foto-duplicate-finder/docs/ROADMAP.md

Roadmap

Foto Dup Finder is built against a fixed milestone plan (M0–M10). This file is the single source of truth for what is done and what remains. Before this file existed the plan lived only in developer notes, and the CHANGELOG refers to milestone labels (M7, M8).

Legend: ✅ done · 🚧 in progress · ⏳ not started · 💡 candidate (proposed, not scheduled)

Milestones

#	Milestone	Status	Evidence / notes
M0	Toolchain & scaffold	✅	User-local SDK, Gradle 9.3.1 + AGP 9.1.0, wrapper and version catalog, empty debug APK builds
M1	Pure-Kotlin duplicate engine + JVM tests	✅	SHA-256 quick/full hashing, pHash + RGB dHash, union-find grouping, Exact/Balanced/Aggressive policies; tests under app/src/test
M2	Data layer	✅	MediaStore query, coroutine-parallel hashing, incremental SQLite hash index, permission + partial-access handling
M3	Compose UI	✅	Scan progress, grouped results with thumbnails, two-step staging, selection helpers
M4	Safe deletion	✅	MediaStore.createDeleteRequest / createTrashRequest; legacy direct delete on Android 10
M5	Performance pass	✅	Size short-circuit, provider-thumbnail hashing, batched hashing (folded into M2/M3)
M6	Release config & Play readiness	✅	R8/minify, optional signing, .aab, PLAY_RELEASE_CHECKLIST, PRIVACY.md, README
M7	On-device validation & hardening	✅	Foreground dataSync service, one failure boundary per file, core/DecodeMath, hostile fixtures (EDGE_CASE_TESTING), versionName → 1.0.0
M8	Localisation groundwork	✅	Every user-visible string in res/values/strings.xml with real <plurals>, shared text/TextRes.kt; English is the only locale
M9	Monetisation	✅	Decided: a one-time paid app — no free tier, no trial, no subscription and no in-app purchase, so there is no Billing code and no new permission. Checked before deciding: com.android.billingclient:billing:9.1.0's manifest declares only com.android.vending.BILLING, so IAP would not have added INTERNET either — but a price on the listing is the one model that changes nothing at all about the "no internet permission" claim. Base price €2.99 one-time with a 50% launch sale at €1.49, both set in the Console (Products > App pricing). €1 as the base price was considered and rejected: a sale can always be added, but a low anchor cannot be undone, and a paid app's first transaction is its only transaction. Free → paid becomes impossible after the first upload, so this had to be settled before release. Rationale, copy changes and Console steps: STORE_LISTING › App pricing, PLAY_RELEASE_CHECKLIST step 4
M10	Store assets	✅	tools/make-store-assets.sh renders the 512×512 icon and the 1024×500 feature graphic from the app's own vectors; tools/make-store-screenshots.sh normalises device captures to Play's 2:1 limit, one directory per form factor (phone → 1080×2160, tablet-7in → 1200×1920, tablet-10in → 1600×2560); tools/make-demo-photos.py generates the photo library the results captures are taken over, so no real photos are published; all listing copy is drafted and length-checked in STORE_LISTING. The phone set was re-shot on a real device after a real permission grant, and the two tablet sets were captured on AOSP AVDs (see the blocker below); the finished assets — icon, feature graphic, the twelve normalised screenshots and the demonstration video — are committed, so Gitea serves them publicly and pushing is the deployment step

Release blockers (work that is not a numbered milestone)

Item	Detail
Large-library scan stall ✅ fixed — verified on device	The 5,363-photo library used to freeze at “74 / 100 · Comparing file signatures…” (a blocked syscall: zero CPU, workers sleeping). BoundedCall now abandons a stuck provider call and trips a stall breaker after three consecutive timeouts. Verified on the real test device (Android 12 / MIUI): the scan completes — 20.2 s cold, 11.0 s warm, 15 groups, 6 unreadable — where it used to hang. Covered by BoundedCallTest and ScanEngineEndToEndTest
Unreleased BoundedCall fix ✅	The provider-call deadline shipped in 1.0.1 (versionCode 2)
Play Console: foreground-service declaration	Declaring the dataSync type (App content › Foreground service permissions) is release-blocking. [code] the manifest already declares it, PLAY_RELEASE_CHECKLIST step 5 carries all four things the form asks for (description, defer/interrupt impact, use case Local processing: Other, video link), and the video now exists: recorded on the test device on 2026-10-14 with INSTALL=0 WARMUP=0 tools/record-fgs-demo.sh, then verified frame by frame rather than assumed — intro at 0 s, the scan starting, ~6 s of the shade with the live "Finding duplicate photos / Looking for visually similar photos… / CANCEL" notification while the scan kept running, and the results at the end. It is committed, and that is what published it — the link is the file's page in Gitea (/src/branch/main/…), which plays it anonymously. The /raw/ URL is deliberately not the link: Gitea sends Content-Security-Policy: default-src 'none' with raw responses, so a browser navigating to the video sits on a blank tab even though the bytes are perfect. Pasting the page URL into the declaration is all that is left. Two details of the take are recorded in step 5 because they each cost an attempt: a warm scan is 5.4 s, shorter than the shade takes to open, so WARMUP=0 films the cold one; and MIUI refuses adb install outright, so INSTALL=0 records with the build already on the device. On a KVM-less emulator the same video cannot be made at all: every scan start dies as am_crash … ForegroundServiceDidNotStartInTimeException → Force finishing activity with no am_kill, i.e. emulation is too slow to reach startForeground() inside Android's budget (QEMU's -icount clock dilation made it work once, not reproducibly)
Remaining Play paperwork	Console actions only, no code: the first upload + Play App Signing enrolment, the hosted privacy policy URL (the working copy is now published to Gitea as fishfacegit/foto-duplicate-finder, so the policy renders at a public, login-free URL and only the Console paste is left), Data safety, the Photo/video permissions declaration, the content rating / audience / app access / ads / export questions, and the listing copy + the three screenshot sets (phone, 7-inch and 10-inch, all captured), plus the paid-app setup: a payments profile with tax rates, the €2.99 price and the 14-day €1.49 launch sale on Products > App pricing — the price must be set before the first upload, because free → paid is not possible afterwards (M9). Keystore, versionCode, listing copy, graphics, permission audit and the signed .aab (sha256 f8e6a29a…) are all in place; rollout goes internal → closed → production. Step-by-step: PLAY_RELEASE_CHECKLIST
Store screenshots need one re-shoot ✅ done — verified on device	The old captures showed the Photo access needed banner (an app-op is not a grant) and 03-results.png showed the developer's own library. After a real grant the set was re-shot over the generated demo library: 01-empty (no tap needed — results and selection live in ScannerViewModel, so force-stop + relaunch returns to the empty state with the grant still in place), 02-scanning (5353 / 5385), 03-results (17 groups, 54 of 5385 photos, 83.5 MB reclaimable; the headline group's 43.1 MB out-ranks the device's own 39.8 MB, so no real photo is in frame) and 04-options. Captures are taken by watching for UI text changes, because MIUI refuses synthetic taps (INJECT_EVENTS). The demo library is deleted from the test device afterwards — MediaStore 5,386 → 5,364 rows, and the 22 stale rows it leaves in the hash index are pruned by PhotoIndexStore.pruneTo on the next scan. Deliberately not captured: the staged state and the system confirmation dialog, because staging clears the demo group and would put real photos back in frame. Details: STORE_LISTING
Tablet store screenshots outstanding ✅ done — captured on AVDs	Play has a 7-inch tablet and a 10-inch tablet screenshot slot of its own (asking for ≥ 4 screenshots on large screens). Both are now captured on AOSP Android 12 AVDs — Nexus 7 2013 (1200×1920, sw600dp) and medium_tablet (1600×2560, sw800dp) — because this machine exposes no /dev/kvm: they ran in pure software emulation (-accel off -no-window -gpu swiftshader_indirect), ≈3 min to boot, with hide_error_dialogs on so SystemUI's ANR dialog could not sit in frame. Four screens per tablet over the same generated demo library: empty, scanning (20 / 22), results (2 groups · 16 of 22 photos · 43.7 MB reclaimable, 39.7 s / 53.1 s) and Options. tools/make-store-screenshots.sh is form-factor aware (FORM_FACTOR=phone|tablet-7in|tablet-10in) and the tablet form factors crop 0 px of chrome, because a tablet frame is already inside Play's 2:1 cap. Recipe: STORE_LISTING
Device-only verifications	RAW/DNG files, a real iPhone HEIC with a non-upright EXIF orientation, permission revoked mid-scan, and the Android 14 “Selected photos” flow. ✅ The index-reuse check is done: after a scan the index holds 5,363 rows, 5,357 with a perceptual hash, and a second scan runs in 11.0 s vs 20.2 s cold

Candidate milestones (proposed, not scheduled)

Candidate	Rationale
Colour signature	Flat-colour images (blank scans, dark UI screenshots) hash identically regardless of colour, so they are reported as mutual duplicates — see the “Known gap” in EDGE_CASE_TESTING. A small colour histogram is orthogonal to the grayscale structure hash, and the benchmark harness already has an implementation to measure against
Video support	Only images are scanned today (README “Known limitations”)
“Similar shots” section	Bursts / same-subject shots as a separate, never-pre-selected list. Needs a different algorithm and must not feed the deletion flow
Warm-scan speed	A second scan is faster (11.0 s) but its “similar” stage still costs ~10 s even though all 5,357 perceptual hashes are cached — the per-photo withTimeoutOrNull wrapper still runs for all 5,363 photos. Profiling this could make an unchanged library re-scan in well under a second

Suggested order

1. ✅ Done — the scan-stall hardening and the BoundedCall fix shipped as 1.0.1 (versionCode 2). Only the on-device re-check of the 5,363-photo scan remains.
2. Finish the Play Console paperwork and roll out through internal → closed → production.
3. ✅ Done — M10 store assets: the icon and feature graphic are generated from the app's own vectors, the screenshot normaliser enforces Play's 2:1 limit, the listing copy is drafted and length-checked, and the demo library that keeps real photos out of the results capture is generated and validated. The re-shoot after a real permission grant is done as well (see blockers): four captures, normalised to 1080×2160. The normaliser is form-factor aware too, and the 7-inch and 10-inch tablet sets were captured on AOSP AVDs in software emulation (1200×1920 and 1600×2560), so all three screenshot sets now exist.
4. Colour signature — the flat-colour false-positive fix.
5. ✅ Done — M9 monetisation: decided as a one-time paid app (€2.99, launched with a 14-day 50% sale at €1.49), which needs no code at all. The remaining work is Console-only — a payments profile, the price and the launch sale on Products > App pricing — and the price must happen before the first upload, because free → paid stops being possible once the app has been offered for free.

Deliberately deferred: video support and the “similar shots” section.