#!/bin/sh
echo() { printf %s\\n "$*"; }

print_tips() { cat << \TIPS
----------------- TIPS --------------------
- set root password to enable ssh root login
- consider 'sh <this-file> -x' to update PS1 and add $extra
- change filesystem allocated ram, e.g. mount -o remount,size=5G /
- xorg: setup-xorg-base && apk add fvwn && echo exec fvwm >> ~/.xinitrc
TIPS
}


: <<\TIPS
Alpine linux standard (or the tiny virtual, or extended) live cd/dvd image:

Login:
  root (no password)

RAM/tmpfs split:
  by default half the RAM is dedicated to the filesystem. the FS size can be
  set using kernel boot param rootflags=size=300M, or after login using e.g.:
    mount -o remount,size=5G /

network:
  setup-interfaces -ar  # auto dhcp, restart networking

*** rest of this file can be automatd by serving it over http, and then: ***
  wget <this-file-url> -O - | sh

apk (by default only the CD media is configured. try: apk list):
  setup-apkrepos -1c  # 1st mirror (CDN) and community repo

  # Then e.g. "apk update && apk add docker"

ssh:
  setup-sshd openssh

optionally allow root login (needs password), add {port,x11}-forwarding
  # set the following in /etc/ssh/sshd_config:
  #   PermitRootLogin yes
  #   AllowTcpForwarding yes
  #   X11Forwarding yes

  apk add xauth
  rc-service sshd restart
  # and set root password using "passwd", else root can't ssh

TIPS

extra="bash git git-gitk htop xclip xterm vim font-dejavu less source-highlight"

sponge() {
    set -- "$1" "$(cat; echo x)"
    printf %s "${2%x}" > "$1"
}

if [ "${1-}" != -x ]; then
	set -x

	setup-apkrepos -1c
	setup-sshd openssh

	apk add xauth bash &&
		sed < /etc/passwd \
		-e 's,/root:/bin/sh,/root:/bin/bash,' \
		-e 's,/root:/bin/ash,/root:/bin/bash,' \
		| sponge /etc/passwd
	
	comment_sshd_root_config() {( set +x
		f=/etc/ssh/sshd_config
		for v; do shift; set -- "$@" -e "s/^$v\\s/# --x-- $v/"; done
		set -x
		sed "$@" < "$f" > "$f.tmp" && mv "$f.tmp" "$f"
	)}

	comment_sshd_root_config \
		PermitRootLogin AllowTcpForwarding X11Forwarding

	echo PermitRootLogin yes >> /etc/ssh/sshd_config
	echo AllowTcpForwarding yes >> /etc/ssh/sshd_config
	echo X11Forwarding yes >> /etc/ssh/sshd_config

	rc-service sshd restart

	print_tips
else
	apk add $extra
	print_tips

: <<\ORIG_PROFILE
	echo '! [ -r ~/.bashrc ] || . ~/.bashrc' >> ~/.bash_profile
	cat >> ~/.bashrc <<\BASH_PROMPT_SETUP
		case $- in *i*) ;; *) return; esac
		# useful PS1: \n, B-yellow errcode if not 0, B-cyan \w, [git], blue \u@\h, \n:
		case x${SHLVL-} in x|x1|x*[!0-9]*) _psL=;; *) _psL="+$((SHLVL-1)) "; esac
		_psA='\e[m\n\e[33;1m$(e="$? "; echo "${e#0 }")\e[36m\w\e[m'
		_psB='\e[34;1m\u@\h\e[m\n'$_psL'\$ '

		PS1="$_psA $_psB"  # default, without git-prompt

		_psgitU=https://raw.githubusercontent.com/git/git/master/contrib/completion/git-prompt.sh
		_psgitF=~/.git-prompt.sh  # touch this file to disable net-fetch attempts

		if [ -s "$_psgitF" ] || { ! [ -e "$_psgitF" ] &&
		   (set -x; wget "$_psgitU" -O "$_psgitF" || curl "$_psgitU" -o "$_psgitF")}
		then
			. "$_psgitF"
			export GIT_PS1_SHOWCOLORHINTS=1
			export GIT_PS1_SHOWDIRTYSTATE=1
			export GIT_PS1_SHOWUPSTREAM=verbose
			GIT_PS1_DESCRIBE_STYLE=tag
			PROMPT_COMMAND="__git_ps1 '$_psA' ' $_psB'"
		fi
	BASH_PROMPT_SETUP
ORIG_PROFILE

	cat >> ~/.profile <<-\SH_PROMPT_SETUP
		
		# fetch git-prompt.sh as ~/.git-prompt.sh if it doesn't exit.
		# touch it (size 0) to skip the fetch (and disable git-prompt)
		_psgitU=https://raw.githubusercontent.com/git/git/master/contrib/completion/git-prompt.sh
		_psgitU=https://git.kernel.org/pub/scm/git/git.git/plain/contrib/completion/git-prompt.sh
		_psgitF=~/.git-prompt.sh  # full path expected without '\' or '"'

		[ -e "$_psgitF" ] ||
		(set -x; wget "$_psgitU" -O "$_psgitF" || curl "$_psgitU" -o "$_psgitF")

		# stand-alone sequence to source and run __git_ps1. cross-sh
		# and doesn't require sourcing it in each new [ba]sh instance
		# perf impact vs sourcing it only once is less than 10 ms .
		_psgit_cmd='
		    e=$?; [ -s "'"$_psgitF"'" ] || exit "$e"  # subshell
		    . "'"$_psgitF"'"
		    : ${GIT_PS1_SHOWCOLORHINTS=1}
		    : ${GIT_PS1_SHOWDIRTYSTATE=1}
		    : ${GIT_PS1_SHOWUPSTREAM=verbose}
		    : ${GIT_PS1_DESCRIBE_STYLE=tag}
		    __git_ps1; exit "$e"
		'

		# useful PS1: \n, B-yellow errcode if not 0, B-cyan \w, [git], blue \u@\h, \n, [+SHLVL]:
		_psL='$(case x${SHLVL-} in x|x1|x*[!0-9]*);; *) echo "+$((SHLVL-1)) "; esac)'
		_psA='\e[m\n\e[33;1m$(e="$? "; echo "${e#0 }")\e[36m\w\e[m'
		_psB='\e[34;1m\u@\h\e[m\n'$_psL'\$ '

		export PS1="$_psA\$($_psgit_cmd) $_psB"  # + git-prompt if exist

		export LESS='-RMi --incsearch'
		export LESSOPEN='|/usr/bin/src-hilite-lesspipe.sh %s'
SH_PROMPT_SETUP


fi