# Create a BASH shell script called momo (My Own Music Organizer)
# in ~/uli101.a2/ directory according to the following specifications:"

# Your script will be used to organize a collection of MP3 files.
# Files to be processed are expected to reside in a single directory
# (no sub-directories).
# Your script, must create subdirectories for each artist and
# create symbolic links to each song in appropriate directories.

# The script usage will be as follows:
# momo source_directory [destination directory]

# If the destination directory is not provided, the present working directory
# is the destination.
# The name of the file/link will be based on album and song name
# in the following format: Album - SongTitle.mp3

# Additional information:
# - All song metadata will be based on information in ID3v1 tags
# - Assume that all .mp3 files in the source directory have a valid ID3v1 tag
#   (ID3v1 details can be found on-line: http://en.wikipedia.org/wiki/ID3#ID3v1)
# - .mp3 extensions can have any combination of upper- and lower-case letters
# - Assume that you have read permission for the source directory
#   and write permission for destination
# - Ignore files in the source directory that do not have the .mp3 extension
# - Display an error message and exit with status 1 if no parameters are given
# - Display an error message and exit with status 2 if source is not a directory
# - Display an error message and exit with status 3 if destination
#   does not exist or is not a directory

# TIP: Keep a secure backup of your script outside of other users' access.

# Practice files can be found on matrix in ~uli101/public/songs[1-5]
# directories.  Although they are not actual mp3 files, they contain
# valid ID3v1 tags.

# In addition to creating a directory/file structure, your script must create
# a valid XHTML report file containing the output of the tree command,
# showing the above structure. The report will also show a footer section
# showing the source directory path, date/time when report was created
# and number of artist and songs organized.

# A sample report is available: https://cs.senecac.on.ca/~fac/uli101/momo.html

# Place the report file in the output directory and call it: .songs.html
# Use the Courier typeface throughout the page and set the text colour to
# 0011 0011 0110 0110 1001 1001 using hexadecimal numbers.
# Pick a background colour that contrasts well with your text colour.
# Do not just use white for background.

# TIP: Have a dedicated testing directory for output and make a symbolic link
# in your ~/public_html directory to your report file in there.
# This way it will be easy to view and validate the report using your browser.

# Your script will produce a single line of output to the shell
# (other than possible error messages), containing two numbers, separated by
# a single space: number of artists processed and number of songs processed.

# Check your progress using the following command: uli101.a2.check
# Submit your completed assignment using the following command: uli101.a2.submit

# PLEASE NOTE THAT PLAGIARISM CASES WILL BE HANDLED ACCORDING TO THE ACADEMIC
# POLICY. YOUR SCRIPT MUST BE WRITTEN WITHOUT HELP FROM OTHERS AND YOU ARE NOT
# ALLOWED TO ACCESS OTHER STUDENTS' ASSIGNMENTS
# DO NOT SHARE YOUR SOLUTION. ASK ONLY YOUR PROFESSOR FOR HELP.

### TO DO: Check if at least one parameter is supplied, exit on error
if [ $# ]
then
        exit
fi

### TO DO: Check if first parameter is a directory, exit on error

# Set the destination to default (pwd) if no destination is provided
if [ $# -lt 2 ]
then
        set "$1" .
fi

### TO DO: Check if destination exists and is a directory, exit on error

for path in $(### TO DO: Get the list of mp3 files in the source directory)
do
        # Extract the ID3 TAG from file
        tag=$(tail -c 128 $path)

        # Extract the song name and trim space padding
        song_name=$(echo "$tag" | cut -c 4-33 | sed -r 's/ +$//')

        ### TO DO: Extract the artist and album, trim both
        ### TO DO: Create a directory for artist in the destination directory
        ### (if not already there)
### TO DO: Create a symbolic link to the song in the artist's directory
done

### TO DO: Finish the output line to the terminal
echo

cat << TOP > $2/### TO DO: Set the report file name here
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US" lang="en-US">
<head>
        <title>ID3 Report Page</title>

        ### TO DO: Display the tree for the artists/songs directory structure

        <style type="text/css">
        ### TO DO: Set the font typeface for the entire report page as assigned
        ### TO DO: Set the font colour for the entire page as assigned
        ### TO DO: Set the report background to a colour of your choosing
        </style>
</head>
<body>
        <h2>ID3 Report Page</h2>
TOP

### TO DO: Add the path to the source directory to the report
### TO DO: Add current date/time to the report
### TO DO: Add to the report how many artists and songs were processed
### TO DO: Add the W3C XHTML Validator link and icon to the report
### TO DO: Add the W3C CSS Validator link and icon to the report

echo "</body></html>" >> $2/### TO DO: Set the report file name here

for path in $(### TO DO: Get the list of mp3 files in the source directory)
do
        # Extract the ID3 TAG from file
        tag=$(tail -c 128 $path)

        # Extract the song name and trim space padding
        song_name=$(echo "$tag" | cut -c 4-33 | sed -r 's/ +$//')

        ### TO DO: Extract the artist and album, trim both
        ### TO DO: Create a directory for artist in the destination directory
        ### (if not already there)
### TO DO: Create a symbolic link to the song in the artist's directory
done

for path in $1 ls .*[mM][pP]3
do
        tag=$(tag -c 128 $path)

        song_name=$(echo "$tag" | cut -c 4-33 | sed -r 's/ +$//')
        artist=$(echo "$tag" | cut -c 34-63 | sed -r 's/ +$//')
        album=$(echo "$tag" | cut -c 64-93 | sed -r 's/ +$//')
done

filename="$artist" - "$song_name".mp3

if [ ! -d "$2/$artist" ]
        mkdir "$2/$artist"
fi

ln -s $tag $filename