#!/bin/bash

function do_step(){
  echo "Executing: $@"
  echo
  if "$@"
  then
    echo
    echo "==================== Step $@ ran OK ===================="
  else
    echo
    >&2 echo "!!!!!!!!!!!!!!!!!!!!! Step $@ Failed !!!!!!!!!!!!!!!!!!!!!"
    return 1
  fi

}

function step_type(){
  echo "$1"|cut -d _ -f 1|cut -d : -f 1
}

function step_3digit_number(){
  printf "%03d" "$(step_number "$1")"
}

function step_number(){
  for number in "${!steps[@]}"
  do
   if [ "${steps[$number]}" = "$1" ]
   then
       echo "$number"
   fi
  done
}

function step_script(){
  echo "$1"|cut -d : -f 2-
}

function has_step(){
  found=false
  for step in "${steps[@]}"
  do
    if [ "$(step_3digit_number "$step")" == "$1" ]
    then
      found=true
      break;
    fi
  done
  $found
}

function step_check(){
  script_type="$(step_type "$1")"
  script="$(step_script "$1")"
  if [ "$script_type" == "function" ]
  then
    type "$script" > /dev/null 2>&1
  else
    [ -x "$script" ]
  fi
}

function next_step(){
  printf "%03d" "$(($(step_number "$1")+1))"
}

function prepend_timestamp(){
  while IFS= read -r line; do printf '[%s] %s\n' "$(date '+%Y-%m-%d %H:%M:%S')" "$line"; done
}

function do_menu(){
  next_step="$(step_3digit_number "${steps[0]}")"
  while true
  do
    echo "Environment:"
    echo "Azure master: $AZURE_MASTER"
    echo "Azure slaves: ${AZURE_SLAVES[*]}"
    echo "Azure pgbouncers: ${AZURE_PGBOUNCERS[*]}"
    echo "GCP master candidate: $GCP_MASTER_CANDIDATE"
    echo "GCP slaves: ${GCP_SLAVES[*]}"
    echo "GCP pgbouncers: ${GCP_PGBOUNCERS[*]}"
    echo
    echo "Available steps:"
    echo
    for step in "${steps[@]}"
    do
      echo "$(step_3digit_number "$step")) $(step_script "$step")"
    done
    echo
    if has_step "$next_step"
    then
      read_prompt="Enter the step number to execute, next to execute step $next_step or quit to exit? "
    else
      read_prompt="Enter the step number to execute or quit to exit? "
    fi
    if which rlwrap > /dev/null 2>&1
    then
      command="$(rlwrap -f migration.dict -C migration bash -c 'read -r -p "'"$read_prompt"'" command; echo "$command"')"
    else
      read -r -p "$read_prompt" command
    fi
    step=
    case "$command" in
      quit)
        exit 0
        ;;
      next)
        found=false
        for step in "${steps[@]}"
        do
          if [ "$(step_3digit_number "$step")" == "$next_step" ]
          then
            found=true
            break;
          fi
        done
        if ! $found
        then
          step=
        fi
        ;;
      [0-9][0-9][0-9])
        found=false
        for step in "${steps[@]}"
        do
          if [ "$(step_3digit_number "$step")" == "$command" ]
          then
            found=true
            break;
          fi
        done
        if ! $found
        then
          echo "Sorry, no step $command found! Please enter all step digits."
          step=
        fi
        ;;
    esac
    if [ ! -z "$step" ]
    then
      script_type="$(step_type "$step")"
      script="$(step_script "$step")"
      echo "Step $step will be executed ($script_type $script):"
      echo
      if [ "$script_type" == "function" ]
      then
        type "$script" | head -n -1 | tail -n +4
      else
        script="${BASE}/$(step_script "$step")"
        cat "$script"
      fi
      echo
      read -r -s -N 1 -p "Press [y] to continue, any other key to abort." key
      echo
      if [ "$key" == "y" ]
      then
        if do_step "$script" > >(prepend_timestamp | tee -a migration.log) 2> >(prepend_timestamp | tee -a migration.log >&2)
        then
          next_step="$(next_step "$step")"
        else
          next_step="$(step_3digit_number "$step")"
        fi
        # wait for the redirect subshells to complete
        sleep 1
      fi
      echo
      step=
    fi
  done
}