#!/bin/bash
# [b]rowse - overview of given files or current directory
# depends: tput stat bat checkaccess(in my dotfiles)
# optdepends: timg, neovim (compressed files), pdftoppm (PDF), mtn (video), audiowaveform
# args: files to inspect
#
# Supports:
# - listing directories
# - listing contents of any compressed file with neovim
# - visual files are displayed with timg
#   video thumbnails via mtn, pdf pages from pdftoppm
# - text files are displayed through bat
# Automatically requests elevation through sudo when needed

set -o pipefail
for last; do true; done
last=${last:-.}

checkperm() {
	checkaccess -r "$@" || elevate=sudo
	mime="$(test -n "$shifted" || $elevate file --dereference --mime "$@")"
}
checkperm "$last"

fileinfo() {
	tput setaf 6
	for arg
	do case "$arg" in (-*) continue;; esac
		$elevate file -E "$arg" &&
			ffprobe "$arg" 2>&1 | grep Duration | grep -v '00:00:00.04' | sed 's/, start:[^,]\+,/,/' ||
			stat --format '%A %s - birth %.10w mod %.10y' "$arg" | numfmt --field=2 --to=iec-i --padding=6 --suffix=B
	done
}

prefix=/tmp/b
mkdir -p "$prefix"
declare -a timg bat ls
for arg; do
	case "$arg" in (-*) args="$args $arg"; continue;; esac
	checkperm "$arg"
	grid=$(expr $(tput cols) / 20)
	tmpfile="$prefix/$(basename "$arg")"
	case "$mime" in
	(*\ application/pdf\;*)
		test -f "$tmpfile-1.png" || pdftoppm -r 70 "$arg" "$tmpfile" -l $(expr $grid '*' 2)
		timg -W --grid=$grid "$tmpfile"*
		;;
	(*\ video/*)
		suffix=_thumbs.jpg
		mtn -i -t -W -D6 -b 0,6 -c $grid -w $(expr $(tput cols) '*' 20) -O $prefix -o $suffix "$arg" 2>/dev/null
		timg -W "$prefix/$(basename "${arg%.*}")$suffix"
		;;
	(*\ image/*)
		timg+=("$arg"); continue;;
	(*\ inode/directory\;*)
		ls+=("$arg"); continue;;
	(*)
		case "$(file "$arg")" in
		(*\ ?udio*)
			img="$tmpfile.png"
			if which audiowaveform 2>/dev/null >&2
			then find "$img" -not -empty 2>/dev/null | grep --quiet . ||
				audiowaveform --quiet --pixels-per-second 2 --height 36 --width 2000 --amplitude-scale auto \
					--background-color 000000 --waveform-color 99BBFF --axis-label-color 000000 \
					--input-filename "$arg" --output-format png >"$img" && {
						timg -g $(tput cols)x2 "$arg" && printf "\\033[2A     "
						timg -g $(tput cols)x2 --auto-crop --upscale "$img"
					}
			fi
			;;
		(*:\ *compress*|*tar\ archive)
			if test $# = 1
			then nvim "$arg"
			else case "$arg" in (*.part);; (*)
				nvim -es "+2w$tmpfile|5,w>>$tmpfile" "$arg"
				bat+=("$tmpfile");;
			esac; fi
			;;
		(*) bat+=("$arg"); continue;;
		esac
		;;
	esac
	fileinfo "$arg"
done

if test "$timg"; then
	tput sgr0
	$elevate timg --center -t0.3 $(test $# -gt 1 &&
		echo "--title --grid=$(expr $(tput cols) / 30)" ||
		echo "-g 60x$(expr $(tput lines) / 2)") "$@" 2>/dev/null
	for img in "${timg[@]}"
	do printf "%11s %-30s	%s\n" "$(identify -format "%wx%h" "$img")" "$img" "$(identify -precision 3 -format "%b %m %[bit-depth]-bit %[colorspace]" "$img")"
	done
fi

if test "$bat"; then
	tput sgr0
	test $# -gt ${#bat[@]} && test -z "$args" &&
		$elevate head "${bat[@]}" ||
		$elevate bat --style header --pager 'less -RF' $args "${bat[@]}"
	fileinfo "${bat[@]}"
fi

if test "$ls"; then
	tput sgr0
	$elevate ls -l $(test $# -gt ${#ls[@]} && echo "-d") --color=always --human-readable --group-directories-first --file-type --dereference-command-line --all "${ls[@]}" | less -RF
fi