#!/bin/sh

SCRIPT="$(basename "$0")"

long='width,verbose,help'
short='wvh'

if ! opts="$(getopt -o $short -l $long -n "$SCRIPT" -- "$@")"; then
	exit 1
fi

eval set -- "$opts"

help() {
	cat <<-EOF
		$SCRIPT
		Toby Vincent <tobyv13@gmail.com>

		$SCRIPT
		    Filter script used for lesspipe.sh filtering

		USAGE:
		    $SCRIPT [OPTION ...] <PATH> [PATH ...]

		OPTIONS:
		    -w, --width           Specify width. By default uses FZF_PREVIEW_COLUMNS if
		                              set, and falls back to COLUMNS
		    -v, --verbose         Increase verbosity
		    -h, --help            Show this help
	EOF
}

say() {
	printf "%s: %s\n" "$SCRIPT" "$@"
}

say_verbose() {
	if [ "$verbose" -gt "0" ]; then
		say "$@"
	fi
}

say_err() {
	say "$@" >&2
}

err() {
	err_dir="$1"
	shift
	say_err "cannot preview '$err_dir': $*"
	exit 1
}

err_help() {
	help
	err "$*"
}

has() {
	command -v "$1" >/dev/null
}

is_git_repo() {
	[ -d "$1/.git" ] || git -C "$1" rev-parse --is-inside-work-tree >/dev/null 2>&1
}

mime() {
	if [ -e "$1" ]; then
		mtype=$(file -L -s -b --mime "$1" 2>/dev/null)
		fcat="${mtype%/*}"
		mtype="${mtype#*/}"
		mtype="${mtype%;*}"
		mtype="${mtype#x-}"
		mtype="${mtype#vnd\.}"

		if [ "$fcat" = "application" ] &&
			[ "$ftype" = "octet-stream" ] ||
			[ "$fcat" = "text" ] &&
			[ "$ftype" = "plain" ]; then
			mtype=$(file -L -s -b "$1" 2>/dev/null)
		fi
	else
		case "$1" in
		http://*)
			mtype='x-scheme-handler/http'
			;;
		https://*)
			mtype='x-scheme-handler/https'
			;;
		*)
			mtype='repo'
			;;
		esac
	fi

	printf %s\\n "$mtype"
}

fileext() {
	case "$1" in
	.*.*) extension=${1##*.} ;;
	.*) extension= ;;
	*.*) extension=${1##*.} ;;
	esac

	printf %s\\n "$extension"
}

filetype() {
	fname="$1"
	fext=$(fileext "$fname")
	mtype=$(mime "$fname")

	ft="${mtype#*/}"
	ft="${ft%;*}"
	ft="${ft#x-}"
	ftype="${ft#vnd\.}"

	case "$fext" in
	epub) [ "$ftype" = "zip" ] && ftype='epub' ;;
	ipynb) [ "$ftype" = "json" ] && ftype='ipynb' ;;
	mp3) [ "$ftype" = "mpeg" ] && ftype='mp3' ;;
	crt | pem) ftype='x509' ;;
	crl) ftype='crl' ;;
	csr) ftype='csr' ;;
	pod) ftype='pod' ;;
	pm) ftype='perl' ;;
	md | MD | mkd | markdown | rst) ftype='markdown' ;;
	log) ftype='log' ;;
	ebuild | eclass) ftype='sh' ;;
	esac

	case "$ftype" in
	openxmlformats-officedocument.wordprocessingml.document) ftype='docx' ;;
	openxmlformats-officedocument.presentationml.presentation) ftype='pptx' ;;
	openxmlformats-officedocument.spreadsheetml.sheet) ftype='xlsx' ;;
	oasis.opendocument.text*) ftype='odt' ;;
	oasis.opendocument.spreadsheet) ftype='ods' ;;
	oasis.opendocument.presentation) ftype='odp' ;;
	sun.xml.writer) ftype='ooffice1' ;;
	shellscript) ftype='sh' ;;
	makefile) ftype='make' ;;
	epub+zip) ftype='epub' ;;
	matlab-data) ftype='matlab' ;;
	troff) case "${fname##*/}" in
		[Mm]akefile | [Mm]akefile.* | BSDMakefile) ftype='make' ;;
		esac ;;
	*mat-file*) ftype='matlab' ;;
	*POD\ document*) ftype='pod' ;;
	*PEM\ certificate\ request) ftype='csr' ;;
	*PEM\ certificate) ftype='csr' ;;
	*Microsoft\ OOXML) ftype='docx' ;;
	Apple\ binary\ property\ list) ftype='plist' ;;
	PGP\ *ncrypted* | GPG\ encrypted*) ftype='pgp' ;;
	Audio\ file\ with\ ID3\ *) ftype='mp3' ;;
	'OpenOffice.org 1.x Writer document') ftype='ooffice1' ;;
	# if still unspecific, determine file type by extension
	data)
		### binary only file formats, type not guessed by 'file'
		case "$fext" in
		mat) ftype='matlab' ;;
		br | bro | tbr) ftype='brotli' ;;
		lz4 | lt4 | tz4 | tlz4) ftype='lz4' ;;
		esac
		;;
	esac

	printf %s\\n "$ftype"
}

verbose=0
width=${FZF_PREVIEW_COLUMNS:-$COLUMNS}
while true; do
	case "$1" in
	-h | --help)
		help
		exit 0
		;;
	-v | --verbose)
		verbose=$((verbose + 1))
		shift
		;;
	-w | --width)
		width=$2
		shift 2
		;;
	--)
		shift
		break
		;;
	*)
		err_help "Invalid argument: $1"
		;;
	esac
done

if [ "$#" -eq 0 ]; then
	IFS='
'
	set -o noglob
	# shellcheck disable=2046
	set -- $(cat)
fi

if [ -z "$width" ]; then
	width=$(tput cols)
fi

ft=$(filetype "$1")
case "$ft" in
directory)
	if has onefetch && is_git_repo "$1" 2>/dev/null; then
		onefetch --hidden --show-logo="$([ "$width" -lt "80" ] && printf 'never' || printf 'always')" "$1" 2>/dev/null
	elif [ -f "$1/README.md" ]; then
		$SCRIPT "$1/README.md"
	else
		exa --tree --git-ignore --level=3 --icons "$1" 2>/dev/null
	fi
	;;
markdown)
	bat --color always "$1" 2>/dev/null
	;;
http | https)
	if printf %s\\n "$1" | grep -q "git.sr.ht"; then
		has hut && hut git show --repo "$1" 2>/dev/null
	elif printf %s\\n "$1" | grep -q "github.com"; then
		has gh && gh repo view "$1" 2>/dev/null
	fi
	;;
repo)
	hut git show --repo "https://git.sr.ht/$1" 2>/dev/null ||
		gh repo view "https://github.com/$1" 2>/dev/null
	;;
*)
	exit 1
	;;
esac