#include "JW01.h"

#include <ctype.h>
#include <stdlib.h>
#include <string.h>

#include "driver/uart.h"
#include "esp_check.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"

static const char *TAG = "JW01";
static bool s_inited = false;
static uint32_t s_parse_fail_count = 0;

static esp_err_t jw01_parse_binary_frames(const uint8_t *buf, int len, jw01_data_t *out)
{
	bool found = false;
	float last_co2 = 0.0f;

	for (int i = 0; i + 5 < len; ++i) {
		if (buf[i] != 0x2C) {
			continue;
		}

		uint8_t cs = (uint8_t)(buf[i] + buf[i + 1] + buf[i + 2] + buf[i + 3] + buf[i + 4]);
		if (cs != buf[i + 5]) {
			continue;
		}

		uint16_t value = ((uint16_t)buf[i + 1] << 8) | buf[i + 2];
		last_co2 = (float)value;
		found = true;
		i += 5;
	}

	if (!found) {
		return ESP_ERR_INVALID_RESPONSE;
	}

	out->co2 = last_co2;
	out->co2_valid = true;
	return ESP_OK;
}

static void str_to_upper_inplace(char *s)
{
	while (*s != '\0') {
		*s = (char)toupper((unsigned char)*s);
		++s;
	}
}

static bool extract_float_by_key(const char *line, const char *key, float *out)
{
	char up_line[160];
	char up_key[24];

	strncpy(up_line, line, sizeof(up_line) - 1);
	up_line[sizeof(up_line) - 1] = '\0';
	strncpy(up_key, key, sizeof(up_key) - 1);
	up_key[sizeof(up_key) - 1] = '\0';

	str_to_upper_inplace(up_line);
	str_to_upper_inplace(up_key);

	char *pos = strstr(up_line, up_key);
	if (pos == NULL) {
		return false;
	}

	while (*pos != '\0' && *pos != ':' && *pos != '=') {
		++pos;
	}
	if (*pos == '\0') {
		return false;
	}
	++pos;

	while (*pos != '\0' && (isspace((unsigned char)*pos) || *pos == ',')) {
		++pos;
	}

	char *endptr = NULL;
	float value = strtof(pos, &endptr);
	if (endptr == pos) {
		return false;
	}

	*out = value;
	return true;
}

static esp_err_t jw01_parse_line(const char *line, jw01_data_t *out)
{
	jw01_data_t data = {0};

	data.tvoc_valid = extract_float_by_key(line, "TVOC", &data.tvoc);
	if (!data.tvoc_valid) {
		data.tvoc_valid = extract_float_by_key(line, "VOC", &data.tvoc);
	}

	data.hcho_valid = extract_float_by_key(line, "HCHO", &data.hcho);
	if (!data.hcho_valid) {
		data.hcho_valid = extract_float_by_key(line, "CH2O", &data.hcho);
	}

	data.co2_valid = extract_float_by_key(line, "CO2", &data.co2);

	if (!data.tvoc_valid && !data.hcho_valid && !data.co2_valid) {
		return ESP_ERR_INVALID_RESPONSE;
	}

	*out = data;
	return ESP_OK;
}

esp_err_t jw01_init(void)
{
	if (s_inited) {
		return ESP_OK;
	}

	const uart_config_t uart_cfg = {
		.baud_rate = JW01_UART_BAUDRATE,
		.data_bits = UART_DATA_8_BITS,
		.parity = UART_PARITY_DISABLE,
		.stop_bits = UART_STOP_BITS_1,
		.flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
		.source_clk = UART_SCLK_DEFAULT,
	};

	ESP_RETURN_ON_ERROR(uart_driver_install((uart_port_t)JW01_UART_PORT, 1024, 0, 0, NULL, 0),
						TAG, "uart driver install failed");
	ESP_RETURN_ON_ERROR(uart_param_config((uart_port_t)JW01_UART_PORT, &uart_cfg),
						TAG, "uart param config failed");
	ESP_RETURN_ON_ERROR(uart_set_pin((uart_port_t)JW01_UART_PORT,
									 JW01_UART_TX_GPIO,
									 JW01_UART_RX_GPIO,
									 UART_PIN_NO_CHANGE,
									 UART_PIN_NO_CHANGE),
						TAG, "uart set pin failed");
	ESP_RETURN_ON_ERROR(uart_flush_input((uart_port_t)JW01_UART_PORT), TAG, "uart flush failed");

	s_inited = true;
	ESP_LOGI(TAG, "JW01 init done on UART%d TX=%d RX=%d baud=%d",
			 JW01_UART_PORT, JW01_UART_TX_GPIO, JW01_UART_RX_GPIO, JW01_UART_BAUDRATE);
	return ESP_OK;
}

esp_err_t jw01_read(jw01_data_t *out_data, int timeout_ms)
{
	ESP_RETURN_ON_FALSE(out_data != NULL, ESP_ERR_INVALID_ARG, TAG, "out_data is null");
	ESP_RETURN_ON_FALSE(s_inited, ESP_ERR_INVALID_STATE, TAG, "jw01 not init");

	char line[160] = {0};
	int n = uart_read_bytes((uart_port_t)JW01_UART_PORT,
							(uint8_t *)line,
							sizeof(line) - 1,
							pdMS_TO_TICKS(timeout_ms));
	if (n <= 0) {
		return ESP_ERR_TIMEOUT;
	}
	line[n] = '\0';
	jw01_data_t data = {0};
	esp_err_t ret = jw01_parse_binary_frames((const uint8_t *)line, n, &data);
	if (ret != ESP_OK) {
		ret = jw01_parse_line(line, &data);
	}

	if (ret == ESP_OK) {
		*out_data = data;
	}

	if (ret != ESP_OK) {
		s_parse_fail_count++;
		if (s_parse_fail_count <= 5 || (s_parse_fail_count % 20) == 0) {
			ESP_LOGW(TAG, "parse failed (%s), rx_len=%d", esp_err_to_name(ret), n);
			ESP_LOG_BUFFER_HEX_LEVEL(TAG, (const uint8_t *)line, n, ESP_LOG_WARN);
		}
	}

	return ret;
}