package door

import (
	"fmt"
	"log"
	"strconv"
	"strings"
	"time"
	"unicode"
)

type Extended int8

const (
	NOP Extended = iota
	UP_ARROW
	DOWN_ARROW
	RIGHT_ARROW
	LEFT_ARROW
	HOME
	END
	PAGE_UP
	PAGE_DOWN
	INSERT
	DELETE
	F1
	F2
	F3
	F4
	F5
	F6
	F7
	F8
	F9
	F10
	F11
	F12
	MOUSE
	CURSOR
	UNKNOWN
)

//go:generate stringer -type=Extended

const DEBUG_INPUT = true

var ErrInactivity error = fmt.Errorf("Inactivity")
var ErrTimeout error = fmt.Errorf("Timeout")
var ErrDisconnected error = fmt.Errorf("Disconnected")

var DefaultTimeout time.Duration = time.Duration(60) * time.Second

var extendedKeys map[string]Extended = map[string]Extended{
	"[A":   UP_ARROW,
	"[B":   DOWN_ARROW,
	"[C":   RIGHT_ARROW,
	"[D":   LEFT_ARROW,
	"[H":   HOME,
	"[F":   END, // terminal
	"[K":   END,
	"[V":   PAGE_UP,
	"[U":   PAGE_DOWN,
	"[@":   INSERT,
	"[2~":  INSERT,    // terminal
	"[3~":  DELETE,    // terminal
	"[5~":  PAGE_UP,   // terminal
	"[6~":  PAGE_DOWN, // terminal
	"[15~": F5,        // terminal
	"[17~": F6,        // terminal
	"[18~": F7,        // terminal
	"[19~": F8,        // terminal
	"[20~": F9,        // terminal
	"[21~": F10,       // terminal
	"[23~": F11,
	"[24~": F12, // terminal
	"OP":   F1,
	"OQ":   F2,
	"OR":   F3,
	"OS":   F4, // syncterm "[1" = F1,F2,F3, and F4)
	"Ot":   F5, // syncterm
}

// ReadRune fails on IAC AYT => unicode.ReplacementChar X 2

// getch -> ReadRune  Low Level
func (d *Door) ReadRune() (rune, error) {
	var r rune

	if d.ReaderClosed {
		return r, ErrDisconnected
	}

	for {
		select {
		case r = <-d.readerChannel:
			return r, nil
		case <-time.After(ReaderInterval):
			return r, ErrTimeout
		}
	}
}

func (d *Door) RunePushback(r rune) {
	d.Pushback.Push(r)
}

// getkey_or_pushback -> ReadRunePushback()
func (d *Door) ReadRunePushback() (rune, error) {
	if !d.Pushback.Empty() {
		if DEBUG_INPUT {
			log.Println("Read From PushBack")
		}
		return d.Pushback.Pop(), nil
	}
	return d.ReadRune()
}

func RuneToInt8(r rune) int8 {
	return int8(r)
}

// Confusion - It's possible to return a null rune
// that we received.  So it's a little sloppy having
// to check Extended == NOP.  :(

// High Level function - returns rune or extended

func (d *Door) GetKey() (rune, Extended, error) {
	var r, r2 rune
	var err, err2 error
	var ex Extended

	if d.ReaderClosed {
		return r, ex, ErrDisconnected
	}

	// if bio.Disconnected() {
	//	return r, ex, DisconnectedError
	// }

	r, err = d.ReadRunePushback()

	if err != nil {
		return r, ex, err
	}

	// fyneterm CR
	if r == '\x0a' {
		r2, err2 = d.ReadRunePushback()
		if err2 == nil {
			// Not an error
			if r2 != '\x00' && r2 != '\x0a' {
				// Wasn't 0x00 or 0x0a
				d.RunePushback(r2)
			}
		}
		return '\x0d', ex, nil
	}

	// We get 0x0d, 0x00, or 0x0d 0x0a from syncterm
	if r == '\x0d' {
		r2, err2 = d.ReadRunePushback()
		if err2 == nil {
			// Not an error
			if r2 != '\x00' && r2 != '\x0a' {
				// Wasn't 0x00 or 0x0a
				d.RunePushback(r2)
			}
		}
		return r, ex, nil
	}

	if r == '\x00' {
		// Possibly doorway mode - deprecated?
		// syncterm does support this, so it isn't entirely dead (NNY!)
		r2, _ = d.ReadRunePushback()

		r = rune(0)

		switch r2 {
		case '\x50':
			return r, DOWN_ARROW, nil
		case '\x48':
			return r, UP_ARROW, nil
		case '\x4b':
			return r, LEFT_ARROW, nil
		case 0x4d:
			return r, RIGHT_ARROW, nil
		case 0x47:
			return r, HOME, nil
		case 0x4f:
			return r, END, nil
		case 0x49:
			return r, PAGE_UP, nil
		case 0x51:
			return r, PAGE_DOWN, nil
		case 0x3b:
			return r, F1, nil
		case 0x3c:
			return r, F2, nil
		case 0x3d:
			return r, F3, nil
		case 0x3e:
			return r, F4, nil
		case 0x3f:
			return r, F5, nil
		case 0x40:
			return r, F6, nil
		case 0x41:
			return r, F7, nil
		case 0x42:
			return r, F8, nil
		case 0x43:
			return r, F9, nil
		case 0x44:
			return r, F10, nil
		/*
			case 0x45:
				return F11
			case 0x46:
				return F12
		*/
		case 0x52:
			return r, INSERT, nil
		case 0x53:
			return r, DELETE, nil
		default:
			log.Printf("ERROR Doorway mode: 0x00 %x\n", r2)
			return r, UNKNOWN, nil
		}
	} // End doorway

	if r == '\x1b' {
		// Escape key?
		r2, err2 = d.ReadRunePushback()
		if err2 != nil {
			// Just escape key
			return r, ex, nil
		}

		if r2 == '\x1b' {
			d.RunePushback(r2)
			return r, ex, nil
		}

		var extended []rune = make([]rune, 1)
		extended[0] = r2

		r2, err2 = d.ReadRunePushback()
		for err2 == nil {
			if r2 == '\x1b' {
				// This is the end of the extended code.
				d.RunePushback(r2)
				break
			}
			extended = append(extended, r2)

			ext, has := extendedKeys[string(extended)]
			if has {
				return rune(0), ext, nil
			}

			if unicode.IsLetter(r2) {
				// The end of the extended code
				break
			}
			r2, err2 = d.ReadRunePushback()
		}

		var exString string = string(extended)
		if strings.HasPrefix(exString, "[M") && len(extended) == 5 {
			// Mouse Extended - input zero based (I add +1 to X, Y, and button)
			var mouse Mouse = Mouse{Button: RuneToInt8(extended[2]) - ' ' + 1,
				X: RuneToInt8(extended[3]) - '!' + 1,
				Y: RuneToInt8(extended[4]) - '!' + 1}

			d.mcMutex.Lock()
			defer d.mcMutex.Unlock()
			d.LastMouse = append(d.LastMouse, mouse)
			log.Println("Mouse:", mouse)
			return rune(0), MOUSE, nil
		}

		if strings.HasSuffix(exString, "R") {
			// Cursor Position information
			var cursor CursorPos
			// ^[[1;1R^[[2;3R^[[41;173R

			// Y;X
			exString = exString[1 : len(exString)-1] // Remove [ and R
			pos := SplitToInt(exString, ";")
			if len(pos) == 2 {
				cursor.X = pos[1]
				cursor.Y = pos[0]
				d.mcMutex.Lock()
				defer d.mcMutex.Unlock()
				d.LastCursor = append(d.LastCursor, cursor)
				log.Println("Cursor Pos:", cursor)
				return rune(0), CURSOR, nil
			} else {
				log.Println("ERROR Cursor:", extended)
				return rune(0), UNKNOWN, nil
			}

		}
		if exString == "\x1b" {
			return extended[0], Extended(0), nil
		}

		log.Println("ERROR Extended:", extended)
		return rune(0), UNKNOWN, nil
	}

	// AYT (Telnet Are You There?)
	/*
		if r == '\xff' {
			log.Printf("IAC")
			r2, err2 = bio.ReadRunePushback()
			if err2 != nil {
				// Return value
				return r, ex, nil
			}
			if r2 == '\xf6' {
				// Are You There?
				log.Println("AYT? - Yes")
				bio.Write("Yes?")
				// bio.Write(string([]byte{0x00})) // 0xff, 0xf2}))
				// Eat these keys, and re-call ourselves...
				// Or goto very top?

				return bio.GetKey()
			}
		}
	*/

	return r, ex, nil
}

// "[1":   XKEY_UNKNOWN, // Syncterm is lost, could be F1..F5?

// Low level read key function.
// This gets the raw keys from the client, it doesn't handle extended keys,
// functions, arrows.
// Return key, or -1 (Timeout/No key available), -2 hangup
/*
func (d *Door) getch() int {
	select {
	case res, ok := <-d.readerChannel:
		if ok {
			return int(res)
		} else {
			d.Disconnected = true
			// atomic.StoreInt32(&d.Disconnected, 1)
			return -2
		}
	case <-time.After(time.Duration(100) * time.Millisecond):
		return -1
	}
}

func (d *Door) getkey_or_pushback() int {
	if !d.Pushback.Empty() {
		return d.Pushback.Pop()
	}

	if false {
		var key int = d.getch()
		log.Printf("%d / %X\n", key, key)
		return key
	} else {
		return d.getch()
	}
}

// Return key received, or XKEY_* values.
// -1 timeout/no key
// -2 hangup
// -3 out of time
func (d *Door) GetKey() int {
	var c, c2 int

	if d.Disconnect() {
		return -2
	}

	if d.TimeLeft() < 0 {
		return -3
	}
	c = d.getkey_or_pushback()

	if c < 0 {
		return c
	}

	// We get 0x0d 0x00, or 0x0d 0x0a from syncterm.
	if c == 0x0d {
		c2 = d.getkey_or_pushback()
		if c2 > 0 {
			// wasn't an error
			if c2 != 0x00 && c2 != 0x0a {
				// wasn't 0x00 or 0x0a
				d.Pushback.Push(c2)
				// log.Printf("Push 0x0d trailer %d / %x\n", c2, c2)
			}
		}
		return c
	}

	if c == 0 {
		// possibly doorway mode
		var tries int = 0
		c2 = d.getkey_or_pushback()
		for c2 < 0 {
			if tries > 7 {
				return c
			}
			c2 = d.getkey_or_pushback()
			tries++
		}

		switch c2 {
		case 0x50:
			return DOWN_ARROW
		case 0x48:
			return UP_ARROW
		case 0x4b:
			return LEFT_ARROW
		case 0x4d:
			return RIGHT_ARROW
		case 0x47:
			return HOME
		case 0x4f:
			return END
		case 0x49:
			return PAGE_UP
		case 0x51:
			return PAGE_DOWN
		case 0x3b:
			return F1
		case 0x3c:
			return F2
		case 0x3d:
			return F3
		case 0x3e:
			return F4
		case 0x3f:
			return F5
		case 0x40:
			return F6
		case 0x41:
			return F7
		case 0x42:
			return F8
		case 0x43:
			return F9
		case 0x44:
			return F10
		case 0x52:
			return INSERT
		case 0x53:
			return DELETE
		default:
			log.Printf("ERROR Doorway mode: 0x00 %x\n", c2)
			return XKEY_UNKNOWN
		}
	}

	if c == 0x1b {
		// Escape key?
		c2 = d.getkey_or_pushback()
		if c2 < 0 {
			// Just escape key
			return c
		}
		var extended []byte = make([]byte, 1)
		extended[0] = byte(c2) // string = string(byte(c2))

		c2 = d.getkey_or_pushback()
		for c2 > 0 {
			if c2 == 0x1b {
				d.Pushback.Push(c2)
				break
			}
			extended = append(extended, byte(c2)) // += string(byte(c2))

			var has bool
			c2, has = extendedKeys[string(extended)]
			if has {
				// break out here if \x1b[ + letter or @
				// break out if \x1b[ + digits + ~
				// break out if \x1bO + letter
				return c2
			}
			c2 = d.getkey_or_pushback()
		}

		if strings.HasPrefix(string(extended), "[M") && len(extended) == 5 {
			// log.Printf("MOUSE Extended %#v\n", extended)
			var mouse Mouse = Mouse{Button: int8(extended[2]) - ' ' + 1,
				X: int8(extended[3]) - '!' + 1,
				Y: int8(extended[4]) - '!' + 1}
			d.AddMouse(mouse)
			log.Printf("MOUSE %d (%d,%d)\n", mouse.Button, mouse.X, mouse.Y)
			return XKEY_MOUSE
		}

		log.Printf("ERROR Extended %#v\n", extended)
		return XKEY_UNKNOWN
	}

	return c
}

func (d *Door) Key() int {
	return d.WaitKey(Inactivity, 0)
}

// usecs = Microseconds
func (d *Door) WaitKey(secs int64, usecs int64) int {
	if d.Disconnect() {
		return -2
	}

	if !d.Pushback.Empty() {
		return d.GetKey()
	}

	var timeout time.Duration = time.Duration(secs)*time.Second + time.Duration(usecs)*time.Microsecond

	select {
	case res, ok := <-d.readerChannel:
		if ok {
			d.Pushback.Push(int(res))
			return d.GetKey()
		} else {
			// Reader Closed

			d.Disconnected = true

			// If I wrap this with if !d.WriterClosed .. races ?

			// Why can't I do this?  This isn't a go routine...
			if !d.WriterClosed {
				d.writerChannel <- ""
			}

			// d.closeChannel <- struct{}{}

			// atomic.StoreInt32(&d.Disconnected, 1)
			return -2
		}
	case <-time.After(timeout):
		return -1
	}
}
*/

// port over WaitKey
func (d *Door) WaitKey(timeout time.Duration) (rune, Extended, error) {
	// disconnected test

	d.readerMutex.Lock()
	if d.ReaderClosed {
		d.readerMutex.Unlock()
		return rune(0), Extended(0), ErrDisconnected
	}
	d.readerMutex.Unlock()

	if !d.Pushback.Empty() {
		log.Println("WaitKey: Pushback ! empty.")
		r, ex, e := d.GetKey()
		if DEBUG_INPUT {
			log.Println("WaitKey:", r, ex, e)
		}
		// return bio.GetKey()
		return r, ex, e
	}

	// expiration := time.NewTicker(timeout)
	// defer expiration.Stop()

	select {
	case r, ok := <-d.readerChannel:
		if ok {
			// Is this blocking? Ignoring expiration?
			d.RunePushback(r)
			log.Printf("readerChannel %#v ...\n", r)
			r, ex, e := d.GetKey()
			if DEBUG_INPUT {
				log.Println("WaitKey:", r, ex, e)
			}
			// return bio.GetKey()
			return r, ex, e
		} else {
			log.Println("WaitKey: Disconnected")
			// Reader has closed.
			// Disconnected = true
			return rune(0), Extended(0), ErrDisconnected
		}
	case <-time.After(timeout):
		return rune(0), Extended(0), ErrTimeout
	}
}

// Outputs spaces and backspaces
// If you have set a background color, this shows the input area.
func DisplayInput(max int) string {
	return strings.Repeat(" ", max) + strings.Repeat("\x08", max)
}

// Input a string of max length.
// This displays the input area if a bg color was set.
// This handles timeout, input, backspace, and enter.
func (d *Door) Input(max int) string {
	var line string

	// draw input area
	d.Write(DisplayInput(max))

	var r rune
	var ex Extended
	var err error

	for {
		r, ex, err = d.WaitKey(DefaultTimeout)
		if err != nil {
			// timeout/hangup
			return ""
		}

		if ex != NOP {
			continue
		}

		if strconv.IsPrint(r) {
			if len(line) < max {
				d.Write(string(r))
				line += string(r)
			} else {
				d.Write("\x07")
			}
		} else {
			// Non-print
			switch r {
			case 0x7f, 0x08:
				if len(line) > 0 {
					d.Write("\x08 \x08")
					line = line[:len(line)-1]
				}
			case 0x0d:
				return line
			}
		}
	}
}

func (d *Door) GetOneOf(possible string) rune {
	var r rune
	var err error

	for {
		r, _, err = d.WaitKey(DefaultTimeout)
		if err != nil {
			return rune(0)
		}
		r := unicode.ToUpper(r)
		if strings.ContainsRune(possible, r) {
			// return upper case rune
			return r
		}
		/*
			c = strings.IndexRune(possible, r)
			if c != -1 {
				return c
			}
		*/
	}
}