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

#include <tak.h>
#include <minimax_cnn1986.h>

FILE *lcd = NULL;

static char *gamelog = 0;
static int human, search_depth;

static void
append_to_gamelog(const char *line, const uint8_t win_line) {
	// I _could_ dynamically compute the size but ... don't let
	// `perfect' be the enemy of `good' ?
	char prepend[8];

	if (win_line) {
		prepend[0] = '\n';
		prepend[1] = 0;
	} else if (ply & 1) {
		snprintf(prepend, 7, "%s%d. ",
						 (ply == 1) ? "" : "\n", ply/2+1);
	} else {
		strcpy(prepend, " ");
	}
	// Make room for this line
	gamelog = realloc(gamelog,
										strlen(gamelog)
										+ strlen(prepend)
										+ strlen(line) + 1);
	strcat(gamelog,prepend);
	strcat(gamelog,line);
}

static void
end_game(char *line, char *win) {
	append_to_gamelog(line, 0);
	append_to_gamelog(win, 1);
	fputs("Game over: ",lcd);
	fputs(win,lcd);
	fflush(lcd);
}

static int
handle_turn(char *line) {
	// Track win state
	uint8_t new_win = (won == 0xFF);
	switch (do_ptn(line)) {
		// Errors
		case PTN_INVALID:  { fputs("Invalid PTN.",lcd); return -1; break; }
		case ACT_ILLEGAL:  { fputs("Illegal action.",lcd); return -1; break; }
		case ACT_OVERFLOW: {
			fputs("Move would cause internal overflow, select another.");
			return EXIT_FAILURE;
			break;
		}
			// Game has ended
		case GAME_END: {
			// Did it end this turn?
			if (new_win) {
				switch (won) {
					case WIN_DRAW:       { end_game(line,"1/2-1/2"); break; }
					case WIN_FLAT_BLACK: { end_game(line,"0-F");     break; }
					case WIN_FLAT_WHITE: { end_game(line,"F-0");     break; }
					case WIN_ROAD_BLACK: { end_game(line,"0-R");     break; }
					case WIN_ROAD_WHITE: { end_game(line,"R-0");     break; }
				}
			}
			fputs("Game over, enter `new' to play again.");
			if (! new_win) return EXIT_FAILURE;
			break;
		}
			// Valid, append to game log
		case PTN_VALID:
		case ACT_OK: {
			append_to_gamelog(line, 0);
			break;
		}
	}

	return EXIT_SUCCESS;
}

static void
new_game(uint8_t size) {
	reset_state(size);
	fputs("New 5x5 game! ct1986 at search depth ");
	fputc(search_depth + '0', lcd);
	fputc('.', lcd);
	fflush(lcd);
	if (gamelog) gamelog = realloc(gamelog, sizeof(char));
	else gamelog = malloc(sizeof(char));
	gamelog[0] = 0;
}

static void
dot(const uint8_t depth) {
	if (depth == 0) {
		fputc('#', lcd);
	}
}

static int
ct1986_turn(const uint8_t search_depth) {
	// Prepare progress bar
	fputs("Computing ");
	// Run the minimax
	float minimax = ct1986_generate(search_depth);
	// Failed to find a move?
	if ((minimax <= -infty && (ply & 1) == 1)
			||(minimax >= infty && (ply & 1) == 0)) {
		fputs("Opponent concedes!");
		return EXIT_FAILURE;
	} else {
		fputs("Result: ");
		fputs(ct1986_ptn);
		handle_turn(ct1986_ptn);
		return EXIT_SUCCESS;
	}
}

static int
input_is_not_turn(const char *line) {
	if (!strcmp(line,"help")) {
		fputs("Valid commands: depth [0-9], help, new, \
play (b|w), self-play, <PTN>.");
	} else if (!strcmp(line,"log")) {
		fputs(gamelog);
	} else if (!strcmp(line,"new")) {
		new_game(5);
	} else if (!strcmp(line,"self-play")) {
		while (ct1986_turn(search_depth) == 0);
	} else if (!strncmp(line,"depth",5)) {
		if (strnlen(line,7) == 7 && line[6] >= '0' && line[6] <= '9') {
			search_depth = line[6] - '0';
			fputs("New search depth: ",lcd);
			fputc(line[6], lcd);
			fflush(lcd);
		} else {
			fputs("Usage: depth [0-9].",lcd);
		}
	} else if (!strncmp(line,"play",4)) {
		if (strnlen(line,7) == 6
				&& ((line[5] == 'b' || line[5] == 'B')
						|| (line[5] == 'w' || line[5] == 'W'))) {
			// 'b' is even :)
			human = 1 - (line[5] & 1);
			new_game(5);
		} else {
			fputs("Usage: play (b|w).\n", lcd);
		}
	} else {
		return EXIT_FAILURE;
	}
	return EXIT_SUCCESS;
}

int
main(int argc, char **argv) {
	(void)(argc);
	(void)(argv);

	lcd = fopen("/dev/lcd","w");
	if (lcd == NULL) return EXIT_FAILURE;

	// Set up output function for ct1986
	ct1986_display_progress = &dot;

	human = 0;
	search_depth = 3;
	new_game(5);

	char *line = NULL;
	ssize_t read;
	size_t alloc_size;

	for (int playing = 1; playing;) {
		fputs("Welcome to ct1986!\n",lcd); fflush(lcd);
		fflush(stdout);
		while ((human == 0) && (read = getline(&line, &alloc_size, stdin)) != -1) {
			if (read) {
				line[read - 1] = 0;
				if (input_is_not_turn(line)) {
					int r = handle_turn(line);
					if (r == EXIT_SUCCESS && won == 0xFF) {
						human = 1;
					}
				}
			}
		}
		if ((human == 0) && (read == -1)) {
			playing = 0;
		} else {
			ct1986_turn(search_depth);
			human = 0;
		}
	}
	return 0;
}