[mp3] Add a few helper functions to manage music files

mp3helpers

@@ -0,0 +1,153 @@
+#!/bin/sh
+
+renameid3 () {
+    if [ -z "$1" ]; then
+        >&2 echo "Usage : $0 <file>"
+        return 1
+    fi
+
+    filename=$(mid3v2 "$1" | awk -F "=" '
+        /TIT2/{title = $2}
+        /TPE1/{artist = $2}
+        END {printf("%s - %s.mp3", artist, title)}
+    ')
+
+    dir=$(dirname "$1")
+    mv -v "$1" "$dir/$filename"
+}
+
+#mp3tag () {
+#    if [ -z "$1" ]; then
+#        >&2 echo "Usage : $0 <file>"
+#        return 1
+#    fi
+#
+#    if [ -d "$1" ]; then
+#        >&2 echo "Cannot open $1"
+#        return 1
+#    fi
+#
+#    artist=$(basename "$1")
+#    for f in "$1"/*; do
+#        id3=$(mid3v2 "$f")
+#        id3_artist=$(awk -F= '/TPE1/{print $2; // Will fail with a "="}')
+#        if ! grep "^TPE1=";  then
+#            # If artist is not already tagged
+#        fi
+#        if [ -n "$id3_artist" ] && [ "$artist" != "$id3_artist" ]; then
+#            artist
+#        fi
+#    done
+#}
+
+mp3sort () {
+    # TODO
+    # Fuzzy matching (ex Anti Nightcore -> Anti-Nightcore
+    # Best guess for artist enforcement -> Artist - Title.mp3
+    # Integrate filename cleanup (remove [offical video] etc.)
+
+    if [ "$#" -eq 0 ]; then
+        >&2 echo "Usage  $0 <file1...file2...>"
+        return 1
+    fi
+
+    mus_folder=${MUS_FOLDER:-"$HOME/mus"}
+
+    # Check that all the songs are from the same artist
+    artist=""
+    first=1
+    for f in "$@"; do
+        name=$(basename "$f")
+        # Fuck unicode
+        tmp=$(echo "$name" | awk -F " [-–] " '{print $1}')
+        # Trim a single whitespace
+        tmp="${tmp%% }"
+        if [ "$first" -eq 1 ]; then
+            first=0
+        elif [ "$tmp" != "$artist" ]; then
+            >&2 echo "File '$f' doesn't match artist name '$artist'"
+            return 1
+        fi
+        artist="$tmp"
+    done
+
+    folder="$mus_folder/$artist"
+
+    alt_folders=$(find "$mus_folder" -type d -iname '*'"$artist"'*' ! -name "$artist")
+    while [ -n "$alt_folders" ]; do
+        tmp=$(echo "$alt_folders" | head -n1)
+        >&2 printf 'One or more folders with mismatched casing already exist:\n%s\n' "$alt_folders"
+        >&2 printf "Use '%s' instead (y)\\nKeep original or skip to next choice (n)\\nQuit (q) " "$tmp"
+        old_stty_cfg=$(stty -g)
+        stty raw -echo
+        answer=$( while ! head -c 1 | grep -i '[nyq]' ;do true ;done )
+        stty "$old_stty_cfg" # Careful playing with stty
+        >&2 printf '\n'
+        # Use first line of $alt_folders (will break with newlines in dirnames)
+        if echo "$answer" | grep -iq "^y" ;then
+            folder="$tmp"
+            artist=$(basename "$folder")
+            break
+        # Quit
+        elif echo "$answer" | grep -iq "^q"; then
+            return 0
+        # Skip to next choice, or keep original if none are left
+        else
+            alt_folders=$(echo "$alt_folders" | tail -n +2)
+        fi
+    done
+
+    mkdir -p "$folder"
+
+    mid3v2 -a "$artist" "$@"
+
+    for f in "$@"; do
+        name=$(basename "$f")
+        # Make artist name in the filename match the folder
+        if [ -n "$alt_folders" ]; then
+            # https://stackoverflow.com/questions/19154996/awk-split-only-by-first-occurrence
+            name=$(echo "$name" | awk -F " [-–] " -v art="$artist" '{
+                st = match($0," [-–] ");
+                printf("%s %s", art, substr($0, st+1));
+            }')
+        fi
+        mv -v "$f" "$folder/$name"
+    done
+}
+
+mp3swaptitle () {
+    if [ -z "$1" ]; then
+        >&2 echo "Usage : $0 <file>"
+        return 1
+    fi
+
+    filename=$(echo "$1" | sed 's/\.mp3$//' | awk -F " - " -v OFS=" - " '{
+        gsub(/[ \t]+$/, "", $1); // Suffix trim
+        gsub(/[ \t]+$/, "", $2); // Suffix trim
+        gsub(/^[ \t]+/, "", $2); // Prefix trim
+        artist = $2;
+        title = $1;
+        $1 = $2 = "";
+        printf("%s - %s%s.mp3", artist, title, substr($0, 4));
+    }')
+
+    dir=$(dirname "$1")
+    mv -v "$1" "$dir/$filename"
+}
+
+mp3fixdash () {
+    if [ -z "$1" ]; then
+        >&2 echo "Usage : $0 <file>"
+        return 1
+    fi
+
+    filename=$(echo "$1" | sed -E -e 's/\S[-~–]\s+/ - /g; s/\s+[-~–]\S/ - /g; s/\s+[-~–]\s+/ - /g')
+    #filename=$(echo "$1" | sed -E -e 's/\S-\s+/(a)/g; s/\s+-\S/(b)/g; s/\s+-\s+/(c)/g')
+
+    if [ "$filename" = "$1" ]; then
+        >&2 echo "Nothing to be done"
+        return 0
+    fi
+    dir=$(dirname "$1")
+    mv -v "$1" "$dir/$filename"
+}