package game

// move.c — hero movement commands.

// doRun starts the hero running (move.c do_run).
func (g *RogueGame) doRun(ch byte) {
	g.Running = true
	g.After = false
	g.RunCh = ch
}

// doMove checks that a move is legal and handles the consequences —
// fighting, picking up, etc. (move.c do_move).
func (g *RogueGame) doMove(dy, dx int) {
	p := &g.Player
	g.Firstmove = false
	if g.NoMove > 0 {
		g.NoMove--
		g.msg("you are still stuck in the bear trap")
		return
	}
	// Do a confused move (maybe)
	var nh Coord
	if p.On(IsHuh) && g.rnd(5) != 0 {
		nh = g.rndmove(&p.Creature)
		if nh == p.Pos {
			g.After = false
			g.Running = false
			g.ToDeath = false
			return
		}
	} else {
		nh = Coord{Y: p.Pos.Y + dy, X: p.Pos.X + dx}
	}

over:
	// Check if he tried to move off the screen or make an illegal diagonal
	// move, and stop him if he did.
	hitBound := nh.X < 0 || nh.X >= NumCols || nh.Y <= 0 || nh.Y >= NumLines-1
	var ch byte
	var fl PlaceFlags
	if !hitBound {
		if !g.diagOk(p.Pos, nh) {
			g.After = false
			g.Running = false
			return
		}
		if g.Running && p.Pos == nh {
			g.After = false
			g.Running = false
		}
		fl = *g.Level.FlagsAt(nh.Y, nh.X)
		ch = g.Level.VisibleChar(nh.Y, nh.X)
		if !fl.Has(FReal) && ch == Floor {
			if !p.On(IsLevit) {
				ch = Trap
				g.Level.SetChar(nh.Y, nh.X, Trap)
				g.Level.FlagsAt(nh.Y, nh.X).Set(FReal)
			}
		} else if p.On(IsHeld) && ch != 'F' {
			g.msg("you are being held")
			return
		}
	}
	if hitBound {
		ch = ' ' // fall into the wall case below
	}
	switch ch {
	case ' ', '|', '-':
		if g.Options.PassGo && g.Running && p.Room.Flags.Has(IsGone) &&
			!p.On(IsBlind) {
			var b1, b2 bool
			switch g.RunCh {
			case 'h', 'l':
				b1 = p.Pos.Y != 1 && g.turnOk(p.Pos.Y-1, p.Pos.X)
				b2 = p.Pos.Y != NumLines-2 && g.turnOk(p.Pos.Y+1, p.Pos.X)
				if b1 != b2 {
					if b1 {
						g.RunCh = 'k'
						dy = -1
					} else {
						g.RunCh = 'j'
						dy = 1
					}
					dx = 0
					g.turnref()
					nh = Coord{Y: p.Pos.Y + dy, X: p.Pos.X + dx}
					goto over
				}
			case 'j', 'k':
				b1 = p.Pos.X != 0 && g.turnOk(p.Pos.Y, p.Pos.X-1)
				b2 = p.Pos.X != NumCols-1 && g.turnOk(p.Pos.Y, p.Pos.X+1)
				if b1 != b2 {
					if b1 {
						g.RunCh = 'h'
						dx = -1
					} else {
						g.RunCh = 'l'
						dx = 1
					}
					dy = 0
					g.turnref()
					nh = Coord{Y: p.Pos.Y + dy, X: p.Pos.X + dx}
					goto over
				}
			}
		}
		g.Running = false
		g.After = false
	case Door:
		g.Running = false
		if g.Level.FlagsAt(p.Pos.Y, p.Pos.X).Has(FPass) {
			g.enterRoom(nh)
		}
		g.moveStuff(nh, fl)
	case Trap:
		tr := g.beTrapped(nh)
		if tr == TDoor || tr == TTelep {
			return
		}
		g.moveStuff(nh, fl)
	case Passage:
		// when you're in a corridor, you don't know if you're in a maze
		// room or not, and there ain't no way to find out if you're
		// leaving a maze room, so it is necessary to always recalculate
		// proom.
		p.Room = g.roomin(p.Pos)
		g.moveStuff(nh, fl)
	case Floor:
		if !fl.Has(FReal) {
			g.beTrapped(p.Pos)
		}
		g.moveStuff(nh, fl)
	default:
		if ch == Stairs {
			g.SeenStairs = true
		}
		g.Running = false
		if isUpper(ch) || g.Level.MonsterAt(nh.Y, nh.X) != nil {
			g.fight(nh, p.CurWeapon, false)
		} else {
			if ch != Stairs {
				g.Take = ch
			}
			g.moveStuff(nh, fl)
		}
	}
}

// moveStuff is the move_stuff label in do_move: complete the step.
func (g *RogueGame) moveStuff(nh Coord, fl PlaceFlags) {
	p := &g.Player
	g.mvaddch(p.Pos.Y, p.Pos.X, g.floorAt())
	if fl.Has(FPass) && g.Level.Char(g.Oldpos.Y, g.Oldpos.X) == Door {
		g.leaveRoom(nh)
	}
	p.Pos = nh
}

// turnOk decides whether it is legal to turn onto the given space
// (move.c turn_ok).
func (g *RogueGame) turnOk(y, x int) bool {
	pp := g.Level.At(y, x)
	return pp.Ch == Door || pp.Flags&(FReal|FPass) == (FReal|FPass)
}

// turnref decides whether to refresh at a passage turning (move.c turnref).
func (g *RogueGame) turnref() {
	p := &g.Player
	pp := g.Level.At(p.Pos.Y, p.Pos.X)
	if !pp.Flags.Has(FSeen) {
		if g.Options.Jump {
			g.refresh()
		}
		pp.Flags.Set(FSeen)
	}
}

// doorOpen is called to wake up things in a room that might move when the
// hero enters (move.c door_open).
func (g *RogueGame) doorOpen(rp *Room) {
	if rp.Flags.Has(IsGone) {
		return
	}
	for y := rp.Pos.Y; y < rp.Pos.Y+rp.Max.Y; y++ {
		for x := rp.Pos.X; x < rp.Pos.X+rp.Max.X; x++ {
			if isUpper(g.Level.VisibleChar(y, x)) {
				g.wakeMonster(y, x)
			}
		}
	}
}

// beTrapped makes him pay for stepping on a trap (move.c be_trapped).
func (g *RogueGame) beTrapped(tc Coord) int {
	p := &g.Player
	if p.On(IsLevit) {
		return TRust // anything that's not a door or teleport
	}
	g.Running = false
	g.Count = 0
	pp := g.Level.At(tc.Y, tc.X)
	pp.Ch = Trap
	tr := int(pp.Flags & FTMask)
	pp.Flags.Set(FSeen)
	switch tr {
	case TDoor:
		g.Depth++
		g.NewLevel()
		g.msg("you fell into a trap!")
	case TBear:
		g.NoMove += g.spread(3) // BEARTIME
		g.msg("you are caught in a bear trap")
	case TMyst:
		switch g.rnd(11) {
		case 0:
			g.msg("you are suddenly in a parallel dimension")
		case 1:
			g.msg("the light in here suddenly seems %s", rainbow[g.rnd(len(rainbow))])
		case 2:
			g.msg("you feel a sting in the side of your neck")
		case 3:
			g.msg("multi-colored lines swirl around you, then fade")
		case 4:
			g.msg("a %s light flashes in your eyes", rainbow[g.rnd(len(rainbow))])
		case 5:
			g.msg("a spike shoots past your ear!")
		case 6:
			g.msg("%s sparks dance across your armor", rainbow[g.rnd(len(rainbow))])
		case 7:
			g.msg("you suddenly feel very thirsty")
		case 8:
			g.msg("you feel time speed up suddenly")
		case 9:
			g.msg("time now seems to be going slower")
		case 10:
			g.msg("you pack turns %s!", rainbow[g.rnd(len(rainbow))])
		}
	case TSleep:
		g.NoCommand += g.spread(5) // SLEEPTIME
		p.Flags.Clear(IsRun)
		g.msg("a strange white mist envelops you and you fall asleep")
	case TArrow:
		if g.swing(p.Stats.Lvl-1, p.Stats.Arm, 1) {
			p.Stats.HP -= g.roll(1, 6)
			if p.Stats.HP <= 0 {
				g.msg("an arrow killed you")
				g.death('a')
			} else {
				g.msg("oh no! An arrow shot you")
			}
		} else {
			arrow := newObject()
			g.initWeapon(arrow, Arrow)
			arrow.Count = 1
			arrow.Pos = p.Pos
			g.fall(arrow, false)
			g.msg("an arrow shoots past you")
		}
	case TTelep:
		// since the hero's leaving, look() won't put a TRAP down for us,
		// so we have to do it ourself
		g.teleport()
		g.mvaddch(tc.Y, tc.X, Trap)
	case TDart:
		if !g.swing(p.Stats.Lvl+1, p.Stats.Arm, 1) {
			g.msg("a small dart whizzes by your ear and vanishes")
		} else {
			p.Stats.HP -= g.roll(1, 4)
			if p.Stats.HP <= 0 {
				g.msg("a poisoned dart killed you")
				g.death('d')
			}
			if !p.IsWearing(RSustStr) && !g.save(VsPoison) {
				g.chgStr(-1)
			}
			g.msg("a small dart just hit you in the shoulder")
		}
	case TRust:
		g.msg("a gush of water hits you on the head")
		g.rustArmor(p.CurArmor)
	}
	g.flushType()
	return tr
}

// rndmove moves in a random direction if the monster/person is confused
// (move.c rndmove).
func (g *RogueGame) rndmove(who *Creature) Coord {
	ret := Coord{
		Y: who.Pos.Y + g.rnd(3) - 1,
		X: who.Pos.X + g.rnd(3) - 1,
	}
	// Now check to see if that's a legal move.  If not, don't move.
	// (I.e., bump into the wall or whatever)
	if ret == who.Pos {
		return ret
	}
	if !g.diagOk(who.Pos, ret) {
		return who.Pos
	}
	ch := g.Level.VisibleChar(ret.Y, ret.X)
	if !stepOk(ch) {
		return who.Pos
	}
	if ch == Scroll {
		var found *Object
		for _, obj := range g.Level.Objects {
			if ret.Y == obj.Pos.Y && ret.X == obj.Pos.X {
				found = obj
				break
			}
		}
		if found != nil && found.Which == SScare {
			return who.Pos
		}
	}
	return ret
}

// rustArmor rusts the given armor, if it is a legal kind to rust, and we
// aren't wearing a magic ring (move.c rust_armor).
func (g *RogueGame) rustArmor(arm *Object) {
	if arm == nil || arm.Type != Armor || arm.Which == Leather ||
		arm.Arm >= 9 {
		return
	}

	if arm.Flags.Has(IsProt) || g.Player.IsWearing(RSustArm) {
		if !g.ToDeath {
			g.msg("the rust vanishes instantly")
		}
	} else {
		arm.Arm++
		if !g.Options.Terse {
			g.msg("your armor appears to be weaker now. Oh my!")
		} else {
			g.msg("your armor weakens")
		}
	}
}