#version 450

struct DirectionalLightStruct
{
  vec3 direction;
  uint isActive;
  uint cullingMask;
  vec4 diffuseColor;
  mat4 pvMatrix;
  uint shadowData;
};

struct AmbientLightStruct
{
  vec4 ambientColor;
  float strength;
  uint isActive;
  uint cullingMask;
};

layout(local_size_x = 16, local_size_y = 16) in;
layout(set = 3, binding = 0, rgba32f) uniform image2D positions;
layout(set = 3, binding = 1, rgba32f) uniform image2D normals;
layout(set = 3, binding = 2, rgba8) uniform image2D albedo;
layout(set = 3, binding = 3, r32ui) uniform uimage2D lightLayerData;
layout(set = 3, binding = 4, r8) uniform image2D ssaoBlurredImage;
layout(set = 3, binding = 5, rgba8) uniform image2D targetImage;

layout (set = 4, binding = 0) uniform sampler2D shadowMaps[]; // for textures (global)

layout(set = 1, binding = 0) uniform LightCounts
{
  uint directionalLights;
  uint pointLights;
  uint spotLights;
  uint ambientLights;

} lightCounts;

layout(std430, set = 1, binding = 1) buffer DirectionalLightData
{
  DirectionalLightStruct dLightData[];
} DirLightData;

layout(std430, set = 1, binding = 4) buffer AmbientLightData
{
  AmbientLightStruct aLightData[];
} AmbLightData;

// bool IsInShadow (sampler2D shadowMap, vec2 coords, float depth, mat4 lightVP)
// {
//   // vec4 fragPosLightPOV = lightVP * 
// }

void main()
{ 
  // convenient variables
  ivec2 globalThread = ivec2(gl_GlobalInvocationID);

  // Get the diffuse color of the pixel
  vec3 pixelDiffuse = imageLoad (albedo, globalThread).rgb;

  // Get position of fragment in world space
  vec3 positionView = imageLoad (positions, globalThread).rgb;

  // normal of fragment
  vec3 normalView = imageLoad(normals, globalThread).rgb;

  // light layer index
  uint lightLayer = imageLoad (lightLayerData, globalThread).r;

  vec3 fragColor = vec3 (0.0f);

  vec4 shadowMapColor = vec4 (1.0f);

  for (int i = 0; i < lightCounts.ambientLights; ++i)
  {
    if ((lightLayer & AmbLightData.aLightData[i].cullingMask) != 0)
    {
      // Just do some add
      //fragColor += pixelDiffuse.rgb * AmbLightData.aLightData[i].ambientColor.rgb * vec3 (0.5f);
      fragColor += pixelDiffuse.rgb * AmbLightData.aLightData[i].ambientColor.rgb * vec3 (AmbLightData.aLightData[i].strength);
    }
  }

  for (int i = 0; i < lightCounts.directionalLights; ++i)
  {
    if ((lightLayer & DirLightData.dLightData[i].cullingMask) != 0)
    {
      // get normalized direction of light 
      vec3 dLightNormalized = normalize (DirLightData.dLightData[i].direction);

      // Get diffuse strength
      float diffuseStrength = max (0, dot (dLightNormalized, normalView));

      // Calculate the fragment color
      fragColor += DirLightData.dLightData[i].diffuseColor.rgb * diffuseStrength.rrr * pixelDiffuse;

      // If the shadow map is enabled (test the bit)
      if ((DirLightData.dLightData[i].shadowData & uint(1)) == 1)
      {
        // calculate shadow map here
        vec2 texCoord = vec2 (gl_GlobalInvocationID.xy) / vec2 (imageSize (targetImage));
      }
    }
  }

  float ssaoVal = imageLoad (ssaoBlurredImage, globalThread).r;
  fragColor *= ssaoVal;

  // store result into result image
  imageStore(targetImage, ivec2(gl_GlobalInvocationID.xy), vec4(fragColor.rgb, 1.0f));

  // imageStore(targetImage, ivec2(gl_GlobalInvocationID.xy), shadowMapColor);
  //imageStore(targetImage, ivec2(gl_GlobalInvocationID.xy), vec4(ssaoVal.rrr, 1.0f));

}