using System;
using System.Collections;
using System.Collections.Generic;

using UnityEngine;
using UnityEngine.InputSystem;

public class ShipControls : MonoBehaviour {
    public Camera aim;
    public Timing timing;

    SpaceRaceInput input;

    Rigidbody rigidBody;

    Vector3 initialPosition;
    Vector3 initialForce;
    Quaternion initialAim;

    ForceMode forceMode;
    Vector3 thrust;
    Vector3 strafe;

    // Camera Controls
    float camPitch;
    float camYaw;
    float clampAngle = 90.0f;

    public PowerUnit powerUnit = new();

    void Start() {
        Cursor.lockState = CursorLockMode.Locked;
        rigidBody = GetComponent<Rigidbody>();

        // just stop the body from being affected by rotation for now
        // until the 3p camera is in to explain why
        rigidBody.freezeRotation = true;

        initialPosition = rigidBody.transform.position;
        initialAim = rigidBody.transform.rotation;
        initialForce = Vector3.forward;

        thrust = Vector3.zero;
        strafe = Vector3.zero;

        camPitch = initialAim.eulerAngles.x;
        camYaw = initialAim.eulerAngles.y;
        forceMode = ForceMode.Acceleration;

        SetupActions();
        Respawn();
    }

    // to minimise input lag we poll for the thrust vector every frame and set it
    // same with the camera, we always look around
    void Update() {
        // hot reloading fks up the input
        if (input == null) Start();

        UpdateCamera();
        thrust = getThrust();
    }

    void FixedUpdate() {
        // when you hit the trigger... GO
        // needs to be done here in fixedUpdate because otherwise the input is checked on every frame
        // so they will have already hit the button before this tick and they actually start moving
        // aka ripoff
        bool shouldBegin = !timing.timerEnabled && (thrust != Vector3.zero || strafe != Vector3.zero);
        if (shouldBegin) Begin();

        // the ship being propelled forward
        // this is in world space because of the xform from the camera pos
        //
        rigidBody.AddForce(thrust, forceMode);

        // moving side to side
        // this is relative because it's easy to just multiply by the strafe vector
        rigidBody.AddRelativeForce(strafe, forceMode);

        // rotating towards the camera's orientation
        // not being done by a force because of strange behaviour
        // needs investigation
        float step = powerUnit.Stabilisation * Time.fixedDeltaTime;

        // stop the ship jiggling because of micro camera movement
        if (Quaternion.Angle(aim.transform.rotation, rigidBody.rotation) > 1f)
            rigidBody.rotation = Quaternion.RotateTowards(transform.rotation, aim.transform.rotation, step);

        if (timing.timerEnabled) {
            powerUnit.Tick();
        }
    }

    void UpdateCamera() {
        // there's some hokey scaling that went on with the old input
        // we were originally using

        // in the action mapping the mouse is scaled by 0.05
        // delta *= 0.5f; // Account for scaling applied directly in Windows code by old input system.
        // delta *= 0.1f; // Account for sensitivity setting on old Mouse X and Y axes.
        // def needs to be configurable

        Vector2 lookDelta = input.ship.look.ReadValue<Vector2>();
        camYaw += lookDelta.x;
        camPitch -= lookDelta.y;
        camPitch = Mathf.Clamp(camPitch, -clampAngle, clampAngle);
        aim.transform.eulerAngles = new Vector3(camPitch, camYaw, 0.0f);
    }

    // if you are decelerating you can't accelerate as well
    // otherwise you can flip the ship around and
    // decelerate + accelerate against the velocity vector
    // aka cheating?
    Vector3 getThrust() {
        float accelerateInput = input.ship.accelerate.ReadValue<float>();
        float decelerateInput = input.ship.decelerate.ReadValue<float>();

        // decelerates the ship against the direction it is moving
        if (decelerateInput > 0f) {
            // the velocity is already in world space so we just invert it
            return rigidBody.velocity.normalized * -1f * powerUnit.Deceleration * decelerateInput;
        }

        // thrust in the direction of the camera
        if (accelerateInput > 0f)
            // transform from the camera's forward vector into world space
            return aim.transform.TransformDirection(Vector3.forward) * powerUnit.Acceleration * accelerateInput;

        return Vector3.zero;
    }

    public void Respawn() {
        // IMPORTANT
        // stop the timer before we move the ship or anything
        // otherwise it might generate a checkpoint time
        // for the final sector
        timing.StopTimer();

        thrust = new Vector3(0.0f, 0.0f, 0.0f);
        transform.position = initialPosition;
        rigidBody.transform.forward = initialForce;
        rigidBody.velocity = new Vector3(0f, 0f, 0f);
        rigidBody.angularVelocity = new Vector3(0f, 0f, 0f);
        rigidBody.transform.rotation = initialAim;
        aim.transform.rotation = initialAim;

        camPitch = initialAim.eulerAngles.x;
        camYaw = initialAim.eulerAngles.y;

        powerUnit.Reset();
    }

    // stuff we have to do right as they come off the line
    void Begin() {
        timing.StartTimer();
    }

    public float Speed() {
        return rigidBody.velocity.magnitude;
    }

    public void Damage(float amt, string src) {
        Debug.Log($"Damage {amt} from {src}");

        bool destroyed = powerUnit.ShieldReduce(amt);
        if (destroyed) {
            Debug.Log($"Ddddestroyed by {src}");
            Respawn();
        }
    }

    void Deploy(Output output) {
        powerUnit.Deploy(output);
    }

    // I prefer doing it this way than registering the callbacks etc
    // the control of the actions is more granular
    // plus the callbacks don't have to be public, bonus
    void SetupActions() {
        if (input == null)
            input = new SpaceRaceInput();

        input.ship.Enable();

        // we have to update strafe the whole time it's being pressed
        // including setting it back to zero when released
        input.ship.strafe.started   += OnStrafe;
        input.ship.strafe.performed += OnStrafe;
        input.ship.strafe.canceled  += OnStrafe;

        // these we only care about the initial press
        input.ship.respawn.started      += OnRespawn;
        input.ship.quit.started         += OnQuit;
        input.ship.powerUnit1.started   += OnPowerUnit1;
        input.ship.powerUnit2.started   += OnPowerUnit2;
        input.ship.powerUnit3.started   += OnPowerUnit3;
        input.ship.powerUnit4.started   += OnPowerUnit4;
    }

    void OnStrafe(InputAction.CallbackContext ctx) {
        Vector2 str = ctx.ReadValue<Vector2>();
        strafe = new Vector3(str.x, str.y, 0f) * powerUnit.Strafing;
    }

    void OnQuit(InputAction.CallbackContext ctx) => Application.Quit();
    void OnRespawn(InputAction.CallbackContext ctx) => Respawn();

    void OnPowerUnit1(InputAction.CallbackContext ctx) => Deploy(Output.Acceleration);
    void OnPowerUnit2(InputAction.CallbackContext ctx) => Deploy(Output.Deceleration);
    void OnPowerUnit3(InputAction.CallbackContext ctx) => Deploy(Output.Strafing);
    void OnPowerUnit4(InputAction.CallbackContext ctx) => Deploy(Output.Shield);

    void OnDrawGizmosSelected() {
        if (Application.isPlaying == false)
            return;

        Gizmos.color = Color.red;
        Vector3 right = aim.transform.TransformDirection(Vector3.right) * 10;
        Gizmos.DrawRay(transform.position, right);

        Gizmos.color = Color.green;
        Vector3 direction = aim.transform.TransformDirection(Vector3.up) * 10;
        Gizmos.DrawRay(transform.position, direction);

        Gizmos.color = Color.blue;
        Vector3 forward = aim.transform.TransformDirection(Vector3.forward) * 10;
        Gizmos.DrawRay(transform.position, forward);

        Gizmos.color = Color.yellow;
        Vector3 velocity = rigidBody.velocity;
        Gizmos.DrawRay(transform.position, velocity);

        Gizmos.color = Color.cyan;
        Gizmos.DrawRay(transform.position, thrust);
    }
}