package terminal

import (
	"time"
)

// Wish list here: http://invisible-island.net/xterm/ctlseqs/ctlseqs.html

type TerminalCharSet int

type escapeSequenceHandler func(pty chan rune, terminal *Terminal) error

var escapeSequenceMap = map[rune]escapeSequenceHandler{
	0x05: enqSequenceHandler,
	0x07: bellSequenceHandler,
	0x08: backspaceSequenceHandler,
	0x09: tabSequenceHandler,
	0x0a: newLineSequenceHandler,
	0x0b: newLineSequenceHandler,
	0x0c: newLineSequenceHandler,
	0x0d: carriageReturnSequenceHandler,
	0x0e: shiftOutSequenceHandler,
	0x0f: shiftInSequenceHandler,
	0x1b: ansiHandler,
}

func newLineSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.ActiveBuffer().NewLine()
	terminal.isDirty = true
	return nil
}

func tabSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.ActiveBuffer().Tab()
	terminal.isDirty = true
	return nil
}

func carriageReturnSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.ActiveBuffer().CarriageReturn()
	terminal.isDirty = true
	return nil
}

func backspaceSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.ActiveBuffer().Backspace()
	terminal.isDirty = true
	return nil
}

func bellSequenceHandler(pty chan rune, terminal *Terminal) error {
	// @todo ring bell - flash red or some shit?
	return nil
}

func enqSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.logger.Errorf("Received ENQ!")
	return nil
}

func shiftOutSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.logger.Errorf("Received shift out")
	return nil
}

func shiftInSequenceHandler(pty chan rune, terminal *Terminal) error {
	terminal.logger.Errorf("Received shift in")
	return nil
}

func (terminal *Terminal) processInput(pty chan rune) {

	// https://en.wikipedia.org/wiki/ANSI_escape_code

	var b rune

	for {

		if terminal.config.Slomo {
			time.Sleep(time.Millisecond * 100)
		}

		b = <-pty

		if b < 0x20 {
			if handler, ok := escapeSequenceMap[b]; ok {
				//terminal.logger.Debugf("Handling escape sequence: 0x%x", b)
				if err := handler(pty, terminal); err != nil {
					terminal.logger.Errorf("Error handling escape sequence: %s", err)
				}
				terminal.isDirty = true
				continue
			}
		}

		//terminal.logger.Debugf("Received character 0x%X: %q", b, string(b))
		terminal.ActiveBuffer().Write(b)
		terminal.isDirty = true
	}
}