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

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

const char* esc = "";

FILE *lcd = NULL;
static char *gamelog = 0;
static int human, search_depth;

static void
write_line(const char *line) {
	fputs(line, lcd);
	fflush(lcd);
}

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);
	fprintf(lcd, "Game over: %s\n", win);
	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:  { write_line("Invalid PTN.");  break; }
		case ACT_ILLEGAL:  { write_line("Illegal ply.");  break; }
		case ACT_OVERFLOW: { write_line("Overflow.");     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; }
				}
				return EXIT_SUCCESS;
			} else {
				write_line("Game over.");
				break;
			}
		}
			// Valid, append to game log
		default: {
			append_to_gamelog(line, 0);
			return EXIT_SUCCESS;
		}
	}
	return EXIT_FAILURE;
}

static void
new_game(uint8_t size) {
	reset_state(size);
	write_line("New 5x5 game.");
	if (gamelog) gamelog = realloc(gamelog, sizeof(char));
	else gamelog = malloc(sizeof(char));
	gamelog[0] = 0;
}

// Set up output function for ct1986

static uint8_t perc;
inline void
ct1986_display_progress(const uint8_t depth) {
	if (depth == 0) {
		perc++;
		// back four spaces
		for (int k=0;k<4;k++) {
			fprintf(lcd, "%sl", esc);
			fflush(lcd);
		}
		// clear line
		fprintf(lcd, "%sk", esc);
		fflush(lcd);
		// write percentage
		fprintf(lcd, "%3d%%", perc*4);
	}
}

static int
ct1986_turn(const uint8_t search_depth) {
	// Prepare progress bar
	fputs("Computing..     ", lcd); fflush(lcd);
	// Run the minimax
	perc = 0;
	float minimax = ct1986_generate(search_depth);
	fputc('\n', lcd);
	// Failed to find a move?
	if (minimax <= -infty) {
		fprintf(lcd, "%s concedes!\n", (ply & 1) ? "Black" : "White");
		return EXIT_FAILURE;
	} else {
		fprintf(lcd, "%s: %s\n",
						(ply & 1) ? "Black" : "White",
						ct1986_ptn);
		handle_turn(ct1986_ptn);
		return EXIT_SUCCESS;
	}
}

static void
do_game_log(void) {
	fputs(gamelog, lcd);
}

static int
input_is_not_turn(const char *line) {
	switch (line[0]) {
		case 'l': { do_game_log(); break; }
		case 'n': { new_game(5);   break; }
		case 'd': {
			search_depth = line[1] - '0';
			fprintf(lcd, "Search depth: %d\n", search_depth);
			fflush(lcd);
			break;
		}
		case 'b': { human = 1; new_game(5); break; }
		case 'w': { human = 0; new_game(5); break; }
		default: 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;

	human = 0;
	search_depth = 1;
	new_game(5);

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

	for (int playing = 1; playing;) {
		write_line("Loaded ct1986!\n");
		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;
		}
	}

	fclose(lcd);
	return EXIT_SUCCESS;
}