dotfiles/common/.config/lf/preview

#!/bin/sh
# shellcheck disable=SC2016

# Preview functions for each filetype must print their results to stdout.
# The preview functions are called by the "run" wrapper function, which handles caching.
# This wrapper function can take "-s" as an argument to indicate that the
# preview should be regenerated if the terminal is resized.

f="$(realpath "$1")" w=$2 h=$3 _x=$4 _y=$5
rs="$(printf "\037")"

CACHE_DIR="${XDG_CACHE_HOME:-"${HOME}/.cache"}/lf"
BAT="bat \
    --style=plain \
    --color=always \
    --italic-text=always \
    --pager=never \
    --tabs=4 \
    --theme=base16
"
CHAFA="chafa \
    -f sixel \
    -s ${w}x${h} \
    --polite on \
    --animate false
"

archive() {
    ouch list -Htyq "$f" | tail -n +2
}

csv() {
    f=${1:-$f}
    mlr --icsv --omd cat "$f" |
        CLICOLOR_FORCE=1 COLORTERM=truecolor \
            glow -w "$w" -s tokyo-night
}

docx() {
    docx2txt "$f" -
}

epub() {
    gnome-epub-thumbnailer -s 1024 "$f" /dev/stdout | $CHAFA
}

html() {
    lynx -dump "$f"
}

image() {
    $CHAFA "$f"
}

iso() {
    iso-info --no-header -l "$f"
}

json() {
    jq -C . "$f"
}

lua() {
    $BAT --language=lua "$f"
}

markdown() {
    CLICOLOR_FORCE=1 COLORTERM=truecolor \
        glow -w "$w" -s tokyo-night "$f"
}

word() {
    catdoc "$f"
}

ods() {
    td=$(mktemp -d)

    libreoffice --headless --convert-to csv "$f" --outdir "$td" >/dev/null
    b=$(basename "$f")
    csv "${td}/${b%.*}.csv"

    rm -rf "$td"
}

odt() {
    odt2txt "$f"
}

pdf() {
    pdftoppm -jpeg -f 1 -singlefile "$f" | $CHAFA
}

sqlite() {
    printf ".headers on\n.mode list\nSELECT name FROM sqlite_master WHERE type='table';\n" |
        sqlite3 "$f" |
        grep -v name |
        while read -r table; do
            [ "$table" != "name" ] &&
                printf "SELECT * FROM %s;" "$table" |
                sqlite3 -header -separator "$rs" "$f"
        done |
        column -t -s "$rs"
}

svg() {
    inkscape \
        --convert-dpi-method=none \
        --export-filename=- \
        --export-overwrite \
        --export-area-drawing \
        --export-png-color-mode=RGBA_16 "$f" |
        $CHAFA
}

text() {
    $BAT "$f"
}

torrent() {
    transmission-show "$f"
}

video() {
    ffmpegthumbnailer -s 0 -i "$f" -o "/dev/stdout" | $CHAFA
}

yaml() {
    $BAT --language=yaml "$f"
}

gz_compressed() {
    gzip -l "$f"
}

xz_compressed() {
    xz -l "$f"
}

run() {
    if [ "$1" = "-s" ]; then
        cache="${CACHE_DIR}/$(
            stat --printf "%n %i %F %s %W %Y ${w} ${h}" -- "$(readlink -f "$f")" |
                sha256sum | awk '{print $1}'
        )"
        shift
    else
        cache="${CACHE_DIR}/$(
            stat --printf "%n %i %F %s %W %Y" -- "$(readlink -f "$f")" |
                sha256sum | awk '{print $1}'
        )"
    fi

    if [ -r "$cache" ]; then
        cat "$cache"
    else
        if out=$("$@"); then
            printf "%s" "$out" | tee "$cache"
        else
            printf "%s" "$out"
        fi
    fi
}

preview() {
    mimetype=$1
    case "$mimetype" in
        */vnd.openxmlformats-officedocument.spreadsheetml.sheet | */vnd.oasis.opendocument.spreadsheet) run -s ods ;;
        */vnd.sqlite3) run sqlite ;;
        */gzip) run gz_compressed ;;
        */x-xz) run xz_compressed ;;
        */x-7z-compressed | */vnd.rar | */x-tar | */zip | */x-java-archive | */x-bzip-compressed-tar | */x-compressed-tar | */x-xz-compressed-tar) run archive ;;
        */epub+zip) run -s epub ;;
        image/svg+xml) run -s svg ;;
        image/*) run -s image ;;
        */pdf) run -s pdf ;;
        video/*) run -s video ;;
        */vnd.oasis.opendocument.text) run odt ;;
        */vnd.openxmlformats-officedocument.wordprocessingml.document) run docx ;;
        */csv) run -s csv ;;
        */markdown) run -s markdown ;;
        */html) run html ;;
        */*json) run json ;;
        */msword) run word ;;
        */x-bittorrent) run torrent ;;
        */x-cd-image) run iso ;;
        */*lua) run lua ;;
        */*yaml) run yaml ;;
        *text*) run text ;;
        *) return 1 ;;
    esac
}

extension_override() {
    case "${f##*.}" in
        heex) printf "%s" "text/plain" ;;
        *) return 1 ;;
    esac
}

# We don't want to reprocess files in the cache, as this will generate a bunch of duplicate cache entries
[ "$(readlink -f "$f" | xargs dirname)" = "${CACHE_DIR}" ] && {
    stat -c "%w" "$f"
    exit
}

mimetype_override="$(extension_override "$f")"
preview "$mimetype_override" && exit

mimetype_gio="$(gio info "$f" 2>/dev/null | grep standard::content-type | cut -d' ' -f4)"
preview "$mimetype_gio" && exit

mimetype_file="$(file --brief --dereference --mime-type "$f")"
preview "$mimetype_file" && exit

[ -n "$mimetype_gio" ] && printf '$(gio info)\t\t\t\t : %s\n' "${mimetype_gio}"
[ -n "$mimetype_file" ] && printf '$(file --mime-type)\t\t\t : %s\n' "${mimetype_file}"
mediainfo "$1" | head -n -2 | grep -v -e "Complete name" -e "General"