#version 330

// Input vertex attributes (from vertex shader)
in vec2 fragTexCoord;
in vec4 fragColor;
in vec3 fragPosition;
in vec3 fragNormal;

// Input uniform values
uniform sampler2D texture0;
uniform sampler2D texture1;
uniform sampler2D texture2;
uniform vec4 colDiffuse;

// Output fragment color
out vec4 finalColor;

// NOTE: Add here your custom variables

#define     MAX_LIGHTS              4
#define     LIGHT_DIRECTIONAL       0
#define     LIGHT_POINT             1

struct MaterialProperty {
    vec3 color;
    int useSampler;
    sampler2D sampler;
};

struct Light {
    int enabled;
    int type;
    vec3 position;
    vec3 target;
    vec4 color;
};

// Input lighting values
uniform Light lights[MAX_LIGHTS];
uniform vec4 ambient;
uniform vec3 viewPos;

void main()
{
    // Texel color fetching from texture sampler
    vec4 texelColor = texture(texture0, fragTexCoord);
    vec3 lightDot = vec3(0.0);
    vec3 normal = normalize(fragNormal);
    vec3 viewD = normalize(viewPos - fragPosition);
    vec3 specular = vec3(0.0);

    // NOTE: Implement here your fragment shader code

    for (int i = 0; i < MAX_LIGHTS; i++)
    {
        if (lights[i].enabled == 1)
        {
            vec3 light = vec3(0.0);
            if (lights[i].type == LIGHT_DIRECTIONAL) {
                light = -normalize(lights[i].target - lights[i].position);
            }
            if (lights[i].type == LIGHT_POINT) {
                light = normalize(lights[i].position - fragPosition);
            }
            float NdotL = max(dot(normal, light), 0.0);
            lightDot += lights[i].color.rgb * NdotL;

            float specCo = 0.0;
            if(NdotL > 0.0)
                specCo = pow(max(0.0, dot(viewD, reflect(-(light), normal))), 16);//16 =shine
            //specular += specCo;

        }
    }

    finalColor =  (texelColor * ((colDiffuse+vec4(specular,1)) * vec4(lightDot, 1.0)));
    finalColor += texelColor * (ambient/5.0);
    // gamma
    finalColor = pow(finalColor, vec4(1.0/2.2));
}
