#!/bin/bash
# [b]rowse - overview of given files or current directory
# depends: tput stat bat checkaccess
# optdepends: timg, neovim (compressed files), pdftoppm (PDF), mtn (video)
# 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 -eo pipefail
for last; do true; done
last=${last:-.}

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

fileinfo() {
	for arg
	do case "$arg" in (-*) continue;; esac
		tput setaf 4 && $elevate file -E "$arg"
		tput setaf 3 && $elevate stat --format '%A size %sB, birth %.10w mod %.10y' "$arg"
	done
}

case "$mime" in
(*\ inode/directory\;*) tput sgr0 &&
	$(test -x "$last" || echo "sudo") ls -l --color=always --human-readable --group-directories-first --file-type --dereference-command-line --all "$@" | less -RF;;
(*binary|*-8bit)
	prefix=/tmp/b
	mkdir -p "$prefix"
	for arg; do
		case "$arg" in (-*) continue;; esac
		checkperm "$arg"
		fileinfo "$arg"
		grid=$(expr $(tput cols) / 20)
		case "$mime" in
		(*\ application/pdf\;*)
			out="$prefix/$(basename "$arg")"
			test -f "$out-1.png" || pdftoppm -r 70 "$arg" "$out" -l $(expr $grid '*' 2)
			timg -W --grid=$grid "$out"*
			;;
		(*\ 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"
			;;
		(*)
			case "$(file "$arg")" in
				(*:\ *compress*) /usr/share/nvim/runtime/macros/less.sh "$arg";;
				(*:\ *\ image\ data*) timg --center $(test $# -gt 1 &&
					echo "--title --grid=$(expr $(tput cols) / 30)" ||
					echo "-g 60x$(expr $(tput lines) / 2)") "$@"
					exit $?;;
			esac
			;;
		esac
	done
	;;
(*)
	fileinfo "$@"
	$elevate bat --style header "$@" --pager 'less -RF'
	;;
esac