using OctoCore.Inputs;
using System.Globalization;
using UnityEngine;
using UnityEngine.InputSystem;

namespace OctoCore.Components
{
    public class OctoPlayer : MonoBehaviour
    {
        public static OctoPlayer Instance { get; private set; }

        public enum PlayerModes { FirstPerson, ThirdPerson }
        public enum Orientations { World, Camera }

        [System.Serializable]
        public class StateMachine
        {
            public bool IsFocussed;
            public bool IsPaused;
            public bool IsRunning;
            public float Yaw;
            public float Pitch;
            public OctoPlayerDriver Driver;
        }

        [System.Serializable]
        private class References
        {
            public CharacterController Controller;
        }

        [System.Serializable]
        private class Settings
        {
            public PlayerModes Mode = PlayerModes.FirstPerson;
            public Orientations Orientation = Orientations.Camera;

            [Tooltip("Walk speed (km/h).")]
            public float WalkSpeed = 10;

            [Tooltip("Run speed (km/h).")]
            public float RunSpeed = 20;

            [Tooltip("Jump duration (seconds).")]
            public float JumpDuration = .4f;

            [Tooltip("Maximum jump height reached at the apex (meters).")]
            public float JumpHeight = .4f;

            [Tooltip("Maximum step height (meters).")]
            public float StepHeight = 0.3f;

            [Tooltip("Downward acceleration applied to the player (m/s²).")]
            public float Gravity = 9.8f;

            [Tooltip("Enable jump.")]
            public bool CanJump = true;

            [Tooltip("Enable sprint.")]
            public bool CanRun = true;
        }

        [System.Serializable]
        private class Mapping
        {
            public OctoActions MoveAction;
            public OctoActions LookAction;
            public OctoActions RunAction;
            public OctoActions JumpAction;
        }

        [System.Serializable]
        public class FirstPerson
        {
            [Header("References")]

            public Camera Camera;

            [Header("Settings")]

            [Tooltip("Horizontal sensitivity (Yaw).")]
            public float SensitivityX = 0.1f;

            [Tooltip("Vertical sensitivity (Pitch).")]
            public float SensitivityY = 0.1f;

            [Tooltip("Minimum pitch (looking down).")]
            public float MinPitch = -80f;

            [Tooltip("Maximum pitch (looking up).")]
            public float MaxPitch = 80f;
        }

        [OctoReadOnly] public StateMachine State;
        [SerializeField] private References _references;
        [SerializeField] private Settings _settings;
        [SerializeField] private Mapping _mapping;
        [SerializeField] private FirstPerson _firstPerson;

        private bool _wasPausedBeforeUnfocuss;
        private bool _jumpInput;
        private bool _jumpping;
        private bool _runInput;
        private float _runInertia;
        private float _jumpLerp;
        private float _jumpTime;
        private float _jumpAltitude;
        private Vector2 _moveInput;
        private Vector2 _lookInput;
        private Vector3 _moveInertia;
        private Vector3 _moveDirection;

        public bool IsPaused => State.IsPaused;
        public float Radius  => _references.Controller ? _references.Controller.radius : 0;
        public FirstPerson _FirstPerson => _firstPerson;

        /// <summary>True when the player is actively sprinting (inertia > 0.1 and CanRun enabled).</summary>
        public bool IsRunning => _settings.CanRun && _runInertia > 0.1f;

        // Public access to yaw and pitch for external aim assist systems
        public float Yaw
        {
            get => State.Yaw;
            set => State.Yaw = value;
        }

        public float Pitch
        {
            get => State.Pitch;
            set => State.Pitch = Mathf.Clamp(value, _firstPerson.MinPitch, _firstPerson.MaxPitch);
        }

        public bool CanJump
        {
            get => _settings.CanJump;
            set => _settings.CanJump = value;
        }

        public bool CanRun
        {
            get => _settings.CanRun;
            set => _settings.CanRun = value;
        }

        void OnEnable()
        {
            if (!Instance) Instance = this;
            else Destroy(gameObject);

            OctoCore.Instance.Inputs.SubscribeAction(_mapping.MoveAction, Move);
            OctoCore.Instance.Inputs.SubscribeAction(_mapping.LookAction, Look);
            OctoCore.Instance.Inputs.SubscribeAction(_mapping.RunAction, Run);
            OctoCore.Instance.Inputs.SubscribeAction(_mapping.JumpAction, Jump);

            State.Yaw = transform.eulerAngles.y;

            State.IsFocussed = Application.isFocused;

            Pause(State.IsPaused);
        }

        void OnDisable()
        {
            OctoCore.Instance.Inputs.UnsubscribeAction(_mapping.MoveAction, Move);
            OctoCore.Instance.Inputs.UnsubscribeAction(_mapping.RunAction, Run);
            OctoCore.Instance.Inputs.UnsubscribeAction(_mapping.JumpAction, Jump);

            if (Instance == this) Instance = null;
        }

        void Update()
        {
            HandleFocus();
            HandleMovement();
        }

        public void Teleport(string positionAndYaw)
        {
            string[] s = positionAndYaw.Replace(" ", string.Empty).Split(',');
            float x = float.Parse(s[0], CultureInfo.InvariantCulture.NumberFormat);
            float y = float.Parse(s[1], CultureInfo.InvariantCulture.NumberFormat);
            float z = float.Parse(s[2], CultureInfo.InvariantCulture.NumberFormat);
            float a = float.Parse(s[3], CultureInfo.InvariantCulture.NumberFormat);

            Teleport(new Vector3(x, y, z), Quaternion.Euler(0, a, 0));
        }

        public void Teleport(Vector3 position, Quaternion rotation)
        {
            State.IsPaused = _jumpInput = _jumpping = _runInput = false;
            _runInertia = _jumpLerp = _jumpTime = _jumpAltitude = 0;
            _moveInput = _lookInput = Vector2.zero;
            _moveInertia = _moveDirection = Vector3.zero;
            State.Yaw = rotation.eulerAngles.y;
            State.Pitch = 0;

            if (_references.Controller)
                _references.Controller.enabled = false;

            transform.position = position;
            transform.rotation = rotation;

            if (_references.Controller)
                _references.Controller.enabled = true;
        }

        public void Pause(bool pause)
        {
            State.IsPaused = pause;

            if (OctoCore.Instance)
                OctoCore.Instance.UI.SetCursor();
        }

        public void Drive(OctoPlayerDriver driver) { State.Driver = driver; }
        public void ReleaseDrive() { State.Driver = null; }

        public void SetYaw(float yaw)     { State.Yaw = yaw; }
        public void SetPitch(float pitch) { State.Pitch = pitch; }

        // Convenience methods for external scripts
        public void SetCanJump(bool value) => _settings.CanJump = value;
        public void SetCanRun(bool value)  => _settings.CanRun  = value;

        private void Move(Vector2 value) { _moveInput = value; }
        private void Look(Vector2 value) { _lookInput = value; }
        private void Run()  { _runInput  = true; }
        private void Jump() { _jumpInput = true; }

        private void HandleFocus()
        {
            bool escapePressed = false;
            bool mouseClicked  = false;
#if ENABLE_INPUT_SYSTEM
            escapePressed = Keyboard.current != null && Keyboard.current.escapeKey.wasPressedThisFrame;
            mouseClicked  =
                Mouse.current != null &&
                (
                    Mouse.current.leftButton.wasPressedThisFrame    ||
                    Mouse.current.rightButton.wasPressedThisFrame   ||
                    Mouse.current.middleButton.wasPressedThisFrame  ||
                    Mouse.current.forwardButton.wasPressedThisFrame ||
                    Mouse.current.backButton.wasPressedThisFrame
                );
#else
            escapePressed = Input.GetKeyDown(KeyCode.Escape);
            mouseClicked  =
                Input.GetMouseButtonDown(0) ||
                Input.GetMouseButtonDown(1) ||
                Input.GetMouseButtonDown(2);
#endif

            if (!Application.isFocused || escapePressed)
            {
                if (State.IsFocussed)
                {
                    State.IsFocussed = false;
                    _wasPausedBeforeUnfocuss = State.IsPaused;
                    Pause(true);
                }
            }
            else if (!State.IsFocussed && mouseClicked)
            {
                State.IsFocussed = true;
                if (!_wasPausedBeforeUnfocuss)
                    Pause(false);
            }
        }

        private void HandleMovement()
        {
            _moveInput = (State.IsPaused || !State.IsFocussed) ? Vector2.zero : Vector2.ClampMagnitude(_moveInput, 1);
            Camera cam = (_firstPerson.Camera && _firstPerson.Camera.enabled && _firstPerson.Camera.gameObject.activeInHierarchy)
                ? _firstPerson.Camera
                : Camera.main;

            bool accelerating = _moveInput.magnitude > .1f;
            bool isGrounded   = _references.Controller ? _references.Controller.isGrounded : true;
            float t           = Time.deltaTime / 3.6f;

            // ── Move ────────────────────────────────────────────────────────────

            Vector3 move = new Vector3(_moveInput.x, 0, _moveInput.y);

            if (_settings.Orientation == Orientations.Camera && cam)
            {
                Vector3 camForward = cam.transform.forward; camForward.y = 0; camForward.Normalize();
                Vector3 camRight   = cam.transform.right;   camRight.y   = 0; camRight.Normalize();
                move = camRight * move.x + camForward * move.z;
            }

            if (State.Driver)
                State.Driver.ApplyMoveInfluence(move, move.magnitude * t, out move);

            float deltaSmooth = t * (accelerating ? 30 : 15);
            _moveDirection = Vector3.Lerp(_moveDirection, move, deltaSmooth * 1.5f);

            deltaSmooth *= 1 - Vector3.Cross(_moveInertia, _moveDirection).magnitude;
            _moveInertia  = Vector3.Lerp(_moveInertia, move, deltaSmooth);

            if (!accelerating && _moveInertia.magnitude < .01f) _moveInertia = Vector3.zero;

            // Sprint inertia — clamped to 0 if CanRun is off
            _runInertia = Mathf.Lerp(
                _runInertia,
                (_runInput && _settings.CanRun) ? 1f : 0f,
                t * (accelerating ? 5 : 3)
            );
            State.IsRunning = IsRunning;

            Vector3 moveDelta = _moveInertia * t * Mathf.Lerp(_settings.WalkSpeed, _settings.RunSpeed, _runInertia);

            // ── Jump ────────────────────────────────────────────────────────────

            if (isGrounded && _jumpInput && !_jumpping && _settings.CanJump)
            {
                _jumpInput    = false;
                _jumpping     = true;
                _jumpLerp     = 0;
                _jumpTime     = Time.timeSinceLevelLoad;
                _jumpAltitude = transform.position.y;
            }

            // Consume the input even if CanJump is off, so it doesn't queue up
            if (_jumpInput && !_settings.CanJump) _jumpInput = false;

            float jumpOffset = 0;

            if (_jumpping)
            {
                _jumpInput = false;
                _jumpLerp  = (Time.timeSinceLevelLoad - _jumpTime) / _settings.JumpDuration;

                // FIX: added 0.15s grace period before checking isGrounded to avoid immediate re-trigger
                bool landingAllowed = (Time.timeSinceLevelLoad - _jumpTime) > 0.15f;

                if (_jumpLerp >= 1 || (_jumpLerp > .5f && isGrounded && landingAllowed))
                {
                    _jumpping = false;
                    _jumpLerp = 0;
                }
                else
                {
                    float x = _jumpLerp * 2 - 1f;
                    float y = x < 0
                        ? Mathf.Sqrt(1f - x * x)
                        : Mathf.Cos(x * .5f * Mathf.PI);

                    y          = _jumpAltitude + y * _settings.JumpHeight;
                    jumpOffset = y - transform.position.y;
                }
            }

            // ── Step-up ─────────────────────────────────────────────────────────

            if (_references.Controller && isGrounded && !_jumpping)
            {
                float feetY      = transform.position.y - (_references.Controller.height * 0.5f);
                float castFromY  = feetY + _settings.StepHeight;

                Vector3 stepOrigin = new Vector3(transform.position.x, castFromY, transform.position.z);
                Vector3 stepDir    = new Vector3(moveDelta.x, 0, moveDelta.z).normalized;

                if (stepDir.magnitude > 0.1f)
                {
                    float stepDist = _references.Controller.radius + 0.05f;

                    if (!Physics.Raycast(stepOrigin, stepDir, stepDist))
                    {
                        Vector3 probeOrigin = stepOrigin + stepDir * stepDist;
                        if (Physics.Raycast(probeOrigin, Vector3.down, out RaycastHit hit, _settings.StepHeight))
                        {
                            float stepUp = hit.point.y - feetY;
                            if (stepUp > 0.05f)
                                moveDelta.y = Mathf.Max(moveDelta.y, stepUp);
                        }
                    }
                }
            }

            // ── Apply ───────────────────────────────────────────────────────────

            if (_jumpping)
                moveDelta.y = jumpOffset;
            else if (!isGrounded)
                moveDelta.y -= _settings.Gravity * Time.deltaTime;
            else
                moveDelta.y = -0.1f;

            if (_references.Controller && _references.Controller.enabled)
                _references.Controller.Move(moveDelta);
            else
                transform.position += moveDelta;

            // ── Rotate ──────────────────────────────────────────────────────────

            switch (_settings.Mode)
            {
                case PlayerModes.FirstPerson:
                    if (cam && !State.IsPaused)
                    {
                        Vector2 delta = (State.IsPaused || !State.IsFocussed) ? Vector2.zero : _lookInput;

                        float mouseX = delta.x * _firstPerson.SensitivityX;
                        float mouseY = delta.y * _firstPerson.SensitivityY * -1;

                        State.Yaw   += mouseX;
                        State.Pitch  = Mathf.Clamp(State.Pitch + mouseY, _firstPerson.MinPitch, _firstPerson.MaxPitch);

                        if (State.Driver)
                            State.Driver.ApplyLookInfluence(State.Yaw, State.Pitch, Time.deltaTime, out State.Yaw, out State.Pitch);

                        transform.rotation          = Quaternion.Euler(0, State.Yaw, 0);
                        cam.transform.localRotation = Quaternion.Euler(State.Pitch, 0, 0);
                    }
                    break;

                case PlayerModes.ThirdPerson:
                    {
                        Quaternion targetRot = transform.rotation;
                        if (_moveInertia.magnitude > .002f)
                        {
                            Vector3 offset = _moveInertia - _moveDirection;
                            offset  *= _moveInertia.magnitude * _runInertia;
                            offset   = Vector3.ClampMagnitude(offset, 1f);
                            Vector3 up     = (Vector3.up - offset).normalized;
                            Quaternion lookRot = Quaternion.LookRotation(_moveInertia, up);
                            targetRot  = Quaternion.Lerp(targetRot, lookRot, t * 30);
                        }
                        transform.rotation = targetRot;
                        break;
                    }
            }

            // ── Reset ───────────────────────────────────────────────────────────

            _moveInput = Vector2.zero;
            _lookInput = Vector2.zero;
            _runInput  = false;
        }

        private void SetMode()
        {
            switch (_settings.Mode)
            {
                case PlayerModes.FirstPerson:
                    // Activate First Person Camera
                    break;

                case PlayerModes.ThirdPerson:
                    // Activate Third Person Camera
                    break;
            }
        }
    }
}