package mujica

import (
	"log/slog"

	"github.com/egoist/mygo/ui"
)

// ContextMenuOptions configure a ContextMenu.
type ContextMenuOptions struct {
	Disabled bool
}

// contextMenuState is where the menu opened, relative to the target.
type contextMenuState struct {
	open bool
	x, y float32
}

// ContextMenu gives target an in-window menu that build fills. A secondary
// click opens it at the pointer; the menu key or Shift+F10, while the focus
// is in target, opens it below target. It flips to stay in the window, and
// the focus returns on close. target must be a container: the menu adds an
// anchor child to it, and takes its HandleInput. It returns target.
func ContextMenu(c *ui.Context, target *ui.Element, opts ContextMenuOptions, build func(m *PopupMenu)) *ui.Element {
	if target == nil {
		panic("mujica: ContextMenu needs a target")
	}
	if build == nil {
		panic("mujica: ContextMenu needs a build function")
	}
	st := ui.Local(target, "mujica.contextmenu", func() contextMenuState { return contextMenuState{} })
	if opts.Disabled {
		st.open = false
		return target
	}
	target.HandleInput(func(ev ui.InputEvent) bool {
		if ev.Kind != ui.InputPointerDown || ev.Button != 1 {
			return false
		}
		st.open, st.x, st.y = true, ev.X, ev.Y
		slog.Debug("mujica: context_menu open", "by", "pointer")
		return true
	})
	if target.Shortcut(0, ui.KeyContextMenu) || target.Shortcut(ui.Shift, ui.KeyF10) {
		st.open, st.x, st.y = true, 0, target.Bounds().H
		slog.Debug("mujica: context_menu open", "by", "keyboard")
	}
	if !st.open {
		return target
	}
	var anchor *ui.Element
	target.Children(func() {
		anchor = ui.Box(c).Key("mujica.contextmenu.anchor").Absolute().Left(st.x).Top(st.y).Size(1, 1).PassThrough()
	})
	popupMenuOpen(c, anchor, &st.open, build)
	return target
}