#! /bin/bash

set -e

###--------------------------------------------------------------------------
### Table of contents representation.
###
### We need a simple table of contents representation.  A toc file consists
### of a number of records, one per line; each record is a number of
### blank-delimited fields.  Fields don't contain whitespace, so no quoting
### is needed.  The first field of each record is a type which explains how
### to decode the rest.
###
### `T' START	Audio track starts at START frames.
###
### `D' START	Data track, starts at START frames.
###
### `E' END	Leadout at END frames.

###--------------------------------------------------------------------------
### Command line options.

hidden=0
data=none
while getopts "d:h:" opt; do
  case "$opt" in
    h) hidden=$OPTARG ;;
    d) data=$OPTARG ;;
    *) exit 1 ;;
  esac
done
shift $((OPTIND - 1))

case "$#" in
  1) ;;
  *) echo >&2 "Usage: $0 [-d DATA] [-h HIDDEN] DIR|CD-DEVICE"; exit 1 ;;
esac
source=$1

###--------------------------------------------------------------------------
### Work out what to do.

if [ -d "$source" ]; then

  ## Intuit what's going on from a directory full of FLAC files.
  cd "$source"
  for i in [0-9][0-9][-.\ ]*.flac; do
    metaflac --show-total-samples "$i"
  done | {
    tn=1 tot=$hidden
    while read samples; do
      frames=$((samples/588))
      echo "T $tot"
      tot=$((tot + frames))
    done
    case "$data" in
      none)
	;;
      *)
	tot=$((tot + 11400))
	echo "D $tot"
	tot=$((tot + data))
	;;
    esac
    echo "E $tot"
  }

elif [ -b "$source" ]; then

  ## Read a table of contents from a CD.
  wodim dev="$source" -toc | sed '
	/^track:/ !d
	s/^track:\(.*\) lba: *\([0-9][0-9]*\) (.*mode: *\([-0-9][0-9]*\) *$/\1 \3 \2/
  ' | while read track mode offset; do
    case "$track,$mode" in
      lout,-1) echo "E $offset" ;;
      *,0 | *,-1) echo "T $offset" ;;
      *,1 | *,2) echo "D $offset" ;;
    esac
  done

else
  echo >&2 "$0: don't know how to read a toc from $source"
fi