FD Manager — Android mock UI

Front-end mock of the Fixed Deposit (FD) Manager app from the spec. Kotlin + Jetpack Compose, Material 3, runs 100% on local sample data — no Firebase, no auth, no backend (per request).

What it does

Area	Details
Home (HomeScreen + BankSummaryCard + BankMonogram)	Total invested hero (Rs, LKR) — Lkr.words + Lkr.exact + StatMini ×3, active-FD / institution counts, next-maturity stat, "Maturing soon" strip (respects configured lead window, spec default 5 days, Lkr.compact + CountdownChip), By-institution cards Option B (BankSummaryCard right column: Lkr.words e.g. Rs 1 Million / Rs 750 K + Lkr.exact + invested label) → bank FD list (FdListScreen). Notification bell with badge shows same maturing list. Wire diagram: docs/app-wire-diagram.md + .html.
Bank FD list (FdListScreen + FdCard)	FDs sorted by maturity date (spec) with sort menu (maturity / amount / rate) and status filter chips (All / Active / Matured / Renewed). Cards show FD number, amount Option B natural wording (Lkr.words e.g. Rs 1 Million / Rs 750 K primary titleLarge bold primary + Lkr.exact e.g. Rs 1,000,000.00 secondary labelSmall gray) + countdown chip (in 4d, 6d overdue) — extended from By-institution to FD cards 2026-10-07. Overflow menu → Edit / Renew / Delete (RenewDialog). TopAppBar shows BankMonogram.
FD detail	Amount header, status + countdown, simple-interest returns estimate (interest earned, maturity value), full detail rows, auto-renew notice, renewal-history chain (follows parentFdId, oldest→newest, tap to navigate), Renew and Delete actions with confirmations.
Add / Edit FD	Validated form matching the spec schema: FD number, bank (Sri Lankan bank list), amount, rate, duration presets + custom, opened-date picker, branch/code, auto-renew switch. Live maturity preview (maturity date, est. interest, est. value). Edit mode is pre-filled.
Calendar	Month grid (Monday-first) with dots on days that have maturity events (color-coded by status), per-day lists, month counts.
Recycle bin	Soft-delete (isDeleted) per spec: restore or "delete forever" (explicitly flagged as bypassing the safeguard).
Settings	Theme (System/Light/Dark — working), notification toggle + lead-days slider (feeds the Home strip/bell), biometric lock (placeholder, needs auth), currency (LKR), CSV export + demo-data reset, About.

Spec behaviours modeled

• Firestore-like document shape (FixedDeposit mirrors every schema field incl. parentFdId, isDeleted, isActive).
• Renewal: old FD → status=RENEWED, isActive=false; new ACTIVE child opens on the old one's maturity date with same terms, linked via parentFdId, numbered …-R1, …-R2. Second-renewal of an already-renewed FD is rejected.
• Soft delete everywhere; totals exclude RENEWED parents and deleted rows.
• Sorted-by-maturity lists and 5-day maturing-soon window (default).

Sample data

8 fictional FDs across 6 Sri Lankan banks (NSB, Sampath, HNB, Commercial, BOC, People's + one deleted DFCC), LKR amounts, dates generated relative to today so the mock always shows live countdowns, an in-window maturity, an overdue one and a renewal chain.

Build

Open in Android Studio and Run, or CLI:

./gradlew :app:assembleDebug        # APK → app/build/outputs/apk/debug/app-debug.apk
./gradlew :app:testDebugUnitTest    # JVM unit tests (domain math, queries, repository)

• minSdk 24, target/compile 34 · AGP 8.5.2 · Kotlin 2.0.20 · Compose BOM 2024.09.00 · core library desugaring for java.time.

Architecture (mock)

data/            FixedDeposit model (mirrors Firestore schema), FdRepository (in-memory StateFlow store), SampleData, SettingsStore
domain/          FdMath (interest, maturity dates, countdowns, LKR formatting) & FdQueries (summaries, filters, chains) — pure Kotlin, unit-tested
ui/              theme (teal M3 + status palettes), shared components, screens, FdViewModel
MainActivity     Routes + bottom nav + FAB

Swap points for the real backend: FdRepository (→ Firestore) and SettingsStore (→ user doc).

Security & trust

The public security architecture — multi-user tenancy, threat model, defense in depth, data-handling promises and honest limitations — is documented in docs/SECURITY.md.

Current mock phase: all data is in-memory only, never persisted, and never leaves the device.

Deliberately not implemented (backend-era)

Authentication, real push notifications (10:00 AM daily job), biometric unlock, CSV export, interest rate history, multi-currency.