SE206 Assignment 1 - Name Sayer bash script

name_sayer.sh

#!/usr/bin/env bash

# Creation parameters
CREATION_EXTENSION="mkv"
CREATION_DURATION=5

# Folder structure
DIR_WORKING=$(pwd)
DIR_CREATIONS="$DIR_WORKING/creations"
DIR_TEMPORARY="$DIR_WORKING/tmp"
FILE_LOGS="$DIR_WORKING/errors.log"

# Terminal escape sequences
# TODO: Improve terminal-portability
UPARROW=$'\e[A'
DOWNARROW=$'\e[B'
LEFTARROW=$'\e[C'
RIGHTARROW=$'\e[D'
ENTER=$'\n'
BACKSPACE=$'\b'
DELETE=$'\x7f'
ESCAPE=$'\x1b'

# Colour configuration
COLOR_SCREEN_BG="4"
COLOR_RAW_BG="0"
COLOR_RAW_FG="7"
COLOR_WINDOW_BG="7"
COLOR_WINDOW_FG="0"
COLOR_HIGHLIGHT_FG="0"
COLOR_HIGHLIGHT_BG="3"

# Turn off monitor mode - suppress job control messages
set +m

#
#
# Program entry, exits, and traps
#
#

function init
{
  if ! validate_screen_size
  then
    echo Your terminal size is too small for NameSayer to run. Aborting.
    exit 1
  fi
  screen_init
  IFS=$'\n\b'

  screen_width=$(tput cols)
  screen_height=$(tput lines)
  (( screen_midx = $screen_width / 2 ))
  (( screen_midy = $screen_height / 2 ))

  mkdir -p $DIR_CREATIONS

  state_machine_loop
}

function teardown
{
  window_progressbar_stop
  IFS=$
  screen_teardown
}

trap resize SIGWINCH
function resize
{
  screen_width=$(tput cols)
  screen_height=$(tput lines)
  (( screen_midx = $screen_width / 2 ))
  (( screen_midy = $screen_height / 2 ))
  if ! validate_screen_size
  then
    env_window
    teardown
    echo "Screen too small. Aborting..."
    exit 1
  fi
}

trap quit INT
function quit
{
  screen_clear
  state_quit
}

#
#
# Screen - terminal configurations
#
#

function validate_screen_size
{
  [ "$(tput lines)" -ge 10 ] && [ "$(tput cols)" -ge 70 ]
}

function screen_init
{
  tput init
  tput smcup
  tput civis
  stty_original=$(stty -g)
  stty -echo raw
}

function screen_teardown
{
  stty $stty_original
  tput cnorm
  tput reset
  tput rmcup
}

function screen_clear
{
  tput setab "$COLOR_SCREEN_BG"
  tput clear
}

#
#
# Ext - External commands for audio/video manipulation
#
#

function ext_record_audio
{
  ffmpeg \
    -f alsa \
    -i default \
    -t $CREATION_DURATION \
    audio.wav
}

function ext_replay_audio
{
  ffplay \
    -autoexit \
    -i audio.wav
}

function ext_create_video
{
  ffmpeg \
    -f lavfi \
    -i color=black:d=$CREATION_DURATION \
    -vf "drawtext='text=$selected_creation':fontsize=10:fontcolor=white:x=(w-text_w)/2:y=(h-text_h)/2" \
    video.mp4
}

function ext_merge_audio_video
{
  ffmpeg \
    -i audio.wav \
    -i video.mp4 \
    -c copy \
    $selected_file
}

function ext_play_creation
{
  ffplay \
    -autoexit \
    -i $selected_file
}

function ext_wrap_error
{
  local error_title=$1
  shift
  local error_message=$1
  shift
  local cleanup_command=$1
  shift
  local command=$@

  if ! $command &> $FILE_LOGS
  then
    $cleanup_command
    screen_clear
    window_set 4 70 "$error_title"
    window_draw
    window_text 2 2 "$error_message"
    window_text 3 2 "Press any key to see what happened."
    wait_key
    screen_teardown
      cat $FILE_LOGS
      printf "\n\rPress any key to continue..."
      wait_key
      printf "\n"
    screen_init
    return 1
  else
    rm $FILE_LOGS
    $cleanup_command
  fi
}

#
#
# Tmpdir - scratchpad directory access
#
#

function tmpdir_start
{
  rm -rf "$DIR_TEMPORARY"
  mkdir -p "$DIR_TEMPORARY"
  cd "$DIR_TEMPORARY"
}

function tmpdir_end
{
  cd "$DIR_WORKING"
  rm -rf "$DIR_TEMPORARY"
}

#
#
# Window and env - Windowing and user interface
#
#

function window_set
{
  window_height=$1
  window_width=$2
  window_title=$3
  window_title_len=${#3}
  (( window_title_left = $screen_midx - ($window_title_len / 2) ))
  (( window_top = $screen_midy - ($window_height / 2) ))
  (( window_left = $screen_midx - ($window_width / 2) ))
  (( window_bottom = $window_top + $window_height ))
  (( window_right = $window_left + $window_width ))
}

function env_window
{
  tput sgr0
  tput setab "$COLOR_WINDOW_BG"
  tput setaf "$COLOR_WINDOW_FG"
}

function env_highlight
{
  tput sgr0
  tput setab "$COLOR_HIGHLIGHT_BG"
  tput setaf "$COLOR_HIGHLIGHT_FG"
}

function window_draw
{
  env_window
  tput cup $window_top $window_left
  for y in $(seq "$window_top" "$window_bottom")
  do
    tput cup "$y" "$window_left"
    for x in $(seq $window_width)
    do
      printf " "
    done
  done

  tput rev
  tput cup "$window_top" "$window_left"
  for x in $(seq $window_width)
  do
    printf " "
  done
  tput cup "$window_top" "$window_title_left"
  printf "$window_title"
  tput sgr0
}

function window_cursor
{
  tput cup $(( $1 + $window_top )) $(( $2 + $window_left ))
}

function window_box
{
  env_window
  (( row1 = $window_top + $1 ))
  (( col1 = $window_left + $2 ))
  (( row2 = $window_top + $3 ))
  (( col2 = $window_left + $4 ))

  tput cup $row1 $col1
  for x in $(seq $(( $col1 + 1 )) $col2)
  do
    printf "─"
  done
  tput cup $row2 $col1
  for x in $(seq $(( $col1 + 1 )) $col2)
  do
    printf "─"
  done
  for y in $(seq $(( $row1 + 1 )) $row2)
  do
    tput cup $y $col1
    printf "│"
    tput cup $y $col2
    printf "│"
  done
  tput cup $row1 $col1
  printf "┌"
  tput cup $row2 $col2
  printf "┘"
  tput cup $row2 $col1
  printf "└"
  tput cup $row1 $col2
  printf "┐"
}

function window_text
{
  case "$1" in
    "hl")
      env_highlight
      shift
      ;;
    *)
      env_window
      ;;
  esac
  local row
  local col
  (( row = $1 + $window_top ))
  (( col = $2 + $window_left ))
  tput cup "$row" "$col"
  printf "$3"
}

function window_progressbar_start
{
  local row
  local col_start
  local col_end
  (( row = $1 + $window_top ))
  (( col_start = $2 + $window_left ))
  local subdivisions=$3
  local duration=$4
  (( col_end = $col_start + $duration * $subdivisions ))
  local step="$(bc <<< "scale = 3; 1 / $subdivisions")"

  env_window

  tput cup "$(($row - 1))" "$col_start"
  printf "0s"
  tput cup "$(($row - 1))" "$(($col_end - 1))"
  printf "${duration}s"

  tput cup "$row" "$col_start"
  for t in $(seq "$col_start" "$col_end")
  do
    printf "░"
  done

  {
    env_window
    for col in $(seq "$col_start" "$col_end")
    do
      tput cup "$(($row - 1))" "$col_start"
      printf "$(( ($col - $col_start) / $subdivisions ))s"

      tput cup "$row" "$col"
      printf "█"
      sleep "$step"
    done
    sleep 1000
  } &

  window_progressbar_jobpid="$!"
}

function window_progressbar_stop
{
  if jobs -p | grep "$window_progressbar_jobpid" &> /dev/null
  then
    kill "$window_progressbar_jobpid" &> /dev/null
  fi
}

function window_clear
{
  (( row = $1 + $window_top ))
  (( col_start = $2 + $window_left ))
  (( col_end = $3 + $window_left ))
  tput cup "$row" "$col_start"
  for x in $(seq $col_start $col_end)
  do
    printf " "
  done
}

function window_clear_row
{
  tput cup "$(( $window_top + $1 ))" "$window_left"
  for x in $(seq $window_left $(($window_right - 1)))
  do
    printf " "
  done
}

#
#
# Keyboard input
#
#

function read_key
{
  local key
  local key1
  local key2
  local key3
  read -sN1 key
  read -sN1 -t 0.0001 key1 2> /dev/null
  read -sN1 -t 0.0001 key2 2> /dev/null
  read -sN1 -t 0.0001 key3 2> /dev/null

  if [[ "$key" =~ [^a-zA-Z0-9] ]]
  then
    key+=$key1$key2$key3
  fi

  case $key in
    $UPARROW)
      key=UPARROW
      ;;
    $DOWNARROW)
      key=DOWNARROW
      ;;
    $LEFTARROW)
      key=LEFTARROW
      ;;
    $RIGHTARROW)
      key=RIGHTARROW
      ;;
    $ENTER|"")
      key=ENTER
      ;;
    $DELETE|$BACKSPACE)
      key=BACKSPACE
      ;;
    $ESCAPE)
      key=ESCAPE
      ;;
  esac

  echo "$key"
}

function wait_key
{
  local gobble=$(read_key)
  # Redirecting to /dev/null does strange things when ctrl-c ing
}

#
#
# Creation specific helpers
#
#

function list_creations
{
  pushd "$DIR_CREATIONS" > /dev/null
  find -name "$1*.$CREATION_EXTENSION" | sort
  popd > /dev/null
}

function filename_to_name
{
  local ext_length_including_dot=$(( ${#CREATION_EXTENSION} + 1 ))
  echo ${1:2:-$ext_length_including_dot}
}

function select_creation
{
  local selection_mode=$2
  local h=6
  if [ "$selection_mode" == "existing" ]
  then
    h=$screen_height
    if [ -z "$(list_creations)" ]
    then
      window_set 4 50 "$1"
      window_draw
      window_text 2 2 "There are no creations."
      window_text 3 2 "Press any key to continue..."
      wait_key
      return 1
    fi
  fi
  window_set "$h" 70 "$1"
  window_draw
  window_text 3 2 "Enter Name:"
  window_box 2 18 4 66

  local input_text
  local prev_last_dirty_row=8
  while true
  do
    window_clear 3 19 65
    window_clear_row 5
    window_text 3 20 "$input_text"
    window_text 5 20 "Press escape to cancel"

    if [ $selection_mode == "existing" ]
    then
      # Show matching creation names if selecting an existing creation

      window_clear_row 7
      for clearing_row in $(seq 9 "$prev_last_dirty_row")
      do
        window_clear_row $clearing_row
      done

      local row=9
      local matches=$(list_creations $input_text)

      if [ "$matches" ]
      then
        local num_matches=$(wc -l <<< "$matches")
        window_text 7 2 "Found $num_matches matching creations:"
        for match in $matches
        do
          [ "$row" -ge "$screen_height" ] && break
          window_text "$row" 5 $(filename_to_name $match)
          (( row++ ))
        done
      else
        window_text 7 2 "No matching creations found."
      fi
      prev_last_dirty_row="$row"
    fi

    window_cursor 3 $(( 20 + ${#input_text} ))
    tput cnorm
    key=$(read_key)
    tput civis
    case $key in
      "ENTER")
        local creation_file="$DIR_CREATIONS/$input_text.$CREATION_EXTENSION"
        if [ -z $input_text ]
        then
          window_clear_row 5
          window_text 5 20 "Please enter a name.       "
          sleep 1
        elif [ ! -f $creation_file ] && [ "$selection_mode" == "existing" ]
        then
          window_clear_row 5
          window_text 5 20 "Creation not found."
          sleep 1
        elif [ -f $creation_file ] && [ "$selection_mode" == "new" ]
        then
          window_clear_row 5
          window_text 5 20 "Creation already exists."
          sleep 1
        else
          selected_creation="$input_text"
          selected_file="$creation_file"
          break
        fi
        ;;
      "BACKSPACE")
        [ "$input_text" ] && input_text=${input_text::-1}
        window_text 3 $(( 20 + ${#input_text} )) " "
        ;;
      "ESCAPE")
        selected_creation=
        selected_file=
        return 1
        break
        ;;
      [a-zA-Z]|" ")
        if [ "${#input_text}" -ge 45 ]
        then
          window_clear_row 5
          window_text 5 20 "Name too long."
          sleep 1
        else
          input_text+=$key
        fi
        ;;
    esac
  done

  screen_clear
}

#
#
# Program states
#
#

function state_list
{
  local creations=$(list_creations)
  if [ -z "$creations" ]
  then
    screen_clear
    window_set 4 50 "List of Creations"
    window_draw
    window_text 2 2 "There are no creations."
    window_text 3 2 "Press any key to continue..."
    wait_key
    return
  fi

  local num_creations=$(wc -l <<< "$creations")

  window_set "$screen_height" 70 "List of Creations"
  window_draw

  window_text 2 2 "There are $num_creations creations:"
  local row=4
  for filename in $creations
  do
    if [ "$(($row + 2))" -ge "$screen_height" ]
    then
      screen_clear
      window_set 5 50 "List of Creations"
      window_draw
      window_text 2 2 "There are $num_creations creations."
      window_text 3 2 "Too many creations to fit onto screen."
      window_text 4 2 "Would you like to view in a pager? [y/n]"
      [ "$(read_key)" != "y" ] && return
      screen_teardown
        {
          for filename in $creations
          do
            filename_to_name "$filename"
          done
        } | less
      screen_init
      return
    fi
    window_text "$row" 5 $(filename_to_name $filename)
    (( row++ ))
  done
  (( row++ ))
  window_text "$row" 2 "Press any key to continue..."
  wait_key
}

function state_play
{
  select_creation "Select Creation to Play" existing || return

  window_set 3 40 "Playing Creation"
  window_draw
  window_text 2 2 "A window should popup."

  ext_wrap_error \
    "Error during playback" \
    "Oops! Something went wrong while playing the creation." \
    "" \
    ext_play_creation
}

function state_delete
{
  select_creation "Select Creation to Delete" existing || return
  window_set 4 70 "Confirm Deletion"
  window_draw
  window_text 2 2 "About to delete \"$selected_creation\""
  window_text 3 2 "Proceed? [y/n]"
  while true
  do
    local key=$(read_key)
    [ $key == "y" ] && break
    [ $key == "n" ] && return
  done
  screen_clear
  window_set 4 70 "Deleting Creation"
  window_draw
  window_text 2 2 "Deleting \"$selected_creation\"..."
  rm $selected_file
  window_text 2 2 "Deleting \"$selected_creation\"... done."
  window_text 3 2 "Press any key to continue"
  wait_key
}

function state_create
{
  select_creation "Choose Name for New Creation" new || return

  tmpdir_start

    ext_wrap_error \
      "Error while generating video" \
      "Oops! Something went wrong while creating video." \
      "" \
      ext_create_video || { tmpdir_end; return; }

    while true
    do
      window_set 5 70 "About to Create \"$selected_creation\""
      window_draw
      window_text 2 2 "You will need to record the audio for this creation."
      window_text 3 2 "Press escape to cancel."
      window_text 4 2 "Press any other key to begin recording (lasts five seconds)."
      local key=$(read_key)
      [ "$key" == "ESCAPE" ] && { tmpdir_end; return; }
      screen_clear

      window_set 5 70 "Recording \"$selected_creation\""
      window_draw

      window_progressbar_start 3 15 8 5
      ext_wrap_error \
        "Error while recording" \
        "Oops! Something went wrong while recording the audio." \
        window_progressbar_stop \
        ext_record_audio || { tmpdir_end; return; }

      screen_clear
      window_set 5 70 "Review \"$selected_creation\""
      window_draw
      window_text 3 2 "Would you like to hear the recorded audio? [y/n]..."

      if [ "$(read_key)" == "y" ]
      then
        window_draw
        window_progressbar_start 3 10 8 5
        ext_wrap_error \
          "Error with playback" \
          "Oops! Something went wrong while playing the audio." \
          window_progressbar_stop \
          ext_replay_audio || { tmpdir_end; return; }
      fi

      screen_clear
      window_set 7 70 "Confirm \"$selected_creation\""
      window_draw
      local sel_row=0
      local decision
      while true
      do
        window_text $([ $sel_row == 0 ] && echo hl) 2 6 " (k)eep audio and save creation"
        window_text $([ $sel_row == 1 ] && echo hl) 3 6 " (r)edo audio                  "
        window_text $([ $sel_row == 2 ] && echo hl) 4 6 " (c)ancel creation             "
        window_text 6 2 "Select an option [k/r/c]..."

        local key=$(read_key)

        if [ "$key" == "ENTER" ]
        then
          key="S$sel_row"
        fi

        case "${key^^}" in
          "S0"|"K")
            decision=keep
            break
            ;;
          "S1"|"R")
            decision=redo
            break
            ;;
          "S2"|"C"|"ESCAPE")
            tmpdir_end
            return
            ;;
          "UPARROW"|"K") (( sel_row = (sel_row + 2) % 3 )) ;;
          "DOWNARROW"|"J") (( sel_row = (sel_row + 1) % 3 )) ;;
        esac
      done
      if [ "$decision" == "keep" ]
      then
        break
      fi
      screen_clear
      rm audio.wav
    done

    ext_wrap_error \
      "Error while merging" \
      "Oops! Something went wrong while finalizing the creation." \
      "" \
      ext_merge_audio_video

  tmpdir_end

  screen_clear
  window_set 4 70 "Created \"$selected_creation\""
  window_draw
  window_text 2 2 "Your new creation has been created."
  window_text 3 2 "Press any key to continue..."
  wait_key
}

function state_quit
{
  window_set 3 40 "NameSayer"
  window_draw
  window_text 2 2 "NameSayer is closing. Goodbye."
  sleep 1
  teardown
  exit 0
}

function state_menu
{
  window_set 11 60 "Welcome to NameSayer"
  window_draw

  local sel_row=0

  while true
  do
    window_text 2 2 "Please select from one of the following options:"
    window_text $([ $sel_row == 0 ] && echo hl) 4 6 " (l)ist existing creations     "
    window_text $([ $sel_row == 1 ] && echo hl) 5 6 " (p)lay an existing creation   "
    window_text $([ $sel_row == 2 ] && echo hl) 6 6 " (d)elete an existing creation "
    window_text $([ $sel_row == 3 ] && echo hl) 7 6 " (c)reate a new creation       "
    window_text $([ $sel_row == 4 ] && echo hl) 8 6 " (q)uit authoring tool         "
    window_text 10 2 "Enter a selection [l/p/d/c/q]..."

    local key=$(read_key)

    if [ "$key" == "ENTER" ]
    then
      key="S$sel_row"
    fi

    case "${key^^}" in
      "S0"|"L") state_next=state_list ;;
      "S1"|"P") state_next=state_play ;;
      "S2"|"D") state_next=state_delete ;;
      "S3"|"C") state_next=state_create;;
      "S4"|"Q"|"ESCAPE") state_next=state_quit;;
      "UPARROW"|"K") (( sel_row = (sel_row + 4) % 5 )) ;;
      "DOWNARROW"|"J") (( sel_row = (sel_row + 1) % 5 )) ;;
    esac

    if [ "$state_next" != "state_menu" ]
    then
      break
    fi
  done
}

function state_machine_loop
{
  state_next=state_menu
  local state_current
  while true
  do
    state_current=$state_next
    state_next=state_menu
    screen_clear
    $state_current
  done
}

# And we begin...
init