/*
 * db.c - Parts database
 *
 * Copyright 2012 by Werner Almesberger
 *
 * 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 2 of the License, or
 * (at your option) any later version.
 */


#include <stdlib.h>
#include <glib.h>

#include "util.h"
#include "lang.h"
#include "chr.h"
#include "db.h"


static GTree *tree = NULL;


static gint comp(gconstpointer a, gconstpointer b)
{
	const struct part *pa = a;
	const struct part *pb = b;

	/*
	 * Just subtracting the pointers may produce values outside the
	 * range of gint values.
	 */
	return pa->domain == pb->domain ?
	    pa->name < pb->name ? -1 : pa->name > pb->name ? 1 : 0 :
	    pa->domain < pb->domain ? -1 : 1;
}


struct part *part_lookup(const char *domain, const char *name)
{
	struct part part = {
		.domain = domain,
		.name = name,
	};

	if (!tree)
		return NULL;
	return g_tree_lookup(tree, &part);
}


struct part *part_add(const char *domain, const char *name)
{
	struct part part = {
		.domain = domain,
		.name = name,
	};
	struct part *p;

	if (!tree)
		tree = g_tree_new(comp);
	p = g_tree_lookup(tree, &part);
	if (!p) {
		p = alloc_type(struct part);
		p->stock = NULL;
		p->next = p->prev = p;
		g_tree_insert(tree, p, p);
	}
	return p;
}


void part_alias(struct part *a, struct part *b)
{
	struct part *tmp, *tmp2;

	tmp = a->next;
	a->next = b;
	b->prev->next = tmp;

	tmp2 = b->prev;
	b->prev = a;
	tmp->prev = tmp2;
}


static void convert_params(struct param **params,
    const struct field *f, struct param ***res)
{
	struct param **p, *prm;
	const struct selector *sel;
	const struct condition *cond;

	while (f) {
		for (p = params; *p; p = &(*p)->next)
			if ((*p)->u.name == f->name)
				break;
		if (!*p) {
			f = f->next;
			continue;
		}

		/* remove from list */
		prm = *p;
		*p = prm->next;

		/* convert parameter */
		prm->u.field = f;
		if (!evaluate(f->fmt, prm->value.u.name, &prm->value))
			yyerrorf("invalid value for %s", f->name);

		/* add to result list */
		**res = prm;
		*res = &prm->next;
		prm->next = NULL;

		/* process selections */
		for (sel = f->sel; sel; sel = sel->next) {
			for (cond = sel->cond; cond; cond = cond->next)
				if (compare(f->fmt, &prm->value, cond->relop,
				    &cond->value))
					break;
			if (cond) {
				convert_params(params, sel->act.fields, res);
				convert_params(params, sel->act.rules, res);
				break;
			}
		}
		if (!sel) {
			convert_params(params, f->any.fields, res);
			convert_params(params, f->any.rules, res);
		}

		f = f->next;
	}
}


void part_finalize(struct part *part, const struct field *field)
{
	struct param *param = part->param;
	struct param **res = &part->param;
	struct param *next;

	part->param = NULL;
	convert_params(&param, field, &res);
	while (param) {
		yywarnf("extra parameter: %s", param->u.name);
		next = param->next;
		free(param);
		param = next;
	}
}