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

#include <gtest/gtest.h>
#include <di/drv/hl854x.h>

extern "C" {
#include "drv/hl854x/udp.c"
}

using namespace std;

struct test_drv_hl854x_readwrite_cb_items {
	size_t n;
	const char **tv;
	size_t tvlen;
	string writebuf;
};
static struct test_drv_hl854x_readwrite_cb_items g_tvs;

size_t test_drv_hl854x_read_cb(void *buf, size_t nbyte)
{
	const size_t len = strlen(g_tvs.tv[g_tvs.n]);
	const char *str = g_tvs.tv[g_tvs.n];

	if (nbyte < len)
		return 0;

	memcpy(buf, str, nbyte);

	g_tvs.n++;
	if (g_tvs.n == g_tvs.tvlen)
		g_tvs.n = 0;

	return len;
}

size_t test_drv_hl854x_write_cb(const void *buf, size_t nbyte)
{
	g_tvs.writebuf.append(static_cast<const char *>(buf), nbyte);
	return nbyte;
}

/**
 * Initialize an test string for reading (and set the correct UDP sessions states)
 * @param ctx Modem context (uinitialized)
 * @param str Mocked modem string readable by the driver
 */
void test_hl854x_udp_init(struct di_drv_hl854x_ctx *ctx, const char **tv, const size_t tvlen)
{
	di_drv_hl854x_init(ctx);

	// The reader is default initialized as locked for the unit tests we must be able to
	//  read synchronous. In the real world there is an async reader so we dont miss any
	//  data.
	di_bsem_post(&ctx->lock.reader);

	di_drv_hl854x_set_read(ctx,  test_drv_hl854x_read_cb);
	di_drv_hl854x_set_write(ctx, test_drv_hl854x_write_cb);

	g_tvs.n     = 0;
	g_tvs.tv    = tv;
	g_tvs.tvlen = tvlen;
	g_tvs.writebuf.clear();

	ctx->carrier.status = HL854X_CARRIER_STATUS_REG_HOME;
	ctx->udp.session_id = HL854X_SESSION_ID_MIN;
	ctx->udp.state      = HL854X_UDP_STATE_READY;
}

/**
 * Verify the initialisation is correct of the UDP session
 */
TEST(drv_hl854x_udp, init) {
	struct di_drv_hl854x_ctx ctx;

	di_drv_hl854x_init(&ctx);

	ASSERT_EQ(HL854X_SESSION_ID_UNKNOWN, ctx.udp.session_id);
	ASSERT_EQ(HL854X_UDP_STATE_UNKNOWN,  ctx.udp.state);
	ASSERT_EQ(nullptr, ctx.udp.remote_addr);
	ASSERT_EQ(nullptr, ctx.udp.remote_port);
}

/**
 * Test the sending mechanism
 * * AT+KUDPSND=...
 * * Wait for modem `CONNECT\r\n` reply
 * * Write data bytes
 * * Wait for modem `OK` reply
 */
TEST(drv_hl854x_udp, send) {
	static const char *addr = "10.0.0.1";
	static const char *port = "4000";
	static const char *data = "hello world!";
	static const char *tv[2] = {"CONNECT\r\n", "OK\r\n"};
	struct di_drv_hl854x_ctx ctx;

	test_hl854x_udp_init(&ctx, tv, 2);

	di_drv_hl854x_udp_set_remote_endpoint(&ctx, addr, port);
	ASSERT_EQ(addr, ctx.udp.remote_addr);
	ASSERT_EQ(port, ctx.udp.remote_port);
	ASSERT_EQ(DNOK, di_drv_hl854x_udp_send(&ctx, data, strlen(data)));
	ASSERT_EQ(61, g_tvs.writebuf.size());
	ASSERT_TRUE(nullptr != strstr(g_tvs.writebuf.c_str(), "AT+KUDPSND=1,\"10.0.0.1\",4000,12\r\n"));
	ASSERT_TRUE(nullptr != strstr(g_tvs.writebuf.c_str(), "hello world!"));
}

/**
 * Verify if the recv_wait_ndata_available works as expected when an async URC KUDP_DATA is send
 * * Test DNE_TIMEOUT on 1ms
 * * Recv 12 bytes KUDP_DATA URC
 * * Test DNOK on 1ms
 * * Check ndata_available is 12 bytes
 */
TEST(drv_hl854x_udp, recv_wait_ndata_available) {
	size_t ndata_available = 0;
	struct di_drv_hl854x_ctx ctx;
	static const char *tv[1] = {"+KUDP_DATA: 1,12\r\n"};

	test_hl854x_udp_init(&ctx, tv, 1);

	// Check the mutex works and has a timeout because there are not data bytes available
	ASSERT_EQ(DNE_TIMEOUT, di_drv_hl854x_udp_recv_wait_ndata_available(&ctx, 1, &ndata_available));
	ASSERT_EQ(ndata_available, 0);

	// Send URC for session 1 with 12 bytes ready
	di_drv_hl854x_read(&ctx);
	ASSERT_EQ(ctx.udp.ndata_available, 12);

	// Read amount of data bytes available
	ASSERT_EQ(DNOK, di_drv_hl854x_udp_recv_wait_ndata_available(&ctx, 1, &ndata_available));

	// Check application has read the correct amount of bytes available and udp session
	//  is reset to zero
	ASSERT_EQ(ndata_available, 12);
	ASSERT_EQ(ctx.udp.ndata_available, 0);
}

/**
 * Test the receive mechanism
 */
TEST(drv_hl854x_udp, recv) {
	size_t ndata_available = 0;
	uint8_t recv_buf[256];
	static const char *tv[] = {"+KUDP_DATA: 1,8\r\n", "CONNECT\r\n", "TESTDATA--EOF--Pattern--\r\n", "OK\r\n"};
	struct di_drv_hl854x_ctx ctx;

	memset(recv_buf, 0, sizeof(recv_buf));
	test_hl854x_udp_init(&ctx, tv, DI_ARRAY_SIZE(tv));

	// Send URC for session 1 with 8 bytes ready
	di_drv_hl854x_read(&ctx);
	ASSERT_EQ(8, ctx.udp.ndata_available);

	// Read amount of data bytes available
	ASSERT_EQ(DNOK, di_drv_hl854x_udp_recv_wait_ndata_available(&ctx, HL854X_TIMEOUT_INFINITE, &ndata_available));

	// Check application has read the correct amount of bytes available and udp session
	ASSERT_EQ(8, ndata_available);

	ASSERT_EQ(8U, di_drv_hl854x_udp_recv(&ctx, recv_buf, sizeof(recv_buf)));
	EXPECT_TRUE( 0 == memcmp( "TESTDATA", recv_buf, 8 ) );
}