#version 330 core

in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoord;

out vec4 FragColor;

uniform vec3 uLightPos;
uniform vec3 uViewPos;
uniform vec4 uColor;
uniform sampler2D uTexture;
uniform bool uUseTexture;

void main() {
    // Ambient
    vec3 ambient = 0.3 * vec3(1.0);

    // Diffuse
    vec3 norm = normalize(Normal);
    vec3 lightDir = normalize(uLightPos - FragPos);
    float diff = max(dot(norm, lightDir), 0.0);
    vec3 diffuse = diff * vec3(1.0);

    // Specular
    vec3 viewDir = normalize(uViewPos - FragPos);
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32.0);
    vec3 specular = 0.5 * spec * vec3(1.0);

    vec3 result = (ambient + diffuse + specular);

    if (uUseTexture) {
        FragColor = texture(uTexture, TexCoord) * vec4(result, 1.0);
    } else {
        FragColor = uColor * vec4(result, 1.0);
    }
}