#!/bin/bash

LOCK_DIR=/var/lock

SIM_EXAMPLE_FILE=./res/test.wav

#Laenge der WAV Dateien in Sekunden
REC_FILE_TIME=360

#Ordner, ind dem die WAV Dateien abgelegt werden
#wenn der Ordner nicht existiert, wird er angelegt
REC_DIR=./recordings

#Dateiname der WAV Dateien
# sums-01.wav, sums-02.wav, ...
REC_PREFIX=sums

#Ordner in dem die MP3 Dateien abgelegt werden
#wenn der Ordner nicht existiert, wird er angelegt
UPL_DIR=./upqueue

#Dateiname der MP3 Dateien
# 20210130101112-sumsi.mp3, 20210130101120-sumsi.mp3, ...
UPL_SUFFIX=sumsi

usage() {
  echo "Usage: $0 [-h] (-s|-r|-t) [-C <configfile>]" 1>&2;
  echo -e '\t-h               Usage'
  echo -e '\t-s               Simulation' 
  echo -e '\t-r               Aufnahme'
  echo -e '\t-c               Konvertierung'
  echo -e '\t-C <configfile>  ssss'
  exit 1;
}

while getopts ":hsrcC:" options;
do
  case "${options}" in
    h)
      usage
      ;;
    "s" | "r" | "c") #simulate
      mode=${options}
      ;;
    C)
      config=${OPTARG}
      if [ -f ${config} ]; then
	. ${config}
      else 
	echo "file not found: ${config}"
	exit
      fi
      ;;
    *)
      echo "unknown option"
      usage
      ;;
  esac
done

check_var_exists() {
  local var_name=$1

  if [[ ! -v ${var_name} ]]; then
    echo "${var_name} not set"
    exit 1
  fi
}

set_lockfile() {
  local BASENAME=$(basename "$0")
  local LOCK_FILE="${LOCK_DIR}/${BASENAME}"
  local RANDOM_FILE=$(mktemp --tmpdir=${LOCK_DIR})
  echo $$ > ${RANDOM_FILE}
  mv -n ${RANDOM_FILE} ${LOCK_FILE}

  if [ -e ${RANDOM_FILE} ] ; then
    false
  else
    true
  fi
}

del_lockfile() {
  local BASENAME=$(basename "$0")
  local LOCK_FILE="${LOCK_DIR}/${BASENAME}"

  rm ${LOCK_FILE}
}

simulate() {
  check_var_exists "REC_DIR"
  check_var_exists "REC_PREFIX"
  check_var_exists "SIM_EXAMPLE_FILE"

  local COUNTER=0

  mkdir -p ${REC_DIR}
  echo "Press [CTRL+C] to stop.."
  while :
    do
      sleep 1
      COUNTER=$[$COUNTER +1]
      dst_fn="${REC_DIR}/${REC_PREFIX}-${COUNTER}.wav"
      cp ${SIM_EXAMPLE_FILE} ${dst_fn}
    done
    exit 0
}

record() {
  check_var_exists "REC_DEVICE"
  check_var_exists "REC_FILE_TIME"
  check_var_exists "REC_PREFIX"
  check_var_exists "REC_DIR"

  mkdir -p ${REC_DIR}
  arecord --format=cd --device=${REC_DEVICE} --max-file-time ${REC_FILE_TIME} ${REC_DIR}/${REC_PREFIX}.wav 
  exit 0
}

convert() {
  check_var_exists "REC_DIR"
  check_var_exists "UPL_DIR"
  check_var_exists "UPL_SUFFIX"
  check_var_exists "REMOTE_DIR"

  if set_lockfile;
  then

    mkdir -p ${REC_DIR}
    mkdir -p ${UPL_DIR}

    #Alle WAV Files ausser das letzte File. 
    #Das letzte File wird gerade recorded und wird beim naechsten Durchlauf verarbeitet
    local FILES=$(ls -tr ${REC_DIR} |head -n -1)

    for F in ${FILES}
    do
      #Ermittle ctime des WAV Files
      local CTIME=$(date -r "${REC_DIR}/${F}" +"%Y%m%d%H%M%S")
      ffmpeg -i "${REC_DIR}/${F}" -acodec mp3 "${UPL_DIR}/${CTIME}_${UPL_SUFFIX}.mp3" 
      rm "${REC_DIR}/${F}"
    done

    rsync -avzh --remove-source-files ${UPL_DIR} ${REMOTE_DIR}
    del_lockfile
    exit 0
  else
    echo "LOCK error"
    exit 1
  fi
}

case ${mode} in
  s) #Simulation
    simulate
    exit
    ;;
  r) #Aufnahme
    record
    ;;
  c) #Konvertierung
    convert
    ;;
  *)
    echo "mode not set"
    exit 1
    ;;
esac