#include <assert.h>
#include <stdio.h>
#include <string.h>

#include "gps/gps_ephemeris_cache.h"

static gps_ephemeris_t make_ephemeris(
	unsigned int prn,
	unsigned char iode)
{
	gps_ephemeris_t ephemeris;
	memset(&ephemeris, 0, sizeof(ephemeris));
	ephemeris.SVID = (unsigned char)prn;
	ephemeris.iode = iode;
	ephemeris.ephemeris_valid = true;
	ephemeris.toe.week = 2430;
	ephemeris.toe.sec = 123456.0;
	return ephemeris;
}

static void test_store_restore_and_expiry(void)
{
	gps_ephemeris_cache_t cache;
	gps_ephemeris_cache_init(&cache, 100u);
	gps_ephemeris_t input = make_ephemeris(4u, 17u);
	gps_ephemeris_t output;
	memset(&output, 0, sizeof(output));

	assert(gps_ephemeris_cache_store(
		&cache, 4u, &input, 1000u));
	input.iode = 99u;
	assert(gps_ephemeris_cache_restore(
		&cache, 4u, 1100u, &output));
	assert(output.iode == 17u);
	assert(output.SVID == 4u);
	assert(!gps_ephemeris_cache_restore(
		&cache, 4u, 1101u, &output));
	/* Expiration invalidates the slot, not only this read. */
	assert(!gps_ephemeris_cache_restore(
		&cache, 4u, 1001u, &output));
}

static void test_validation_independence_and_invalidate(void)
{
	gps_ephemeris_cache_t cache;
	gps_ephemeris_cache_init(&cache, 500u);
	gps_ephemeris_t prn4 = make_ephemeris(4u, 21u);
	gps_ephemeris_t prn19 = make_ephemeris(19u, 44u);
	gps_ephemeris_t output;

	prn4.ephemeris_valid = false;
	assert(!gps_ephemeris_cache_store(
		&cache, 4u, &prn4, 0u));
	prn4.ephemeris_valid = true;
	assert(!gps_ephemeris_cache_store(
		&cache, 5u, &prn4, 0u));
	assert(!gps_ephemeris_cache_store(
		&cache, GPS_PRN_COUNT, &prn4, 0u));

	assert(gps_ephemeris_cache_store(
		&cache, 4u, &prn4, 20u));
	assert(gps_ephemeris_cache_store(
		&cache, 19u, &prn19, 30u));
	assert(gps_ephemeris_cache_restore(
		&cache, 19u, 40u, &output));
	assert(output.iode == 44u);

	gps_ephemeris_cache_invalidate(&cache, 4u);
	assert(!gps_ephemeris_cache_restore(
		&cache, 4u, 40u, &output));
	assert(gps_ephemeris_cache_restore(
		&cache, 19u, 40u, &output));
}

static void test_repeated_issue_does_not_hide_staleness(void)
{
	gps_ephemeris_cache_t cache;
	gps_ephemeris_cache_init(&cache, 100u);
	gps_ephemeris_t issue17 = make_ephemeris(6u, 17u);
	gps_ephemeris_t output;

	assert(gps_ephemeris_cache_store(
		&cache, 6u, &issue17, 1000u));
	assert(gps_ephemeris_cache_store(
		&cache, 6u, &issue17, 1090u));
	assert(!gps_ephemeris_cache_restore(
		&cache, 6u, 1101u, &output));

	/* A changed IOD is a fresh broadcast issue and receives a new TTL. */
	issue17.iode = 18u;
	issue17.iodc = 18u;
	assert(gps_ephemeris_cache_store(
		&cache, 6u, &issue17, 1200u));
	assert(gps_ephemeris_cache_restore(
		&cache, 6u, 1300u, &output));
	assert(output.iode == 18u);
}

static void test_time_anchor_is_independent_and_short_lived(void)
{
	gps_ephemeris_cache_t cache;
	gps_ephemeris_cache_init(&cache, 1000u);
	gps_ephemeris_t ephemeris = make_ephemeris(11u, 9u);
	gps_cached_time_anchor_t anchor = {
		.tow = {.week = 2430, .sec = 345678.0},
		.raw_sample = 0xffff0000u,
		.corrected_sample = 4294901759.75,
		.week_valid = true,
		.valid = true
	};
	gps_cached_time_anchor_t restored;

	/* An anchor cannot outlive or exist without its ephemeris slot. */
	assert(!gps_ephemeris_cache_store_time_anchor(
		&cache, 11u, &anchor, 50u));
	assert(gps_ephemeris_cache_store(
		&cache, 11u, &ephemeris, 50u));
	assert(gps_ephemeris_cache_store_time_anchor(
		&cache, 11u, &anchor, 60u));
	assert(gps_ephemeris_cache_restore_time_anchor(
		&cache, 11u, 170u, 110u, &restored));
	assert(restored.tow.week == 2430);
	assert(restored.raw_sample == 0xffff0000u);
	assert(!gps_ephemeris_cache_restore_time_anchor(
		&cache, 11u, 171u, 110u, &restored));
	/* The two-hour-class ephemeris remains usable after the short counter
	 * anchor expires; firmware then waits for one fresh HOW, not SF1/2/3. */
	assert(gps_ephemeris_cache_restore(
		&cache, 11u, 171u, &ephemeris));
}

int main(void)
{
	test_store_restore_and_expiry();
	test_validation_independence_and_invalidate();
	test_repeated_issue_does_not_hide_staleness();
	test_time_anchor_is_independent_and_short_lived();
	puts("gps ephemeris cache tests passed");
	return 0;
}