/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef SPA_POD_FILTER_H
#define SPA_POD_FILTER_H

#include <errno.h>
#include <stdint.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>

#include <spa/param/props.h>
#include <spa/pod/iter.h>
#include <spa/pod/builder.h>
#include <spa/pod/compare.h>
#include <spa/pod/dynamic.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifndef SPA_API_POD_FILTER
 #ifdef SPA_API_IMPL
  #define SPA_API_POD_FILTER SPA_API_IMPL
 #else
  #define SPA_API_POD_FILTER static inline
 #endif
#endif

/**
 * \addtogroup spa_pod
 * \{
 */

SPA_API_POD_FILTER int spa_pod_filter_flags_value(struct spa_pod_builder *b,
		uint32_t type, const void *r1, const void *r2, uint32_t size)
{
	switch (type) {
	case SPA_TYPE_Int:
	{
		int32_t val;
		if (size < sizeof(int32_t))
			return -EINVAL;
		val = (*(int32_t *) r1) & (*(int32_t *) r2);
		if (val == 0)
			return 0;
		spa_pod_builder_int(b, val);
		break;
	}
	case SPA_TYPE_Long:
	{
		int64_t val;
		if (size < sizeof(int64_t))
			return -EINVAL;
		val = (*(int64_t *) r1) & (*(int64_t *) r2);
		if (val == 0)
			return 0;
		spa_pod_builder_long(b, val);
		break;
	}
	default:
		return -ENOTSUP;
	}
	return 1;
}

SPA_API_POD_FILTER int
spa_pod_filter_prop(struct spa_pod_builder *b,
	    const struct spa_pod_prop *p1,
	    const struct spa_pod_prop *p2)
{
	const struct spa_pod *v1, *v2;
	struct spa_pod_choice *nc, dummy;
	uint32_t j, k, nalt1, nalt2, nc_offs;
	void *alt1, *alt2, *a1, *a2;
	uint32_t type, size, p1c, p2c;
	struct spa_pod_frame f;
	int res, n_copied = 0;

	v1 = spa_pod_get_values(&p1->value, &nalt1, &p1c);
	v2 = spa_pod_get_values(&p2->value, &nalt2, &p2c);

	/* empty/invalid choices */
	if (nalt1 < 1 || nalt2 < 1)
		return -EINVAL;

	alt1 = SPA_POD_BODY(v1);
	alt2 = SPA_POD_BODY(v2);

	type = v1->type;
	size = v1->size;

	/* incompatible property types */
	if (type != v2->type || size != v2->size || p1->key != p2->key)
		return -EINVAL;

	/* start with copying the property */
	spa_pod_builder_prop(b, p1->key, p1->flags & p2->flags);
	spa_pod_builder_push_choice(b, &f, SPA_CHOICE_None, 0);
	spa_zero(dummy);

	nc_offs = f.offset;

	/* start with an empty child and we will select a good default
	 * below */
	spa_pod_builder_child(b, size, type);

	/* we should prefer alt2 values but only if they are within the
	 * range. Swap the order otherwise. */
	if (!spa_pod_compare_is_valid_choice(type, size, alt2, alt2, nalt2, p2c)) {
		SPA_SWAP(alt2, alt1);
		SPA_SWAP(nalt2, nalt1);
		SPA_SWAP(p2c, p1c);
	}

	if ((p1c == SPA_CHOICE_None && p2c == SPA_CHOICE_None) ||
	    (p1c == SPA_CHOICE_None && p2c == SPA_CHOICE_Enum) ||
	    (p1c == SPA_CHOICE_Enum && p2c == SPA_CHOICE_None) ||
	    (p1c == SPA_CHOICE_Enum && p2c == SPA_CHOICE_Enum)) {
		/* copy all equal values. Start with alt2 so that they are prefered.  */
		for (j = 0, a2 = alt2; j < nalt2; j++, a2 = SPA_PTROFF(a2, size, void)) {
			for (k = 0, a1 = alt1; k < nalt1; k++, a1 = SPA_PTROFF(a1,size,void)) {
				if (spa_pod_compare_value(type, a1, a2, size) == 0) {
					if (n_copied++ == 0)
						spa_pod_builder_raw(b, a1, size);
					spa_pod_builder_raw(b, a1, size);
				}
			}
		}
	}
	else if ((p1c == SPA_CHOICE_None && p2c == SPA_CHOICE_Range) ||
	    (p1c == SPA_CHOICE_Enum && p2c == SPA_CHOICE_Range) ||
	    (p1c == SPA_CHOICE_None && p2c == SPA_CHOICE_Step) ||
	    (p1c == SPA_CHOICE_Enum && p2c == SPA_CHOICE_Step)) {
		void *min = SPA_PTROFF(alt2,size,void);
		void *max = SPA_PTROFF(min,size,void);
		void *step = p2c == SPA_CHOICE_Step ? SPA_PTROFF(max,size,void) : NULL;
		bool found_def = false;

		/* we should prefer the alt2 range default value but only if valid */
		if (spa_pod_compare_value(type, alt2, min, size) >= 0 &&
		    spa_pod_compare_value(type, alt2, max, size) <= 0) {
			for (j = 0, a1 = alt1; j < nalt1; j++, a1 = SPA_PTROFF(a1,size,void)) {
				if (spa_pod_compare_value(type, a1, alt2, size) == 0) {
					/* it is in the enum, use as default then */
					spa_pod_builder_raw(b, a1, size);
					found_def = true;
					break;
				}
			}
		}
		/* copy all values inside the range */
		for (j = 0, a1 = alt1; j < nalt1; j++, a1 = SPA_PTROFF(a1,size,void)) {
			if ((res = spa_pod_compare_is_in_range(type, a1, min, max, step, size)) < 0)
				return res;
			if (res == 0)
				continue;
			if (n_copied++ == 0 && !found_def)
				spa_pod_builder_raw(b, a1, size);
			spa_pod_builder_raw(b, a1, size);
		}
	}
	else if ((p1c == SPA_CHOICE_Range && p2c == SPA_CHOICE_None) ||
	    (p1c == SPA_CHOICE_Range && p2c == SPA_CHOICE_Enum) ||
	    (p1c == SPA_CHOICE_Step && p2c == SPA_CHOICE_None) ||
	    (p1c == SPA_CHOICE_Step && p2c == SPA_CHOICE_Enum)) {
		void *min = SPA_PTROFF(alt1,size,void);
		void *max = SPA_PTROFF(min,size,void);
		void *step = p1c == SPA_CHOICE_Step ? SPA_PTROFF(max,size,void) : NULL;

		/* copy all values inside the range, this will automatically prefer
		 * a valid alt2 value */
		for (j = 0, a2 = alt2; j < nalt2; j++, a2 = SPA_PTROFF(a2,size,void)) {
			if ((res = spa_pod_compare_is_in_range(type, a2, min, max, step, size)) < 0)
				return res;
			if (res == 0)
				continue;
			if (n_copied++ == 0)
				spa_pod_builder_raw(b, a2, size);
			spa_pod_builder_raw(b, a2, size);
		}
	}
	else if ((p1c == SPA_CHOICE_Range && p2c == SPA_CHOICE_Range) ||
	    (p1c == SPA_CHOICE_Range && p2c == SPA_CHOICE_Step) ||
	    (p1c == SPA_CHOICE_Step && p2c == SPA_CHOICE_Range) ||
	    (p1c == SPA_CHOICE_Step && p2c == SPA_CHOICE_Step)) {
		void *min1 = SPA_PTROFF(alt1,size,void);
		void *max1 = SPA_PTROFF(min1,size,void);
		void *min2 = SPA_PTROFF(alt2,size,void);
		void *max2 = SPA_PTROFF(min2,size,void);

		/* max of min */
		if (spa_pod_compare_value(type, min1, min2, size) < 0)
			min1 = min2;
		/* min of max */
		if (spa_pod_compare_value(type, max2, max1, size) < 0)
			max1 = max2;

		/* reject impossible range */
		if (spa_pod_compare_value(type, max1, min1, size) < 0)
			return -EINVAL;

		/* prefer alt2 if in new range */
		a1 = alt2;
		if ((res = spa_pod_compare_is_in_range(type, a1, min1, max1, NULL, size)) < 0)
			return res;
		if (res == 0) {
			/* try alt1 otherwise */
			a1 = alt1;
			if ((res = spa_pod_compare_is_in_range(type, a1, min1, max1, NULL, size)) < 0)
				return res;
			/* fall back to new min value then */
			if (res == 0)
				a1 = min1;
		}

		spa_pod_builder_raw(b, a1, size);
		spa_pod_builder_raw(b, min1, size);
		spa_pod_builder_raw(b, max1, size);
		nc = (struct spa_pod_choice*)spa_pod_builder_deref_fallback(b, nc_offs, &dummy.pod);
		nc->body.type = SPA_CHOICE_Range;
	}
	else if ((p1c == SPA_CHOICE_None && p2c == SPA_CHOICE_Flags) ||
	    (p1c == SPA_CHOICE_Flags && p2c == SPA_CHOICE_None) ||
	    (p1c == SPA_CHOICE_Flags && p2c == SPA_CHOICE_Flags)) {
		if (spa_pod_filter_flags_value(b, type, alt1, alt2, size) != 1)
			return -EINVAL;
		nc = (struct spa_pod_choice*)spa_pod_builder_deref_fallback(b, nc_offs, &dummy.pod);
		nc->body.type = SPA_CHOICE_Flags;
	}
	else if (p1c == SPA_CHOICE_Range && p2c == SPA_CHOICE_Flags)
		return -ENOTSUP;
	else if (p1c == SPA_CHOICE_Enum && p2c == SPA_CHOICE_Flags)
		return -ENOTSUP;
	else if (p1c == SPA_CHOICE_Step && p2c == SPA_CHOICE_Flags)
		return -ENOTSUP;
	else if (p1c == SPA_CHOICE_Flags && p2c == SPA_CHOICE_Range)
		return -ENOTSUP;
	else if (p1c == SPA_CHOICE_Flags && p2c == SPA_CHOICE_Step)
		return -ENOTSUP;
	else if (p1c == SPA_CHOICE_Flags && p2c == SPA_CHOICE_Enum)
		return -ENOTSUP;

	nc = (struct spa_pod_choice*)spa_pod_builder_deref_fallback(b, nc_offs, &dummy.pod);
	if (nc->body.type == SPA_CHOICE_None) {
		if (n_copied == 0) {
			return -EINVAL;
		} else if (n_copied == 1) {
			/* we always copy the default value twice, so remove it
			 * again when it was the only one added */
			spa_pod_builder_remove(b, size);
		} else if (n_copied > 1) {
			nc->body.type = SPA_CHOICE_Enum;
		}
	}
	spa_pod_builder_pop(b, &f);

	return 0;
}

SPA_API_POD_FILTER int spa_pod_filter_part(struct spa_pod_builder *b,
	       const struct spa_pod *pod, uint32_t pod_size,
	       const struct spa_pod *filter, uint32_t filter_size)
{
	const struct spa_pod *pp, *pf;
	int res = 0;

	pf = filter;

	SPA_POD_FOREACH(pod, pod_size, pp) {
		bool do_copy = false, do_advance = false;
		uint32_t filter_offset = 0;
		struct spa_pod_frame f;

		switch (pp->type) {
		case SPA_TYPE_Object:
			if (pf != NULL) {
				struct spa_pod_object *op = (struct spa_pod_object *) pp;
				struct spa_pod_object *of = (struct spa_pod_object *) pf;
				const struct spa_pod_prop *p1, *p2;

				if (pf->type != pp->type)
					return -EINVAL;

				spa_pod_builder_push_object(b, &f, op->body.type, op->body.id);
				p2 = NULL;
				SPA_POD_OBJECT_FOREACH(op, p1) {
					p2 = spa_pod_object_find_prop(of, p2, p1->key);
					if (p2 != NULL)
						res = spa_pod_filter_prop(b, p1, p2);
					else if (SPA_FLAG_IS_SET(p1->flags, SPA_POD_PROP_FLAG_MANDATORY))
						res = -EINVAL;
					else if (!SPA_FLAG_IS_SET(p1->flags, SPA_POD_PROP_FLAG_DROP))
						spa_pod_builder_raw_padded(b, p1, SPA_POD_PROP_SIZE(p1));
					if (res < 0)
						break;
				}
				if (res >= 0) {
					p1 = NULL;
					SPA_POD_OBJECT_FOREACH(of, p2) {
						p1 = spa_pod_object_find_prop(op, p1, p2->key);
						if (p1 != NULL)
							continue;
						if (SPA_FLAG_IS_SET(p2->flags, SPA_POD_PROP_FLAG_MANDATORY))
							res = -EINVAL;
						else if (!SPA_FLAG_IS_SET(p2->flags, SPA_POD_PROP_FLAG_DROP))
							spa_pod_builder_raw_padded(b, p2, SPA_POD_PROP_SIZE(p2));
						if (res < 0)
							break;
					}
				}
				spa_pod_builder_pop(b, &f);
				do_advance = true;
			}
			else
				do_copy = true;
			break;

		case SPA_TYPE_Struct:
			if (pf != NULL) {
				if (pf->type != pp->type)
					return -EINVAL;

				filter_offset = sizeof(struct spa_pod_struct);
				spa_pod_builder_push_struct(b, &f);
				res = spa_pod_filter_part(b,
					SPA_PTROFF(pp,filter_offset,const struct spa_pod),
					SPA_POD_SIZE(pp) - filter_offset,
					SPA_PTROFF(pf,filter_offset,const struct spa_pod),
					SPA_POD_SIZE(pf) - filter_offset);
			        spa_pod_builder_pop(b, &f);
				do_advance = true;
			}
			else
				do_copy = true;
			break;

		default:
			if (pf != NULL) {
				if (spa_pod_memcmp(pp, pf) != 0)
					return -EINVAL;
				do_advance = true;
			}
			do_copy = true;
			break;
		}
		if (do_copy)
			spa_pod_builder_raw_padded(b, pp, SPA_POD_SIZE(pp));
		if (do_advance) {
			pf = (const struct spa_pod*)spa_pod_next(pf);
			if (!spa_pod_is_inside(filter, filter_size, pf))
				pf = NULL;
		}
		if (res < 0)
			break;
	}
	return res;
}

SPA_API_POD_FILTER int
spa_pod_filter(struct spa_pod_builder *b,
	       struct spa_pod **result,
	       const struct spa_pod *pod,
	       const struct spa_pod *filter)
{
	int res;
	struct spa_pod_builder_state state;

        spa_return_val_if_fail(pod != NULL, -EINVAL);
        spa_return_val_if_fail(b != NULL, -EINVAL);

	spa_pod_builder_get_state(b, &state);
	if (filter == NULL) {
		res = spa_pod_builder_raw_padded(b, pod, SPA_POD_SIZE(pod));
	} else {
		struct spa_pod_dynamic_builder db;
		spa_pod_dynamic_builder_continue(&db, b);
		res = spa_pod_filter_part(&db.b, pod, SPA_POD_SIZE(pod), filter, SPA_POD_SIZE(filter));
		if (res >= 0)
			res = spa_pod_builder_raw_padded(b, db.b.data, db.b.state.offset);
		spa_pod_dynamic_builder_clean(&db);
	}
	if (res >= 0 && result) {
		*result = (struct spa_pod*)spa_pod_builder_deref(b, state.offset);
		if (*result == NULL)
			res = -ENOSPC;
	}
	return res;
}

SPA_API_POD_FILTER int spa_pod_filter_object_make(struct spa_pod_object *pod)
{
	struct spa_pod_prop *res;
	int count = 0;

	SPA_POD_OBJECT_FOREACH(pod, res) {
		if (spa_pod_is_choice(&res->value) &&
		    !SPA_FLAG_IS_SET(res->flags, SPA_POD_PROP_FLAG_DONT_FIXATE)) {
			uint32_t nvals, choice;
			struct spa_pod *v = spa_pod_get_values(&res->value, &nvals, &choice);
			const void *vals = SPA_POD_BODY(v);

			if (nvals < 1)
				continue;

			if (spa_pod_compare_is_valid_choice(v->type, v->size,
						vals, vals, nvals, choice)) {
				((struct spa_pod_choice*)&res->value)->body.type = SPA_CHOICE_None;
				count++;
			}
		}
	}
	return count;
}
SPA_API_POD_FILTER int spa_pod_filter_make(struct spa_pod *pod)
{
	if (!spa_pod_is_object(pod))
		return -EINVAL;
	return spa_pod_filter_object_make((struct spa_pod_object *)pod);
}
/**
 * \}
 */

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* SPA_POD_FILTER_H */