package soko

import (
	"opslag.de/schobers/geom"
)

type Level struct {
	Width  int
	Height int

	Tiles    []TileType
	Entities []EntityType
}

func (l Level) IdxToPos(i int) geom.Point { return geom.Pt(i%l.Width, i/l.Width) }

func (l Level) PosToIdx(p geom.Point) int {
	if p.X < 0 || p.Y < 0 || p.X >= l.Width || p.Y >= l.Height {
		return -1
	}
	return p.Y*l.Width + p.X
}

func (l Level) Moves() []Moves {
	moves := make([]Moves, len(l.Tiles))
	w := l.Width
	for y := 0; y < l.Height; y++ {
		for x := 0; x < w; x++ {
			var m Moves
			idx := y*w + x
			if y > 0 {
				m.Valid = append(m.Valid, idx-w)
				m.All[DirectionUp] = idx - w
			} else {
				m.All[DirectionUp] = -1
			}
			if y < (l.Height - 1) {
				m.Valid = append(m.Valid, idx+w)
				m.All[DirectionDown] = idx + w
			} else {
				m.All[DirectionDown] = -1
			}
			if x > 0 {
				m.Valid = append(m.Valid, idx-1)
				m.All[DirectionLeft] = idx - 1
			} else {
				m.All[DirectionLeft] = idx - 1
			}
			if x < (w - 1) {
				m.Valid = append(m.Valid, idx+1)
				m.All[DirectionRight] = idx + 1
			} else {
				m.All[DirectionRight] = idx + 1
			}
			moves[idx] = m
		}
	}
	return moves
}

func (l Level) MoveIdx(idx int, dir Direction) int {
	switch dir {
	case DirectionUp:
		if idx < l.Width {
			return -1
		}
		return idx - l.Width
	case DirectionRight:
		if (idx+1)%l.Width == 0 {
			return -1
		}
		return idx + 1
	case DirectionDown:
		if idx >= (l.Width*l.Height)-l.Width {
			return -1
		}
		return idx + l.Width
	case DirectionLeft:
		if idx%l.Width == 0 {
			return -1
		}
		return idx - 1
	}
	return -1
}

func (l Level) Size() int { return l.Width * l.Height }

func (l Level) State() State {
	return NewState(l)
}