#include <stdio.h>
#include <math.h>
#include <driver/ledc.h>
#include <esp_err.h>

#include <freertos/FreeRTOS.h>
#include <freertos/task.h>

#ifdef __cplusplus
extern "C" {
#endif
void app_main();
#ifdef __cplusplus
}
#endif
// --- Motor Control ---
#define NUM_MOTORS 4

// Motor speeds (simulated PWM values, 0-255)
int motorSpeeds[NUM_MOTORS] = {0};

// --- IMU Simulation ---
// Simple example: Assume a level drone initially
float rollAngle = 0;
float pitchAngle = 0;
float yawRate = 0;   // Degrees per second

// --- Control Inputs (Simulated) ---
// Example values:  Potentiometer readings (0-1023)
int throttleInput = 0;
int rollInput = 512;   // Center stick
int pitchInput = 512;
int yawInput = 512;

// --- Simulation Parameters ---
float deltaTime = 0.01; // Seconds per simulation step
float gravity = 9.81;  // m/s^2 (approximate value)

// --- Function Prototypes ---
void simulateIMU();
void calculateMotorSpeeds();
void printMotorSpeeds();
esp_err_t ledc_init();
//=============================================================================
esp_err_t ledc_init() {
    // Prepare and set configuration for timers
    ledc_timer_config_t ledc_timer = {
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .timer_num = LEDC_TIMER_0,
        .duty_resolution = LEDC_TIMER_13_BIT,
        .freq_hz = 5000,
        .clk_cfg = LEDC_AUTO_CLK,
    };

    esp_err_t ret = ledc_timer_config(&ledc_timer);
    if (ret != ESP_OK) {
        printf("LEDC timer config failed\n");
        return ret;
    }

    // Prepare and set configuration for individual channels
   ledc_channel_config_t ledc_channel[NUM_MOTORS] = {
        {
            .speed_mode = LEDC_LOW_SPEED_MODE,
            .channel = LEDC_CHANNEL_0,
            .timer_sel = LEDC_TIMER_0,
            .gpio_num = 12,
            .duty = 0,
            .hpoint = 0,
        },
        {
            .speed_mode = LEDC_LOW_SPEED_MODE,
            .channel = LEDC_CHANNEL_1,
            .timer_sel = LEDC_TIMER_0,
            .gpio_num = 13,
            .duty = 0,
            .hpoint = 0,
        },
        {
            .speed_mode = LEDC_LOW_SPEED_MODE,
            .channel = LEDC_CHANNEL_2,
            .timer_sel = LEDC_TIMER_0,
            .gpio_num = 14,
            .duty = 0,
            .hpoint = 0,
        },
        {
            .speed_mode = LEDC_LOW_SPEED_MODE,
            .channel = LEDC_CHANNEL_3,
            .timer_sel = LEDC_TIMER_0,
            .gpio_num = 15,
            .duty = 0,
            .hpoint = 0,
        }
    };
    for (int i = 0; i < NUM_MOTORS; i++) {
         ret = ledc_channel_config(&ledc_channel[i]);
        if (ret != ESP_OK) {
            printf("ledc_channel_config(%d) failed: %d\n", i, ret);
            return ret;
        }
    }
    return ESP_OK;
}
//=============================================================================
//=============================================================================
void app_main() {
    printf("Drone Simulation in C\n");
    esp_err_t ret = ledc_init();
    if (ret != ESP_OK) {
        printf("LEDC initialization failed\n");
        return;
    }
    printf("LEDC initialization complete\n");

    // Simulation loop
    for (int i = 0; i < 1000; i++) {
        // Simulate sensor readings
        simulateIMU();

        // Calculate motor speeds based on sensor data and pilot input
        calculateMotorSpeeds();

        // Print motor speeds to the console
        printMotorSpeeds();
        for (int j = 0; j < NUM_MOTORS; j++) {
            ledc_set_duty(LEDC_LOW_SPEED_MODE, (ledc_channel_t)j, motorSpeeds[j] * 16);
            ledc_update_duty(LEDC_LOW_SPEED_MODE, (ledc_channel_t)j);
        }
        vTaskDelay(pdMS_TO_TICKS(10));
        throttleInput += 1;
        throttleInput %= 1023; //cycle to 0

        rollInput += 1;
        rollInput %= 1023; //cycle to 0
    }
    printf("Complete!");
}
//=============================================================================
// --- Simulate IMU Readings ---
void simulateIMU() {
    // * Simplest Example *
    //  Read the gyro data, assuming a stable level position
    //  The accelerometer values are not used in this example for simplicity.

    //Simulate IMU readings based on inputs
    rollAngle = (rollInput - 512) * 0.1; //Map to an angle

    pitchAngle = (pitchInput - 512) * 0.1;
    yawRate = (yawInput - 512) * 0.05; // Adjust scale as needed


    //Print
    printf("Roll: %.2f Pitch: %.2f Yaw Rate: %.2f\n", rollAngle, pitchAngle, yawRate);

}
//=============================================================================

// --- Calculate Motor Speeds ---
void calculateMotorSpeeds() {
    // **Basic Stabilization & Control Example**

    //1.  Base Throttle: This determines the overall "lift" of the drone.
    int baseThrottle = throttleInput / 4;  //Scale to a PWM range (0-255)

    //2. Compensation for roll, pitch, yaw
    //  *Simple* proportional control.  In real life, PID is far more stable.
    int rollCorrection = (int)(rollAngle * 2); //Example Scaling
    int pitchCorrection = (int)(pitchAngle * 2);
    int yawCorrection = (int)(yawRate * 1);

    //3. Mix motor speeds based on control inputs
    motorSpeeds[0] = baseThrottle + rollCorrection - pitchCorrection + yawCorrection;  // Front-Right
    motorSpeeds[1] = baseThrottle - rollCorrection - pitchCorrection - yawCorrection;  // Rear-Right
    motorSpeeds[2] = baseThrottle - rollCorrection + pitchCorrection + yawCorrection;  // Rear-Left
    motorSpeeds[3] = baseThrottle + rollCorrection + pitchCorrection - yawCorrection;  // Front-Left

    //4.  Constrain the motor speeds to the valid range of 0-255
    for (int i = 0; i < NUM_MOTORS; i++) {
        if (motorSpeeds[i] < 0) {
            motorSpeeds[i] = 0;
        } else if (motorSpeeds[i] > 255) {
            motorSpeeds[i] = 255;
        }
    }
}
//=============================================================================
// --- Print Motor Speeds ---
void printMotorSpeeds() {
    printf("Motor Speeds: ");
    for (int i = 0; i < NUM_MOTORS; i++) {
        printf("%d ", motorSpeeds[i]);
    }
    printf("\n");
}
//=============================================================================