// Copyright 2014 The gocui Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package gocui

import "github.com/jesseduffield/termbox-go"

// Keybidings are used to link a given key-press event with a handler.
type keybinding struct {
	viewName string
	contexts []string
	key      Key
	ch       rune
	mod      Modifier
	handler  func(*Gui, *View) error
}

// newKeybinding returns a new Keybinding object.
func newKeybinding(viewname string, contexts []string, key Key, ch rune, mod Modifier, handler func(*Gui, *View) error) (kb *keybinding) {
	kb = &keybinding{
		viewName: viewname,
		contexts: contexts,
		key:      key,
		ch:       ch,
		mod:      mod,
		handler:  handler,
	}
	return kb
}

func eventMatchesKey(ev *termbox.Event, key interface{}) bool {
	// assuming ModNone for now
	if Modifier(ev.Mod) != ModNone {
		return false
	}

	k, ch, err := getKey(key)
	if err != nil {
		return false
	}

	return k == Key(ev.Key) && ch == ev.Ch
}

// matchKeypress returns if the keybinding matches the keypress.
func (kb *keybinding) matchKeypress(key Key, ch rune, mod Modifier) bool {
	return kb.key == key && kb.ch == ch && kb.mod == mod
}

// matchView returns if the keybinding matches the current view (and the view's context)
func (kb *keybinding) matchView(v *View) bool {
	// if the user is typing in a field, ignore char keys
	if v == nil {
		return false
	}
	if v.Editable == true && kb.ch != 0 {
		return false
	}
	if kb.viewName != v.name {
		return false
	}
	// if the keybinding doesn't specify contexts, it applies for all contexts
	if len(kb.contexts) == 0 {
		return true
	}
	for _, context := range kb.contexts {
		if context == v.Context {
			return true
		}
	}
	return false
}

// Key represents special keys or keys combinations.
type Key termbox.Key

// Special keys.
const (
	KeyF1         Key = Key(termbox.KeyF1)
	KeyF2             = Key(termbox.KeyF2)
	KeyF3             = Key(termbox.KeyF3)
	KeyF4             = Key(termbox.KeyF4)
	KeyF5             = Key(termbox.KeyF5)
	KeyF6             = Key(termbox.KeyF6)
	KeyF7             = Key(termbox.KeyF7)
	KeyF8             = Key(termbox.KeyF8)
	KeyF9             = Key(termbox.KeyF9)
	KeyF10            = Key(termbox.KeyF10)
	KeyF11            = Key(termbox.KeyF11)
	KeyF12            = Key(termbox.KeyF12)
	KeyInsert         = Key(termbox.KeyInsert)
	KeyDelete         = Key(termbox.KeyDelete)
	KeyHome           = Key(termbox.KeyHome)
	KeyEnd            = Key(termbox.KeyEnd)
	KeyPgup           = Key(termbox.KeyPgup)
	KeyPgdn           = Key(termbox.KeyPgdn)
	KeyArrowUp        = Key(termbox.KeyArrowUp)
	KeyArrowDown      = Key(termbox.KeyArrowDown)
	KeyArrowLeft      = Key(termbox.KeyArrowLeft)
	KeyArrowRight     = Key(termbox.KeyArrowRight)

	MouseLeft      = Key(termbox.MouseLeft)
	MouseMiddle    = Key(termbox.MouseMiddle)
	MouseRight     = Key(termbox.MouseRight)
	MouseRelease   = Key(termbox.MouseRelease)
	MouseWheelUp   = Key(termbox.MouseWheelUp)
	MouseWheelDown = Key(termbox.MouseWheelDown)
)

// Keys combinations.
const (
	KeyCtrlTilde      Key = Key(termbox.KeyCtrlTilde)
	KeyCtrl2              = Key(termbox.KeyCtrl2)
	KeyCtrlSpace          = Key(termbox.KeyCtrlSpace)
	KeyCtrlA              = Key(termbox.KeyCtrlA)
	KeyCtrlB              = Key(termbox.KeyCtrlB)
	KeyCtrlC              = Key(termbox.KeyCtrlC)
	KeyCtrlD              = Key(termbox.KeyCtrlD)
	KeyCtrlE              = Key(termbox.KeyCtrlE)
	KeyCtrlF              = Key(termbox.KeyCtrlF)
	KeyCtrlG              = Key(termbox.KeyCtrlG)
	KeyBackspace          = Key(termbox.KeyBackspace)
	KeyCtrlH              = Key(termbox.KeyCtrlH)
	KeyTab                = Key(termbox.KeyTab)
	KeyCtrlI              = Key(termbox.KeyCtrlI)
	KeyCtrlJ              = Key(termbox.KeyCtrlJ)
	KeyCtrlK              = Key(termbox.KeyCtrlK)
	KeyCtrlL              = Key(termbox.KeyCtrlL)
	KeyEnter              = Key(termbox.KeyEnter)
	KeyCtrlM              = Key(termbox.KeyCtrlM)
	KeyCtrlN              = Key(termbox.KeyCtrlN)
	KeyCtrlO              = Key(termbox.KeyCtrlO)
	KeyCtrlP              = Key(termbox.KeyCtrlP)
	KeyCtrlQ              = Key(termbox.KeyCtrlQ)
	KeyCtrlR              = Key(termbox.KeyCtrlR)
	KeyCtrlS              = Key(termbox.KeyCtrlS)
	KeyCtrlT              = Key(termbox.KeyCtrlT)
	KeyCtrlU              = Key(termbox.KeyCtrlU)
	KeyCtrlV              = Key(termbox.KeyCtrlV)
	KeyCtrlW              = Key(termbox.KeyCtrlW)
	KeyCtrlX              = Key(termbox.KeyCtrlX)
	KeyCtrlY              = Key(termbox.KeyCtrlY)
	KeyCtrlZ              = Key(termbox.KeyCtrlZ)
	KeyEsc                = Key(termbox.KeyEsc)
	KeyCtrlLsqBracket     = Key(termbox.KeyCtrlLsqBracket)
	KeyCtrl3              = Key(termbox.KeyCtrl3)
	KeyCtrl4              = Key(termbox.KeyCtrl4)
	KeyCtrlBackslash      = Key(termbox.KeyCtrlBackslash)
	KeyCtrl5              = Key(termbox.KeyCtrl5)
	KeyCtrlRsqBracket     = Key(termbox.KeyCtrlRsqBracket)
	KeyCtrl6              = Key(termbox.KeyCtrl6)
	KeyCtrl7              = Key(termbox.KeyCtrl7)
	KeyCtrlSlash          = Key(termbox.KeyCtrlSlash)
	KeyCtrlUnderscore     = Key(termbox.KeyCtrlUnderscore)
	KeySpace              = Key(termbox.KeySpace)
	KeyBackspace2         = Key(termbox.KeyBackspace2)
	KeyCtrl8              = Key(termbox.KeyCtrl8)
)

// Modifier allows to define special keys combinations. They can be used
// in combination with Keys or Runes when a new keybinding is defined.
type Modifier termbox.Modifier

// Modifiers.
const (
	ModNone   Modifier = Modifier(0)
	ModAlt             = Modifier(termbox.ModAlt)
	ModMotion          = Modifier(termbox.ModMotion)
)
