package game

import (
	"fmt"
	"strings"
)

// things.c — item naming, random item creation, and the discovery list.

// invName returns the name of something as it would appear in an inventory
// (things.c inv_name).
func (g *RogueGame) inventoryName(obj *Object, drop bool) string {
	var pb strings.Builder

	which := obj.Which
	it := &g.Items

	switch obj.Kind {
	case KindPotion:
		g.nameit(&pb, obj, potionName, it.PotColors[which], &it.Potions[which], nullstr)
	case KindRing:
		g.nameit(&pb, obj, ringName, it.RingStones[which], &it.Rings[which], ringNum)
	case KindWand:
		g.nameit(&pb, obj, it.WandType[which], it.WandMade[which], &it.Sticks[which], chargeStr)
	case KindScroll:
		g.nameScroll(&pb, obj)
	case KindFood:
		g.nameFood(&pb, obj)
	case KindWeapon:
		g.nameWeapon(&pb, obj)
	case KindArmor:
		g.nameArmor(&pb, obj)
	case KindAmulet:
		pb.WriteString("The Amulet of Yendor")
	case KindGold:
		fmt.Fprintf(&pb, "%d Gold pieces", obj.GoldValue)
	}

	return fixNameCase(g.describeWorn(obj, pb.String()), drop)
}

// nameScroll writes a scroll's inventory name (things.c inv_name).
func (g *RogueGame) nameScroll(pb *strings.Builder, obj *Object) {
	if obj.Count == 1 {
		pb.WriteString("A scroll ")
	} else {
		fmt.Fprintf(pb, "%d scrolls ", obj.Count)
	}

	op := &g.Items.Scrolls[obj.Which]

	switch {
	case op.Know:
		fmt.Fprintf(pb, "of %s", op.Name)
	case op.Guess != "":
		fmt.Fprintf(pb, "called %s", op.Guess)
	default:
		fmt.Fprintf(pb, "titled '%s'", g.Items.ScrNames[obj.Which])
	}
}

// nameFood writes a food item's inventory name; which 1 is the fruit
// (things.c inv_name).
func (g *RogueGame) nameFood(pb *strings.Builder, obj *Object) {
	if obj.Which == 1 {
		if obj.Count == 1 {
			fmt.Fprintf(pb, "A%s %s", vowelstr(g.Fruit), g.Fruit)
		} else {
			fmt.Fprintf(pb, "%d %ss", obj.Count, g.Fruit)
		}

		return
	}

	if obj.Count == 1 {
		pb.WriteString("Some food")
	} else {
		fmt.Fprintf(pb, "%d rations of food", obj.Count)
	}
}

// nameWeapon writes a weapon's inventory name (things.c inv_name).
func (g *RogueGame) nameWeapon(pb *strings.Builder, obj *Object) {
	sp := g.Items.Weapons[obj.Which].Name

	if obj.Count > 1 {
		fmt.Fprintf(pb, "%d ", obj.Count)
	} else {
		fmt.Fprintf(pb, "A%s ", vowelstr(sp))
	}

	if obj.Flags.Has(Known) {
		fmt.Fprintf(pb, "%s %s", num(obj.HPlus, obj.DPlus, Weapon), sp)
	} else {
		pb.WriteString(sp)
	}

	if obj.Count > 1 {
		pb.WriteString("s")
	}

	if obj.Label != "" {
		fmt.Fprintf(pb, " called %s", obj.Label)
	}
}

// nameArmor writes an armor's inventory name (things.c inv_name).
func (g *RogueGame) nameArmor(pb *strings.Builder, obj *Object) {
	sp := g.Items.Armors[obj.Which].Name
	if obj.Flags.Has(Known) {
		fmt.Fprintf(pb, "%s %s [",
			num(g.data.aClass[obj.Which]-obj.ArmorClass, 0, Armor), sp)

		if !g.Options.Terse {
			pb.WriteString("protection ")
		}

		fmt.Fprintf(pb, "%d]", 10-obj.ArmorClass)
	} else {
		pb.WriteString(sp)
	}

	if obj.Label != "" {
		fmt.Fprintf(pb, " called %s", obj.Label)
	}
}

// describeWorn appends the equipped-status notes to an inventory name
// (things.c inv_name).
func (g *RogueGame) describeWorn(obj *Object, out string) string {
	if !g.InvDescribe {
		return out
	}

	p := &g.Player
	if obj == p.CurArmor {
		out += " (being worn)"
	}

	if obj == p.CurWeapon {
		out += " (weapon in hand)"
	}

	switch obj {
	case p.CurRing[Left]:
		out += " (on left hand)"
	case p.CurRing[Right]:
		out += " (on right hand)"
	}

	return out
}

// fixNameCase upper- or lowercases the leading letter to suit the
// sentence it will land in (things.c inv_name).
func fixNameCase(out string, drop bool) string {
	if out == "" {
		return out
	}

	if drop && isUpper(out[0]) {
		return string(toLower(out[0])) + out[1:]
	}

	if !drop && isLower(out[0]) {
		return string(toUpper(out[0])) + out[1:]
	}

	return out
}

// dropIt puts something down (things.c drop; renamed to avoid the
// leavePack/detach vocabulary collision).
func (g *RogueGame) dropIt() {
	p := &g.Player

	ch := g.Level.Char(p.Pos.Y, p.Pos.X)
	if ch != Floor && ch != Passage {
		g.After = false
		g.msg("there is something there already")

		return
	}

	obj, ok := g.promptPackItem("drop", KindNone)
	if !ok {
		return
	}

	if !g.dropCheck(obj) {
		return
	}

	obj = g.leavePack(obj, true, !obj.Kind.MergesInPack())
	// Link it into the level object list
	g.Level.AddObject(obj)
	g.Level.SetChar(p.Pos.Y, p.Pos.X, obj.Kind.Glyph())
	g.Level.FlagsAt(p.Pos.Y, p.Pos.X).Set(FDropped)

	obj.Pos = p.Pos
	if obj.Kind == KindAmulet {
		g.HasAmulet = false
	}

	g.msg("dropped %s", g.inventoryName(obj, true))
}

// dropCheck does special checks for dropping or unwielding|unwearing|
// unringing (things.c dropcheck).
func (g *RogueGame) dropCheck(obj *Object) bool {
	if obj == nil {
		return true
	}

	p := &g.Player
	if obj != p.CurArmor && obj != p.CurWeapon &&
		obj != p.CurRing[Left] && obj != p.CurRing[Right] {
		return true
	}

	if obj.Flags.Has(Cursed) {
		g.msg("you can't.  It appears to be cursed")

		return false
	}

	switch obj {
	case p.CurWeapon:
		p.CurWeapon = nil
	case p.CurArmor:
		g.wasteTime()

		p.CurArmor = nil
	default:
		g.dropRing(obj)
	}

	return true
}

// dropRing takes a worn ring off with its side effects (things.c
// dropcheck).
func (g *RogueGame) dropRing(obj *Object) {
	p := &g.Player

	hand := Right
	if obj == p.CurRing[Left] {
		hand = Left
	}

	p.CurRing[hand] = nil

	switch obj.RingKind() {
	case RingAddStrength:
		g.changeStrength(-obj.Bonus)
	case RingSeeInvisible:
		g.unsee(0)
		g.Extinguish(DUnsee)
	}
}

// newThing returns a new random thing for the dungeon (things.c new_thing).
func (g *RogueGame) newThing() *Object {
	cur := newObject()
	cur.Damage = dice("0x0")
	cur.HurlDmg = dice("0x0")
	cur.ArmorClass = 11
	cur.Count = 1

	// Decide what kind of object it will be; if we haven't had food for a
	// while, let it be food.
	var kind int
	if g.Player.NoFood > 3 {
		kind = 2
	} else {
		kind = pickOne(g, g.Items.Things[:])
	}

	switch kind {
	case 0:
		cur.Kind = KindPotion
		cur.Which = pickOne(g, g.Items.Potions[:])
	case 1:
		cur.Kind = KindScroll
		cur.Which = pickOne(g, g.Items.Scrolls[:])
	case 2:
		g.newFoodThing(cur)
	case 3:
		g.newWeaponThing(cur)
	case 4:
		g.newArmorThing(cur)
	case 5:
		g.newRingThing(cur)
	case 6:
		cur.Kind = KindWand
		cur.Which = pickOne(g, g.Items.Sticks[:])
		g.fixStick(cur)
	}

	return cur
}

// newFoodThing rolls food, one time in ten the fruit (things.c
// new_thing).
func (g *RogueGame) newFoodThing(cur *Object) {
	cur.Kind = KindFood

	g.Player.NoFood = 0
	if g.rnd(10) != 0 {
		cur.Which = 0
	} else {
		cur.Which = 1
	}
}

// newWeaponThing rolls a weapon, sometimes cursed or blessed (things.c
// new_thing).
func (g *RogueGame) newWeaponThing(cur *Object) {
	g.initWeapon(cur, WeaponKind(pickOne(g, g.Items.Weapons[:NumWeaponTypes])))

	if r := g.rnd(100); r < 10 {
		cur.Flags.Set(Cursed)
		cur.HPlus -= g.rnd(3) + 1
	} else if r < 15 {
		cur.HPlus += g.rnd(3) + 1
	}
}

// newArmorThing rolls armor, sometimes cursed or blessed (things.c
// new_thing).
func (g *RogueGame) newArmorThing(cur *Object) {
	cur.Kind = KindArmor
	cur.Which = pickOne(g, g.Items.Armors[:])

	cur.ArmorClass = g.data.aClass[cur.Which]
	if r := g.rnd(100); r < 20 {
		cur.Flags.Set(Cursed)
		cur.ArmorClass += g.rnd(3) + 1
	} else if r < 28 {
		cur.ArmorClass -= g.rnd(3) + 1
	}
}

// newRingThing rolls a ring, cursing the bad ones (things.c new_thing).
func (g *RogueGame) newRingThing(cur *Object) {
	cur.Kind = KindRing

	cur.Which = pickOne(g, g.Items.Rings[:])
	switch cur.RingKind() {
	case RingAddStrength, RingProtection, RingDexterity, RingIncreaseDamage:
		if cur.Bonus = g.rnd(3); cur.Bonus == 0 {
			cur.Bonus = -1
			cur.Flags.Set(Cursed)
		}
	case RingAggravateMonsters, RingTeleportation:
		cur.Flags.Set(Cursed)
	}
}

// pickOne picks an item out of a list of possible objects using their
// cumulative probabilities (things.c pick_one).
func pickOne(g *RogueGame, info []ObjInfo) int {
	i := g.rnd(100)
	for idx := range info {
		if i < info[idx].Prob {
			return idx
		}
	}

	return 0 // bad pick_one: C resets to the start of the table
}

// invPage is the things.c static pagination state for the discovery/
// inventory list windows (line_cnt, newpage, lastfmt/lastarg, maxlen).
type invPage struct {
	lineCnt  int
	newpage  bool
	lastLine string
	maxlen   int
	init     bool
}

// discovered lists what the player has found of a certain type
// (things.c discovered).
func (g *RogueGame) discovered() {
	var ch byte

	for {
		discList := false

		if !g.Options.Terse {
			g.addmsgf("for ")
		}

		g.addmsgf("what type")

		if !g.Options.Terse {
			g.addmsgf(" of object do you want a list")
		}

		g.msg("? (* for all)")

		ch = g.readchar()
		switch ch {
		case Escape:
			g.msg("")

			return
		case Potion, Scroll, Ring, Stick, '*':
			discList = true
		default:
			if g.Options.Terse {
				g.msg("Not a type")
			} else {
				g.msg("Please type one of %c%c%c%c (ESCAPE to quit)",
					Potion, Scroll, Ring, Stick)
			}
		}

		if discList {
			break
		}
	}

	if ch == '*' {
		g.printDisc(Potion)
		g.addLine("")
		g.printDisc(Scroll)
		g.addLine("")
		g.printDisc(Ring)
		g.addLine("")
		g.printDisc(Stick)
		g.endLine()
	} else {
		g.printDisc(ch)
		g.endLine()
	}
}

// printDisc prints what we've discovered of the given type
// (things.c print_disc).
func (g *RogueGame) printDisc(typ byte) {
	var info []ObjInfo

	switch typ {
	case Scroll:
		info = g.Items.Scrolls[:]
	case Potion:
		info = g.Items.Potions[:]
	case Ring:
		info = g.Items.Rings[:]
	case Stick:
		info = g.Items.Sticks[:]
	}

	order := make([]int, len(info))
	g.setOrder(order)

	obj := Object{Count: 1}
	numFound := 0

	for i := range info {
		if info[order[i]].Know || info[order[i]].Guess != "" {
			obj.Kind = objectKindForGlyph(typ)
			obj.Which = order[i]
			g.addLine("%s", g.inventoryName(&obj, false))

			numFound++
		}
	}

	if numFound == 0 {
		g.addLine("%s", g.nothing(typ))
	}
}

// setOrder shuffles the display order for the discovery list
// (things.c set_order).
func (g *RogueGame) setOrder(order []int) {
	for i := range order {
		order[i] = i
	}

	for i := len(order); i > 0; i-- {
		r := g.rnd(i)
		order[i-1], order[r] = order[r], order[i-1]
	}
}

// addLine adds a line to the list of discoveries (things.c add_line). A
// format of exactly "\x00" is the C fmt==NULL page-flush sentinel — use
// flushLine() for that.
const flushSentinel = "\x00"

func (g *RogueGame) addLine(format string, a ...any) int {
	pg := &g.invPage
	isFlush := format == flushSentinel

	var line string
	if !isFlush {
		line = fmt.Sprintf(format, a...)
	}

	if pg.lineCnt == 0 {
		g.scr.Hw.Clear()

		if g.Options.InvType == InvSlow {
			g.Msgs.Mpos = 0
		}
	}

	if g.Options.InvType == InvSlow {
		return g.addLineSlow(line, isFlush)
	}

	g.addLinePaged(line, isFlush)

	return ^Escape
}

// addLineSlow shows one discovery line as a message (the slow-inventory
// arm of things.c add_line).
func (g *RogueGame) addLineSlow(line string, isFlush bool) int {
	if !isFlush && line != "" {
		if g.msg("%s", line) == Escape {
			return Escape
		}
	}

	g.invPage.lineCnt++

	return ^Escape
}

// addLinePaged accumulates discovery lines into the paged window,
// prompting between full pages (the windowed arm of things.c add_line).
func (g *RogueGame) addLinePaged(line string, isFlush bool) {
	pg := &g.invPage
	prompt := "--Press space to continue--"

	if !pg.init {
		pg.maxlen = len(prompt)
		pg.init = true
	}

	if pg.lineCnt >= NumLines-1 || isFlush {
		g.addLinePageBreak(prompt, isFlush)
	}

	if !isFlush && (pg.lineCnt != 0 || line != "") {
		g.scr.Hw.MvAddStr(pg.lineCnt, 0, line)

		pg.lineCnt++
		if pg.maxlen < len(line) {
			pg.maxlen = len(line)
		}

		pg.lastLine = line
	}
}

// addLinePageBreak prompts at a full page and starts a fresh one
// (things.c add_line).
func (g *RogueGame) addLinePageBreak(prompt string, isFlush bool) {
	pg := &g.invPage
	if g.Options.InvType == InvOver && isFlush && !pg.newpage {
		g.addLineOverlay(prompt)
	} else {
		g.scr.Hw.MvAddStr(NumLines-1, 0, prompt)
		g.scr.RefreshWin(g.scr.Hw)
		g.waitFor(' ')
		g.scr.Hw.Clear()
		g.refresh()
	}

	pg.newpage = true
	pg.lineCnt = 0
	pg.maxlen = len(prompt)
}

// addLineOverlay draws the accumulated list in a box at the top right
// of the screen, prompts, and restores what was beneath (things.c
// add_line).
func (g *RogueGame) addLineOverlay(prompt string) {
	pg := &g.invPage

	g.msg("")
	g.refresh()

	saved := NewWindow(NumLines, NumCols)
	saved.CopyFrom(g.scr.Std)

	lx := NumCols - pg.maxlen - 2
	for y := 0; y <= pg.lineCnt; y++ {
		for x := 0; x <= pg.maxlen; x++ {
			g.scr.Std.MvAddCh(y, lx+x, g.scr.Hw.MvInch(y, x))
		}
	}

	g.scr.Std.MvAddStr(pg.lineCnt, lx, prompt)
	g.refresh()
	g.waitFor(' ')
	g.scr.Std.CopyFrom(saved)
	g.refresh()
}

// flushLine is add_line(NULL): force out the accumulated page.
func (g *RogueGame) flushLine() int { return g.addLine(flushSentinel) }

// endLine ends the list of lines (things.c end_line).
func (g *RogueGame) endLine() {
	pg := &g.invPage
	if g.Options.InvType != InvSlow {
		if pg.lineCnt == 1 && !pg.newpage {
			g.Msgs.Mpos = 0
			g.msg("%s", pg.lastLine)
		} else {
			g.flushLine()
		}
	}

	pg.lineCnt = 0
	pg.newpage = false
}

// nothing builds the "nothing found" message for a type (things.c nothing).
func (g *RogueGame) nothing(typ byte) string {
	var out string
	if g.Options.Terse {
		out = "Nothing"
	} else {
		out = "Haven't discovered anything"
	}

	if typ != '*' {
		var tystr string

		switch typ {
		case Potion:
			tystr = potionName
		case Scroll:
			tystr = scrollName
		case Ring:
			tystr = ringName
		case Stick:
			tystr = "stick"
		}

		out += fmt.Sprintf(" about any %ss", tystr)
	}

	return out
}

// nameit gives the proper name to a potion, stick, or ring
// (things.c nameit).
func (g *RogueGame) nameit(pb *strings.Builder, obj *Object, typ, which string,
	op *ObjInfo, prfunc func(*RogueGame, *Object) string) {
	switch {
	case op.Know || op.Guess != "":
		if obj.Count == 1 {
			fmt.Fprintf(pb, "A %s ", typ)
		} else {
			fmt.Fprintf(pb, "%d %ss ", obj.Count, typ)
		}

		if op.Know {
			fmt.Fprintf(pb, "of %s%s(%s)", op.Name, prfunc(g, obj), which)
		} else {
			fmt.Fprintf(pb, "called %s%s(%s)", op.Guess, prfunc(g, obj), which)
		}
	case obj.Count == 1:
		fmt.Fprintf(pb, "A%s %s %s", vowelstr(which), which, typ)
	default:
		fmt.Fprintf(pb, "%d %s %ss", obj.Count, which, typ)
	}
}

// nullstr returns an empty string (things.c nullstr).
func nullstr(*RogueGame, *Object) string { return "" }

// prList lists possible potions, scrolls, etc. for the wizard (things.c
// pr_list).
func (g *RogueGame) prList() {
	if !g.Options.Terse {
		g.addmsgf("for ")
	}

	g.addmsgf("what type")

	if !g.Options.Terse {
		g.addmsgf(" of object do you want a list")
	}

	g.msg("? ")

	ch := g.readchar()
	switch ch {
	case Potion:
		g.prSpec(g.Items.Potions[:])
	case Scroll:
		g.prSpec(g.Items.Scrolls[:])
	case Ring:
		g.prSpec(g.Items.Rings[:])
	case Stick:
		g.prSpec(g.Items.Sticks[:])
	case Armor:
		g.prSpec(g.Items.Armors[:])
	case Weapon:
		g.prSpec(g.Items.Weapons[:NumWeaponTypes])
	}
}

// prSpec prints a specific list of possible items to choose from
// (things.c pr_spec).
func (g *RogueGame) prSpec(info []ObjInfo) {
	lastprob := 0

	i := byte('0')
	for idx := range info {
		if i == '9'+1 {
			i = 'a'
		}

		g.addLine("%c: %s (%d%%)", i, info[idx].Name, info[idx].Prob-lastprob)
		lastprob = info[idx].Prob
		i++
	}

	g.endLine()
}