package input

import (
	"github.com/gotk3/gotk3/gdk"
	"github.com/gotk3/gotk3/gtk"
)

const shiftMask = uint(gdk.SHIFT_MASK)
const cntrlMask = uint(gdk.CONTROL_MASK)

func bithas(bit, has uint) bool {
	return bit&has == has
}

func convEvent(ev *gdk.Event) (key, mask uint) {
	var keyEvent = gdk.EventKeyNewFromEvent(ev)
	return keyEvent.KeyVal(), keyEvent.State()
}

// connects to key-press-event
func (f *Field) keyDown(tv *gtk.TextView, ev *gdk.Event) bool {
	var key, mask = convEvent(ev)

	switch key {
	// If Enter is pressed.
	case gdk.KEY_Return:
		// If Shift is being held, insert a new line.
		if bithas(mask, shiftMask) {
			f.buffer.InsertAtCursor("\n")
			return true
		}

		// Else, send the message.
		f.sendInput()
		return true

	// If Arrow Up is pressed, then we might want to edit the latest message if
	// any.
	case gdk.KEY_Up:
		// Do we have input? If we do, then we shouldn't touch it.
		if f.textLen() > 0 {
			return false
		}

		// Try and find the latest message ID that is ours.
		id, ok := f.ctrl.LatestMessageFrom(f.UserID)
		if !ok {
			// No messages found, so we can passthrough normally.
			return false
		}

		// If we don't support message editing, then passthrough events.
		if !f.Editable(id) {
			return false
		}

		// Start editing.
		f.StartEditing(id)

		// TODO: add a visible indicator to indicate a message being edited.

		// Take the event.
		return true

	// There are multiple things to do here when we press the Escape key.
	case gdk.KEY_Escape:
		// First, we'd want to cancel editing if we have one.
		if f.editingID != "" {
			return f.StopEditing() // always returns true
		}
	}

	// Passthrough.
	return false
}