using UnityEngine;
using Mirror;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.LowLevel;

public class CharacterMovement : NetworkBehaviour
{
    Animator animator;

    int isWalkingHash;
    int isRunningHash;

    PlayerInput input;

    Vector2 currentMovement;
    Vector2 combinedMovement;
    bool movementPressed;
    bool runPressed;

    // track last sent state to avoid network spam
    bool lastSentWalking;
    bool lastSentRunning;

    Camera mainCamera;

    // Mouse-look orbit camera: yaw/pitch driven purely by the mouse, never by the player's
    // own transform.rotation, so turning/facing movement direction doesn't snap the camera.
    [Header("Camera Look")]
    public float cameraDistance = 4.5f;
    public float cameraPivotHeight = 1.6f;
    public float cameraPitchDefault = 15f;
    public float cameraPitchMin = -10f;
    public float cameraPitchMax = 65f;
    public float mouseSensitivity = 6f;
    // Degrees/sec at full stick deflection — a different scale than mouseSensitivity since
    // the right stick reports a steady -1..1 tilt rather than a per-frame pixel delta.
    public float gamepadLookSensitivity = 150f;

    // Sideways offset of the orbit pivot (over-the-shoulder), so the character doesn't
    // block the center of the screen. Weapons set this; 0 keeps the classic centered orbit.
    [HideInInspector] public float cameraShoulderOffset = 0f;

    // While true the character turns to face the camera's yaw (strafe-style, like a shooter)
    // instead of facing its movement direction.
    [HideInInspector] public bool faceCameraYaw;

    [Header("Camera Recoil")]
    public float recoilKickSharpness = 35f;
    public float recoilRecoverDelay = 0.12f;
    public float recoilRecoverSharpness = 7f;

    float cameraYaw;
    float cameraPitch;
    bool wantsCursorLocked = true;
    Vector2 currentLook;

    // Recoil lives in its own offset on top of the mouse-driven yaw/pitch, so it can kick
    // and then recover back to where the player was aiming without fighting mouse input.
    Vector2 recoilTarget;   // x = degrees up, y = degrees right
    Vector2 recoilCurrent;
    float lastRecoilTime = -10f;

    public float CameraYaw => cameraYaw;

    // Set by cutscenes (e.g. RangeIntroCinematic): freezes movement/look and hands the camera over.
    public static bool CinematicControl;

    public void AddRecoil(float up, float right)
    {
        recoilTarget += new Vector2(up, right);
        lastRecoilTime = Time.time;
    }

    void Awake()
    {
        input = new PlayerInput();

        input.CharacterControls.Movement.performed += ctx =>
        {
            currentMovement = ctx.ReadValue<Vector2>();
            movementPressed = currentMovement.x != 0 || currentMovement.y != 0;
        };
        input.CharacterControls.Movement.canceled += ctx =>
        {
            currentMovement = Vector2.zero;
            movementPressed = false;
        };

        input.CharacterControls.Run.performed += ctx => runPressed = ctx.ReadValueAsButton();
        input.CharacterControls.Run.canceled += ctx => runPressed = false;

        // Right stick — camera look, same yaw/pitch the mouse drives (see LateUpdate).
        input.CharacterControls.Look.performed += ctx => currentLook = ctx.ReadValue<Vector2>();
        input.CharacterControls.Look.canceled += ctx => currentLook = Vector2.zero;
    }

    void Start()
    {
        animator = GetComponent<Animator>();

        isWalkingHash = Animator.StringToHash("isWalking");
        isRunningHash = Animator.StringToHash("isRunning");
    }

    // Only the local player should drive input/movement
    void Update()
    {
        if (!isLocalPlayer) return;
        if (CinematicControl)
        {
            ForceIdle();
            return;
        }

        HandleMovement();
        HandleRotation();
    }

    // Camera follow/look should be in LateUpdate so it reacts to the final character pose
    // for the frame instead of lagging a frame behind Update's movement.
    void LateUpdate()
    {
        if (!isLocalPlayer) return;
        if (mainCamera == null) return;

        // A cinematic owns the camera: no look input, no camera writes, cursor stays hidden.
        if (CinematicControl)
        {
            ApplyCursorLockState(true);
            return;
        }

        var kb = Keyboard.current;
        if (kb != null && kb.escapeKey.wasPressedThisFrame)
        {
            if (ChatUI.IsInputFieldFocused)
            {
                ChatUI.Instance?.ExitChatFocus();
                wantsCursorLocked = true;
            }
            else
            {
                wantsCursorLocked = !wantsCursorLocked;
            }
        }

        // Re-assert the lock state every frame rather than trusting Cursor.lockState to have
        // stuck: the Editor Game view (and some platforms) silently drop the lock on focus
        // loss, so gating mouse-look on reading it back can permanently stall the camera.
        bool shouldLockNow = wantsCursorLocked && !ChatUI.IsInputFieldFocused;
        ApplyCursorLockState(shouldLockNow);

        bool canLook = !ChatUI.IsInputFieldFocused && Application.isFocused;

        if (canLook && shouldLockNow)
        {
            var mouse = Mouse.current;
            if (mouse != null)
            {
                Vector2 delta = mouse.delta.ReadValue();
                cameraYaw += delta.x * mouseSensitivity * Time.deltaTime;
                cameraPitch = Mathf.Clamp(cameraPitch - delta.y * mouseSensitivity * Time.deltaTime, cameraPitchMin, cameraPitchMax);

                // CursorLockMode.Locked hides the cursor but doesn't reliably keep the OS
                // pointer confined/re-centered (especially inside the Editor Game view), so
                // without this the real cursor eventually reaches a screen edge and rotation
                // caps out in that direction instead of spinning freely. Warping back to
                // center every frame removes that ceiling — but WarpCursorPosition alone only
                // moves the OS cursor; the Input System's own tracked position doesn't know
                // about the jump and keeps computing future deltas as if the cursor were still
                // out near the edge, which is what was still capping rotation. InputState.Change
                // tells the Input System directly where the cursor now is, so the next delta
                // read is correct instead of walled off.
                Vector2 center = new Vector2(Screen.width * 0.5f, Screen.height * 0.5f);
                mouse.WarpCursorPosition(center);
                InputState.Change(mouse.position, center);
            }
        }

        // Right stick look — independent of cursor lock (a gamepad doesn't have a cursor to
        // fight over), but still suppressed while typing in chat or the window is unfocused.
        if (canLook && currentLook.sqrMagnitude > 0.0001f)
        {
            cameraYaw += currentLook.x * gamepadLookSensitivity * Time.deltaTime;
            cameraPitch = Mathf.Clamp(cameraPitch - currentLook.y * gamepadLookSensitivity * Time.deltaTime, cameraPitchMin, cameraPitchMax);
        }

        UpdateRecoil();
        UpdateCameraTransform();
    }

    void UpdateRecoil()
    {
        if (Time.time - lastRecoilTime > recoilRecoverDelay)
            recoilTarget = Vector2.Lerp(recoilTarget, Vector2.zero, 1f - Mathf.Exp(-recoilRecoverSharpness * Time.deltaTime));

        recoilCurrent = Vector2.Lerp(recoilCurrent, recoilTarget, 1f - Mathf.Exp(-recoilKickSharpness * Time.deltaTime));
    }

    void ApplyCursorLockState(bool locked)
    {
        Cursor.lockState = locked ? CursorLockMode.Locked : CursorLockMode.None;
        Cursor.visible = !locked;
    }

    // Orbits the camera around a pivot above the player at a fixed distance, using
    // cameraYaw/cameraPitch — never the player's own transform.rotation.
    void UpdateCameraTransform()
    {
        GetGameplayCameraPose(out Vector3 position, out Quaternion rotation);
        mainCamera.transform.SetPositionAndRotation(position, rotation);
    }

    // Where the gameplay camera sits this frame — cinematics blend into this pose so the
    // hand-off back to the player is seamless.
    public void GetGameplayCameraPose(out Vector3 position, out Quaternion rotation)
    {
        rotation = Quaternion.Euler(cameraPitch - recoilCurrent.x, cameraYaw + recoilCurrent.y, 0f);
        Vector3 pivot = transform.position + Vector3.up * cameraPivotHeight;
        position = pivot + rotation * new Vector3(cameraShoulderOffset, 0f, -cameraDistance);
    }

    // WASD input is camera-relative (like most third-person games): "forward" is whichever
    // way the camera currently faces, projected onto the ground, not a fixed world axis or
    // the player's own facing. Turning the camera therefore turns which way W walks you.
    Vector3 GetCameraRelativeMoveDirection()
    {
        Quaternion cameraYawRotation = Quaternion.Euler(0f, cameraYaw, 0f);
        return cameraYawRotation * new Vector3(combinedMovement.x, 0f, combinedMovement.y);
    }

    // While a cinematic holds control, HandleMovement doesn't run to clear the walk/run flags —
    // and with root motion on, a stuck walk state would stroll the character across the map.
    void ForceIdle()
    {
        if (animator == null) return;
        animator.SetBool(isWalkingHash, false);
        animator.SetBool(isRunningHash, false);
        if (lastSentWalking || lastSentRunning)
        {
            lastSentWalking = false;
            lastSentRunning = false;
            CmdSendAnimationState(false, false);
        }
    }

    void HandleRotation()
    {
        if (faceCameraYaw)
        {
            Quaternion aimYaw = Quaternion.Euler(0f, cameraYaw, 0f);
            transform.rotation = Quaternion.Slerp(transform.rotation, aimYaw, 1f - Mathf.Exp(-20f * Time.deltaTime));
            return;
        }

        Vector3 currentPosition = transform.position;
        Vector3 moveDirection = GetCameraRelativeMoveDirection();
        // only rotate when there is movement to look at
        if (moveDirection.sqrMagnitude > 0f)
        {
            Vector3 positionToLookAt = currentPosition + moveDirection;
            transform.LookAt(positionToLookAt);
        }
    }

    void HandleMovement()
    {
        // read keyboard WASD (supplements / works alongside Input System action bindings)
        Vector2 keyboardMovement = Vector2.zero;
        var kb = Keyboard.current;
        if (kb != null)
        {
            if (kb.wKey.isPressed) keyboardMovement.y += 1f;
            if (kb.sKey.isPressed) keyboardMovement.y -= 1f;
            if (kb.aKey.isPressed) keyboardMovement.x -= 1f;
            if (kb.dKey.isPressed) keyboardMovement.x += 1f;
        }

        // Disable keyboard WASD while typing in chat input
        if (ChatUI.IsInputFieldFocused)
        {
            keyboardMovement = Vector2.zero;
        }

        // combine input action movement and keyboard movement
        combinedMovement = currentMovement + keyboardMovement;
        // prevent faster diagonal movement
        combinedMovement = Vector2.ClampMagnitude(combinedMovement, 1f);
        movementPressed = combinedMovement.x != 0 || combinedMovement.y != 0;

        // detect Shift keys as an additional run input
        bool shiftPressed = kb != null && (kb.leftShiftKey.isPressed || kb.rightShiftKey.isPressed);
        bool runActive = runPressed || shiftPressed;

        bool isRunning = animator.GetBool(isRunningHash);
        bool isWalking = animator.GetBool(isWalkingHash);

        if (movementPressed && !isWalking)
        {
            animator.SetBool(isWalkingHash, true);
            isWalking = true;
        }

        if (!movementPressed && isWalking)
        {
            animator.SetBool(isWalkingHash, false);
            isWalking = false;
        }

        if ((movementPressed && runActive) && !isRunning)
        {
            animator.SetBool(isRunningHash, true);
            isRunning = true;
        }

        if ((!movementPressed || !runActive) && isRunning)
        {
            animator.SetBool(isRunningHash, false);
            isRunning = false;
        }

        // send animator state to server only when changed
        if (isWalking != lastSentWalking || isRunning != lastSentRunning)
        {
            lastSentWalking = isWalking;
            lastSentRunning = isRunning;
            CmdSendAnimationState(isWalking, isRunning);
        }

        // movement translation, camera-relative (see GetCameraRelativeMoveDirection)
        float speed = isRunning ? 6f : 3f;
        Vector3 move = GetCameraRelativeMoveDirection() * speed * Time.deltaTime;
        transform.position += move;
    }

    public override void OnStartLocalPlayer()
    {
        Debug.Log("Local player started: " + netId);
        input.CharacterControls.Enable();

        // Setup camera for local player (unparented — position/rotation are driven every
        // frame from LateUpdate/UpdateCameraTransform, not by being a child of the player).
        mainCamera = Camera.main;
        if (mainCamera == null)
        {
            Debug.LogWarning("No Camera.main found in scene to attach to player.");
            return;
        }

        // Start aligned behind the player's current facing; mouse look takes over from here.
        cameraYaw = transform.eulerAngles.y;
        cameraPitch = cameraPitchDefault;
        mainCamera.transform.SetParent(null, true);
        UpdateCameraTransform();

        wantsCursorLocked = true;
        ApplyCursorLockState(wantsCursorLocked);

        // ensure only the local player's camera has an active AudioListener
        var audio = mainCamera.GetComponent<AudioListener>();
        if (audio != null) audio.enabled = true;
    }

    public override void OnStopLocalPlayer()
    {
        input.CharacterControls.Disable();

        // optionally disable audio listener to avoid duplicates
        if (mainCamera != null)
        {
            var audio = mainCamera.GetComponent<AudioListener>();
            if (audio != null) audio.enabled = false;
        }
        mainCamera = null;

        wantsCursorLocked = false;
        ApplyCursorLockState(false);
    }

    // Called on the server when client issues the command
    [Command]
    void CmdSendAnimationState(bool walking, bool running)
    {
        // update server-side animator if present
        if (animator == null) animator = GetComponent<Animator>();
        if (animator != null)
        {
            animator.SetBool(isWalkingHash, walking);
            animator.SetBool(isRunningHash, running);
        }

        // broadcast to all clients
        RpcUpdateAnimationState(walking, running);
    }

    // Executed on all clients to apply animator changes
    [ClientRpc]
    void RpcUpdateAnimationState(bool walking, bool running)
    {
        if (animator == null) animator = GetComponent<Animator>();
        if (animator == null) return;

        animator.SetBool(isWalkingHash, walking);
        animator.SetBool(isRunningHash, running);
    }
}