/*
	ctaklm, a line mode interface to the ctak library

	Copyright (C) 2021, tslil clingman

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

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

#include <tak.h>
#include <negamax.h>

static const char *blk = "\033[41m", *wht = "\033[44m";
static const char *und = "\033[4m",  *rst = "\033[0m";

#define SQUARE_W 5
#define SQUARE_H 3

#define CHAR_FLT '#'
#define CHAR_STN '/'
#define CHAR_CAP '*'

static void
put_stone(const enum STONE_VARIANT stone, const enum COLOUR colour,
					const uint8_t top, const uint8_t beyond_carry_limit) {
	if (beyond_carry_limit) {
		fputs(und,stdout);
	} else {
		if (colour == C_BLACK) fputs(blk, stdout);
		else fputs(wht,stdout);
	}
	if (top) {
		switch (stone) {
			case STONE_FLAT:     putchar(CHAR_FLT); break;
			case STONE_STANDING: putchar(CHAR_STN); break;
			case STONE_CAPSTONE: putchar(CHAR_CAP); break;
		}
	} else {
		putchar( (colour == C_BLACK) ? 'B' : 'W' );
	}
	fputs(rst,stdout);
}

static void
print_cell_line(const uint8_t line,
								const uint8_t col, const uint8_t row) {

	const uint8_t location = THE_COORDS(col, row),
		stack_size = COUNT_AT(location);

	uint8_t idx;
	for (uint8_t k = 0; k < SQUARE_W; k++) {
		idx = line + k*SQUARE_H;
		// Are we in the last column to be displayed?
		if ((k+1)*SQUARE_H > stack_size) {
			// If so, then if we can't fill it offset the starting line so
			// that it fills from the bottom up instead of the top down
			if (line < (k+1)*SQUARE_H - stack_size ) {
				// skip these lines
				idx = 0xFF;
			} else {
				// offset back
				idx -= (k+1)*SQUARE_H - stack_size;
			}
		}
		if (idx < stack_size) {
			put_stone(STONE_AT(location),
								(colours[location] & (1 << idx)) ? C_BLACK : C_WHITE,
								idx == 0, idx >= board_size);
		} else {
			putchar(' ');
		}
	}
}

// It takes board_size*(SQUARE_H+1)+1 lines to print the board, they
// may be requested in any order and at any time
static void
print_board_line(const uint8_t line) {
	const uint8_t mod = line % (SQUARE_H + 1),
		row = board_size - line/(SQUARE_H + 1) - 1;

	// Print leader, either row number if half-way through square or
	// padding spaces otherwise
	if (mod == (SQUARE_H + 1)/2 ) printf("%d. ",row + 1);
	else fputs("   ",stdout);

	// Top and bottom of squares receive borders
	if (mod == 0) {
		for (uint8_t x = 0; x < board_size; x++) {
			putchar('+');
			for (uint8_t k = 0; k < SQUARE_W; k++) putchar('-');
		}
		puts("+");
	} else {
		// Interior of board should be filled by borders and pieces
		if (line < board_size*(SQUARE_H+1)) {
			for (uint8_t x = 0; x < board_size; x++) {
				putchar('|');
				print_cell_line(mod - 1 , x, row);
			}
			puts("|");
		} else {
			// Bottom of board has column markers
			for (uint8_t x = 0; x < board_size; x++) {
				for (uint8_t k = 0; k <= SQUARE_W/2; k++) putchar(' ');
				printf("%c.",x+'a');
				for (uint8_t k = 0; k < SQUARE_W-SQUARE_W/2-2; k++) putchar(' ');
			}
			putchar('\n');
		}
	}
}

// Simple wrapper to print the whole board in one go
static void
print_board(void) {
	for (uint8_t k = 0; k<board_size*(SQUARE_H+1)+2; k++) {
		print_board_line(k);
	}
}

// Print the contents of a single square
static void
print_square(const uint8_t col, const uint8_t row) {
	if (row < board_size && col < board_size) {
		printf("%c%c: ",'a'+col,'1'+row);
		const uint8_t stack_size = COUNT_AT(THE_COORDS(col, row));
		if (stack_size > 0) {
			uint8_t mask = 1 << (stack_size - 1);
			for (uint8_t k = 0; k < stack_size; k++, mask >>= 1) {
				put_stone(STONE_AT(THE_COORDS(col, row)),
									(colours[THE_COORDS(col, row)] & mask) ? C_BLACK : C_WHITE,
									k+1 == stack_size,
									stack_size-k-1 >= board_size);
			}
			puts(" <-- top");
		} else {
			puts("(empty)");
		}
	} else {
		printf("Requested square not on board (%dx%d).\n",board_size,board_size);
	}
}

static void
print_info(void) {
	printf("Turn: %2d, %s%s%s%s\n",
				 ply/2 + 1,
				 (ply & 1) ? blk : wht,
				 (ply & 1) ? "Black" : "White",
				 rst,
				 (ply < 2) ? " (counter-play start)" : "");
	printf("Flats/Caps remaining: %s%02d/%d%s, %s%02d/%d%s\n",
				 wht, white_count & 127, white_count >> 7, rst,
				 blk, black_count & 127, black_count >> 7, rst);
}

static int human;
static char *gamelog = 0;
static uint8_t auto_board = 0xFF, auto_info = 0xFF;

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);
	print_board();
	puts("Game over:");
	puts(gamelog);
	putchar('\n');
}

static int
handle_turn(char *line) {
	// Track win state
	uint8_t new_win = (won == 0xFF);
	switch (do_ptn(line)) {
		// Errors
		case PTN_INVALID:  { puts("Invalid PTN."); return -1; break; }
		case ACT_ILLEGAL:  { puts("Illegal action."); return -1; break; }
		case ACT_OVERFLOW: {
			puts("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; }
				}
			}
			puts("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);
			if (auto_board) print_board();
			if (auto_info) print_info();
			break;
		}
	}

	return EXIT_SUCCESS;
}

static void
new_game(uint8_t size) {
	reset_state(size);
	printf("New %dx%d game! negamax at search depth %d.\n",
				 size, size, negamax_search_depth);
	if (gamelog) gamelog = realloc(gamelog, sizeof(char));
	else gamelog = malloc(sizeof(char));
	gamelog[0] = 0;
}

static int
load_ptn(const char* fn) {
	FILE *fh = NULL;

	fh = fopen(fn, "r");
	if (fh == NULL) return EXIT_FAILURE;

	int space1, space2;
	enum E_RESULT r;

	ssize_t read;
	size_t alloc_size;
	char *line = NULL;
	while ((read = getline(&line, &alloc_size, fh)) != -1) {
		if (read && line[0] <= '9' && line[0] >= '0') {
			// Trim trailing \n
			line[read-1] = 0;
			// Find first separator
			space1 = 0;
			while (space1 < read && line[space1++] != ' ');
			// If still on line
			if (space1 < read) {
				// Find next separator or end of line, either way mark the split
				space2 = space1;
				while (space2 < read && line[space2] != ' ') space2++;
				line[space2] = 0;
				// Try the first piece we found
				r = handle_turn(line+space1);
				if (r) {
					printf("Error on: %s\n", line+space1);
					break;
				}
				// If there's a second piece, try it
				if (space2 + 1 < read) {
					r = handle_turn(line+space2+1);
					if (r) {
						printf("Error on: %s", line+space2+1);
						break;
					}
				} else {
					break;
				}
			}
		}
	}

	if (line) free(line);
	fclose(fh);


	return EXIT_SUCCESS;
}

static float num_check, progress;

// Set up output function for negamax
inline void
negamax_display_progress(const uint8_t depth, const uint32_t length) {
	num_check += 1;
	if (depth == negamax_search_depth) {
		progress++;
		printf("\x1B[0GComputing: %.0f/%d",
					 progress,length);
		fflush(stdout);
	}
}

static int
negamax_turn(void) {
	if (won == 0xFF) {
		// Run the minimax
		num_check = 0; progress = 0;
		float minimax = negamax_generate();
		putchar('\n');
		// Failed to find a move?
		if (minimax <= -infty) {
			puts("Opponent failed to find a move!");
			return EXIT_FAILURE;
		} else {
			printf("Result: %s (%.2f, checked %.1e)\n",
						 negamax_ptn,
						 minimax*100.0,
						 num_check);
			return handle_turn(negamax_ptn);
		}
	} else {
		return EXIT_FAILURE;
	}
}

static int
input_is_not_turn(const char *line) {
	if (!strcmp(line,"help")) {
		puts("Valid commands: auto (board|info), board, depth [0-9], eval, help,\
info, load, log, new, play (b|w), self-play, square <col><row>, <PTN>.");
	} else if (!strcmp(line,"board")) {
		print_board();
	} else if (!strcmp(line,"info")) {
		print_info();
	} else if (!strcmp(line,"eval")) {
		float eval = cnn1986_evaluate_black_win()*100;
		if (ply & 1) {
			printf("Black heuristic chance: %s%.2f%s\n",
						 blk, eval, rst);
		} else {
			printf("White heruistic chance: %s%.2f%s\n",
						 wht, -eval, rst);
		}
	} else if (!strcmp(line,"log")) {
		puts(gamelog);
	} else if (!strcmp(line,"new")) {
		new_game(5);
	} else if (!strcmp(line,"self-play")) {
		while (negamax_turn() == 0);
	} else if (!strncmp(line,"depth",5)) {
		if (strnlen(line,7) == 7 && line[6] >= '0' && line[6] <= '9') {
			negamax_search_depth = line[6] - '0';
			printf("New search depth: %d.\n",
						 negamax_search_depth);
		} else {
			puts("Usage: depth [0-9].");
		}
	} else if (!strncmp(line,"load",4)) {
		if (strnlen(line,6) >= 6) {
			if (load_ptn(line+5)) {
				printf("Errors in file %s\n",line);
			}
		} else {
			puts("Usage: load <file.ptn>.");
		}
	} else if (!strncmp(line,"auto",4)) {
		if (!strcmp(line,"auto board")) {
			auto_board = ~auto_board;
			printf("Automatic board display %s.\n",
						 (auto_board) ? "Enabled" : "Disabled");
		} else if (!strcmp(line,"auto info")) {
			auto_info = ~auto_info;
			printf("Automatic info display %s.\n",
						 (auto_info) ? "Enabled" : "Disabled");
		} else {
			puts("Usage: auto (board|info).");
		}
	} else if (!strncmp(line,"square",6)) {
		if (strnlen(line, 10) == 9
				&& line[7] >= 'a' && line[7] <= '`'+board_size
				&& line[8] >= '1' && line[8] <= '0'+board_size) {
			print_square(line[7]-'a', line[8]-'1');
		} else {
			printf("Usage: square [a-%c][1-%c].\n",'`'+board_size,'0'+board_size);
		}
	} 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 {
			puts("Usage: play (b|w).");
		}
	} else {
		return EXIT_FAILURE;
	}
	return EXIT_SUCCESS;
}

const char* license = "ctaklm, a line mode interface to the ctak library\n\
\n\
Copyright (C) 2021, tslil clingman\n\
\n\
This program comes with ABSOLUTELY NO WARRANTY; and is made available under the terms of the GNU GPL v3 license. This is free software, and you are welcome to redistribute it under certain conditions; see COPYING for details.\n";

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

	puts(license);

	negamax_search_depth = 3;
	new_game(5);
	negamax_init(5);

	// Test harness
	if (argc > 1) {
		negamax_search_depth = 5;
		load_ptn("data/0.ptn");
		negamax_turn();
	return 0;
	}
	// Test harness

	char *line = NULL;
	ssize_t read = -1;
	size_t alloc_size;

	human = 0;
	for (int playing = 1; playing;) {
		while (human == 0) {
			fputs("ctaklm> ", stdout);
			fflush(stdout);
			read = getline(&line, &alloc_size, stdin);
			if (read > 0) {
				line[read - 1] = 0;
				if (input_is_not_turn(line)) {
					int r = handle_turn(line);
					if (r == EXIT_SUCCESS && won == 0xFF) {
						human = 1;
					}
				}
				free(line);
				line = NULL;
			} else {
				playing = 0;
				human = 1;
			}
		}
		if (playing) {
			negamax_turn();
			human = 0;
		}
	}

	free(line);
	free(gamelog);
	negamax_free();

	return EXIT_SUCCESS;
}