#include <pico/stdio.h>

#include <lwip/opt.h>
#include <lwip/sys.h>
#include <lwip/api.h>
#include <string.h>

#include "init.h"
#include "config.h"
#include "puzbusv1.h"
#include "sock.h"

struct netconn* current_connection = NULL;
struct pb_msg recv_msg;

void i2c_send(uint16_t addr, const char * data, size_t data_size) {
	if (current_connection == NULL) return;

	struct pb_msg send_msg = {
		.addr = addr,
		.data = (char *) data,
		.length = data_size,
	};

	char * buf;
	size_t buf_sz;

	if (!pb_write(&send_msg, &buf, &buf_sz)) return;

	// NOTE: netconn does return an error code, but the data needs to be freed
	// whether netconn throws an error or not, so it remains unused
	netconn_write(current_connection, buf, buf_sz, NETCONN_COPY);

	free(buf);
}

void i2c_recv(uint16_t addr, const char * data, size_t data_size) {
	printf("address: 0x%02x\n", addr);
	printf("data:    \"%.*s\"\n", data_size, data);

	// send message back
	char reply[] = "Test message back!";
	i2c_send(0x69, reply, strlen(reply));

	// TODO: this function should forward the recieved message onto the puzzle
	// bus instead of printing/replying
}

void recv_handler(struct netconn* conn, struct netbuf* buf) {
	pb_read_reset(&recv_msg);

	do {
		char* data;
		uint16_t len;
		netbuf_data(buf, (void**)&data, &len);

		// continue early if more data is needed to complete message
		if (!pb_read(&recv_msg, data, len)) continue;

		// forward received message to puzzle bus
		i2c_recv(recv_msg.addr, recv_msg.data, recv_msg.length);
		free(recv_msg.data);
	} while (netbuf_next(buf) >= 0);

	netbuf_delete(buf);
}

void accept_handler(struct netconn* conn) {
	current_connection = conn;

	struct netbuf* buf;
	while (netconn_recv(conn, &buf) == ERR_OK)
		recv_handler(conn, buf);

	netconn_close(conn);
	netconn_delete(conn);

	current_connection = NULL;
}

void serve_task() {
	await_init();

	printf("starting server...\n");
	struct netconn* conn = netconn_new(NETCONN_TCP);
	netconn_bind(conn, IP_ADDR_ANY, CONF_SRV_PORT);
	netconn_listen(conn);

	printf("listening on %s:%d\n", ip4addr_ntoa(netif_ip4_addr(netif_list)), CONF_SRV_PORT);
	while (1) {
		struct netconn* incoming;
		if (netconn_accept(conn, &incoming) == ERR_OK)
			accept_handler(incoming);
	}
}