#include "gps.h"
#include "driver/uart.h"
#include "esp_log.h"
#include "esp_http_client.h"
#include <string.h>
#include <stdlib.h>

#define GPS_UART_NUM UART_NUM_1
#define GPS_TX_PIN 4
#define GPS_RX_PIN 5
#define BUF_SIZE 1024

static uint8_t gps_buffer[BUF_SIZE];
void init_gps() {
    const uart_config_t uart_config = {
        .baud_rate = 9600,
        .data_bits = UART_DATA_8_BITS,
        .parity    = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
    };

    uart_param_config(GPS_UART_NUM, &uart_config);
    uart_set_pin(GPS_UART_NUM, GPS_TX_PIN, GPS_RX_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
    uart_driver_install(GPS_UART_NUM, BUF_SIZE, 0, 0, NULL, 0);
}

// Convertit NMEA "ddmm.mmmm" + N/S/E/W en degrés décimaux
double nmea_to_decimal(const char* nmea_coord, const char direction) {
    double raw = atof(nmea_coord);
    int degrees = (int)(raw / 100);
    double minutes = raw - (degrees * 100);
    double decimal = degrees + minutes / 60.0;
    if (direction == 'S' || direction == 'W') decimal = -decimal;
    return decimal;
}

char* gps_to_json(char* gps_data) {
    static char json[128];

    double latitude = 0.0;
    double longitude = 0.0;

    if (gps_data && strncmp(gps_data, "$GPGGA,", 7) == 0) {
        char* fields[15];
        int i = 0;
        char gps_copy[BUF_SIZE];
        strncpy(gps_copy, gps_data, BUF_SIZE - 1);
        gps_copy[BUF_SIZE - 1] = '\0';

        char* token = strtok(gps_copy, ",");
        while (token && i < 15) {
            fields[i++] = token;
            token = strtok(NULL, ",");
        }

        if (i >= 6 && fields[2][0] != '\0' && fields[4][0] != '\0') {
            latitude = nmea_to_decimal(fields[2], fields[3][0]);
            longitude = nmea_to_decimal(fields[4], fields[5][0]);
        }
    }

    // Créer le JSON avec des valeurs valides même si GPS pas fixé
    snprintf(json, sizeof(json), "{\"data\":{\"latitude\":%.6f,\"longitude\":%.6f}}",
             latitude, longitude);

    return json;
}


char* read_gps() { 
    int len = uart_read_bytes(GPS_UART_NUM, gps_buffer, BUF_SIZE - 1, 100 / portTICK_PERIOD_MS); 
    if (len > 0) { 
        gps_buffer[len] = '\0'; 
        return (char*)gps_buffer; 
    } 
    return NULL; 
}

void send_gps_data(const char* server_url, const char* json)
{
    if (!json) return;

    ESP_LOGI(TAG, "Sending JSON: %s", json);

    esp_http_client_config_t config = { .url = server_url };
    esp_http_client_handle_t client = esp_http_client_init(&config);
    esp_http_client_set_method(client, HTTP_METHOD_POST);
    esp_http_client_set_post_field(client, json, strlen(json));
    esp_http_client_set_header(client, "Content-Type", "application/json");

    esp_http_client_perform(client);
    esp_http_client_cleanup(client);
}

void send_position_task(void *pvParameters)
{
    const char* position_endpoint = "http://192.168.15.117:5000/devices/notify-position";

    while (1) {
        char* json;
        char* raw_data = read_gps();
        if (raw_data) {
            char* json = gps_to_json(raw_data);
            send_gps_data(position_endpoint, json);
        } else {
            ESP_LOGI(TAG, "NO GPS DATA");
        }
        vTaskDelay(25000 / portTICK_PERIOD_MS);
    }
}