Shader "Glass"
{
    Properties
    {
        _MainTex("Base (RGB) Gloss (A)", 2D) = "white" {}
        _ReflColor("Reflection Color", Color) = (0.26, 0.19, 0.16, 0.0)
        _RimColor("Rim Color", Color) = (0.26, 0.19, 0.16, 0.0)
        _RimPower("Rim Strength", Range(0.5, 8.0)) = 3.0
        _AlphaMin("Alpha Minimum", Range(0.0, 1.0)) = 0.5
        _SpecColor("Specular Color", Color) = (0.5, 0.5, 0.5, 1)
        _Shininess("Shininess", Range(0.01, 1)) = 0.078125
    }

    SubShader
    {
        Tags { "RenderType" = "Transparent" "Queue" = "Overlay" }

        Pass
        {
            Name "FORWARD"
            Tags { "LightMode" = "ForwardBase" }

            HLSLPROGRAM
            #pragma multi_compile_fog
            #pragma vertex vert
            #pragma fragment frag

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"

            // Properties
            float4 _ReflColor;
            float4 _RimColor;
            float _RimPower;
            float _AlphaMin;
            float4 _SpecColor;
            float _Shininess;
            Texture2D _MainTex;
            sampler2D _MainTex_sampler;

            struct Attributes
            {
                float4 position : POSITION;
                float3 normal : NORMAL;
                float2 uv : TEXCOORD0;
            };

            struct Varyings
            {
                float4 position : POSITION;
                float3 worldPos : TEXCOORD0;
                float3 normal : TEXCOORD1;
                float2 uv : TEXCOORD2;
            };

            Varyings vert(Attributes v)
            {
                Varyings o;
                o.position = TransformObjectToHClip(v.position);
                o.worldPos = mul(unity_ObjectToWorld, v.position).xyz;
                o.normal = mul((float3x3)unity_ObjectToWorld, v.normal);
                o.uv = v.uv;
                return o;
            }

            float4 frag(Varyings i) : SV_Target
            {
                float3 viewDir = normalize(_WorldSpaceCameraPos.xyz - i.worldPos);
                float3 normal = normalize(i.normal);

                // Fetch main texture and gloss
                float4 tex = tex2D(_MainTex_sampler, i.uv);
                float gloss = tex.a;

                // Rim lighting calculation
                half rim = 1.0 - saturate(dot(viewDir, normal));
                float4 rimEmission = _RimColor * pow(rim, _RimPower);

                // Final color (ensure it's float4)
                float4 finalColor = float4(tex.rgb + _ReflColor.rgb, 1.0);  // Default alpha to 1.0

                // Calculate the final alpha value
                float alpha = (pow(rim, _RimPower)*(1 - _AlphaMin)) + _AlphaMin * tex.a;

                // Specular reflection
                float3 specular = _SpecColor.rgb * pow(max(0, dot(normal, viewDir)), _Shininess * 128);

                // Combine all components
                return float4(finalColor.rgb + rimEmission.rgb + specular, alpha);
            }
            ENDHLSL
        }
    }

    Fallback "Universal Forward"
}