#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <getopt.h>
#include <limits.h>

#include "match.h"
#include "tty.h"
#include "choices.h"

#include "config.h"

int flag_show_scores = 0;

size_t num_lines = 10;
size_t scrolloff = 1;

void read_choices(choices_t *c){
	char *line = NULL;
	size_t len = 0;
	ssize_t read;

	while ((read = getline(&line, &len, stdin)) != -1) {
		char *nl;
		if((nl = strchr(line, '\n')))
			*nl = '\0';

		choices_add(c, line);

		line = NULL;
	}
	free(line);
}

#define SEARCH_SIZE_MAX 4096
int search_size;
char search[SEARCH_SIZE_MAX + 1] = {0};

void clear(tty_t *tty){
	tty_setcol(tty, 0);
	size_t line = 0;
	while(line++ < num_lines){
		tty_newline(tty);
	}
	tty_moveup(tty, line-1);
	tty_flush(tty);
}

void draw_match(tty_t *tty, const char *choice, int selected){
	int n = strlen(search);
	size_t positions[n + 1];
	for(int i = 0; i < n + 1; i++)
		positions[i] = -1;

	double score = match_positions(search, choice, &positions[0]);

	size_t maxwidth = tty_getwidth(tty);

	if(flag_show_scores)
		tty_printf(tty, "(%5.2f) ", score);

	if(selected)
		tty_setinvert(tty);

	for(size_t i = 0, p = 0; choice[i] != '\0'; i++){
		if(i+1 < maxwidth){
			if(positions[p] == i){
				tty_setfg(tty, TTY_COLOR_HIGHLIGHT);
				p++;
			}else{
				tty_setfg(tty, TTY_COLOR_NORMAL);
			}
			tty_printf(tty, "%c", choice[i]);
		}else{
			tty_printf(tty, "$");
			break;
		}
	}
	tty_setnormal(tty);
}

void draw(tty_t *tty, choices_t *choices){
	size_t start = 0;
	size_t current_selection = choices->selection;
	if(current_selection + scrolloff >= num_lines){
		start = current_selection + scrolloff - num_lines + 1;
		if(start + num_lines >= choices_available(choices)){
			start = choices_available(choices) - num_lines;
		}
	}
	const char *prompt = "> ";
	tty_setcol(tty, 0);
	tty_printf(tty, "%s%s", prompt, search);
	tty_clearline(tty);
	for(size_t i = start; i < start + num_lines; i++){
		tty_printf(tty, "\n");
		tty_clearline(tty);
		const char *choice = choices_get(choices, i);
		if(choice){
			draw_match(tty, choice, i == choices->selection);
		}
	}
	tty_moveup(tty, num_lines);
	tty_setcol(tty, strlen(prompt) + strlen(search));
	tty_flush(tty);
}

void emit(choices_t *choices){
	const char *selection = choices_get(choices, choices->selection);
	if(selection){
		/* output the selected result */
		printf("%s\n", selection);
	}else{
		/* No match, output the query instead */
		printf("%s\n", search);
	}

	exit(EXIT_SUCCESS);
}

void run(tty_t *tty, choices_t *choices){
	choices_search(choices, search);
	char ch;
	do {
		draw(tty, choices);
		ch = tty_getchar(tty);
		if(isprint(ch)){
			if(search_size < SEARCH_SIZE_MAX){
				search[search_size++] = ch;
				search[search_size] = '\0';
				choices_search(choices, search);
			}
		}else if(ch == 127 || ch == 8){ /* DEL || backspace */
			if(search_size)
				search[--search_size] = '\0';
			choices_search(choices, search);
		}else if(ch == 21){ /* C-U */
			search_size = 0;
			search[0] = '\0';
			choices_search(choices, search);
		}else if(ch == 23){ /* C-W */
			if(search_size)
				search[--search_size] = '\0';
			while(search_size && !isspace(search[--search_size]))
				search[search_size] = '\0';
			choices_search(choices, search);
		}else if(ch == 14){ /* C-N */
			choices_next(choices);
		}else if(ch == 16){ /* C-P */
			choices_prev(choices);
		}else if(ch == 9){ /* TAB */
			strncpy(search, choices_get(choices, choices->selection), SEARCH_SIZE_MAX);
			search_size = strlen(search);
		}else if(ch == 10){ /* Enter */
			clear(tty);

			/* ttyout should be flushed before outputting on stdout */
			fclose(tty->fout);

			emit(choices);
		}else if(ch == 27){ /* ESC */
			ch = tty_getchar(tty);
			if(ch == '[' || ch == 'O'){
				ch = tty_getchar(tty);
				if(ch == 'A'){ /* UP ARROW */
					choices_prev(choices);
				}else if(ch == 'B'){ /* DOWN ARROW */
					choices_next(choices);
				}
			}
		}
	}while(1);
}

static const char *usage_str = ""
"Usage: fzy [OPTION]...\n"
" -l, --lines=LINES        Specify how many lines of results to show (default 10)\n"
" -e, --show-matches=QUERY output the sorted matches of QUERY\n"
" -t, --tty=TTY            Specify file to use as TTY device (default /dev/tty)\n"
" -s, --show-scores        show the scores of each match\n"
" -h, --help     display this help and exit\n"
" -v, --version  output version information and exit\n";

void usage(const char *argv0){
	fprintf(stderr, usage_str, argv0);
}

static struct option longopts[] = {
	{ "show-matches", required_argument, NULL, 'e' },
	{ "lines", required_argument, NULL, 'l' },
	{ "tty", required_argument, NULL, 't' },
	{ "show-scores", no_argument, NULL, 's' },
	{ "version", no_argument, NULL, 'v' },
	{ "benchmark", no_argument, NULL, 'b' },
	{ "help",    no_argument, NULL, 'h' },
	{ NULL,      0,           NULL, 0 }
};

int main(int argc, char *argv[]){
	int benchmark = 0;
	char *initial_query = NULL;
	char *tty_filename = "/dev/tty";
	char c;
	while((c = getopt_long(argc, argv, "vhse:l:t:", longopts, NULL)) != -1){
		switch(c){
			case 'v':
				printf("%s " VERSION " (c) 2014 John Hawthorn\n", argv[0]);
				exit(EXIT_SUCCESS);
			case 's':
				flag_show_scores = 1;
				break;
			case 'e':
				initial_query = optarg;
				break;
			case 'b':
				benchmark = 1;
				break;
			case 't':
				tty_filename = optarg;
				break;
			case 'l':
				{
					int l;
					if(!strcmp(optarg, "max")){
						l = INT_MAX;
					}else if(sscanf(optarg, "%d", &l) != 1 || l < 3){
						fprintf(stderr, "Invalid format for --lines: %s\n", optarg);
						fprintf(stderr, "Must be integer in range 3..\n");
						usage(argv[0]);
						exit(EXIT_FAILURE);
					}
					num_lines = l;
				}
				break;
			case 'h':
			default:
				usage(argv[0]);
				exit(EXIT_SUCCESS);
		}
	}
	if(optind != argc){
		usage(argv[0]);
		exit(EXIT_FAILURE);
	}

	choices_t choices;
	choices_init(&choices);
	read_choices(&choices);

	if(num_lines > choices.size)
		num_lines = choices.size;

	if(benchmark){
		if(!initial_query){
			fprintf(stderr, "Must specify -e/--show-matches with --benchmark\n");
			exit(EXIT_FAILURE);
		}
		for(int i = 0; i < 100; i++)
			choices_search(&choices, initial_query);
	}else if(initial_query){
		choices_search(&choices, initial_query);
		for(size_t i = 0; i < choices_available(&choices); i++){
			if(flag_show_scores)
				printf("%f\t", choices_getscore(&choices, i));
			printf("%s\n", choices_get(&choices, i));
		}
	}else{
		/* interactive */
		tty_t tty;
		tty_init(&tty, tty_filename);

		if(num_lines + 1 > tty_getheight(&tty))
			num_lines = tty_getheight(&tty) - 1;

		run(&tty, &choices);
	}

	return 0;
}