screenshot

#!/bin/sh

# DESCRIPTION:
# * make and save a screenshot
# * [optionally] copy to clipboard
# * [optionally] optimize it
# * [optionally] OCR it
#
# ARGUMENTS:
# * mode: full|selected|focused
#
# ENVIRONMENT VARIABLES:
# * SCREENSHOT_DOCKER_HOST: set to prefer using docker for image optimization
#     Examples: `unix:///var/run/docker.sock` for local execution
#               `ssh://root@your.server.com` for remote
#
# DEPENDENCIES:
# * Interpreter: POSIX shell + coreutils
# * Screenshot tool: maim + xdotool | scrot | graphicsmagick + xdotool | imagemagick + xdotool
# * Clipboard tool [opt]: xclip | xsel
# * Image lossless optimizer [opt]: optipng | pngcrush | jpegoptim
# * OCR tool [opt]: tesseract + tesseract-ocr-rus
# * Locks manager [opt]: flock
#


set -o errexit  # exit on fail
set -o nounset  # exit on undeclared variable
# set -o xtrace   # trace execution


save_dir=${HOME}/0files/imgs/screenshots
save_ext=png
save_date=$(date '+%s_%Y.%m.%d_%H:%M:%S')
save_name=${save_date}.${save_ext}
save_path=${save_dir}/${save_name}

mkdir -p "${save_dir}"


if command -v maim xdotool >/dev/null; then
    [ "${1}" = 'full'    ] && maim                                         -- "${save_path}"
    [ "${1}" = 'select'  ] && maim --select                                -- "${save_path}"
    [ "${1}" = 'focused' ] && maim --window "$(xdotool getwindowfocus -f)" -- "${save_path}"

elif command -v scrot >/dev/null; then
    [ "${1}" = 'full'    ] && scrot --multidisp -- "${save_path}"
    [ "${1}" = 'select'  ] && scrot --select    -- "${save_path}"
    [ "${1}" = 'focused' ] && scrot --focused   -- "${save_path}"

elif command -v xdotool gm >/dev/null; then
    [ "${1}" = 'full'    ] && gm import -window root                           "${save_path}"
    [ "${1}" = 'select'  ] && gm import                                        "${save_path}"
    [ "${1}" = 'focused' ] && gm import -window "$(xdotool getwindowfocus -f)" "${save_path}"

elif command -v xdotool import >/dev/null; then
    [ "${1}" = 'full'    ] && import -window root                           -- "${save_path}"
    [ "${1}" = 'select'  ] && import                                        -- "${save_path}"
    [ "${1}" = 'focused' ] && import -window "$(xdotool getwindowfocus -f)" -- "${save_path}"

else
    # current xwd lacks -rect option on ubuntu: can't test
    # escrotum not in the repos
    echo "No graphics/image-magick's import or scrot or maim installed"
    exit 1

fi


if command -v xclip >/dev/null; then
    printf %s "${save_path}" | xclip -in -selection primary
    xclip -selection clipboard -target image/png <"${save_path}"

elif command -v xsel >/dev/null; then
    printf %s "${save_path}" | xsel --input --primary
    printf %s "${save_path}" | xsel --input --clipboard
fi


printf '%s\n' "${save_path}"


(
    # Execute under lock
    # if flock is available
    if command -v flock >/dev/null; then
        flock 9
    fi

    if [ -n "${SCREENSHOT_DOCKER_HOST:-}" ] && docker info >/dev/null 2>&1; then
        (
            export DOCKER_HOST=${SCREENSHOT_DOCKER_HOST}
            # Create a container that would auto-destroy in 10 minutes
            container_id=$(
                docker run --rm -d \
                    skhaz/compression-tools \
                    sleep $(( 60 * 10 ))
            )
            # Destroy container on exit from brackets
            trap 'docker rm -f "${container_id}" >/dev/null; trap - EXIT; exit' EXIT INT HUP
            # Copy file to container, process it, and copy back
            docker cp "${save_path}" "${container_id}:/${save_name}"
            docker exec -ti "${container_id}" ect -9 "/${save_name}"
            docker container cp "${container_id}:/${save_name}" "${save_path}"

            printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"
        )

    elif command -v etc >/dev/null; then
        ect -9 "${save_path}"
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif command -v leanify >/dev/null; then
        leanify --iteration 100 -- "${save_path}"
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif [ "${save_ext}" = "png" ] && command -v pngout  >/dev/null; then
        pngout "${save_path}" "/tmp/${save_name}" || [ $? = 2 ]
        mv "/tmp/${save_name}" "${save_path}"
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif [ "${save_ext}" = "png" ] && command -v optipng   >/dev/null; then
        optipng -o7 -strip all -- "${save_path}"
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif [ "${save_ext}" = "png" ] && command -v pngcrush  >/dev/null; then
        pngcrush -brute -reduce "${save_path}" "/tmp/${save_name}"
        if [ "$(getsize "/tmp/${save_name}")" -lt "$(getsize "${save_path}")" ]; then
            mv "/tmp/${save_name}" "${save_path}"
        fi
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif [ "${save_ext}" = "png" ] && command -v advpng    >/dev/null; then
        advpng --recompress --shrink-insane --iter=100 -- "${save_path}"
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif [ "${save_ext}" = "jpg" ] && command -v jpegoptim >/dev/null; then
        jpegoptim --strip-all -- "${save_path}"
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    elif [ "${save_ext}" = "jpg" ] && command -v jpegoptim >/dev/null; then
        jpegtran -copy none -perfect -optimize -outfile "/tmp/${save_name}" "${save_path}"
        if [ "$(getsize "/tmp/${save_name}")" -lt "$(getsize "${save_path}")" ]; then
            mv "/tmp/${save_name}" "${save_path}"
        fi
        printf "%s\n" "${save_name}" >> "${save_dir}/.optimized"

    fi >&2

    if command -v tesseract >/dev/null; then
        tesseract -l eng+rus --psm 1 "${save_path}" "${save_dir}/${save_date}"
    fi >&2

) 9>"/var/lock/screenshot-$(id -u).lock"


# We expect word splitting here
# shellcheck disable=2046
getsize() { set -- $(ls -dn "$1") && printf %s "$5"; }