#include "MenuSystem.h"

MenuSystem::MenuSystem() {}

void MenuSystem::setRootScreenBuilder (ScreenBuilder fn) { rootBuilder = fn; }

void MenuSystem::rebuildRoot()
{
    if (rootBuilder)
    {
        MenuScreen root = rootBuilder();
        stack.clear();
        stack.push_back (root);
    }
}

void MenuSystem::open()
{
    wasOpen = true;
    rebuildRoot();
}

void MenuSystem::close()
{
    stack.clear();
    wasOpen = false;
}

void MenuSystem::pushScreen (const MenuScreen& screen) { stack.push_back (screen); }

const MenuScreen& MenuSystem::current() const
{
    if (stack.empty())
    {
        static MenuScreen empty;
        empty.title = "";
        empty.selected = 0;
        return empty;
    }
    return stack.back();
}

void MenuSystem::refreshCurrent()
{
    if (! stack.empty())
    {
        int sel = stack.back().selected;
        stack.pop_back();
        if (stack.empty() && rootBuilder)
        {
            MenuScreen root = rootBuilder();
            root.selected = sel;
            stack.push_back (root);
        }
        else if (! stack.empty())
        {
            stack.back().selected = sel;
        }
    }
}

void MenuSystem::up()
{
    if (stack.empty()) return;
    auto& s = stack.back();
    if (s.items.empty()) return;

    int newSel = s.selected - 1;
    while (newSel >= 0 && s.items[(size_t) newSel].kind == MenuItem::Separator)
        --newSel;
    if (newSel < 0)
    {
        newSel = (int) s.items.size() - 1;
        while (newSel >= 0 && s.items[(size_t) newSel].kind == MenuItem::Separator)
            --newSel;
    }
    if (newSel >= 0)
        s.selected = newSel;
}

void MenuSystem::down()
{
    if (stack.empty()) return;
    auto& s = stack.back();
    if (s.items.empty()) return;

    int newSel = s.selected + 1;
    while (newSel < (int) s.items.size() && s.items[(size_t) newSel].kind == MenuItem::Separator)
        ++newSel;
    if (newSel >= (int) s.items.size())
    {
        newSel = 0;
        while (newSel < (int) s.items.size() && s.items[(size_t) newSel].kind == MenuItem::Separator)
            ++newSel;
    }
    if (newSel < (int) s.items.size())
        s.selected = newSel;
}

void MenuSystem::left()
{
    if (stack.empty()) return;
    auto& s = stack.back();
    if (s.items.empty()) return;
    auto& item = s.items[(size_t) s.selected];
    if (item.kind == MenuItem::Value && item.onAdjust)
        item.onAdjust (-0.02f);
}

void MenuSystem::right()
{
    if (stack.empty()) return;
    auto& s = stack.back();
    if (s.items.empty()) return;
    auto& item = s.items[(size_t) s.selected];
    if (item.kind == MenuItem::Value && item.onAdjust)
        item.onAdjust (0.02f);
}

void MenuSystem::enter()
{
    if (stack.empty()) return;
    auto& s = stack.back();
    if (s.items.empty()) return;
    auto& item = s.items[(size_t) s.selected];
    if (item.onEnter)
        item.onEnter();
}

void MenuSystem::escape()
{
    if (stack.size() > 1)
        stack.pop_back();
    else if (stack.size() == 1)
        close();
}