#include <string.h>
#include <cglm/cam.h>
#include <GL/glew.h>
#include "include/camera.h"

struct camera *create_camera(int type) {
    if (type != CAMERA_PERSPECTIVE && 
        type != CAMERA_ORTHOGONAL) {
        return NULL;
    }

    struct camera *c = malloc(sizeof(struct camera));
    if (c == NULL) {
        return NULL;
    }

    memset(c, 0, sizeof(struct camera));

    c->type = type;
    c->fov = 80.0f;
    c->near_z = 0.01f; 
    c->far_z = 1000.0f;
    c->yaw = -90.0f;
    c->pitch = 0.0f;
    c->sensitivity = 0.02f;

    if (c->type == CAMERA_ORTHOGONAL) {
        c->viewport_modifier = 0.5f;
    }

    c->pos[0] = 0.0f;
    c->pos[1] = 0.0f;
    c->pos[2] = 10.0f;

    c->front[0] = 0.0f;
    c->front[1] = 0.0f;
    c->front[2] = -1.0f;
    
    c->up[0] = 0.0f;
    c->up[1] = 1.0f;
    c->up[2] = 0.0f;

    return c;
}

int bake_camera(struct camera *c) {
    glm_mat4_identity(c->view);
    glm_vec3_add(c->pos, c->front, c->center);
    glm_lookat(c->pos, c->center, c->up, c->view);

    glm_mat4_identity(c->projection);

    int screen_viewport[4]; 
    glGetIntegerv(GL_VIEWPORT, screen_viewport);
    if (c->type == CAMERA_PERSPECTIVE) {
        glm_perspective(glm_rad(c->fov), 
                (float) ((float)screen_viewport[2]/(float)screen_viewport[3]), 
                c->near_z, c->far_z,
                c->projection);
    } else if (c->type == CAMERA_ORTHOGONAL) {
        float left = -screen_viewport[2]/2    * c->viewport_modifier; 
        float right = screen_viewport[2]/2    * c->viewport_modifier;
        float top = screen_viewport[3]/2      * c->viewport_modifier;
        float bottom = -screen_viewport[3]/2  * c->viewport_modifier;
        glm_ortho(left, right, bottom, top, c->near_z, c->far_z, c->projection);
    } else {
        return -1;
    }

    return 0;
}