Shader "Custom/URP_Outline_Lit"
{
    Properties
    {
        [Header(Main)]
        _MainTex        ("Albedo (RGB)",    2D)             = "white" {}
        _Color          ("Base Color",      Color)          = (1,1,1,1)

        [Header(Outline)]
        _OutlineColor   ("Outline Color",   Color)          = (0,0,0,1)
        _OutlineWidth   ("Outline Width",   Range(0, 0.2))  = 0.02
    }

    SubShader
    {
        // CAMBIO 1: Cambiamos a Opaque para que reciba sombras correctamente
        Tags
        {
            "RenderType"        = "Opaque"
            "RenderPipeline"    = "UniversalPipeline"
            "Queue"             = "Geometry"
        }

        // ─────────────────────────────────────────────────────────────
        // PASS 1 – Main (Tu código original)
        // ─────────────────────────────────────────────────────────────
        Pass
        {
            Name "ForwardLit"
            Tags { "LightMode" = "UniversalForward" }

            Cull    Back
            ZWrite  On
            ZTest   LEqual
            
            // CAMBIO 2: Desactivamos la transparencia del material principal
            Blend   One Zero 

            // Tu lógica perfecta de Stencil para que el outline no se raye por dentro
            Stencil
            {
                Ref     1
                Comp    Always
                Pass    Replace
            }

            HLSLPROGRAM
            #pragma vertex   MainVert
            #pragma fragment MainFrag

            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS _MAIN_LIGHT_SHADOWS_CASCADE _MAIN_LIGHT_SHADOWS_SCREEN
            #pragma multi_compile_fragment _ _SHADOWS_SOFT

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

            TEXTURE2D(_MainTex);
            SAMPLER(sampler_MainTex);

            CBUFFER_START(UnityPerMaterial)
                float4 _MainTex_ST;
                float4 _Color;
                float4 _OutlineColor;
                float  _OutlineWidth;
            CBUFFER_END

            struct Attributes
            {
                float4 positionOS   : POSITION;
                float3 normalOS     : NORMAL;
                float2 uv           : TEXCOORD0;
            };

            struct Varyings
            {
                float4 positionHCS  : SV_POSITION;
                float3 positionWS   : TEXCOORD1;
                float3 normalWS     : NORMAL;
                float2 uv           : TEXCOORD0;
            };

            Varyings MainVert(Attributes IN)
            {
                Varyings OUT;
                OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);
                OUT.positionWS  = TransformObjectToWorld(IN.positionOS.xyz);
                OUT.normalWS    = TransformObjectToWorldNormal(IN.normalOS);
                OUT.uv          = TRANSFORM_TEX(IN.uv, _MainTex);
                return OUT;
            }

            half4 MainFrag(Varyings IN) : SV_Target
            {
                half4 albedo = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, IN.uv) * _Color;

                float4 shadowCoord = TransformWorldToShadowCoord(IN.positionWS);
                Light mainLight = GetMainLight(shadowCoord);

                half NdotL = saturate(dot(normalize(IN.normalWS), mainLight.direction));
                half3 diffuse = mainLight.color * (NdotL * mainLight.shadowAttenuation);
                half3 ambient = SampleSH(IN.normalWS);

                half3 finalColor = albedo.rgb * (diffuse + ambient);

                return half4(finalColor, albedo.a);
            }
            ENDHLSL
        }

        // ─────────────────────────────────────────────────────────────
        // PASS 2 – ShadowCaster (Para proyectar sombras)
        // ─────────────────────────────────────────────────────────────
        Pass
        {
            Name "ShadowCaster"
            Tags{"LightMode" = "ShadowCaster"}

            ZWrite On
            ZTest LEqual
            ColorMask 0
            Cull Back

            HLSLPROGRAM
            #pragma vertex ShadowPassVertex
            #pragma fragment ShadowPassFragment

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

            struct Attributes
            {
                float4 positionOS   : POSITION;
                float3 normalOS     : NORMAL;
            };

            struct Varyings
            {
                float4 positionCS   : SV_POSITION;
            };

            Varyings ShadowPassVertex(Attributes input)
            {
                Varyings output;
                float3 positionWS = TransformObjectToWorld(input.positionOS.xyz);
                float3 normalWS = TransformObjectToWorldNormal(input.normalOS);
                
                // CAMBIO 3: Usamos la posición de la luz principal para que no dé errores
                float3 lightDir = _MainLightPosition.xyz;
                output.positionCS = TransformWorldToHClip(ApplyShadowBias(positionWS, normalWS, lightDir));
                return output;
            }

            half4 ShadowPassFragment(Varyings input) : SV_TARGET
            {
                return 0;
            }
            ENDHLSL
        }

        // ─────────────────────────────────────────────────────────────
        // PASS 3 – Outline (Tu código original intacto)
        // ─────────────────────────────────────────────────────────────
        Pass
        {
            Name "Outline"
            Tags { "LightMode" = "SRPDefaultUnlit" }

            Cull    Front
            ZWrite  Off
            ZTest   LEqual
            Blend   SrcAlpha OneMinusSrcAlpha

            Stencil
            {
                Ref     1
                Comp    NotEqual
            }

            HLSLPROGRAM
            #pragma vertex   OutlineVert
            #pragma fragment OutlineFrag

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

            CBUFFER_START(UnityPerMaterial)
                float4 _MainTex_ST;
                float4 _Color;
                float4 _OutlineColor;
                float  _OutlineWidth;
            CBUFFER_END

            struct Attributes
            {
                float4 positionOS   : POSITION;
                float3 normalOS     : NORMAL;
            };

            struct Varyings
            {
                float4 positionHCS  : SV_POSITION;
            };

            Varyings OutlineVert(Attributes IN)
            {
                Varyings OUT;
                OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);

                float3 normalWS = TransformObjectToWorldNormal(IN.normalOS);
                float3 normalCS = mul((float3x3)UNITY_MATRIX_VP, normalWS);
                float2 offset   = normalize(normalCS.xy) * (_OutlineWidth * OUT.positionHCS.w);
                OUT.positionHCS.xy += offset;
                return OUT;
            }

            half4 OutlineFrag(Varyings IN) : SV_Target
            {
                return _OutlineColor;
            }
            ENDHLSL
        }
    }
    FallBack "Hidden/Universal Render Pipeline/FallbackError"
}