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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
// An image is v1-<type>-<theme>-<position>-<number>-<uuid>. Its details file
// is <image>.txt and its picker thumbnail is <image>.thumb.
// The library lives one level down, where the wallpaper cleanup in older New Tab
// versions cannot reach it. That cleanup only removes files, never folders.
export const LIBRARY_DIRECTORY_NAME = "library";
const SAVED_WALLPAPER_VERSION = "v1";
const DETAILS_FILE_EXTENSION = ".txt";
const THUMBNAIL_FILE_EXTENSION = ".thumb";
const TEMPORARY_FILE_EXTENSION = ".tmp";
export const WALLPAPER_TYPES = {
Custom: "custom",
Builtin: "builtin",
PictureOfTheDay: "potd",
};
// Every type above can be saved. A Picture of the Day is only kept when
// someone chooses "Set wallpaper", so it is an image like any other.
const SAVED_TYPES = Object.values(WALLPAPER_TYPES);
const THEMES = ["light", "dark"];
// Token in the filename to the CSS background-position it stands for.
const POSITIONS = new Map([
["center", "center"],
["top", "top"],
["bottom", "bottom"],
["left", "left"],
["right", "right"],
["topleft", "top left"],
["topright", "top right"],
["bottomleft", "bottom left"],
["bottomright", "bottom right"],
]);
const DEFAULT_POSITION = "center";
// Counts up once per saved image and is never reused, so an image keeps the
// same number for life even when an earlier one is removed. Never a position.
const NUMBER_PATTERN = /^[1-9][0-9]*$/;
const UUID_PATTERN =
/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/;
// A Remote Settings background_position as a filename token, "center" if we
// don't recognize it.
const encodeBackgroundPosition = position => {
const token = String(position ?? "")
.toLowerCase()
.replace(/[\s-]/g, "");
return POSITIONS.has(token) ? token : DEFAULT_POSITION;
};
const decodeBackgroundPosition = token =>
POSITIONS.get(token) || DEFAULT_POSITION;
export const buildSavedWallpaperFilename = ({
type,
theme,
position,
number,
uuid,
}) => {
if (!SAVED_TYPES.includes(type)) {
throw new Error(`Unknown wallpaper type: ${type}`);
}
if (!THEMES.includes(theme)) {
throw new Error(`Unknown wallpaper theme: ${theme}`);
}
if (!NUMBER_PATTERN.test(String(number))) {
throw new Error("Wallpaper filenames need a counting number");
}
if (!UUID_PATTERN.test(uuid)) {
throw new Error("Wallpaper filenames need a plain lowercase UUID");
}
const positionToken = encodeBackgroundPosition(position);
return `${SAVED_WALLPAPER_VERSION}-${type}-${theme}-${positionToken}-${number}-${uuid}`;
};
// Longest name kept. It is sent with every library update and is only ever read
// aloud, so there is no reason to carry a pathological one.
const MAX_SAVED_NAME_LENGTH = 100;
// Below this, whatever ended the sentence was almost certainly an abbreviation
// rather than the end of a thought, so the whole name is not worth keeping.
const MIN_SENTENCE_NAME_LENGTH = 20;
// Cleans up a Picture of the Day description so a screen reader can read it
// out. An uploaded image never has one: it is numbered, and its file name is
// not kept.
export const sanitizeSavedName = savedName => {
if (typeof savedName !== "string") {
return "";
}
// Control characters would garble the label a screen reader reads out.
// eslint-disable-next-line no-control-regex
const printable = savedName.replace(/[\u0000-\u001f\u007f]/g, "").trim();
if (printable.length <= MAX_SAVED_NAME_LENGTH) {
return printable;
}
// These run to a paragraph, and the opening sentences are the part worth
// hearing: Wikimedia leads with the subject and where it was taken, then goes
// into detail. Cutting on a character count alone ends mid-word, and a screen
// reader reads that out as it stands.
//
// Greedy on purpose, so it takes the last sentence that ends in range rather
// than the first. An abbreviation early on, "St. Peter's Basilica, Rome",
// would otherwise cut the name down to "St.".
const sentence = printable
.slice(0, MAX_SAVED_NAME_LENGTH + 1)
.match(/^.*[.!?](?=\s|$)/);
if (sentence && sentence[0].length >= MIN_SENTENCE_NAME_LENGTH) {
return sentence[0];
}
// No sentence ends in range, so fall back to the last whole word.
const clipped = printable.slice(0, MAX_SAVED_NAME_LENGTH);
const lastSpace = clipped.lastIndexOf(" ");
return lastSpace > 0 ? clipped.slice(0, lastSpace) : clipped;
};
export const getDetailsFilename = imageFilename =>
`${imageFilename}${DETAILS_FILE_EXTENSION}`;
export const getThumbnailFilename = imageFilename =>
`${imageFilename}${THUMBNAIL_FILE_EXTENSION}`;
const EXTRA_FILE_KINDS = [
[DETAILS_FILE_EXTENSION, "details"],
[THUMBNAIL_FILE_EXTENSION, "thumbnail"],
];
// Reads a filename back. `kind` is saved, details, thumbnail, temporary (.tmp),
// legacy (a bare UUID from before the library), or unknown.
export const parseWallpaperFilename = filename => {
if (!filename) {
return { kind: "unknown" };
}
if (filename.endsWith(TEMPORARY_FILE_EXTENSION)) {
return { kind: "temporary" };
}
for (const [extension, kind] of EXTRA_FILE_KINDS) {
if (filename.endsWith(extension)) {
return { kind, imageFilename: filename.slice(0, -extension.length) };
}
}
const parts = filename.split("-");
if (parts[0] === SAVED_WALLPAPER_VERSION) {
const [, type, theme, positionToken, number, ...rest] = parts;
const uuid = rest.join("-");
const known =
SAVED_TYPES.includes(type) &&
THEMES.includes(theme) &&
POSITIONS.has(positionToken) &&
NUMBER_PATTERN.test(number ?? "") &&
UUID_PATTERN.test(uuid);
if (known) {
return {
kind: "saved",
type,
theme,
position: decodeBackgroundPosition(positionToken),
number: Number(number),
uuid,
};
}
return { kind: "unknown" };
}
if (UUID_PATTERN.test(filename)) {
return { kind: "legacy", uuid: filename };
}
return { kind: "unknown" };
};