/*
	This file is part of ct.

	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 ct. If not, see <https://www.gnu.org/licenses/>.
*/

#include "tt_llcht.h"

// ===================================================================
// Variables
// ===================================================================

static tt_entry_t *table[TT_LLCHT_SIZE+1];

// ===================================================================
// Helper declarations
// ===================================================================

tt_entry_t * new_ll_node(const uint64_t key, const enum TT_FLAG flag,
												 const uint8_t depth, const float value,
                         const action_t best);


// ===================================================================
// Exported functions
// ===================================================================

int tt_init(void) {
	for (uint32_t k=0; k<=TT_LLCHT_SIZE; k++)
		table[k] = NULL;
	return EXIT_SUCCESS;
}

void tt_free(void) {
	tt_entry_t *n, *nn;
	for (uint32_t k=0; k<=TT_LLCHT_SIZE; k++) {
		n = table[k];
		while (n) {
			nn = n->next;
			free(n);
			n = nn;
		}
	}
}

tt_entry_t *tt_seek(const uint64_t key) {
	tt_entry_t *lookup = table[key & TT_LLCHT_SIZE];
	while (lookup && lookup->key != key)
		lookup = lookup->next;
	return lookup;
}

int tt_insert(const uint64_t key, const enum TT_FLAG flag,
							const uint8_t depth, const float value,
              const action_t best) {
	tt_entry_t *n,
		*new = new_ll_node(key, flag, depth, value, best);
	// TODO: trap

	const uint32_t idx = key & TT_LLCHT_SIZE;
	if ((n = table[idx]) != NULL) {
		for (; n->next != NULL; n = n->next);
		n->next = new;
	} else {
		table[idx] = new;
	}

	return EXIT_SUCCESS;
}

// ===================================================================
// Helper function implementations
// ===================================================================

tt_entry_t * new_ll_node(const uint64_t key, const enum TT_FLAG flag,
												 const uint8_t depth, const float value,
                         const action_t best) {
	tt_entry_t *new = malloc(sizeof(struct tt_node_s));
	// TODO: trap errno
	new->key = key;
	new->best = best;
	new->next = NULL;
	new->flag = flag;
	new->depth = depth;
	new->value = value;
	return new;
}