#include "Scrollbar.h"

Scrollbar::Scrollbar(int min_value, int max_value, int value, SDL_Rect pos) : Item(pos) {
    vertical = (pos.h > pos.w);
    this->min_value = min_value;
    this->max_value = max_value;
    this->value = value;
    bar_size = 18;
    pressed = false;
    value_changed_func = NULL;
    setSurface(SDL_CreateSurface(getPos()->w, getPos()->h, SDL_GetPixelFormatForMasks(32, 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000)));
    drawScrollbar();
}

Scrollbar::~Scrollbar() {
    SDL_DestroySurface(getSurface());
}

void Scrollbar::drawScrollbar() {
    SDL_Surface *surface = getSurface();
    int w = getPos()->w;
    int h = getPos()->h;

    Uint32 *p = (Uint32 *) surface->pixels;
    SDL_Color color;
    for (int y = 0; y < h; y++) {
        for (int x = 0; x < w; x++) {
            int x_or_y = (vertical ? y : x);
            bool bar_pos_test = (x_or_y > getBarPos() && x_or_y < getBarPos() + bar_size);

            if (y == 0 || y == h-1 || x == 0 || x == w-1 || bar_pos_test) {
                color.r = 0;
                color.g = 0;
                color.b = 0;
            } else {
                color.r = 255;
                color.g = 255;
                color.b = 255;
            }
            *p = SDL_MapRGB(SDL_GetPixelFormatDetails(surface->format), NULL, color.r, color.g, color.b);
            p++;
        }
    }
}

bool Scrollbar::onMousePress(int x, int y) {
    bool is_in_x = x > getPos()->x && x < getPos()->x + getPos()->w;
    bool is_in_y = y > getPos()->y && y < getPos()->y + getPos()->h;
    if (is_in_x && is_in_y) {
        //setSurface(buttonDown);
        mouse_offset = (vertical ? y : x) - getBarPos();
        pressed = true;
        return true;
    }
    return false;
}

void Scrollbar::onMouseRelease(int x, int y) {
    //bool is_in_x = x > getPos()->x && x < getPos()->x + getPos()->w;
    //bool is_in_y = y > getPos()->y && y < getPos()->y + getPos()->h;
    //if (is_in_x && is_in_y && pressed) {
    if (pressed) {
        setValueByBarPos((vertical ? y : x) - mouse_offset);
        drawScrollbar();
        if (value_changed_func) {
            (*value_changed_func)(p);
        }
    }
    //setSurface(buttonUp);
    pressed = false;
}

void Scrollbar::onMouseMove(int x, int y) {
    if (pressed) {
        setValueByBarPos((vertical ? y : x) - mouse_offset);
        drawScrollbar();
        if (value_changed_func)
            (*value_changed_func)(p);
    }
}

int Scrollbar::getBarPos() {
    int w_or_h = (vertical ? getPos()->h : getPos()->w);
    return (w_or_h - bar_size) * (value - min_value) / (max_value - min_value);
}

void Scrollbar::setValueByBarPos(int pos) {
    int w_or_h = (vertical ? getPos()->h : getPos()->w);
    value = (max_value - min_value) * pos / (w_or_h - bar_size) + min_value;
    if (value < min_value)
        value = min_value;
    if (value > max_value)
        value = max_value;
}

void Scrollbar::setValueChangedFunc(void (*value_changed_func)(void *p), void *p) {
    this->value_changed_func = value_changed_func;
    this->p = p;
}

int Scrollbar::getValue() {
    return value;
}