Organize access to media files via tags

mkview.sh

#!/bin/bash

# Purpose: Creates sub-directories with symlinks to files that are scattered over
#          different directories but share a commonality, e.g, being 'a favourite'
# Context: Media collections
# Analogy: Database views, locate-command result saved as filesystem objects
# Author : github.com/andre-st
# Version: 2021-01-28
#
# Usage:
#   1. Copy this file to /usr/loca/bin/
#   2. create a ".views" directory in your collection
#   3. $ ln -s  /usr/local/bin/mkview.sh  your_collection/.views/update.sh
#   4. Tag filenames in your collection with:
#         + or ++ or +++ to indicate favourites (sorts them to the top in each dir too)
#         todo           to indicate a planned edit
#
# Note:
#   - browse XXXmb directories to find and delete big files if HDD space shrinks
#     (favourites are excluded by default)
#   - adjust views in this file as you need or create an "update.cfg" in a .views-directory
#     with nothing more than custom 'mkview', 'mksample' and 'mkquality' 
#     calls similar to this executable.
#     Update.cfg can also sets extra variables such as: FINDOPTEXTRA=-follow  to follow symbolic links
#   - dot-directories are ignored
#
#
# Example result:
#   your_collection
#   |-- .views
#   |   |-- 100mb
#   |   |-- 200mb
#   |   |-- 80mb
#   |   |   |-- 1080p
#   |   |   `-- 360p
#   |   |-- fav+
#   |   |   `-- sample
#   |   |-- fav++
#   |   |   `-- sample
#   |   |-- fav+++
#   |   |-- recent
#   |   `-- todo
#   |
#   |-- your_A
#   |-- your_B
#   |-- ...
#   `-- your_Z


# Creates a "dir/sample" directory with a random selection of files from a source directory "dir"
# given that "dir" has more than 60 symbolic links.
# -> string  dir with symlinks
function mksample()
{
	dir="$1"
	sampledir="sample"
	samplesize=60
	largersamplesize=$(( samplesize*2 ))
	
	pushd "$dir" > /dev/null
	
	rm -rf "$sampledir"
	
	numlinks=$( find . -type l -maxdepth 1 | wc -l )
	
	if (( $numlinks > $samplesize ))
	then
		mkdir "$sampledir"
		find . -type l -maxdepth 1 | shuf -n $largersamplesize | shuf -n $samplesize | while read linkname
		do
			abspath=$( readlink -e "$linkname" )
			relpath=$( realpath --relative-to "$sampledir" "$abspath" )
			ln -sfn "$relpath" "$sampledir/$linkname"
		done
	fi
	
	popd > /dev/null
}


# Creates a subdir based on video resolution from links in a source directory "dir".
# -> string  dir with symlinks
function mkquality()
{
	dir="$1"
	lq_height=360
	hq_height=1080
	lq_dir="${lq_height}p"
	hq_dir="${hq_height}p"
	
	pushd "$dir" > /dev/null
	
	rm -rf "$lq_dir" "$hq_dir"
	mkdir  "$lq_dir" "$hq_dir"
	
	find . -type l -maxdepth 1 | while read linkname
	do
		abspath=$( readlink -e "$linkname" )
		relpath=$( realpath --relative-to "$lq_dir" "$abspath" )
		height=$( ffprobe -v quiet -select_streams v:0 -show_entries stream=height -of csv=s=x:p=0 "$abspath" | head -n 1 )
		
		[ -z "$height" ] && continue
		
		if   (( "$height" <= $lq_height ))
		then
			ln -sfn "$relpath" "$lq_dir/$linkname"
		elif (( "$height" >= $hq_height ))
		then
			ln -sfn "$relpath" "$hq_dir/$linkname"
		fi
	done
	
	popd > /dev/null
}


# -> string  view name
# -> string  find-command expressions and test options (view filter)
# -> --add   dont delete links in view before adding new ones
function mkview()
{
	viewdir=$1
	findopt="-type f $2 -and ! -name '*.txt' -and ! -path '*/.*' $SKIPFINDOPT"
	findcmd="find .. $FINDOPTEXTRA \( $findopt \) -print $findpipe"
	
	mkdir -p $viewdir
	if [[ "$@" != *"--add"* ]]
	then
		find $viewdir -type l -delete
	fi
	
	IFS=$'\n'                                # Bash's field seperator != space (in filenames)
	while read filename
	do
		linkname=$(basename "$filename")
		while [ -e "$viewdir/$linkname" ]   # if dir1/f.mp4 and dir2/f.mp4 rename one link:
		do
			target_of_exist_link=`readlink $viewdir/$linkname`
			
			[[ "$target_of_exist_link" == "../$filename" ]] && break   # identical targets
			
			linkname="_$linkname"          # _f.mp4, then __f.mp4, ___f.mp4 until unique
		done
		
		ln -s "../$filename" "$viewdir/$linkname" 2>/dev/null
	
	done < <(eval "$findcmd")
}






echo "Updating .views"
pushd "$(dirname "${BASH_SOURCE[0]}")" > /dev/null

# Skip sub-directories with own .views (useless redundancy otherwise):
skipfindoptarr=(`find .. -type d -name '.views' -and ! -path '../.views' -printf '-and ! -path "%h/*" '`)
SKIPFINDOPT="${skipfindoptarr[@]}"


# Custom views and changes to global vars with effect on default views:
[[ -e update.cfg ]] && source update.cfg


# Default views:
mkview 'todo'    '-iname "*todo*"'

mkview 'fav+'    '-name "*+*"    -and ! -name "*.jpg" -and ! -name "* + *" '
mkview 'fav++'   '-name "*++*"   -and ! -name "*.jpg" -and ! -name "* + *" '
mkview 'fav+++'  '-name "*+++*"  -and ! -name "*.jpg" -and ! -name "* + *" '
mksample 'fav+'
mksample 'fav++'
mksample 'fav+++'

mkview '80mb'    '-size +80000k  -and ! -name "*+*"'
mkview '100mb'   '-size +100000k -and ! -name "*+*"'
mkview '200mb'   '-size +200000k -and ! -name "*+*"'
mkquality '80mb'

mkview 'recent'  '-mtime -31'  # 31 days
#mkview 'oldfmt' '-name "**.avi" -or -name "*.mpg" -or -name "*.mpeg" -or -name "*.wmv"'
#mkview 'cut'    '-iname "*.cut.*"'


popd > /dev/null