#version 460 core
out vec4 FragColor;

in vec3 Normal;
in vec2 TexCoord;
in vec3 FragPos;
in mat3 TBN;

uniform float ambient_strength;
uniform sampler2D base_texture;
uniform sampler2D normal_texture;

uniform vec4 light_color;
uniform vec3 light_position;

void main() {
    vec4 base_color = texture(base_texture, TexCoord);
    vec3 normal = texture(normal_texture, TexCoord).rgb;
    normal = normal * 2.0 - 1.0;
    normal = normalize(TBN * normal);
    vec3 light_direction = normalize(light_position - FragPos);
    float diff = max(dot(normal, light_direction), 0.0);
    vec4 diffuse_color = diff * light_color;
    vec4 ambient_color = ambient_strength * light_color;

    FragColor = (ambient_color + diffuse_color) * base_color;
}