#include "esphome.h"

#include <vector>

using esphome::Component;
using esphome::PollingComponent;
using esphome::text_sensor::TextSensor;
using esphome::uart::UARTComponent;
using esphome::uart::UARTDevice;

class UART2MQTT : public PollingComponent,
		  public UARTDevice,
		  public TextSensor
{
      public:
	UART2MQTT(UARTComponent *parent)
	    : PollingComponent(200), UARTDevice(parent), TextSensor()
	{
	}

	void update() override
	{
		std::size_t ready = available();
		if (ready > 0) {
			auto take = std::min(ready, buf_.size() - at_);
			ESP_LOGI("uart2mqtt", "taking %d", take);
			read_array(buf_.begin() + at_, take);
			at_ += take;
		}
		if (at_ > 0 && (ready == 0 || at_ >= buf_.size())) {
			ESP_LOGI("uart2mqtt", "flush %d", at_);

			std::string hex;
			for (auto i = 0; i < at_; i++) {
				char byte[3];
				sprintf(byte, "%02X", buf_[i]);
				hex += byte;
			}
			publish_state(hex);
			at_ = 0;
		}
	}

	static uint8_t nibble(char ch)
	{
		if (ch >= '0' && ch <= '9') {
			return ch - '0';
		} else if (ch >= 'a' && ch <= 'F') {
			return 10 + ch - 'a';
		} else {
			return 10 + ch - 'A';
		}
	}
	void tx(std::string msg)
	{
		ESP_LOGI("uart2mqtt", "::tx %s", msg.c_str());
		if (msg.length() % 2 != 0) {
			ESP_LOGE("uart2mqtt", "Dropping odd length message");
			return;
		}

		std::vector<uint8_t> raw(msg.length() / 2, 0);
		for (auto i = 0; i < raw.size(); i++) {
			raw[i] = (nibble(msg[i * 2]) << 4) |
				 nibble(msg[i * 2 + 1]);
		}
		write_array(raw);
	}

      private:
	std::array<uint8_t, 256> buf_;
	std::size_t at_ = 0;
};