url-diff/url-diff.sh

176 rader
5.2 KiB
Bash
Executable File

#!/usr/bin/env bash
loc_storage="${HOME}/.config/url-diff";
if [[ ! -z "${URLDIFF_STORAGE_DIR}" ]]; then loc_storage="${URLDIFF_STORAGE_DIR}"; fi
loc_firefox_profile="${loc_storage}/firefox-profile";
loc_prev_images="${loc_storage}/previous-images";
highlight_colour="${URLDIFF_HIGHLIGHT_COLOUR:-#ff000044}";
quiet="${URLDIFF_QUIET:-false}";
window_width="${URLDIFF_WINDOW_WIDTH}";
change_threshold="${URLDIFF_CHANGE_THRESHOLD:-2}";
###############################################################################
if [[ -z "$(type -p calc)" ]]; then
echo "calc command not detected - it would appear it is not installed" >&2;
echo "Install it like this on debian systems:" >&2;
echo " sudo apt install apcalc" >&2;
fi
###############################################################################
log_msg() {
if [[ "${quiet}" == "true" ]]; then
return 0;
fi
echo "[${SECONDS}] $*";
}
# $1 Image to process
# $2 Colour to find
calculate_percentage_colour() {
loc_image="${1}";
colour="${2}";
if [[ -z "${colour}" ]]; then
log_msg "calculate_percentage_colour/Error: No colour specified." >&2;
return 1;
fi
image_width="$(identify -format "%[fx:w]" "${loc_image}" )";
image_height="$(identify -format "%[fx:h]" "${loc_image}")";
pixel_count_colour="$(convert "${loc_image}" -fill black +opaque "${colour}" -fill white -opaque "${colour}" -format "%[fx:w*h*mean]" info:)";
# echo "image_width: ${image_width}, image_height: ${image_height}, pixel_count_colour: ${pixel_count_colour}" >&2;
calc -p "(${pixel_count_colour} / (${image_width}*${image_height})) * 100" | tr -d '~';
}
###############################################################################
mode="${1}";
shift;
if [[ -z "${mode}" ]]; then
echo -e "Webpage visual diff checker
By Starbeamrainbowlabs
Usage:
webpage-diff {subcommand} [{arguments}]
Subcommands:
check {url} {output_diff_image} [{output_apng}]
Checks the given URL for differences, and saves a diff
image to a specified location. Exits with code 0 if
differences are found, or code 1 if no differences are
found.
Optionally generates an animated PNG that alternates
between the 2 screenshots.
Environment Variables:
Variable Default variable
----------------------------------------------------------------------
URLDIFF_STORAGE_DIR ~/.config/url-diff
The directory in which previous images are stored to diff
against. The firefox profile is also stored in here.
URLDIFF_HIGHLIGHT_COLOUR #ffffffcc
The colour to highlight any changes in.
URLDIFF_WINDOW_WIDTH
The window width to tell firefox to screenshot with.
URLDIFF_CHANGE_THRESHOLD 2
The percentage of the screenshot that should have
changed for it to count.
Allows for ignoring random minor rendering artifacts.
" >&2;
fi
# Create the config directories
mkdir -p "${loc_firefox_profile}";
mkdir -p "${loc_prev_images}";
case "${mode}" in
check )
url="${1}";
url_hash="$(echo "${url}" | sha256sum | cut -d ' ' -f 1)";
loc_output_diffimage="${2}";
loc_output_apng="${3}";
tmpdir="$(mktemp -d)";
on_exit() {
rm -rf "${tmpdir}";
}
trap on_exit EXIT;
loc_img_old="${loc_prev_images}/${url_hash}.png";
loc_img_new="${tmpdir}/new.png";
if [[ ! -d "$(dirname "${loc_output_diffimage}")" ]]; then
echo "Error: Output directory for diff image does not exist";
exit 2;
fi
log_msg "Taking screenshot";
log_msg "$(firefox --window-size "${window_width}" --profile "${loc_firefox_profile}" --headless --screenshot "${loc_img_new}" "${url}" 2>&1)";
if [[ ! -f "${loc_img_old}" ]]; then
log_msg "No image exists yet, storing initial snapshot";
mv "${loc_img_new}" "${loc_img_old}";
exit 1;
fi
# eog "${loc_img_old}";
# eog "${loc_img_new}";
# img_hash_old="$(identify -quiet -format "%#" "${loc_img_old}")";
# img_hash_new="$(identify -quiet -format "%#" "${loc_img_new}")";
# Generate the diff image
compare "${loc_img_old}" "${loc_img_new}" -compose src -highlight-color "${highlight_colour}" "${tmpdir}/diff.png";
convert "${tmpdir}/diff.png" -transparent "#ffffffcc" "${tmpdir}/transp.png";
# Work out how much of the image has changed
percentage_changed="$(calculate_percentage_colour "${tmpdir}/transp.png" "${highlight_colour}")";
if [[ -z "${percentage_changed}" ]]; then
echo "Something went wrong when calculating the percentage changed - no value was returned";
exit 1;
fi
log_msg "Changed: ${percentage_changed}%";
# if [[ "${img_hash_new}" == "${img_hash_old}" ]]; then
if [[ "$(calc -p "${percentage_changed} > ${change_threshold}")" -eq 0 ]]; then
log_msg "No changes detected.";
exit 1;
fi
log_msg "Changes detected, outputting diff image.";
convert "${loc_img_new}" "${tmpdir}/transp.png" -compose over -composite "${loc_output_diffimage}";
if which optipng >/dev/null 2>&1; then
log_msg "Optimising new image";
optipng "${loc_img_new}";
fi
if [[ ! -z "${loc_output_apng}" ]]; then
log_msg "Making animated PNG";
cp "${loc_img_old}" "${tmpdir}/0.png";
cp "${loc_img_new}" "${tmpdir}/1.png";
ffmpeg -hide_banner -r 1 -i "${tmpdir}/%d.png" -plays 0 "${loc_output_apng}";
fi
mv "${loc_img_new}" "${loc_img_old}";
exit 0;
;;
esac