#include "../../include/mgl/graphics/text.h"
#include "../../include/mgl/graphics/font.h"
#include "../../include/mgl/mgl.h"

int mgl_text_init(mgl_text *self, mgl_font *font, const char *text, float x, float y) {
    self->font = font;
    self->text = text;
    self->color = (mgl_color){ 1.0f, 1.0f, 1.0f, 1.0f };
    self->position = (mgl_vec2f){ x, y };
    return 0;
}

void mgl_text_deinit(mgl_text *self) {

}

static void mgl_text_draw_glyph(mgl_context *context, mgl_font_glyph *glyph, mgl_vec2f position) {
    context->gl.glTexCoord2f(glyph->texture_position.x, glyph->texture_position.y);
    context->gl.glVertex3f(position.x + glyph->position.x, position.y + glyph->position.y, 0.0f);

    context->gl.glTexCoord2f(glyph->texture_position.x + glyph->texture_size.x, glyph->texture_position.y);
    context->gl.glVertex3f(position.x + glyph->position.x + glyph->size.x, position.y + glyph->position.y, 0.0f);

    context->gl.glTexCoord2f(glyph->texture_position.x + glyph->texture_size.x, glyph->texture_position.y + glyph->texture_size.y);
    context->gl.glVertex3f(position.x + glyph->position.x + glyph->size.x, position.y + glyph->position.y + glyph->size.y, 0.0f);

    context->gl.glTexCoord2f(glyph->texture_position.x, glyph->texture_position.y + glyph->texture_size.y);
    context->gl.glVertex3f(position.x + glyph->position.x, position.y + glyph->position.y + glyph->size.y, 0.0f);
}

/* TODO: Use opengl buffer object instead */
/* TODO: Cache texture bind to not bind texture if its already bound and do not bind texture 0 */
void mgl_text_draw(mgl_context *context, mgl_text *text) {
    const char *str = text->text;
    mgl_font_glyph glyph;
    mgl_vec2f position = text->position;
    position.y += text->font->size;

    context->gl.glColor4f(text->color.r, text->color.g, text->color.b, text->color.a);
    context->gl.glBindTexture(GL_TEXTURE_2D, text->font->texture.id);
    context->gl.glBegin(GL_QUADS);
    while(*str) {
        unsigned char c = *(unsigned char*)str;
        if((c >= 32 && c < 128)) {
            if(mgl_font_get_glyph(text->font, c, &glyph) == 0) {
                mgl_text_draw_glyph(context, &glyph, position);
                position.x += glyph.advance;
            }
        } else if(c == '\t') {
            if(mgl_font_get_glyph(text->font, ' ', &glyph) == 0) {
                const int tab_width = 4;
                for(int i = 0; i < tab_width; ++i) {
                    mgl_text_draw_glyph(context, &glyph, position);
                    position.x += glyph.advance;
                }
            }
        } else if(c == '\n') {
            position.x = text->position.x;
            position.y += text->font->size;
        }
        ++str;
    }
    context->gl.glEnd();
    context->gl.glBindTexture(GL_TEXTURE_2D, 0);
}