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SnapOtter/apps/api/src/routes/tools/find-duplicates.ts
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342 lines
11 KiB
TypeScript

import type { FastifyInstance } from "fastify";
import sharp from "sharp";
import { z } from "zod";
import { autoOrient } from "../../lib/auto-orient.js";
import { formatZodErrors } from "../../lib/errors.js";
import { validateImageBuffer } from "../../lib/file-validation.js";
import { sanitizeFilename } from "../../lib/filename.js";
import { decodeToSharpCompat, needsCliDecode } from "../../lib/format-decoders.js";
import { decodeHeic } from "../../lib/heic-converter.js";
import { decompressSvgz, sanitizeSvg } from "../../lib/svg-sanitize.js";
const settingsSchema = z.object({
threshold: z.number().min(0).max(20).default(8),
});
const THUMBNAIL_WIDTH = 200;
/**
* Compute a 128-bit dHash (row + column) for perceptual duplicate detection.
* Row hash: resize to 9x8 grayscale, compare adjacent horizontal pixels (64 bits).
* Column hash: resize to 8x9 grayscale, compare adjacent vertical pixels (64 bits).
*/
async function computeDHash128(buffer: Buffer): Promise<string> {
// Row hash: 9 wide x 8 tall
const rowPixels = await sharp(buffer).resize(9, 8, { fit: "fill" }).grayscale().raw().toBuffer();
let hash = "";
for (let y = 0; y < 8; y++) {
for (let x = 0; x < 8; x++) {
hash += rowPixels[y * 9 + x] > rowPixels[y * 9 + x + 1] ? "1" : "0";
}
}
// Column hash: 8 wide x 9 tall
const colPixels = await sharp(buffer).resize(8, 9, { fit: "fill" }).grayscale().raw().toBuffer();
for (let y = 0; y < 8; y++) {
for (let x = 0; x < 8; x++) {
hash += colPixels[y * 8 + x] > colPixels[(y + 1) * 8 + x] ? "1" : "0";
}
}
return hash; // 128 characters
}
function hammingDistance(a: string, b: string): number {
let distance = 0;
for (let i = 0; i < a.length; i++) {
if (a[i] !== b[i]) distance++;
}
return distance;
}
interface FileData {
buffer: Buffer;
filename: string;
originalSize: number;
}
interface FileInfo {
filename: string;
hash: string;
width: number;
height: number;
fileSize: number;
format: string;
thumbnail: string | null;
}
async function extractFileInfo(file: FileData): Promise<FileInfo> {
const meta = await sharp(file.buffer).metadata();
const width = meta.width ?? 0;
const height = meta.height ?? 0;
const format = meta.format ?? "unknown";
// Generate 200px wide JPEG thumbnail as base64
let thumbnail: string | null = null;
try {
const thumbBuffer = await sharp(file.buffer)
.resize(THUMBNAIL_WIDTH, undefined, { withoutEnlargement: true })
.jpeg({ quality: 70 })
.toBuffer();
thumbnail = `data:image/jpeg;base64,${thumbBuffer.toString("base64")}`;
} catch {
// Non-fatal: some formats may fail thumbnail generation
}
return {
filename: file.filename,
hash: "",
width,
height,
fileSize: file.originalSize,
format,
thumbnail,
};
}
export function registerFindDuplicates(app: FastifyInstance) {
app.post("/api/v1/tools/image/find-duplicates", async (request, reply) => {
const files: FileData[] = [];
let settingsRaw: string | null = null;
try {
const parts = request.parts();
for await (const part of parts) {
if (part.type === "file") {
const chunks: Buffer[] = [];
for await (const chunk of part.file) {
chunks.push(chunk);
}
const buf = Buffer.concat(chunks);
if (buf.length > 0) {
files.push({
buffer: buf,
filename: sanitizeFilename(part.filename ?? `image-${files.length}`),
originalSize: buf.length,
});
}
} else if (part.type === "field" && part.fieldname === "settings") {
settingsRaw = part.value as string;
} else if (part.type === "field" && part.fieldname === "threshold") {
// Legacy: accept bare threshold field as settings
settingsRaw = JSON.stringify({ threshold: Number(part.value) });
}
}
} catch (err) {
return reply.status(400).send({
error: "Failed to parse multipart request",
details: err instanceof Error ? err.message : String(err),
});
}
// Parse and validate settings
let settings: z.infer<typeof settingsSchema>;
try {
const parsed = settingsRaw ? JSON.parse(settingsRaw) : {};
const result = settingsSchema.safeParse(parsed);
if (!result.success) {
return reply
.status(400)
.send({ error: "Invalid settings", details: formatZodErrors(result.error.issues) });
}
settings = result.data;
} catch {
return reply.status(400).send({ error: "Settings must be valid JSON" });
}
const threshold = settings.threshold;
if (files.length < 2) {
return reply
.status(400)
.send({ error: "At least 2 images are required for duplicate detection" });
}
try {
const skippedFiles: Array<{ filename: string; reason: string }> = [];
const processableFiles: FileData[] = [];
for (const file of files) {
const validation = await validateImageBuffer(file.buffer, file.filename);
if (!validation.valid) {
skippedFiles.push({ filename: file.filename, reason: validation.reason });
continue;
}
if (validation.format === "heif") {
try {
file.buffer = await decodeHeic(file.buffer);
} catch {
skippedFiles.push({ filename: file.filename, reason: "Failed to decode HEIC" });
continue;
}
}
if (needsCliDecode(validation.format)) {
try {
const fileExt = file.filename.split(".").pop()?.toLowerCase();
file.buffer = await decodeToSharpCompat(file.buffer, validation.format, fileExt);
} catch {
try {
await sharp(file.buffer).metadata();
} catch {
skippedFiles.push({
filename: file.filename,
reason: `Failed to decode ${validation.format.toUpperCase()}`,
});
continue;
}
}
}
if (validation.format === "svg") {
try {
file.buffer = decompressSvgz(file.buffer);
file.buffer = sanitizeSvg(file.buffer);
} catch {
skippedFiles.push({ filename: file.filename, reason: "Invalid SVG" });
continue;
}
}
try {
file.buffer = await autoOrient(file.buffer);
} catch {
skippedFiles.push({
filename: file.filename,
reason: "Failed to read image orientation",
});
continue;
}
processableFiles.push(file);
}
if (processableFiles.length < 2) {
return reply.status(400).send({
error:
processableFiles.length === 0
? "No supported images found"
: "At least 2 processable images are required for duplicate detection",
skippedFiles,
});
}
// Extract metadata, thumbnails, and compute hashes
const fileInfos: FileInfo[] = [];
for (const file of processableFiles) {
try {
const info = await extractFileInfo(file);
info.hash = await computeDHash128(file.buffer);
fileInfos.push(info);
} catch {
skippedFiles.push({ filename: file.filename, reason: "Failed to compute image hash" });
}
}
if (fileInfos.length < 2) {
return reply.status(400).send({
error:
fileInfos.length === 0
? "No images could be analyzed"
: "At least 2 processable images are required for duplicate detection",
skippedFiles,
});
}
// Group duplicates by hamming distance
const assigned = new Set<number>();
const groups: Array<{
groupId: number;
files: Array<{
filename: string;
similarity: number;
width: number;
height: number;
fileSize: number;
format: string;
isBest: boolean;
thumbnail: string | null;
}>;
}> = [];
let groupCounter = 0;
for (let i = 0; i < fileInfos.length; i++) {
if (assigned.has(i)) continue;
const members: Array<{ index: number; similarity: number }> = [
{ index: i, similarity: 100 },
];
for (let j = i + 1; j < fileInfos.length; j++) {
if (assigned.has(j)) continue;
const dist = hammingDistance(fileInfos[i].hash, fileInfos[j].hash);
if (dist <= threshold) {
const similarity = Math.round((1 - dist / 128) * 10000) / 100;
members.push({ index: j, similarity });
assigned.add(j);
}
}
if (members.length > 1) {
assigned.add(i);
groupCounter++;
// Determine "best" image: highest pixel count, tie-break by file size
let bestIdx = 0;
for (let m = 1; m < members.length; m++) {
const curr = fileInfos[members[m].index];
const best = fileInfos[members[bestIdx].index];
const currPixels = curr.width * curr.height;
const bestPixels = best.width * best.height;
if (
currPixels > bestPixels ||
(currPixels === bestPixels && curr.fileSize > best.fileSize)
) {
bestIdx = m;
}
}
groups.push({
groupId: groupCounter,
files: members.map((m, idx) => ({
filename: fileInfos[m.index].filename,
similarity: m.similarity,
width: fileInfos[m.index].width,
height: fileInfos[m.index].height,
fileSize: fileInfos[m.index].fileSize,
format: fileInfos[m.index].format,
isBest: idx === bestIdx,
thumbnail: fileInfos[m.index].thumbnail,
})),
});
}
}
// Sort groups by highest similarity descending
groups.sort((a, b) => {
const maxA = Math.max(...a.files.map((f) => f.similarity));
const maxB = Math.max(...b.files.map((f) => f.similarity));
return maxB - maxA;
});
// Calculate space saveable (sum of non-best duplicate file sizes)
let spaceSaveable = 0;
for (const group of groups) {
for (const file of group.files) {
if (!file.isBest) spaceSaveable += file.fileSize;
}
}
return reply.send({
totalImages: fileInfos.length,
duplicateGroups: groups,
uniqueImages: fileInfos.length - assigned.size,
spaceSaveable,
skippedFiles: skippedFiles.length > 0 ? skippedFiles : undefined,
});
} catch (err) {
return reply.status(422).send({
error: "Duplicate detection failed",
details: err instanceof Error ? err.message : "Unknown error",
});
}
});
}