package game

import "strings"

// options.c — the option command and ROGUEOPTS parsing.

// optKind selects the get/put behavior of an option (the C function
// pointers o_putfunc/o_getfunc).
type optKind int

const (
	optBool optKind = iota
	optSeeFloor
	optInvT
	optStr
)

// optDesc describes an option (options.c OPTION).
type optDesc struct {
	name   string
	prompt string
	kind   optKind
	boolP  *bool
	intP   *int
	strP   *string
}

// optList builds the options.c optlist for this game.
func (g *RogueGame) optList() []optDesc {
	o := &g.Options
	return []optDesc{
		{"terse", "Terse output", optBool, &o.Terse, nil, nil},
		{"flush", "Flush typeahead during battle", optBool, &o.FightFlush, nil, nil},
		{"jump", "Show position only at end of run", optBool, &o.Jump, nil, nil},
		{"seefloor", "Show the lamp-illuminated floor", optSeeFloor, &o.SeeFloor, nil, nil},
		{"passgo", "Follow turnings in passageways", optBool, &o.PassGo, nil, nil},
		{"tombstone", "Print out tombstone when killed", optBool, &o.Tombstone, nil, nil},
		{"inven", "Inventory style", optInvT, nil, &o.InvType, nil},
		{"name", "Name", optStr, nil, nil, &g.Whoami},
		{"fruit", "Fruit", optStr, nil, nil, &g.Fruit},
		{"file", "Save file", optStr, nil, nil, &g.FileName},
	}
}

// option prints and then sets options from the terminal (options.c option).
func (g *RogueGame) option() {
	hw := g.scr.Hw
	optlist := g.optList()
	hw.Clear()
	// Display current values of options
	for i := range optlist {
		op := &optlist[i]
		g.prOptname(op)
		g.putOpt(op)
		hw.AddCh('\n')
	}
	// Set values
	hw.Move(0, 0)
	for i := 0; i < len(optlist); i++ {
		op := &optlist[i]
		g.prOptname(op)
		retval := g.getOpt(op)
		if retval != Norm {
			if retval == Quit {
				break
			}
			// MINUS: back up one option
			if i > 0 {
				hw.Move(i-1, 0)
				i -= 2
			} else { // trying to back up beyond the top
				hw.Move(0, 0)
				i--
			}
		}
	}
	// Switch back to original screen
	hw.MvAddStr(NumLines-1, 0, "--Press space to continue--")
	g.scr.RefreshWin(hw)
	g.waitFor(' ')
	g.refresh()
	g.After = false
}

// prOptname prints out the option name prompt (options.c pr_optname).
func (g *RogueGame) prOptname(op *optDesc) {
	g.scr.Hw.Printw("%s (\"%s\"): ", op.prompt, op.name)
}

// putOpt prints an option's current value (options.c put_bool/put_str/
// put_inv_t).
func (g *RogueGame) putOpt(op *optDesc) {
	hw := g.scr.Hw
	switch op.kind {
	case optBool, optSeeFloor:
		hw.AddStr(boolStr(*op.boolP))
	case optInvT:
		hw.AddStr(invTName[*op.intP])
	case optStr:
		hw.AddStr(*op.strP)
	}
}

func boolStr(b bool) string {
	if b {
		return "True"
	}
	return "False"
}

// getOpt reads a new value for an option (options.c get_bool/get_sf/
// get_inv_t/get_str dispatch).
func (g *RogueGame) getOpt(op *optDesc) int {
	switch op.kind {
	case optBool:
		return g.getBool(op.boolP)
	case optSeeFloor:
		return g.getSf(op.boolP)
	case optInvT:
		return g.getInvT(op.intP)
	default:
		return g.getStr(op.strP, g.scr.Hw)
	}
}

// getBool allows changing a boolean option and prints it out (options.c
// get_bool).
func (g *RogueGame) getBool(bp *bool) int {
	win := g.scr.Hw
	oy, ox := win.GetYX()
	win.AddStr(boolStr(*bp))
	for {
		win.Move(oy, ox)
		g.scr.RefreshWin(win)
		switch g.readchar() {
		case 't', 'T':
			*bp = true
		case 'f', 'F':
			*bp = false
		case '\n', '\r':
		case Escape:
			return Quit
		case '-':
			return Minus
		default:
			win.Move(oy, ox+10)
			win.AddStr("(T or F)")
			continue
		}
		break
	}
	win.Move(oy, ox)
	win.AddStr(boolStr(*bp))
	win.AddCh('\n')
	return Norm
}

// getSf changes see_floor and handles the display transition (options.c
// get_sf).
func (g *RogueGame) getSf(bp *bool) int {
	wasSf := g.Options.SeeFloor
	retval := g.getBool(bp)
	if retval == Quit {
		return Quit
	}
	if wasSf != g.Options.SeeFloor {
		if !g.Options.SeeFloor {
			g.Options.SeeFloor = true
			g.eraseLamp(g.Player.Pos, g.Player.Room)
			g.Options.SeeFloor = false
		} else {
			g.look(false)
		}
	}
	return Norm
}

// getStr sets a string option (options.c get_str). win selects between the
// options window and the message line (C's stdscr), which changes the '-'
// and mpos behavior.
func (g *RogueGame) getStr(opt *string, win *Window) int {
	onStd := win == g.scr.Std
	oy, ox := win.GetYX()
	g.scr.RefreshWin(win)
	// loop reading in the string, and put it in a temporary buffer
	var buf []byte
	var c byte
	for {
		c = g.readchar()
		if c == '\n' || c == '\r' || c == Escape {
			break
		}
		if c == 8 || c == 0x7f { // erase character
			if len(buf) > 0 {
				buf = buf[:len(buf)-1]
				win.Move(oy, ox+len(displayStr(buf)))
			}
			win.Clrtoeol()
			g.scr.RefreshWin(win)
			continue
		}
		if c == CTRL('U') { // kill character
			buf = buf[:0]
			win.Move(oy, ox)
			win.Clrtoeol()
			g.scr.RefreshWin(win)
			continue
		}
		if len(buf) == 0 {
			if c == '-' && !onStd {
				break
			}
			if c == '~' {
				buf = append(buf, g.Home...)
				win.AddStr(g.Home)
				win.Clrtoeol()
				g.scr.RefreshWin(win)
				continue
			}
		}
		if len(buf) >= MaxInp || !(isPrint(c) || c == ' ') {
			continue // C beeps here
		}
		buf = append(buf, c)
		win.AddStr(unctrl(c))
		win.Clrtoeol()
		g.scr.RefreshWin(win)
	}
	if len(buf) > 0 { // only change option if something has been typed
		*opt = strucpy(string(buf))
	}
	win.MvPrintw(oy, ox, "%s\n", *opt)
	g.scr.RefreshWin(win)
	if onStd {
		g.Msgs.Mpos += len(buf)
	}
	switch c {
	case '-':
		return Minus
	case Escape:
		return Quit
	default:
		return Norm
	}
}

// displayStr renders a buffer the way the input echo did.
func displayStr(buf []byte) string {
	var sb strings.Builder
	for _, c := range buf {
		sb.WriteString(unctrl(c))
	}
	return sb.String()
}

// getInvT gets an inventory type name (options.c get_inv_t).
func (g *RogueGame) getInvT(ip *int) int {
	win := g.scr.Hw
	oy, ox := win.GetYX()
	win.AddStr(invTName[*ip])
	for {
		win.Move(oy, ox)
		g.scr.RefreshWin(win)
		switch g.readchar() {
		case 'o', 'O':
			*ip = InvOver
		case 's', 'S':
			*ip = InvSlow
		case 'c', 'C':
			*ip = InvClear
		case '\n', '\r':
		case Escape:
			return Quit
		case '-':
			return Minus
		default:
			win.Move(oy, ox+15)
			win.AddStr("(O, S, or C)")
			continue
		}
		break
	}
	win.MvPrintw(oy, ox, "%s\n", invTName[*ip])
	return Norm
}

// ParseOpts parses options from a string, usually taken from the
// environment: comma separated values, booleans stated as "name" (true) or
// "noname" (false), strings as "name=..." (options.c parse_opts).
func (g *RogueGame) ParseOpts(str string) {
	optlist := g.optList()
	for str != "" {
		// Get option name
		i := 0
		for i < len(str) && isAlpha(str[i]) {
			i++
		}
		name := str[:i]
		rest := str[i:]
		matched := false
		for oi := range optlist {
			op := &optlist[oi]
			isBoolOpt := op.kind == optBool || op.kind == optSeeFloor
			if strings.HasPrefix(op.name, name) && name != "" {
				matched = true
				if isBoolOpt {
					*op.boolP = true
				} else {
					// Skip to start of string value
					for rest != "" && rest[0] == '=' {
						rest = rest[1:]
					}
					val := rest
					var prefix string
					if val != "" && val[0] == '~' {
						prefix = g.Home
						val = val[1:]
						for val != "" && val[0] == '/' {
							val = val[1:]
						}
					}
					// Skip to end of string value
					end := strings.IndexByte(val, ',')
					if end < 0 {
						end = len(val)
					}
					word := val[:end]
					rest = val[end:]
					if op.kind == optInvT {
						// check for type of inventory
						w := word
						if w != "" {
							w = string(toUpper(w[0])) + w[1:]
						}
						for ti, tn := range invTName {
							if strings.HasPrefix(tn, w) {
								*op.intP = ti
								break
							}
						}
					} else {
						*op.strP = prefix + strucpy(word)
					}
				}
				break
			} else if isBoolOpt && strings.HasPrefix(name, "no") &&
				strings.HasPrefix(op.name, name[2:]) {
				matched = true
				*op.boolP = false
				break
			}
		}
		_ = matched
		// skip to start of next option name
		for rest != "" && !isAlpha(rest[0]) {
			rest = rest[1:]
		}
		str = rest
	}
}

// strucpy copies a string keeping only printable characters, capped at
// MAXINP (options.c strucpy).
func strucpy(s string) string {
	if len(s) > MaxInp {
		s = s[:MaxInp]
	}
	var sb strings.Builder
	for i := 0; i < len(s); i++ {
		if isPrint(s[i]) || s[i] == ' ' {
			sb.WriteByte(s[i])
		}
	}
	return sb.String()
}