#pragma once

#include "http/request.hpp"
#include "network_connection.hpp"

#include <SoftwareSerial.h>
#include <avr/pgmspace.h>
#include <stddef.h>
#include <stdint.h>

constexpr auto MAX_NETWORK_MODULE_RESPONSE_LENGTH = 128U;

constexpr auto REQUEST_DATA_LENGTH_BUF_SIZE = 16U;
constexpr auto REQUEST_METHOD_STR_MAX_LENGTH = 10U;
constexpr auto REQUEST_PATH_MAX_LENGTH = 64U;
constexpr auto REQUEST_HTTP_VERSION_MAX_LENGTH = 10U;

constexpr auto WIFI_CONNECT_COMMAND_BASE_LENGTH = 7U;
constexpr auto CREATE_TCP_SERVER_COMMAND_BASE_LENGTH = 8U;
constexpr auto CLOSE_CONNECTION_COMMAND_BASE_LENGTH = 51U;
constexpr auto SEND_RESPONSE_COMMAND_BASE_LENGTH = 51U;

constexpr auto ASCII_TO_CHAR = 48U;

constexpr auto TIMEOUT_SHORT = 1500U;
constexpr auto TIMEOUT_MEDIUM = 4000U;
constexpr auto TIMEOUT_LONG = 10000U;

const char RESPONSE_HTTP_VERSION[] PROGMEM = { "HTTP/1.1" };
constexpr auto RESPONSE_STATUS_CODE_LENGTH = 3U;

constexpr auto NUMBER_BASE = 10U;

enum WifiMode
{
	Station = 1,
	SoftAP = 2,
	SoftAPAndStation = 3
};

enum WiFiModuleResponseStatus
{
	OK,
	FAIL,
	ERROR,
	TIMEOUT
};

struct WiFiModuleOptions
{
	uint8_t receive_pin;
	uint8_t transmit_pin;
};

class WiFiModule
{
public:
	explicit WiFiModule(const WiFiModuleOptions &options) noexcept;

	void begin(size_t baudrate) noexcept;

	auto get_available() noexcept -> int;

	void reset() noexcept;

	/**
	 * Connects to a wifi network.
	 *
	 * @param ssid The service set identifier of a wifi network.
	 * @param password The wifi network password.
	 *
	 * @returns Whether or not it succeeded.
	 */
	auto connect_to_wifi(const char *ssid, const char *password) noexcept -> bool;

	void set_wifi_mode(WifiMode wifi_mode) noexcept;

	void set_multiple_connections_enabled(bool is_enabled) noexcept;

	void set_echo_enabled(bool is_enabled) noexcept;

	void create_tcp_server(size_t port) noexcept;

	/**
	 * Tests the connection to the wifi module.
	 *
	 * @returns Whether or not the test succeeded.
	 */
	auto test() noexcept -> bool;

	/**
	 * Gets local IP address of the wifi module.
	 *
	 * @param local_ip_out Local IP output buffer.
	 *
	 * @returns A pointer to the local IP output buffer.
	 */
	auto get_local_ip(char *local_ip_out) noexcept -> const char *;

	/**
	 * Gets the MAC address of the wifi module.
	 *
	 * @param mac_address_out MAC address output buffer.
	 *
	 * @returns A pointer to the MAC address output buffer.
	 */
	auto get_mac_address(char *mac_address_out) noexcept -> const char *;

	/**
	 * Reads a incoming HTTP request.
	 *
	 * @returns A request. Has a connection with a ID of -1 if reading the request failed.
	 */
	auto read_incoming_request() noexcept -> HTTPRequest;

	auto close_connection(NetworkConnection &connection) noexcept -> bool;

	auto send_response(
		const NetworkConnection &connection,
		size_t status_code,
		const char **headers,
		size_t headers_cnt,
		const char *body
	) noexcept -> bool;

private:
	SoftwareSerial _serial;

	/**
	 * Sends a command to the wifi module.
	 *
	 * @param command A command without the "AT+" in the beginning.
	 *
	 * @returns Whether or not it succeeded.
	 */
	auto _send_serial(const char *command) noexcept -> bool;

	auto _read_connection_id() noexcept -> int8_t;

	auto _read_request_data_length() noexcept -> size_t;

	auto _read_request_method(size_t &request_data_length) noexcept -> HTTPRequestMethod;

	/**
	 * Reads from the wifi module until it responds with a status.
	 *
	 * @param timeout Timeout in milliseconds.
	 * @param response_out Response output buffer.
	 *
	 * @returns The response status.
	 *
	 */
	auto _read(uint64_t timeout, char *response_out) noexcept -> WiFiModuleResponseStatus;

	void
	_read_to(char *buffer_out, size_t length, char stop_char, uint64_t timeout) noexcept;

	void _read_bytes(char *buffer_out, size_t length, uint64_t timeout) noexcept;

	auto _read_byte() noexcept -> char;
};