From 522294208e2adff97be24139cbb4b5685058bb1a Mon Sep 17 00:00:00 2001
From: Martin Winkler <efelon@winklerfamilie.eu>
Date: Wed, 4 May 2022 12:14:57 +0200
Subject: [PATCH] WIP rewrite with bash best practices

---
 sequencer.sh | 321 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 321 insertions(+)
 create mode 100755 sequencer.sh

diff --git a/sequencer.sh b/sequencer.sh
new file mode 100755
index 0000000..576a5bc
--- /dev/null
+++ b/sequencer.sh
@@ -0,0 +1,321 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC2034 # variable not used
+
+# Exit on error. Append "|| true" if you expect an error.
+set -o errexit
+# Exit on error inside any functions or subshells.
+set -o errtrace
+# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
+set -o nounset
+# Catch the error in case mysqldump fails (but gzip succeeds) in `mysqldump |gzip`
+set -o pipefail
+# Turn on traces, useful while debugging but commented out by default
+# set -o xtrace
+
+## Globals 
+{
+  ## Seq
+  readonly seq_name="${_sqn_alias:-${0##*/}}"
+  readonly seq_dir="$(cd -- "$(dirname -- "${0}")" && pwd)"
+  readonly seq_origin="$(cd -- "$(dirname -- "$(readlink -f -- "${0}")")" && pwd)"
+  readonly seq_file=$(basename -- "${0}")
+  readonly seq_fileName=${seq_file%%.*}
+  # shellcheck disable=SC2015 # && || is not if else
+  readonly seq_invocation="$(printf '%q' "${0}")$( (($#)) && printf ' %q' "$@" || true)"
+
+  # May be overwritten by seq
+  seq_configFile="${seq_fileName}.cfg"
+  seq_configTemplate="${0%.*}.cfg.example"
+
+  ## Sequencer
+  readonly sqr_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+  readonly sqr_file="$(basename -- "${BASH_SOURCE[0]}")"
+  readonly sqr_name="${sqr_file%%.*}"
+  readonly sqr_origin="$(cd -- "$(dirname -- \
+    "$(readlink -f -- "${BASH_SOURCE[0]}")")" && pwd)"
+
+  _sqr_interactive=1
+  _sqr_debug=0
+  _sqr_dry=0
+  _sqr_logLastColor=
+  _sqr_verbose=0
+
+  # Colors
+  col_black= ; [ -t 1 ] && col_black='\033[0;30m' 
+  col_darkgrey= ; [ -t 1 ] && col_darkgrey='\033[1;30m'
+  col_red= ; [ -t 1 ] && col_red='\033[0;31m'
+  col_lightred= ; [ -t 1 ] && col_lightred='\033[1;31m'
+  col_green= ; [ -t 1 ] && col_green='\033[0;32m'
+  col_lightgreen= ; [ -t 1 ] && col_lightgreen='\033[1;32m'
+  col_orange= ; [ -t 1 ] && col_orange='\033[0;33m'
+  col_yellow= ; [ -t 1 ] && col_yellow='\033[1;33m'
+  col_blue= ; [ -t 1 ] && col_blue='\033[0;34m'
+  col_lightblue= ; [ -t 1 ] && col_lightblue='\033[1;34m'
+  col_purple= ; [ -t 1 ] && col_purple='\033[0;35m'
+  col_lightpurple= ; [ -t 1 ] && col_lightpurple='\033[1;35m'
+  col_cyan= ; [ -t 1 ] && col_cyan='\033[0;36m'
+  col_lightcyan= ; [ -t 1 ] && col_lightcyan='\033[1;36m'
+  col_lightgray= ; [ -t 1 ] && col_lightgray='\033[0;37m'
+  col_white= ; [ -t 1 ] && col_white='\033[1;37m'
+  col_off= ;[ -t 1 ] && col_off='\033[0m' # No Color
+}
+
+# Logging
+{
+  LOG_LEVEL="${LOG_LEVEL:-3}" # 4 = debug -> 0 = fatal (stop)
+  LOG_TIME="${LOG_TIME:-}"    # 1 = show time stamps
+
+  # sqr::log [LOG LEVEL] [LOG_COLOR] [OPTIONS] [LOG MESSAGE]
+  # Construct log messages
+  #
+  #  [OPTIONS]
+  #    -a  :  append text (no info and timestamp)
+  #           Uses color from last sqr::log call without -a
+  #    --  :  End of options
+  #
+  sqr::log () {
+    sqr::debugPause
+    local appendText=
+    local arg=
+    local col_end="${col_off}"
+   
+    local log_level="${1:-}"
+    shift
+    local log_color="${1:-}"
+    shift
+    for arg in "${@}" ; do
+      case "${1:-}" in
+        --)
+          shift && break ;;
+        -a)
+          appendText=1 
+          shift ;;
+      esac
+    done
+
+    _sqr_logLastColor="${log_color}"
+    [[ -z "${log_color}" ]] && col_end=""
+
+    # all remaining arguments are to be printed
+    local log_line=""
+
+    while IFS=$'\n' read -r log_line ; do
+      printf '%b' "${log_color}"
+      if [[ -n "${LOG_TIME}" ]] ; then
+        if (( appendText )) ; then
+          printf '%24s' ""
+        else
+          printf '%s ' "$(date -u +"%Y-%m-%d %H:%M:%S UTC")"
+        fi
+      fi
+
+      if (( ! appendText )) ; then
+        printf " %3s " "[${log_level}]" 
+        printf "%s" "${log_line}" # 1>&2 # send to stderr
+      else
+        # +3 : "[] "
+        printf "%$((${#log_level} + 4))s%s" "" "${log_line}"
+      fi
+
+      printf '%b\n' "${col_end}" 
+    done <<< "${@:-}"
+    sqr::debugContinue
+  }
+
+  stop ()    {                                  sqr::log "stop" "${col_red}" "${@}"; exit 1; }
+  error ()   { [[ "${LOG_LEVEL:-0}" -ge 1 ]] && sqr::log "e" "${col_red}" "${@}"; true; }
+  warning () { [[ "${LOG_LEVEL:-0}" -ge 2 ]] && sqr::log "w" "${col_orange}" "${@}"; true; }
+  info ()    { [[ "${LOG_LEVEL:-0}" -ge 3 ]] && sqr::log "i" "" "${@}"; true; }
+  debug ()   { [[ "${LOG_LEVEL:-0}" -ge 4 ]] && sqr::log "dbug" "${col_lightpurple}" "${@}"; true; }
+
+  # internal printf same loglevel as info
+  sqr::print () { [[ "${LOG_LEVEL:-0}" -ge 3 ]] && printf "$@"; true; }
+  sqr::debugPause() {
+    if (( _sqr_debug )) ; then set +o xtrace; else true; fi
+  }
+  sqr::debugContinue() {
+    if (( _sqr_debug )) ; then set -o xtrace; else true; fi
+  }
+}
+
+# Traps
+{
+  sqr::trap_exit () {
+    exists -f seq_trapExit && seq_trapExit
+    debug "Sequencer exit"
+  }
+  trap sqr::trap_exit EXIT
+
+  # requires `set -o errtrace`
+  sqr::error_report() {
+    local error_code=${?}
+    error "Error in ${sqr_file} in function ${1} on line ${2}"
+    exit ${error_code}
+  }
+
+  # Uncomment the following line for always providing an error backtrace
+  # trap 'sqr::error_report "${FUNCNAME:-.}" ${LINENO}' ERR
+}
+
+# exists [-f] [--] [ELEMENT]
+#  [ELEMENT]
+#       : either a variable name or
+#    -f : function
+exists() {
+  sqr::debugPause
+  local func=
+  local arg=
+
+  for arg in "$@" ; do
+    case "${1:-}" in
+      --)
+        shift && break ;;
+      -f)
+        func="${2:-}"
+    esac
+  done
+  if [[ -n "${func}" ]] ; then
+    declare -F "${func}" &>>/dev/null
+  else
+    [[ -n "${!1:-}" ]]
+  fi
+  sqr::debugContinue
+}
+
+# interactive
+# Started with -q to use defaults for confirmations
+interactive() {
+  (( _sqr_interactive ))
+}
+# quiet
+# Log level smaller 3 (info) are treated as quiet request
+quiet() {
+  [[ $LOG_LEVEL -lt 3 ]]
+}
+# silent
+# Log level equals 0 (stop)
+silent() {
+  [[ $LOG_LEVEL -eq 0 ]]
+}
+
+### interactive
+# confirm [OPTIONS] [--] [QUESTION]
+#  Default (empty character) = no
+# 
+#  [OPTIONS]
+#    -f  :  interactive even if quiet
+#    -n  :  no input help
+#    -y  :  default = yes
+#    --  :  end of options
+confirm() {
+  sqr::debugPause
+  local arg=
+  local rexReply='^[Yy]$' # default no
+  local inputHelp='[y/N] ' # default no
+  local noHelp=0
+  local force=0
+  
+  for arg in "${@}" ; do
+    case "${1:-}" in
+      --)
+        shift && break ;;
+      -f)
+        force=1
+        shift ;;
+      -n)
+        noHelp=1
+        shift ;;
+      -y)
+        rexReply='^[Yy]*$' # default yes
+        inputHelp='[Y/n] ' # default yes
+        shift ;;
+    esac
+  done
+  (( noHelp )) && inputHelp=
+  if interactive || (( force )) ; then
+    read -r -p "${1:-} ${inputHelp}" -n 1
+    echo ""
+  else
+    REPLY=''
+  fi
+  sqr::debugContinue
+  [[ $REPLY =~ ${rexReply} ]]
+}
+
+# ask [OPTION] [QUESTION] [DEFAULT]
+#  Will ask for input even if quiet, when [DEFAULT] is empty
+#
+#  [OPTION]
+#    -e  :  allow empty input
+#           Ignored if [DEFAULT] is available
+#    -s  :  ask for secret (don't print input)
+#           Does not add a newline. Usage:
+#           pass=$(ask -s "Password"); echo
+#    --  :  End of options
+ask() {
+  sqr::debugPause
+  local hidden=
+  local empty=0
+  local arg=
+  for arg in "$@" ; do
+    case "${1}" in
+      --)
+        shift && break ;;
+      -e)
+        empty=1
+        shift ;;
+      -s)
+        hidden="-s"
+        shift ;;
+    esac
+  done
+  local answer=
+  if [[ -n "${2:-}" ]]; then
+    ! interactive && printf '%s\n' "${2}" && sqr::debugContinue && return 0 
+    read ${hidden?} -r -p "${1:-"User input"} ($2) " answer
+  else
+    read ${hidden?} -r -p "${1:-"User input"} " answer
+  fi
+  if [[ -z "$answer" ]] ; then
+    answer="${2:-}"
+  fi
+  printf '%s\n' "${answer}"
+  sqr::debugContinue
+  if (( ! empty )) ; then
+    [[ -n "${answer}" ]]
+  fi
+}
+
+sqr::main() {
+
+  # options check
+  for arg in "$@" ; do
+    case "$1" in
+      --quiet|-q)
+        _sqr_interactive=0
+        shift ;;
+      -qq)
+        _sqr_interactive=0
+        LOG_LEVEL=0
+        shift ;;
+      --debug)
+        _sqr_debug="1"
+        shift ;;
+    esac
+  done
+
+  # debug mode
+  if [[ "${_sqr_debug:-}" = "1" ]]; then
+    set -o xtrace
+    PS4='+(${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
+    # Enable error backtracing
+    trap 'sqr::error_report "${FUNCNAME:-.}" ${LINENO}' ERR
+  fi
+
+  sqr::print 'Running...\n'
+  confirm -y -- 'Continue?'
+  seq_config 2>/dev/null || true
+  step_1 "$@"
+}
+
+sqr::main "$@"