/*
Copyright © Brian Buller <brian@bullercodeworks.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package widgets

import (
	"github.com/gdamore/tcell"
)

type RelativeLayout struct {
	id              string
	style           tcell.Style
	x, y            int
	w, h            int
	widgetRelations map[Widget][]widgetRelation
	widgets         []Widget

	active    bool
	visible   bool
	focusable bool

	keyMap KeyMap
}

var _ Widget = (*RelativeLayout)(nil)

type widgetRelation struct {
	relation RelativeRelation
	relTo    Widget
}

type RelativeRelation int

const (
	RelRelAbove     = iota // Above Widget
	RelRelToRightOf        // To Right of Widget
	RelRelBelow            // Below Widget
	RelRelToLeftOf         // To Left of Widget
	RelAncTL               // Anchored to parent Top-Left
	RelAncT                // Anchored to parent Top
	RelAncTR               // Anchored to parent Top-Right
	RelAncL                // Anchored to parent Left
	RelAncC                // Anchored to parent Center
	RelAncR                // Anchored to parent Right
	RelAncBL               // Anchored to parent Bottom-Left
	RelAncB                // Anchored to parent Bottom
	RelAncBR               // Anchored to parent Bottom-Right
)

func NewRelativeLayout(id string, s tcell.Style) *RelativeLayout {
	ret := &RelativeLayout{}
	ret.Init(id, s)
	return ret
}

func (w *RelativeLayout) Init(id string, style tcell.Style) {
	w.id = id
	w.style = style
	w.visible = true
	w.focusable = true
	w.widgetRelations = make(map[Widget][]widgetRelation)
	w.keyMap = BlankKeyMap()
}
func (w *RelativeLayout) Id() string { return w.id }
func (w *RelativeLayout) HandleResize(ev *tcell.EventResize) {
	w.w, w.h = ev.Size()
	// TODO: Trickle-down HandleResize
}

func (w *RelativeLayout) SetKeyMap(km KeyMap, def bool) { w.keyMap = km }
func (w *RelativeLayout) AddToKeyMap(km KeyMap)         { w.keyMap.Merge(km) }
func (w *RelativeLayout) RemoveFromKeyMap(km KeyMap) {
	for k := range km.Keys {
		w.keyMap.Remove(k)
	}
	for r := range km.Runes {
		w.keyMap.RemoveRune(r)
	}
}
func (w *RelativeLayout) HandleKey(ev *tcell.EventKey) bool { return w.keyMap.Handle(ev) }
func (w *RelativeLayout) HandleTime(ev *tcell.EventTime) {
	for i := range w.widgets {
		w.widgets[i].HandleTime(ev)
	}
}

func (w *RelativeLayout) Draw(screen tcell.Screen) {
	if !w.visible {
		return
	}
	// All widgets should have correct (relative) positions
	/*
		done := make(map[Widget]widgetRelation)
		rem := make(map[Widget]widgetRelation)
		for k, v := range w.widgetRelations {
			if v.relTo == w {
				done[k] = v
			} else {
				rem[k] = v
			}
		}
	*/
}

func (w *RelativeLayout) Active() bool        { return w.active }
func (w *RelativeLayout) SetActive(a bool)    { w.active = a }
func (w *RelativeLayout) Visible() bool       { return w.visible }
func (w *RelativeLayout) SetVisible(a bool)   { w.visible = a }
func (w *RelativeLayout) Focusable() bool     { return w.focusable }
func (w *RelativeLayout) SetFocusable(b bool) { w.focusable = b }
func (w *RelativeLayout) SetX(x int)          { w.x = x }
func (w *RelativeLayout) SetY(y int)          { w.y = y }
func (w *RelativeLayout) GetX() int           { return w.x }
func (w *RelativeLayout) GetY() int           { return w.y }
func (w *RelativeLayout) SetSize(c Coord)     { w.w, w.h = c.X, c.Y }
func (w *RelativeLayout) GetPos() Coord       { return Coord{X: w.x, Y: w.y} }
func (w *RelativeLayout) SetPos(c Coord)      { w.x, w.y = c.X, c.Y }
func (w *RelativeLayout) SetW(wd int)         { w.w = wd }
func (w *RelativeLayout) SetH(h int)          { w.h = h }
func (w *RelativeLayout) GetW() int           { return w.w }
func (w *RelativeLayout) GetH() int           { return w.h }
func (w *RelativeLayout) WantW() int          { return 1 }
func (w *RelativeLayout) WantH() int          { return 1 }
func (w *RelativeLayout) MinW() int {
	// Find the highest value for x in all widgets GetX() + MinW()
	var minW int
	for _, wd := range w.widgets {
		wrk := wd.GetX() + wd.MinW()
		if wrk > minW {
			minW = wrk
		}
	}
	return minW
}

func (w *RelativeLayout) MinH() int {
	// Find the highest value for y in all widgets GetY() + MinH()
	var minH int
	for _, wd := range w.widgets {
		wrk := wd.GetY() + wd.MinH()
		if wrk > minH {
			minH = wrk
		}
	}
	return minH
}

func (w *RelativeLayout) Add(n Widget, relTo Widget, relation RelativeRelation) {
	w.widgetRelations[n] = append(w.widgetRelations[n], widgetRelation{
		relation: relation,
		relTo:    relTo,
	})
}

func (w *RelativeLayout) AddRelation(n Widget, relation RelativeRelation, relTo Widget) {
}