package game

// pack.c — routines to deal with the pack.

// addPack picks up an object and adds it to the pack; if obj is non-nil use
// it instead of getting it off the ground (pack.c add_pack).
func (g *RogueGame) addPack(obj *Object, silent bool) {
	p := &g.Player
	fromFloor := false
	if obj == nil {
		if obj = g.findObj(p.Pos.Y, p.Pos.X); obj == nil {
			return
		}
		fromFloor = true
	}

	// Check for and deal with scare monster scrolls
	if obj.Kind == KindScroll && obj.ScrollKind() == ScrollScareMonster && obj.Flags.Has(WasFound) {
		detachObj(&g.Level.Objects, obj)
		g.mvaddch(p.Pos.Y, p.Pos.X, g.floorCh())
		if p.Room.Flags.Has(Gone) {
			g.Level.SetChar(p.Pos.Y, p.Pos.X, Passage)
		} else {
			g.Level.SetChar(p.Pos.Y, p.Pos.X, Floor)
		}
		g.msg("the scroll turns to dust as you pick it up")
		return
	}

	if len(p.Pack) == 0 {
		p.Pack = append(p.Pack, obj)
		obj.PackCh = g.packChar()
		p.Inpack++
	} else {
		// Walk the pack looking for the insertion point, keeping items of
		// one type together and merging stackable/grouped items — a direct
		// translation of the C linked-list walk. lp is the index to insert
		// after; -1 after a merge means no insertion.
		lp := -1
		merged := false
		for i := 0; i < len(p.Pack); i++ {
			if p.Pack[i].Kind != obj.Kind {
				lp = i
				continue
			}
			// found the group of our type: scan for matching subtype
			for p.Pack[i].Kind == obj.Kind && p.Pack[i].Which != obj.Which {
				lp = i
				if i+1 >= len(p.Pack) {
					break
				}
				i++
			}
			op := p.Pack[i]
			if op.Kind == obj.Kind && op.Which == obj.Which {
				if op.Kind.MergesInPack() {
					if !g.packRoom(fromFloor, obj) {
						return
					}
					op.Count++
					obj = op
					lp = -1
					merged = true
				} else if obj.Group != 0 {
					lp = i
					for p.Pack[i].Kind == obj.Kind &&
						p.Pack[i].Which == obj.Which &&
						p.Pack[i].Group != obj.Group {
						lp = i
						if i+1 >= len(p.Pack) {
							break
						}
						i++
					}
					op = p.Pack[i]
					if op.Kind == obj.Kind && op.Which == obj.Which &&
						op.Group == obj.Group {
						op.Count += obj.Count
						p.Inpack--
						if !g.packRoom(fromFloor, obj) {
							return
						}
						obj = op
						lp = -1
						merged = true
					}
				} else {
					lp = i
				}
			}
			break
		}

		if !merged && lp != -1 {
			if !g.packRoom(fromFloor, obj) {
				return
			}
			obj.PackCh = g.packChar()
			p.Pack = append(p.Pack[:lp+1],
				append([]*Object{obj}, p.Pack[lp+1:]...)...)
		}
	}

	obj.Flags.Set(WasFound)

	// If this was the object of something's desire, that monster will get
	// mad and run at the hero.
	for _, op := range g.Level.Monsters {
		if op.Dest == &obj.Pos {
			op.Dest = &p.Pos
		}
	}

	if obj.Kind == KindAmulet {
		g.HasAmulet = true
	}
	// Notify the user
	if !silent {
		if !g.Options.Terse {
			g.addmsg("you now have ")
		}
		g.msg("%s (%c)", g.invName(obj, !g.Options.Terse), obj.PackCh)
	}
}

// packRoom sees if there's room in the pack; if not, prints an appropriate
// message (pack.c pack_room).
func (g *RogueGame) packRoom(fromFloor bool, obj *Object) bool {
	p := &g.Player
	if p.Inpack++; p.Inpack > MaxPack {
		if !g.Options.Terse {
			g.addmsg("there's ")
		}
		g.addmsg("no room")
		if !g.Options.Terse {
			g.addmsg(" in your pack")
		}
		g.endmsg()
		if fromFloor {
			g.moveMsg(obj)
		}
		p.Inpack = MaxPack
		return false
	}

	if fromFloor {
		detachObj(&g.Level.Objects, obj)
		g.mvaddch(p.Pos.Y, p.Pos.X, g.floorCh())
		if p.Room.Flags.Has(Gone) {
			g.Level.SetChar(p.Pos.Y, p.Pos.X, Passage)
		} else {
			g.Level.SetChar(p.Pos.Y, p.Pos.X, Floor)
		}
	}
	return true
}

// leavePack takes an item out of the pack (pack.c leave_pack).
func (g *RogueGame) leavePack(obj *Object, newobj, all bool) *Object {
	p := &g.Player
	p.Inpack--
	nobj := obj
	if obj.Count > 1 && !all {
		g.LastPick = obj
		obj.Count--
		if obj.Group != 0 {
			p.Inpack++
		}
		if newobj {
			copied := *obj
			nobj = &copied
			nobj.Count = 1
		}
	} else {
		g.LastPick = nil
		p.PackUsed[obj.PackCh-'a'] = false
		detachObj(&p.Pack, obj)
	}
	return nobj
}

// packChar returns the next unused pack character (pack.c pack_char).
func (g *RogueGame) packChar() byte {
	p := &g.Player
	for i := range p.PackUsed {
		if !p.PackUsed[i] {
			p.PackUsed[i] = true
			return byte(i) + 'a'
		}
	}
	return byte(len(p.PackUsed)) + 'a' // C would walk off the array here
}

// inventory lists what is in the pack; returns true if there is something
// of the given type (pack.c inventory).
func (g *RogueGame) inventory(list []*Object, kind ObjectKind) bool {
	g.NObjs = 0
	for _, item := range list {
		if kind != KindNone && kind != item.Kind &&
			!(kind == KindCallable && item.Kind != KindFood &&
				item.Kind != KindAmulet) &&
			!(kind == KindRingOrStick &&
				(item.Kind == KindRing || item.Kind == KindWand)) {
			continue
		}
		g.NObjs++
		g.Msgs.MsgEsc = true
		line := string(item.PackCh) + ") " + g.invName(item, false)
		if g.addLine("%s", line) == Escape {
			g.Msgs.MsgEsc = false
			g.msg("")
			return true
		}
		g.Msgs.MsgEsc = false
	}
	if g.NObjs == 0 {
		if g.Options.Terse {
			if kind == KindNone {
				g.msg("empty handed")
			} else {
				g.msg("nothing appropriate")
			}
		} else {
			if kind == KindNone {
				g.msg("you are empty handed")
			} else {
				g.msg("you don't have anything appropriate")
			}
		}
		return false
	}
	g.endLine()
	return true
}

// pickUp adds something to the character's pack (pack.c pick_up).
func (g *RogueGame) pickUp(ch byte) {
	p := &g.Player
	if p.On(Levitating) {
		return
	}

	obj := g.findObj(p.Pos.Y, p.Pos.X)
	if g.MoveOn {
		g.moveMsg(obj)
		return
	}
	switch ch {
	case Gold:
		if obj == nil {
			return
		}
		g.money(obj.GoldValue)
		detachObj(&g.Level.Objects, obj)
		p.Room.GoldVal = 0
	default:
		g.addPack(nil, false)
	}
}

// moveMsg prints the message if you are just moving onto an object
// (pack.c move_msg).
func (g *RogueGame) moveMsg(obj *Object) {
	if !g.Options.Terse {
		g.addmsg("you ")
	}
	g.msg("moved onto %s", g.invName(obj, true))
}

// pickyInven allows the player to inventory a single item (pack.c
// picky_inven).
func (g *RogueGame) pickyInven() {
	p := &g.Player
	if len(p.Pack) == 0 {
		g.msg("you aren't carrying anything")
		return
	}
	if len(p.Pack) == 1 {
		g.msg("a) %s", g.invName(p.Pack[0], false))
		return
	}
	g.msg("%s", g.chooseTerse("item: ", "which item do you wish to inventory: "))
	g.Msgs.Mpos = 0
	mch := g.readchar()
	if mch == Escape {
		g.msg("")
		return
	}
	for _, obj := range p.Pack {
		if mch == obj.PackCh {
			g.msg("%c) %s", mch, g.invName(obj, false))
			return
		}
	}
	g.msg("'%s' not in pack", unctrl(mch))
}

// getItem picks something out of a pack for a purpose (pack.c get_item).
func (g *RogueGame) getItem(purpose string, kind ObjectKind) *Object {
	p := &g.Player
	if len(p.Pack) == 0 {
		g.msg("you aren't carrying anything")
		return nil
	}
	if g.Again {
		if g.LastPick != nil {
			return g.LastPick
		}
		g.msg("you ran out")
		return nil
	}
	for {
		if !g.Options.Terse {
			g.addmsg("which object do you want to ")
		}
		g.addmsg("%s", purpose)
		if g.Options.Terse {
			g.addmsg(" what")
		}
		g.msg("? (* for list): ")
		ch := g.readchar()
		g.Msgs.Mpos = 0
		// Give the poor player a chance to abort the command
		if ch == Escape {
			g.resetLast()
			g.After = false
			g.msg("")
			return nil
		}
		g.NObjs = 1 // normal case: person types one char
		if ch == '*' {
			g.Msgs.Mpos = 0
			if !g.inventory(p.Pack, kind) {
				g.After = false
				return nil
			}
			continue
		}
		for _, obj := range p.Pack {
			if obj.PackCh == ch {
				return obj
			}
		}
		g.msg("'%s' is not a valid item", unctrl(ch))
	}
}

// money adds or subtracts gold from the pack (pack.c money).
func (g *RogueGame) money(value int) {
	p := &g.Player
	p.Purse += value
	g.mvaddch(p.Pos.Y, p.Pos.X, g.floorCh())
	if p.Room.Flags.Has(Gone) {
		g.Level.SetChar(p.Pos.Y, p.Pos.X, Passage)
	} else {
		g.Level.SetChar(p.Pos.Y, p.Pos.X, Floor)
	}
	if value > 0 {
		if !g.Options.Terse {
			g.addmsg("you found ")
		}
		g.msg("%d gold pieces", value)
	}
}

// floorCh returns the appropriate floor character for her room
// (pack.c floor_ch).
func (g *RogueGame) floorCh() byte {
	if g.Player.Room.Flags.Has(Gone) {
		return Passage
	}
	if g.showFloor() {
		return Floor
	}
	return ' '
}

// floorAt returns the character at the hero's position, taking see_floor
// into account (pack.c floor_at).
func (g *RogueGame) floorAt() byte {
	ch := g.Level.Char(g.Player.Pos.Y, g.Player.Pos.X)
	if ch == Floor {
		ch = g.floorCh()
	}
	return ch
}

// resetLast resets the last command when the current one is aborted
// (pack.c reset_last).
func (g *RogueGame) resetLast() {
	g.LastComm = g.LLastComm
	g.LastDir = g.LLastDir
	g.LastPick = g.LLastPick
}

// chooseTerse picks the terse or verbose variant of a message.
func (g *RogueGame) chooseTerse(terse, verbose string) string {
	if g.Options.Terse {
		return terse
	}
	return verbose
}