, inout -> id);
				}
			}
		}
	}
	for (int i = 0; i < inout -> numOfChildren; i++)
		wait(NULL);
	free(inout);
	free(msgReceive);
	fclose(pipesLog);
	fclose(eventsLog);
	return 0;
}