#!/bin/bash

VERSION="0.3"

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' 1>&2;
  echo -e '\t-v               Version' 1>&2;
  echo -e '' 1>&2;
  echo -e '\t-s               Simulation' 1>&2; 
  echo -e '\t-r               Aufnahme' 1>&2;
  echo -e '\t-c               Konvertierung' 1>&2;
  echo -e '' 1>&2;
  echo -e '\t-C <configfile>  Konfiguration laden' 1>&2;
  echo "" 1>&2;
  echo "Doku: https://git.hs42.de/hs/sumsel" 1>&2;
  exit 1;
}

mode=''
lock_mode=''

while getopts ":hsrcC:v" options;
do
  case "${options}" in
    v)
      echo "$0 version ${VERSION}" 1>&2;
      exit 1
      ;;
    h)
      usage
      ;;
    "s" | "r" | "c") #simulate
      mode=${options}
      ;;
    C)
      config=${OPTARG}
      if [ -f ${config} ]; then
	. ${config}
      else 
	echo "config file not found: ${config}"
	exit
      fi
      ;;
    *)
      echo "unknown option"
      usage
      ;;
  esac
done

set_lockfile() {
  local basename=$(basename "$0")
  if [ ! -z ${1+x} ]; then
    basename="${basename}_$1"
  fi
  local lock_file="${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")
  if [ ! -z ${1+x} ]; then
    basename="${basename}_$1"
  fi
  local lock_file="${LOCK_DIR}/${basename}"

  rm ${lock_file}
}

cleanup() {
  del_lockfile ${lock_mode}
  exit 1
}

check_var_exists() {
  local var_name=$1

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

ctrl_c() {
  echo "** Trapped CTRL-C" 1>&2;
  cleanup
}

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

  local counter=0
  local dst_fn=""

  mkdir -p ${REC_DIR}
  echo "Press [CTRL+C] to stop.." 1>&2;
  trap ctrl_c INT
  while :
  do
    sleep ${REC_FILE_TIME}
    counter=$[$counter +1]
    dst_fn="${REC_DIR}/${REC_PREFIX}-${counter}.wav"
    cp ${SIM_EXAMPLE_FILE} ${dst_fn}
  done
}

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

  mkdir -p ${REC_DIR}
  trap ctrl_c INT
  arecord --format=cd --device=${REC_DEVICE} --buffer-size=192000 --max-file-time=${REC_FILE_TIME} --use-strftime ${REC_DIR}/${REC_PREFIX}%Y%m%d%H%M%v.wav 
}

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

  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}
}

case ${mode} in
  s) #Simulation
    lock_mode=record
    func=simulate
    ;;
  r) #Aufnahme
    lock_mode=record
    func=record
    ;;
  c) #Konvertierung
    lock_mode=convert
    func=convert
    ;;
  *)
    echo "mode not set" 1>&2;
    exit 1
    ;;
esac

if set_lockfile ${lock_mode}; then
  ${func}
  del_lockfile ${lock_mode}
else
  echo "LOCK error" 1>&2;
  exit 1
fi