using UnityEngine;
using System.IO.Ports;
using System.Collections;
using System.Globalization;
using System.Collections.Generic;

public class BoatController : MonoBehaviour
{
    [Header("串口设置")]
    public string portName = "COM4";
    public int baudRate = 9600;

    [Header("移动设置")]
    public float moveSpeed = 1.125f;
    public float rotateFactor = 0.4f;

    [Header("陀螺仪设置")]
    public float gyroDeadZone = 5f;
    public int calibrationSamples = 50;

    private SerialPort serialPort;
    private float currentGyroZ = 0f;
    private float gyroOffset = 0f;
    private bool isCalibrated = false;
    private List<float> calibrationData =
        new List<float>();

    private Rigidbody2D rb;
    private bool isStopped = false;

    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
        StartCoroutine(OpenSerialPort());
    }

    IEnumerator OpenSerialPort()
    {
        yield return new WaitForSecondsRealtime(
            0.5f
        );

        int retryCount = 0;
        int maxRetry = 3;

        while (retryCount < maxRetry)
        {
            bool success = TryOpenPort();

            if (success)
            {
                Debug.Log("✅ 串口连接成功！");
                StartCoroutine(CalibrateGyro());
                yield break;
            }

            retryCount++;
            Debug.LogWarning(
                "⚠️ 串口开启失败第" +
                retryCount + "次"
            );

            yield return new WaitForSecondsRealtime(
                1f
            );
        }

        Debug.LogError("❌ 串口开启失败");
    }

    IEnumerator CalibrateGyro()
    {
        Debug.Log(
            "🔄 开始校准陀螺仪，请保持静止..."
        );
        calibrationData.Clear();

        yield return new WaitForSecondsRealtime(1f);

        while (calibrationData.Count
            < calibrationSamples)
        {
            if (serialPort != null &&
                serialPort.IsOpen &&
                serialPort.BytesToRead > 0)
            {
                try
                {
                    string data =
                        serialPort.ReadLine().Trim();

                    if (float.TryParse(
                        data,
                        NumberStyles.Float,
                        CultureInfo.InvariantCulture,
                        out float gz))
                    {
                        calibrationData.Add(gz);
                        Debug.Log(
                            "校准采样 " +
                            calibrationData.Count +
                            "/" +
                            calibrationSamples +
                            " 值：" + gz
                        );
                    }
                }
                catch { }
            }
            yield return null;
        }

        float sum = 0f;
        foreach (float val in calibrationData)
            sum += val;
        gyroOffset = sum / calibrationData.Count;

        isCalibrated = true;
        Debug.Log(
            "✅ 校准完成！零点偏移：" + gyroOffset
        );
    }

    bool TryOpenPort()
    {
        try
        {
            serialPort = new SerialPort(
                portName, baudRate
            );
            serialPort.ReadTimeout = 5;
            serialPort.Open();
            return true;
        }
        catch (System.Exception e)
        {
            Debug.LogWarning(
                "串口错误：" + e.Message
            );
            return false;
        }
    }

    void Update()
    {
        if (isStopped) return;
        if (!isCalibrated) return;

        if (serialPort != null &&
            serialPort.IsOpen &&
            serialPort.BytesToRead > 0)
        {
            try
            {
                string data =
                    serialPort.ReadLine().Trim();

                if (float.TryParse(
                    data,
                    NumberStyles.Float,
                    CultureInfo.InvariantCulture,
                    out float gz))
                {
                    // 减去零点偏移
                    float correctedGz =
                        gz - gyroOffset;

                    // 死区过滤
                    if (Mathf.Abs(correctedGz)
                        < gyroDeadZone)
                        correctedGz = 0f;

                    currentGyroZ = correctedGz;
                }
                else if (data == "RESTART")
                {
                    ArduinoInput arduinoInput =
                        FindObjectOfType
                        <ArduinoInput>();
                    if (arduinoInput != null)
                        arduinoInput
                            .HandleData(data);
                }
            }
            catch { }
        }

        // 加负号反转旋转方向
        transform.Rotate(
            0, 0,
            -currentGyroZ *
            rotateFactor *
            Time.deltaTime
        );
    }

    void FixedUpdate()
    {
        if (isStopped)
        {
            rb.velocity = Vector2.zero;
            return;
        }

        rb.velocity =
            transform.right * moveSpeed;
    }

    public void StopAndTurnAround()
    {
        StartCoroutine(StopCoroutine());
    }

    IEnumerator StopCoroutine()
    {
        isStopped = true;
        rb.velocity = Vector2.zero;
        currentGyroZ = 0f;
        yield break;
    }

    public void ResumeAfterAnimation()
    {
        StartCoroutine(TurnAndResume());
    }

    IEnumerator TurnAndResume()
    {
        float startAngle =
            transform.eulerAngles.z;
        float targetAngle = startAngle + 180f;
        float duration = 0.5f;
        float elapsed = 0f;

        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            float angle = Mathf.Lerp(
                startAngle,
                targetAngle,
                elapsed / duration
            );
            transform.eulerAngles =
                new Vector3(0, 0, angle);
            yield return null;
        }

        transform.eulerAngles =
            new Vector3(0, 0, targetAngle);
        isStopped = false;
        currentGyroZ = 0f;
    }

    public bool IsStopped => isStopped;

    void OnDestroy()
    {
        CloseSerialPort();
    }

    void OnApplicationQuit()
    {
        CloseSerialPort();
    }

    void CloseSerialPort()
    {
        if (serialPort != null &&
            serialPort.IsOpen)
        {
            serialPort.Close();
            serialPort = null;
            Debug.Log("✅ 串口已关闭");
        }
    }
}