/*
	Wordle game implementation in the C programming language
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

#define RESET  "\x1b[0m"		// color 0
#define RED    "\x1b[31m" 		// color 1
#define GREEN  "\x1b[32m"		// color 2
#define YELLOW "\x1b[33m"		// color 3

char wordlist_path[1024];
char wordlist[16384][6]; // 2^14
int len_wordlist = 0;
int flag_verbose = 0;
int flag_worldlist = 0;
char playfield[6][5] = {
	{ ' ', ' ', ' ', ' ', ' ' },
	{ ' ', ' ', ' ', ' ', ' ' },
	{ ' ', ' ', ' ', ' ', ' ' },
	{ ' ', ' ', ' ', ' ', ' ' },
	{ ' ', ' ', ' ', ' ', ' ' },
	{ ' ', ' ', ' ', ' ', ' ' }
};
char pf_props[6][5][2] = {
	// <char>	<colorcode>  	 
	// letter 	0, 1, 2 or 3 where 
	//				0 (RESET) 	is not yet guessed 
	// 				1 (RED) 	is out-of-place,
	// 				2 (GREEN) 	is correct and  
	//				3 (YELLOW)	is incorrect
	
	{ " 0", " 0", " 0", " 0", " 0" },
	{ " 0", " 0", " 0", " 0", " 0" },
	{ " 0", " 0", " 0", " 0", " 0" },
	{ " 0", " 0", " 0", " 0", " 0" },
	{ " 0", " 0", " 0", " 0", " 0" },
	{ " 0", " 0", " 0", " 0", " 0" }
};
char word_to_guess[5];
int turns = 0;
int win = 0;
int lose = 0;
int quit = 0;


/*
	tests if a file exists
	return 0 - yes
	return 1 - no
*/
int file_exists(char path[]) {
	if (access(path, F_OK) != 0) {
		return 0;
	} else {
		return 1;
	}
}

/*
	prints the help & usage for the user to know what to do
*/
void print_help_and_usage() {
	fprintf(stdout,
		"Help and usage for Wordle:\n"
		"\n"
		"Help:\n"
		"--wordlist <path_to_wordlist_file> ... specify a custom wordlist\n"
		"                                       RULES: five characters on each line (no empty lines),\n"
		"                                              each new line is separated by '\\n' (Enter/Return)\n"
		"--verbose ............................ be verbose (show what the program is doing aka debug info)\n"
		"--help ............................... show this help screen\n"
		"\n"
		"Usage:\n"
		"\n"
		"wordle\n"
		"=> starts Wordle with the default wordlist\n"
		"wordle --wordlist <path_to_wordlist_file>\n"
		"=> starts Wordle with a specified wordlist\n"
	);
}

/*
	gets a random word from the given wordlist
*/
void get_random_word(char word_to_guess[], char wordlist_path[]) {
	FILE* wordlist_file = fopen(wordlist_path, "r");
	char ch;
	int i = 0;
	char temp_word[6];
	while ((ch = fgetc(wordlist_file)) != EOF) {
		if (ch != '\n') {
			temp_word[i] = ch;
			i++;
		} else {
			temp_word[i] = '\0';
			i = 0;
			strcpy(wordlist[len_wordlist], temp_word);
			len_wordlist++;
		}
	}

	srand(time(NULL));

	strcpy(word_to_guess, wordlist[rand() % len_wordlist]);
}

/*
	clears the console/screen
*/
void clear() {
	printf("\e[1;1H\e[2J");
}

/*
	prints the current state of the game
	shows 
		correct letters
		incorrect letters
		and out-of-place letters
		also the previous attempts
*/
void show() {
	clear();
	printf("╔═══╦═══╦═══╦═══╦═══╗\n");
	for (int i = 0; i < 6; i++) {
		for (int j = 0; j < 5; j++) {
			switch (pf_props[i][j][1]) {
			case '0':
				printf("║ %c ", playfield[i][j]);
				break;
			case '1':
				printf("║ " RED "%c " RESET, playfield[i][j]);
				break;
			case '2':
				printf("║ " GREEN "%c " RESET, playfield[i][j]);
				break;
			case '3':
				printf("║ " YELLOW "%c " RESET, playfield[i][j]);
				break;
			}
		}
		printf("║\n");
		if (i < 5) printf("╠═══╬═══╬═══╬═══╬═══╣\n");
	}
	printf("╚═══╩═══╩═══╩═══╩═══╝\n");
}

/*
	prompt the user for their input
*/
void prompt(char user_input[]) {
	printf(">> ");
	scanf("%5s", user_input);
}

/*
	linear search helper function for searching within the wordlist
*/
int search_wordlist(char wordlist[][6], char target[]) {
	for (int i = 0; i < len_wordlist; i++) {
		if (strcmp(wordlist[i], target) == 0) return i;
	}
	return -1;
}

/*
	helper function for searching within a string
*/
int search_word(char word[], char target) {
	for (int i = 0; i < sizeof(word)/sizeof(word[0]); i++) {
		if (word[i] == target) return i;
	}
	return -1;	
}

/*
	evaluate the loss
*/
void eval_lose() {
	if (turns >= 5 && win == 0) {
		lose = 1;
	}
}

/*
	evaluate the win
*/
void eval_win(int i) {
	if (strcmp(wordlist[i], word_to_guess) == 0) {
		win = 1;
	}
}

/*
	helper function for evaluating the properties of a word
*/
void eval_props(char word[]) {
	for (int i = 0; i < 5; i++) {
		if (word_to_guess[i] == word[i]) {
			pf_props[turns][i][0] = word[i];
			pf_props[turns][i][1] = '2';
		} else if (search_word(word_to_guess, word[i]) != -1 && word_to_guess[i] != word[i]) {
			pf_props[turns][i][0] = word[i];
			pf_props[turns][i][1] = '3';
		} else if (search_word(word_to_guess, word[i]) == -1) {
			pf_props[turns][i][0] = word[i];
			pf_props[turns][i][1] = '1';			
		}
	}
}

/*
	put a valid word into the playfield
*/
void put_word_into_playfield(char word[]) {
	strcpy(playfield[turns], word);
	turns++;

	// resetting the rest of the playfield
	for (int i = turns; i < turns + (6 - turns); i++) {
		strcpy(playfield[i], "     ");
	}
}

/*
	evaluate the word
*/
void eval_word(char word[]) {
	printf("\n%d\n", search_wordlist(wordlist, word));
	if (search_wordlist(wordlist, word) != -1) {
		eval_win(search_wordlist(wordlist, word));
		eval_lose();
		eval_props(word); // eval correct/incorrect/oop letters
		put_word_into_playfield(word);
	} else {
		clear();
		printf("Word %s not in wordlist\n", word);
		sleep(2);
	}
}

/*
	# prerequisites:    
	& 1 choose a random word from a wordlist 

	# algo steps:
	& 1 clear the screen
	& 2 display the current state of the playfield
	& 3 prompt the user to enter a word
	& 4 evaluate the word
	& 5 print the word on the screen with the corresponding parameters at each letter (right position, wrong position, not in word)
	& 6.1 if the user entered the right word, show a winning message and exit
	& 6.2 if the user has tried 6 times already, show a losing message, the word and exit
*/
void game() {
	// step 1 & 2
	show();

	// step 3
	char user_input[5];
	prompt(user_input);

	// implemented a quit function
	if (user_input[0] == 'q') quit = 1;

	// step 4 & 5
	eval_word(user_input);
}

/*
	pass the arguments
*/
int argparse(int argc, char *argv[]) {
	int flag_error = 0;
	for (int i = 0; i < argc; i++) {
		/*
			look for invalid arguments
		*/
		for (int j = 1; j < argc; j++) {
			if (strcmp(argv[j], "--wordlist") != 0 && strcmp(argv[j-1], "--wordlist") != 0 && strcmp(argv[j], "--verbose") != 0 && strcmp(argv[j], "--help") != 0) {
				fprintf(stderr, "Invalid argument %s\n", argv[j]);
				flag_error = 1;
			}
		}

		/*
			print the help & usage
		*/

		if (strcmp(argv[i], "--help") == 0) {
			print_help_and_usage();
			return 0;
		}

		/*
			getting the debug flag for debug printing
		*/
		if (strcmp(argv[i], "--verbose") == 0 && flag_verbose == 0) {
			flag_verbose = 1;
		}

		/*
			getting the path to the wordlist
		*/
		if (strcmp(argv[i], "--wordlist") == 0 && flag_worldlist == 0) {
			flag_worldlist = 1;
			if (argv[i+1] != NULL) { // if there is an argument present after that, read it as the wordlist path
				strcpy(wordlist_path, argv[i+1]);
			} else {
				fprintf(stderr, "Missing argument after %s\nUsage: %s <path_to_wordlist_file>\n", argv[i], argv[i]);
				flag_error = 1;
			}			
		} else if (strcmp(argv[i], "--wordlist") != 0 && flag_worldlist == 0) {
			strcpy(wordlist_path, "lib/wordlist");
		}
	}

	if (file_exists(wordlist_path) == 0) {
		fprintf(stderr, "File %s not found\n", wordlist_path);
		flag_error = 1;
	}

	if (flag_verbose == 1) printf("wordlist_path: %s\n", wordlist_path);

	return flag_error;
}

/*
	shows the message after the game ends
*/
void show_win_lose_message() {
	show();
	if (win == 1 && lose == 0) fprintf(stdout, "You won! It took you %d guesses. The word was %s.\n", turns, word_to_guess);
	if (win == 0 && lose == 1) fprintf(stdout, "You lost. :( The word was %s.\n", word_to_guess);
}

int main(int argc, char *argv[]) {
	// pass the arguments
	if (argparse(argc, argv) == 1) return 1;

	// prerequisite 1
	get_random_word(word_to_guess, wordlist_path);

	// steps
	while (win == 0 && lose == 0) {
		game();
		if (quit == 1) return 2;
	}

	// print winning message
	show_win_lose_message();

	return 0;
}