#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include "queue.h"
#include "input.h"

#define INPUT "input/05.txt"
#define EXPECTED1 70369L
#define EXPECTED2 203002L
#define STACK_COUNT 9
	
SLIST_HEAD(crate_list, crate) head[STACK_COUNT];
struct crate {
	char crate_char;
	SLIST_ENTRY(crate) entries;
};
struct crate* last_crate[STACK_COUNT];

void move_9001(int count, struct crate_list* from_head, struct crate* from_crate, struct crate_list* to_head) {
	// use a recursion to move the crates from bottom up
	if(count > 1) {
		move_9001(count - 1, from_head, SLIST_NEXT(from_crate, entries), to_head);
	}
	SLIST_REMOVE(from_head, from_crate, crate, entries);
	SLIST_INSERT_HEAD(to_head, from_crate, entries);
}

void move_crates(struct input_str* input, bool is_crane_9000) {
	// parse stacks
	for(int i = 0; i < STACK_COUNT; i++) {
		SLIST_INIT(head + i);
		last_crate[i] = SLIST_FIRST(head + i);
	}

	size_t line_index = 0;
	while(input->lines[line_index][0] != '\n' && line_index < input->line_count) {
		for(int s = 0; s < STACK_COUNT; s++) {
			int stack_index = 1 + 4 * s;
			char crate_char = input->lines[line_index][stack_index];
			if(crate_char == ' ') // stack is empty here
				continue;
			struct crate* crate = malloc(sizeof(struct crate));
			crate->crate_char = crate_char;
			if(SLIST_EMPTY(head + s))
				SLIST_INSERT_HEAD(head + s, crate, entries);
			else
				SLIST_INSERT_AFTER(last_crate[s], crate, entries);
			last_crate[s] = crate;
		}
		line_index++;
	}
	line_index++;

	// parse and execute crate movements
	for(size_t i = line_index; i < input->line_count; i++) {
		// parse, as usual copy line before strtok
		char* line = copy_line(input->lines[i]);
		//printf("%s\n", line);
		char* number = strtok(line, " "); // move
		//printf("%s\n", number);
		number = strtok(NULL, " ");
	        int crate_count = atoi(number);
		strtok(NULL, " "); // from
		number = strtok(NULL, " ");
		int from = atoi(number);
		strtok(NULL, " "); // to
		number = strtok(NULL, " ");
		int to = atoi(number);
		free(line);
		
		// now execute
		//printf("move %d from %d to %d\n", crate_count, from, to);
		from--;
		to--;
		if(is_crane_9000)
			for(int m = 0; m < crate_count; m++) {
				struct crate* cc = SLIST_FIRST(head + from);
				SLIST_REMOVE_HEAD(head + from, entries);
				SLIST_INSERT_HEAD(head + to, cc, entries);
			}
		else
			move_9001(crate_count, head + from, SLIST_FIRST(head + from), head + to);
	}

	// print result
	for(int s = 0; s < STACK_COUNT; s++) {
		struct crate* cc = SLIST_FIRST(head + s);
		printf("%c", cc->crate_char);
	}
	printf("\n");

	// TODO free all the crates
}

int main() {
	// read input
	struct input_str input;
	input_str_read(&input, INPUT);

	// do stuff
	move_crates(&input, true); // BSDMQFLSP expected
	move_crates(&input, false); // PGSQBFLDP expected

	// cleanup & exit
	input_str_free(&input);
	return 0;
}