#ifdef ESP_PLATFORM

#include <Tactility/Tactility.h>

#include <lvgl.h>

extern "C" {

extern void __real_lv_obj_set_flex_flow(lv_obj_t* obj, lv_flex_flow_t flow);
extern lv_obj_t* __real_lv_obj_create(lv_obj_t* parent);

static bool get_children_bby(lv_obj_t * parent, lv_coord_t * out_min_y, lv_coord_t * out_max_y) {
    lv_coord_t min_y = INT_MAX;
    lv_coord_t max_y = INT_MIN;
    bool has_children = false;
    lv_area_t parent_coords;
    lv_obj_get_coords(parent, &parent_coords);

    for(size_t i = 0; i < lv_obj_get_child_count(parent); i++) {
        lv_obj_t * child = lv_obj_get_child(parent, i);
        // Get absolute position of child
        lv_area_t child_coords;
        lv_obj_get_coords(child, &child_coords);

        // convert to local coordinates
        lv_coord_t c_y1 = child_coords.y1 - parent_coords.y1;
        lv_coord_t c_y2 = child_coords.y2 - parent_coords.y1;

        // Update minimum/maximum
        if(c_y1 < min_y) min_y = c_y1;
        if(c_y2 > max_y) max_y = c_y2;

        has_children = true;
    }

    if(has_children) {
        *out_min_y = min_y;
        *out_max_y = max_y;
    }

    return has_children;
}

static bool is_overflowing(lv_obj_t* obj) {
    lv_coord_t min_y = 0;
    lv_coord_t max_y = 0;

    // Compute childrens' bounding box relative to parent
    if(!get_children_bby(obj, &min_y, &max_y)) {
        // Can't be overflowing when no children are present
        return false;
    }

    lv_coord_t parent_h = lv_obj_get_height(obj);

    return ((min_y < 0) || (max_y >= parent_h));
}

static void apply_scroll_styles(lv_obj_t* obj) {
    static bool init = false;
    static lv_style_t style_scroll_focus;
    static lv_style_t style_scrolling;

    if (!init) {
        // Style which applies if scrollbar is focused
        lv_style_init(&style_scroll_focus);
        lv_style_set_bg_color(&style_scroll_focus, lv_color_make(0x40,0xA0,0xFF));
        lv_style_set_bg_opa(&style_scroll_focus, LV_OPA_COVER);
        lv_style_set_border_width(&style_scroll_focus, 1);
        lv_style_set_border_color(&style_scroll_focus, lv_theme_get_color_primary(nullptr));

        // Style which applies if scrollbar is clicked enough that it defocuses
        lv_style_init(&style_scrolling);
        lv_style_set_bg_color(&style_scrolling, lv_color_make(0x40,0xA0,0xFF));
        lv_style_set_bg_opa(&style_scrolling, LV_OPA_COVER);
        lv_style_set_border_width(&style_scrolling, 1);
        // In Tactilitys' default theme, this is red, maybe there is a better color?
        lv_style_set_border_color(&style_scrolling, lv_theme_get_color_secondary(nullptr));

        init = true;
    }
    lv_obj_add_style(obj, &style_scroll_focus, (lv_style_selector_t)(LV_PART_SCROLLBAR | LV_STATE_FOCUSED));
    lv_obj_add_style(obj, &style_scrolling, (lv_style_selector_t)(LV_PART_SCROLLBAR | LV_STATE_PRESSED));
}

static bool is_scrollable(lv_obj_t* obj) {
    return lv_obj_has_flag(obj, LV_OBJ_FLAG_CLICKABLE) && lv_obj_has_flag(obj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);
}

static void make_scrollable(lv_obj_t* obj) {
    // Make the object interactive, i.e focusable
    lv_obj_add_flag(obj, (lv_obj_flag_t)(LV_OBJ_FLAG_CLICKABLE | LV_OBJ_FLAG_SCROLL_ON_FOCUS));

    // Add to default group to get it into the focus list
    auto* group = lv_group_get_default();
    lv_group_add_obj(group, obj);

    // Apply style to scrollbar to make it visible if focused
    apply_scroll_styles(obj);
}

static void child_added_event_handler(lv_event_t* e) {
    lv_obj_t* obj = (lv_obj_t*)lv_event_get_target(e);

}

void __wrap_lv_obj_set_flex_flow(lv_obj_t* obj, lv_flex_flow_t flow) {
    __real_lv_obj_set_flex_flow(obj, flow);

    if (tt::hal::getConfiguration()->uiScale == tt::hal::UiScale::Smallest) {
        lv_obj_set_style_pad_gap(obj, 4, LV_STATE_DEFAULT);
    }
}

lv_obj_t* __wrap_lv_obj_create(lv_obj_t* parent) {
    auto obj = __real_lv_obj_create(parent);
    if (tt::hal::getConfiguration()->uiScale == tt::hal::UiScale::Smallest) {
        lv_obj_set_style_pad_all(obj, 2, LV_STATE_DEFAULT);
        lv_obj_set_style_pad_gap(obj, 2, LV_STATE_DEFAULT);
        lv_obj_set_style_radius(obj, 3, LV_STATE_DEFAULT);
        lv_obj_set_style_border_width(obj, 1, LV_STATE_DEFAULT);
    }

    if (parent && !is_scrollable(parent) && is_overflowing(parent)) {
        make_scrollable(parent);
    }

    return obj;
}

}

#endif // ESP_PLATFORM