using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace LunaLightXMG
{
    internal class Player
    {
        // Declare variables
        private float hsp;                  // Horizontal speed
        private float vsp;                  // Vertical speed
        private float wallJumpDelay;        // Delay for wall jumping
        private bool grounded;              // Is the player grounded?
        private bool walled;                // Is the player wall sliding?
        private float hsp_acc;              // Horizontal acceleration
        private float hsp_friction_ground;  // Ground friction
        private float hsp_friction_air;     // Air friction
        private float hsp_walk;             // Maximum horizontal speed
        private float grv;                  // Gravity
        private float vsp_max;              // Maximum vertical speed
        private float grv_wall;             // Gravity when wall sliding
        private float vsp_max_wall;         // Maximum vertical speed when wall sliding
        private float vsp_jump;             // Jump speed

        // Player position
        public Vector2 Position;

        // Placeholder for key input states
        private bool key_left;
        private bool key_right;

        // Constructor to initialize variables
        public Player()
        {
            // Initialize your variables here
            hsp = 0;
            vsp = 0;
            wallJumpDelay = 0;
            grounded = false;
            walled = false;
            hsp_acc = 0.5f;
            hsp_friction_ground = 0.2f;
            hsp_friction_air = 0.1f;
            hsp_walk = 4f;
            //grv = 0.5f;
            grv = 0.0f;     // No grav until we have walls, bounding boxes, etc..
            vsp_max = 10f;
            grv_wall = 0.1f;
            vsp_max_wall = 5f;
            vsp_jump = -10f;

            Position = new Vector2(163, 63); // Initialize player position
        }

        // Update method to handle movement logic
        public void Update(GameTime gameTime)
        {
            HandleInput();
            Movement();

            // Update player position based on speed
            Position.X += hsp;
            Position.Y += vsp;
        }

        private void Movement()
        {
            // Horizontal movement with acceleration + wall jump delay
            wallJumpDelay = Math.Max(wallJumpDelay - 1, 0); // counts down every frame

            if (wallJumpDelay == 0) // no left-right control until delay is 0, prevents rapid wall climb
            {
                float move_h = (key_right ? 1 : 0) - (key_left ? 1 : 0);
                hsp += move_h * hsp_acc;

                if (move_h == 0)
                {
                    float hsp_friction_final = grounded ? hsp_friction_ground : hsp_friction_air;
                    hsp = Approach(hsp, 0, hsp_friction_final);
                }

                hsp = MathHelper.Clamp(hsp, -hsp_walk, hsp_walk);
            }

            // Calculate vertical movement
            float grv_final = grv;
            float vsp_max_final = vsp_max;

            if (walled && vsp > 0)
            {
                grv_final = grv_wall;
                vsp_max_final = vsp_max_wall;
            }

            vsp += (vsp == 0 ? grv_final * 2 : grv_final);
            vsp = MathHelper.Clamp(vsp, vsp_jump, vsp_max_final);
        }

        // Helper method to smoothly approach a target value
        private float Approach(float start, float end, float shift)
        {
            if (start < end)
            {
                start += shift;
                if (start > end)
                    return end;
            }
            else
            {
                start -= shift;
                if (start < end)
                    return end;
            }
            return start;
        }

        // Placeholder for key input handling (to be connected to actual input handling logic)
        private void HandleInput()
        {
            KeyboardState keyboardState = Keyboard.GetState();
            key_left = keyboardState.IsKeyDown(Keys.A); 
            key_right = keyboardState.IsKeyDown(Keys.D);
        }

        public void Draw(SpriteBatch spriteBatch, Texture2D texture)
        {
            spriteBatch.Draw(texture, Position, Color.White);
        }
    }

}