#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include <openssl/ssl.h>
#include <openssl/err.h>

#include "socketHelp.h"

/*
 * This function turns a IPv4 four byte octet into
 * an unsigned 32 bit integer which can be used when
 * opening new socket connections
 */
uint32_t addr2sin_addr(char *addr) {
	char *token;
	int i = 0;
	uint32_t addrNum = 0;
	unsigned long addrTempNum = 0;

	token = strtok(addr, ".");
	while(token != NULL) {
		addrTempNum = strtoul(token, NULL,10);
		if ( addrTempNum > 255 ) { // Check if octet is valid
			printf("Invalid IP octet: %ld\n", addrTempNum);

			free(token);
			return -1;
		} // Adding value to addr number
		addrNum = addrNum + ( addrTempNum << (8*(3-i)) );

		token = strtok(NULL, ".");
		i++;
	}

	free(token);
	return addrNum;
}

SSL_CTX* InitServerCTX() {
	const SSL_METHOD *method;
	SSL_CTX *ctx;

	OpenSSL_add_all_algorithms();
	SSL_load_error_strings();
	method = TLS_server_method();
	ctx = SSL_CTX_new(method);
	if ( ctx == NULL ) {
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}
	return ctx;
}

void LoadCertificates(SSL_CTX* ctx, char* certFile, char* keyFile) {
	// Set local certificate from certFile
	if ( SSL_CTX_use_certificate_file(ctx, certFile, SSL_FILETYPE_PEM) <= 0 ) {
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}
	// Set local priv key from keyFile
	if ( SSL_CTX_use_PrivateKey_file(ctx, keyFile, SSL_FILETYPE_PEM) <=0 ) {
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}
	// Verify priv key
	if ( !SSL_CTX_check_private_key(ctx) ) {
		fprintf(stderr, "Private key does not match passed certificate file\n");
		exit(EXIT_FAILURE);
	}
	return;
}

int createSecureSocket(int port, int *server_fd, struct sockaddr_in *address, int *addrlen, uint32_t listenAddr, 
		SSL_CTX **ctx, char certFile[], char keyFile[]) {

	SSL_library_init();
	*ctx = InitServerCTX();
	LoadCertificates(*ctx, certFile, keyFile);

	if ( createSocket(port, server_fd, address, addrlen, listenAddr) ) {
		fprintf(stderr, "Error create socket\n");
		exit(EXIT_FAILURE);
	}

	return 0;
}

int createSocket(int port, int *server_fd, struct sockaddr_in *address, int *addrlen, uint32_t listenAddr) {
	int opt = 1;

	// Create socket fd
	if ((*server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
		perror("socket failed");
		exit(EXIT_FAILURE);
	}

	// Attach socket to PORT
	if (setsockopt(*server_fd, SOL_SOCKET, SO_REUSEADDR |SO_REUSEPORT,
				&opt, sizeof(opt))) {
		perror("Set socket opt failure");
		exit(EXIT_FAILURE);
	}
	address->sin_family = AF_INET;
	if (listenAddr != -1) { // Checking to see if listenAddr is passed
		address->sin_addr.s_addr = htonl(listenAddr);
	} else { // Default to any addr
		address->sin_addr.s_addr = INADDR_ANY;
	}
	address->sin_port = htons (port);

	// Attach to PORT
	if (bind(*server_fd, (struct sockaddr *)address,
				sizeof(*address))<0) {
		perror("Failed to bind");
		exit(EXIT_FAILURE);
	}

	if (listen(*server_fd, 3) < 0) {
		perror("Failed to listen");
		exit(EXIT_FAILURE);
	}

	return 0;
}