#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <assert.h>

// printf Formating
#define X_RED "\x1B[31m"
#define X_GREEN "\x1B[32m"
#define X_YELLOW "\x1B[33m"
#define X_RST "\x1B[0m"


// TEST FRAMEWORK STRUCT
typedef struct testnode{
	char* name;
	int (*op)(void);
	struct testnode* next;
}testnode;

// LL nodes
static testnode* head = NULL;
static testnode* tail = NULL;
static testnode* ptr = NULL;

// TEST FRAMEWORK MACRO
// create a new node and pass in the name of the test. Then make a new function
// that adds the test to the LL. __attribute__((constructor)) has the function
// run before main
#define TEST(UNIT)\
	static int UNIT(void);\
	static testnode UNIT##node = {#UNIT, UNIT, NULL};\
	__attribute__((constructor)) \
	static void add##UNIT(void){ \
		if (head == NULL){\
			head = &UNIT##node;\
			tail = head;\
			return; \
		}\
		ptr = tail;\
		tail = &UNIT##node;\
		ptr->next = tail;\
	}\
	static int UNIT(void)

// TEST HELPER FUNCTIONS and STRUCTS
typedef enum {START, END} header_opt;
static void ptest_headers(header_opt option){
	switch (option){
	case START:
		printf("\n-------------------\n");
		printf("   Starting Tests\n");
		printf("-------------------\n");
		break;
	case END:
		printf("-------------------\n");
		printf("   ENDING TESTS\n");
		printf("-------------------\n\n");
		break;
	default:
		printf("error: Wrong option in ptest_headers()\n");
		exit(-1);
	}
}

typedef enum {PASS, FAIL}rc_opt;
static void ppass_fail(rc_opt rc){
	switch (rc){
	case PASS:
		printf("%s[PASS]%s ", X_GREEN, X_RST);
		printf("%s", ptr->name);
		break;
	case FAIL:
		printf("%s[FAIL]%s ", X_RED, X_RST);
		printf("%s ", ptr->name);
		break;
	default:
		printf("error: Unknown return code");
		exit(-1);
	}

}

static int presult(int status){
	if (WIFEXITED(status)){
		int rc = WEXITSTATUS(status);
		if (rc == 0) {
			ppass_fail(PASS);
			return 0;
		}
		else{
			ppass_fail(FAIL);
			printf("- Exit Code %s(%d)%s",
					X_YELLOW, rc, X_RST);
			return 1;
		}
	}
	else if (WIFSIGNALED(status)){
		ppass_fail(FAIL);
		printf("- Termination Signal %s(%d)%s",
				X_YELLOW, WTERMSIG(status), X_RST);
		return 1;
	}
	else{
		printf("%s[FAIL]%s ", X_RED, X_RST);
		printf("%s ", ptr->name);
		printf("- Unknown Error ");
		return 1;
	}
}

static int run_child(){
	int status;
	pid_t cpid = fork();
	if (cpid < 0){
		perror("fork");
		exit(EXIT_FAILURE);
	}

	if (cpid == 0){
		int rc = ptr->op();
		_exit(rc);
	}else{
		if (waitpid(cpid, &status, 0) < 0){
			perror("waitpid");
			exit(EXIT_FAILURE);
		}
	}

	return status;
}

static int run_tests(){
	int total_tests = 0;
	int errors = 0;

	ptest_headers(START);
	
	ptr = head;
	while (ptr != NULL){
		total_tests++;


		if(presult(run_child())){
			errors++;
		}

		printf("\n");
		ptr = ptr->next;
	}
	

	printf("\nTests completed with %s%d PASS%s", X_GREEN, total_tests - errors, X_RST);
	printf(" and %s%d FAIL%s\n", X_RED, errors, X_RST);

	ptest_headers(END);

	if (errors > 0){
		return 1;
	}
	return 0;
}