#!/usr/bin/env bash

set -o noclobber -o noglob -o nounset -o pipefail
IFS=$'\n'

## If the option `use_preview_script` is set to `true`,
## then this script will be called and its output will be displayed in ranger.
## ANSI color codes are supported.
## STDIN is disabled, so interactive scripts won't work properly

## This script is considered a configuration file and must be updated manually.
## It will be left untouched if you upgrade ranger.

## Because of some automated testing we do on the script #'s for comments need
## to be doubled up. Code that is commented out, because it's an alternative for
## example, gets only one #.

## Meanings of exit codes:
## code | meaning    | action of ranger
## -----+------------+-------------------------------------------
## 0    | success    | Display stdout as preview
## 1    | no preview | Display no preview at all
## 2    | plain text | Display the plain content of the file
## 3    | fix width  | Don't reload when width changes
## 4    | fix height | Don't reload when height changes
## 5    | fix both   | Don't ever reload
## 6    | image      | Display the image `$IMAGE_CACHE_PATH` points to as an image preview
## 7    | image      | Display the file directly as an image

## Script arguments
FILE_PATH="${1}" # Full path of the highlighted file
PV_WIDTH="${2}"  # Width of the preview pane (number of fitting characters)
## shellcheck disable=SC2034 # PV_HEIGHT is provided for convenience and unused
PV_HEIGHT="${3}"        # Height of the preview pane (number of fitting characters)
IMAGE_CACHE_PATH="${4}" # Full path that should be used to cache image preview
PV_IMAGE_ENABLED="${5}" # 'True' if image previews are enabled, 'False' otherwise.

FILE_EXTENSION="${FILE_PATH##*.}"
FILE_EXTENSION_LOWER="$(printf "%s" "${FILE_EXTENSION}" | tr '[:upper:]' '[:lower:]')"

## Settings
HIGHLIGHT_SIZE_MAX=262143 # 256KiB
HIGHLIGHT_TABWIDTH="${HIGHLIGHT_TABWIDTH:-8}"
HIGHLIGHT_STYLE="${HIGHLIGHT_STYLE:-pablo}"
HIGHLIGHT_OPTIONS="--replace-tabs=${HIGHLIGHT_TABWIDTH} --style=${HIGHLIGHT_STYLE} ${HIGHLIGHT_OPTIONS:-}"
PYGMENTIZE_STYLE="${PYGMENTIZE_STYLE:-autumn}"
BAT_STYLE="${BAT_STYLE:-plain}"
OPENSCAD_IMGSIZE="${RNGR_OPENSCAD_IMGSIZE:-1000,1000}"
OPENSCAD_COLORSCHEME="${RNGR_OPENSCAD_COLORSCHEME:-Tomorrow Night}"
SQLITE_TABLE_LIMIT=20 # Display only the top <limit> tables in database, set to 0 for no exhaustive preview (only the sqlite_master table is displayed).
SQLITE_ROW_LIMIT=5    # Display only the first and the last (<limit> - 1) records in each table, set to 0 for no limits.

handle_extension() {
	case "${FILE_EXTENSION_LOWER}" in
	## Archive
	a | ace | alz | arc | arj | bz | bz2 | cab | cpio | deb | gz | jar | lha | lz | lzh | lzma | lzo | \
		rpm | rz | t7z | tar | tbz | tbz2 | tgz | tlz | txz | tZ | tzo | war | xpi | xz | Z | zip)
		atool --list -- "${FILE_PATH}" && exit 5
		bsdtar --list --file "${FILE_PATH}" && exit 5
		exit 1
		;;
	rar)
		## Avoid password prompt by providing empty password
		unrar lt -p- -- "${FILE_PATH}" && exit 5
		exit 1
		;;
	7z)
		## Avoid password prompt by providing empty password
		7z l -p -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## PDF
	pdf)
		## Preview as text conversion
		pdftotext -l 10 -nopgbrk -q -- "${FILE_PATH}" - |
			fmt -w "${PV_WIDTH}" && exit 5
		mutool draw -F txt -i -- "${FILE_PATH}" 1-10 |
			fmt -w "${PV_WIDTH}" && exit 5
		exiftool "${FILE_PATH}" && exit 5
		exit 1
		;;

	## BitTorrent
	torrent)
		transmission-show -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## OpenDocument
	odt | sxw)
		## Preview as text conversion
		odt2txt "${FILE_PATH}" && exit 5
		## Preview as markdown conversion
		pandoc -s -t markdown -- "${FILE_PATH}" && exit 5
		exit 1
		;;
	ods | odp)
		## Preview as text conversion (unsupported by pandoc for markdown)
		odt2txt "${FILE_PATH}" && exit 5
		exit 1
		;;

	## XLSX
	xlsx)
		## Preview as csv conversion
		## Uses: https://github.com/dilshod/xlsx2csv
		xlsx2csv -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## HTML
	htm | html | xhtml)
		## Preview as text conversion
		w3m -dump "${FILE_PATH}" && exit 5
		lynx -dump -- "${FILE_PATH}" && exit 5
		elinks -dump "${FILE_PATH}" && exit 5
		pandoc -s -t markdown -- "${FILE_PATH}" && exit 5
		;;

	## JSON
	json)
		jq --color-output . "${FILE_PATH}" && exit 5
		python -m json.tool -- "${FILE_PATH}" && exit 5
		;;

	## Jupyter Notebooks
	ipynb)
		jupyter nbconvert --to markdown "${FILE_PATH}" --stdout | env COLORTERM=8bit bat --color=always --style=plain --language=markdown && exit 5
		jupyter nbconvert --to markdown "${FILE_PATH}" --stdout && exit 5
		jq --color-output . "${FILE_PATH}" && exit 5
		python -m json.tool -- "${FILE_PATH}" && exit 5
		;;

	## Direct Stream Digital/Transfer (DSDIFF) and wavpack aren't detected
	## by file(1).
	dff | dsf | wv | wvc)
		mediainfo "${FILE_PATH}" && exit 5
		exiftool "${FILE_PATH}" && exit 5
		;; # Continue with next handler on failure
	esac
}

handle_image() {
	## Size of the preview if there are multiple options or it has to be
	## rendered from vector graphics. If the conversion program allows
	## specifying only one dimension while keeping the aspect ratio, the width
	## will be used.
	local DEFAULT_SIZE="1920x1080"

	local mimetype="${1}"
	case "${mimetype}" in
	## SVG
	image/svg+xml | image/svg)
		rsvg-convert --keep-aspect-ratio --width "${DEFAULT_SIZE%x*}" "${FILE_PATH}" -o "${IMAGE_CACHE_PATH}.png" &&
			mv "${IMAGE_CACHE_PATH}.png" "${IMAGE_CACHE_PATH}" &&
			exit 6
		exit 1
		;;

	## DjVu
	image/vnd.djvu)
		ddjvu -format=tiff -quality=90 -page=1 -size="${DEFAULT_SIZE}" \
			- "${IMAGE_CACHE_PATH}" <"${FILE_PATH}" &&
			exit 6 || exit 1
		;;

	## Image
	image/*)
		local orientation
		orientation="$(identify -format '%[EXIF:Orientation]\n' -- "${FILE_PATH}")"
		## If orientation data is present and the image actually
		## needs rotating ("1" means no rotation)...
		if [[ -n "$orientation" && "$orientation" != 1 ]]; then
			## ...auto-rotate the image according to the EXIF data.
			convert -- "${FILE_PATH}" -auto-orient "${IMAGE_CACHE_PATH}" && exit 6
		fi

		## `w3mimgdisplay` will be called for all images (unless overridden
		## as above), but might fail for unsupported types.
		exit 7
		;;

	## Video
	video/*)
		# Get embedded thumbnail
		ffmpeg -i "${FILE_PATH}" -map 0:v -map -0:V -c copy "${IMAGE_CACHE_PATH}" && exit 6
		# Get frame 10% into video
		ffmpegthumbnailer -i "${FILE_PATH}" -o "${IMAGE_CACHE_PATH}" -s 0 && exit 6
		exit 1
		;;

	## Audio
	audio/*)
		# Get embedded thumbnail
		ffmpeg -i "${FILE_PATH}" -map 0:v -map -0:V -c copy \
			"${IMAGE_CACHE_PATH}" && exit 6
		;;

	## PDF
	application/pdf)
		pdftoppm -f 1 -l 1 \
			-scale-to-x "${DEFAULT_SIZE%x*}" \
			-scale-to-y -1 \
			-singlefile \
			-jpeg -tiffcompression jpeg \
			-- "${FILE_PATH}" "${IMAGE_CACHE_PATH%.*}" &&
			exit 6 || exit 1
		;;

	## ePub, MOBI, FB2 (using Calibre)
	# application/epub+zip|application/x-mobipocket-ebook|\
	# application/x-fictionbook+xml)
	#     # ePub (using https://github.com/marianosimone/epub-thumbnailer)
	#     epub-thumbnailer "${FILE_PATH}" "${IMAGE_CACHE_PATH}" \
	#         "${DEFAULT_SIZE%x*}" && exit 6
	#     ebook-meta --get-cover="${IMAGE_CACHE_PATH}" -- "${FILE_PATH}" \
	#         >/dev/null && exit 6
	#     exit 1;;

	## Font
	application/font* | application/*opentype)
		preview_png="/tmp/$(basename "${IMAGE_CACHE_PATH%.*}").png"
		if fontimage -o "${preview_png}" \
			--pixelsize "120" \
			--fontname \
			--pixelsize "80" \
			--text "  ABCDEFGHIJKLMNOPQRSTUVWXYZ  " \
			--text "  abcdefghijklmnopqrstuvwxyz  " \
			--text "  0123456789.:,;(*!?') ff fl fi ffi ffl  " \
			--text "  The quick brown fox jumps over the lazy dog.  " \
			"${FILE_PATH}"; then
			convert -- "${preview_png}" "${IMAGE_CACHE_PATH}" &&
				rm "${preview_png}" &&
				exit 6
		else
			exit 1
		fi
		;;

		## Preview archives using the first image inside.
		## (Very useful for comic book collections for example.)
		# application/zip|application/x-rar|application/x-7z-compressed|\
		#     application/x-xz|application/x-bzip2|application/x-gzip|application/x-tar)
		#     local fn=""; local fe=""
		#     local zip=""; local rar=""; local tar=""; local bsd=""
		#     case "${mimetype}" in
		#         application/zip) zip=1 ;;
		#         application/x-rar) rar=1 ;;
		#         application/x-7z-compressed) ;;
		#         *) tar=1 ;;
		#     esac
		#     { [ "$tar" ] && fn=$(tar --list --file "${FILE_PATH}"); } || \
		#     { fn=$(bsdtar --list --file "${FILE_PATH}") && bsd=1 && tar=""; } || \
		#     { [ "$rar" ] && fn=$(unrar lb -p- -- "${FILE_PATH}"); } || \
		#     { [ "$zip" ] && fn=$(zipinfo -1 -- "${FILE_PATH}"); } || return
		#
		#     fn=$(echo "$fn" | python -c "from __future__ import print_function; \
		#             import sys; import mimetypes as m; \
		#             [ print(l, end='') for l in sys.stdin if \
		#               (m.guess_type(l[:-1])[0] or '').startswith('image/') ]" |\
		#         sort -V | head -n 1)
		#     [ "$fn" = "" ] && return
		#     [ "$bsd" ] && fn=$(printf '%b' "$fn")
		#
		#     [ "$tar" ] && tar --extract --to-stdout \
		#         --file "${FILE_PATH}" -- "$fn" > "${IMAGE_CACHE_PATH}" && exit 6
		#     fe=$(echo -n "$fn" | sed 's/[][*?\]/\\\0/g')
		#     [ "$bsd" ] && bsdtar --extract --to-stdout \
		#         --file "${FILE_PATH}" -- "$fe" > "${IMAGE_CACHE_PATH}" && exit 6
		#     [ "$bsd" ] || [ "$tar" ] && rm -- "${IMAGE_CACHE_PATH}"
		#     [ "$rar" ] && unrar p -p- -inul -- "${FILE_PATH}" "$fn" > \
		#         "${IMAGE_CACHE_PATH}" && exit 6
		#     [ "$zip" ] && unzip -pP "" -- "${FILE_PATH}" "$fe" > \
		#         "${IMAGE_CACHE_PATH}" && exit 6
		#     [ "$rar" ] || [ "$zip" ] && rm -- "${IMAGE_CACHE_PATH}"
		#     ;;
	esac

	# openscad_image() {
	#     TMPPNG="$(mktemp -t XXXXXX.png)"
	#     openscad --colorscheme="${OPENSCAD_COLORSCHEME}" \
	#         --imgsize="${OPENSCAD_IMGSIZE/x/,}" \
	#         -o "${TMPPNG}" "${1}"
	#     mv "${TMPPNG}" "${IMAGE_CACHE_PATH}"
	# }

	case "${FILE_EXTENSION_LOWER}" in
	## 3D models
	## OpenSCAD only supports png image output, and ${IMAGE_CACHE_PATH}
	## is hardcoded as jpeg. So we make a tempfile.png and just
	## move/rename it to jpg. This works because image libraries are
	## smart enough to handle it.
	# csg|scad)
	#     openscad_image "${FILE_PATH}" && exit 6
	#     ;;
	# 3mf|amf|dxf|off|stl)
	#     openscad_image <(echo "import(\"${FILE_PATH}\");") && exit 6
	#     ;;
	drawio)
		draw.io -x "${FILE_PATH}" -o "${IMAGE_CACHE_PATH}" \
			--width "${DEFAULT_SIZE%x*}" && exit 6
		exit 1
		;;
	esac
}

handle_mime() {
	local mimetype="${1}"
	case "${mimetype}" in
	## RTF and DOC
	text/rtf | *msword)
		## Preview as text conversion
		## note: catdoc does not always work for .doc files
		## catdoc: http://www.wagner.pp.ru/~vitus/software/catdoc/
		catdoc -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## DOCX, ePub, FB2 (using markdown)
	## You might want to remove "|epub" and/or "|fb2" below if you have
	## uncommented other methods to preview those formats
	*wordprocessingml.document | */epub+zip | */x-fictionbook+xml)
		## Preview as markdown conversion
		pandoc -s -t markdown -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## E-mails
	message/rfc822)
		## Parsing performed by mu: https://github.com/djcb/mu
		mu view -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## XLS
	*ms-excel)
		## Preview as csv conversion
		## xls2csv comes with catdoc:
		##   http://www.wagner.pp.ru/~vitus/software/catdoc/
		xls2csv -- "${FILE_PATH}" && exit 5
		exit 1
		;;

	## SQLite
	*sqlite3)
		## Preview as text conversion
		sqlite_tables="$(sqlite3 "file:${FILE_PATH}?mode=ro" '.tables')" ||
			exit 1
		[ -z "${sqlite_tables}" ] &&
			{ echo "Empty SQLite database." && exit 5; }
		sqlite_show_query() {
			sqlite-utils query "${FILE_PATH}" "${1}" --table --fmt fancy_grid ||
				sqlite3 "file:${FILE_PATH}?mode=ro" "${1}" -header -column
		}
		## Display basic table information
		sqlite_rowcount_query="$(
			sqlite3 "file:${FILE_PATH}?mode=ro" -noheader \
				'SELECT group_concat(
                        "SELECT """ || name || """ AS tblname,
                                          count(*) AS rowcount
                         FROM " || name,
                        " UNION ALL "
                    )
                    FROM sqlite_master
                    WHERE type="table" AND name NOT LIKE "sqlite_%";'
		)"
		sqlite_show_query \
			"SELECT tblname AS 'table', rowcount AS 'count',
                (
                    SELECT '(' || group_concat(name, ', ') || ')'
                    FROM pragma_table_info(tblname)
                ) AS 'columns',
                (
                    SELECT '(' || group_concat(
                        upper(type) || (
                            CASE WHEN pk > 0 THEN ' PRIMARY KEY' ELSE '' END
                        ),
                        ', '
                    ) || ')'
                    FROM pragma_table_info(tblname)
                ) AS 'types'
                FROM (${sqlite_rowcount_query});"
		if [ "${SQLITE_TABLE_LIMIT}" -gt 0 ] &&
			[ "${SQLITE_ROW_LIMIT}" -ge 0 ]; then
			## Do exhaustive preview
			echo && printf '>%.0s' $(seq "${PV_WIDTH}") && echo
			sqlite3 "file:${FILE_PATH}?mode=ro" -noheader \
				"SELECT name FROM sqlite_master
                    WHERE type='table' AND name NOT LIKE 'sqlite_%'
                    LIMIT ${SQLITE_TABLE_LIMIT};" |
				while read -r sqlite_table; do
					sqlite_rowcount="$(
						sqlite3 "file:${FILE_PATH}?mode=ro" -noheader \
							"SELECT count(*) FROM ${sqlite_table}"
					)"
					echo
					if [ "${SQLITE_ROW_LIMIT}" -gt 0 ] &&
						[ "${SQLITE_ROW_LIMIT}" \
							-lt "${sqlite_rowcount}" ]; then
						echo "${sqlite_table} [${SQLITE_ROW_LIMIT} of ${sqlite_rowcount}]:"
						sqlite_ellipsis_query="$(
							sqlite3 "file:${FILE_PATH}?mode=ro" -noheader \
								"SELECT 'SELECT ' || group_concat(
                                        '''...''', ', '
                                    )
                                    FROM pragma_table_info(
                                        '${sqlite_table}'
                                    );"
						)"
						sqlite_show_query \
							"SELECT * FROM (
                                    SELECT * FROM ${sqlite_table} LIMIT 1
                                )
                                UNION ALL ${sqlite_ellipsis_query} UNION ALL
                                SELECT * FROM (
                                    SELECT * FROM ${sqlite_table}
                                    LIMIT (${SQLITE_ROW_LIMIT} - 1)
                                    OFFSET (
                                        ${sqlite_rowcount}
                                        - (${SQLITE_ROW_LIMIT} - 1)
                                    )
                                );"
					else
						echo "${sqlite_table} [${sqlite_rowcount}]:"
						sqlite_show_query "SELECT * FROM ${sqlite_table};"
					fi
				done
		fi
		exit 5
		;;

	## Text
	text/* | */xml)
		## Syntax highlight
		if [[ "$(stat --printf='%s' -- "${FILE_PATH}")" -gt "${HIGHLIGHT_SIZE_MAX}" ]]; then
			exit 2
		fi
		if [[ "$(tput colors)" -ge 256 ]]; then
			local pygmentize_format='terminal256'
			local highlight_format='xterm256'
		else
			local pygmentize_format='terminal'
			local highlight_format='ansi'
		fi
		env HIGHLIGHT_OPTIONS="${HIGHLIGHT_OPTIONS}" highlight \
			--out-format="${highlight_format}" \
			--force -- "${FILE_PATH}" && exit 5
		env COLORTERM=8bit bat --color=always --style="${BAT_STYLE}" \
			-- "${FILE_PATH}" && exit 5
		pygmentize -f "${pygmentize_format}" -O "style=${PYGMENTIZE_STYLE}" \
			-- "${FILE_PATH}" && exit 5
		exit 2
		;;

	## DjVu
	image/vnd.djvu)
		## Preview as text conversion (requires djvulibre)
		djvutxt "${FILE_PATH}" | fmt -w "${PV_WIDTH}" && exit 5
		exiftool "${FILE_PATH}" && exit 5
		exit 1
		;;

	## Image
	image/*)
		## Preview as text conversion
		# img2txt --gamma=0.6 --width="${PV_WIDTH}" -- "${FILE_PATH}" && exit 4
		exiftool "${FILE_PATH}" && exit 5
		exit 1
		;;

	## Video and audio
	video/* | audio/*)
		mediainfo "${FILE_PATH}" && exit 5
		exiftool "${FILE_PATH}" && exit 5
		exit 1
		;;

	## ELF files (executables and shared objects)
	application/x-executable | application/x-pie-executable | application/x-sharedlib)
		readelf -WCa "${FILE_PATH}" && exit 5
		exit 1
		;;
	esac
}

handle_fallback() {
	echo '----- File Type Classification -----' && file --dereference --brief -- "${FILE_PATH}" && exit 5
}

MIMETYPE="$(file --dereference --brief --mime-type -- "${FILE_PATH}")"
if [[ "${PV_IMAGE_ENABLED}" == 'True' ]]; then
	handle_image "${MIMETYPE}"
fi
handle_extension
handle_mime "${MIMETYPE}"
handle_fallback

exit 1
