# App Overview

Architecture overview of the app's entry point, main container, navigation system, and global session lifecycle.

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## Entry Point — `MainActivity`

`MainActivity` is a transparent trampoline activity. On `onCreate` it reads app state and immediately forwards to the correct destination with no visible UI of its own:

| Condition | Destination |
|---|---|
| Onboarding not done | `OnboardingActivity` |
| No saved credentials | `LoginActivity` |
| Security lock configured | `LockActivity` |
| All checks pass | `HomeActivity` |

### Intent Actions

External intents (from NFC, shortcuts, or notifications) are forwarded to `HomeActivity` via the same intent (`MainActivity.kt:57-65`):

| Action | Destination | Notes |
|---|---|---|
| `sh.sar.basedbank.OPEN_TRANSFER` | `R.id.nav_transfer` | Plain transfer screen |
| `sh.sar.basedbank.OPEN_SCAN_QR` | `R.id.nav_transfer` + `auto_scan=true` | Opens [QR scanner](25-qr-scanner.md) immediately |
| `sh.sar.basedbank.OPEN_PAY_WITH_CARD` | `R.id.nav_pay_with_card` | Opens [Cards](22-cards.md) (`CardsFragment`) |
| `sh.sar.basedbank.TAP_TO_PAY` | `R.id.nav_pay_with_card` + `auto_tap_mode=true` | Enters [Tap to Pay](23-tap-to-pay.md) on the default card |

### Share-to-Scan (`ACTION_SEND`)

When another app shares an image to the **Scan to Pay** activity-alias declared in `AndroidManifest.xml`, `MainActivity.kt:47-55` decodes the bitmap on the spot using `ZxingCpp` (while it still holds the share URI permission) and forwards the decoded QR text as `share_qr_text` to `HomeActivity`.

### NFC Entry Point

`BmlTapToPayActivity` (manifest-registered, NFC payment service redirect) immediately re-fires a `TAP_TO_PAY` intent to `MainActivity` and finishes — see [Tap to Pay](23-tap-to-pay.md).

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## Main Container — `HomeActivity`

`HomeActivity` is the persistent shell containing all in-app screens. It owns:

- The `NavHostFragment` and `NavController`
- The `DrawerLayout` and `NavigationView`
- The `BottomNavigationView`
- The toolbar (lock icon + hide-amounts eye icon)
- The connectivity banner
- The autolock timer
- The MIB session keepAlive scheduler

### Toolbar

| Icon | Behavior |
|---|---|
| Lock icon | Immediately locks the app → `LockActivity` (animated with scale + alpha) |
| Eye icon | Toggles `hideAmounts` in `HomeViewModel`; all balance displays redact to `••••` |
| Bell icon | Opens `NotificationsSheetFragment` ([Notifications](24-notifications.md)). Shows `ic_bell` when there are unread notifications, `ic_bell_read` otherwise (`HomeActivity.kt:640-684`) |

In Circular nav mode the toolbar collapses to just the app title — the lock, eye, and bell items are all hidden (`HomeActivity.kt:646-650`).

### Auto-refresh

On launch and after unlock `HomeActivity.autoRefresh()` fires parallel login refresh calls for all banks with active sessions. Each bank runs independently — a failure in one bank does not block the others.

### Connectivity Banner

A persistent banner appears at the top of `HomeActivity` when network connectivity is lost. It disappears automatically when connectivity is restored. Per-bank connectivity errors (e.g., session expired) are surfaced via `HomeViewModel.connectivityErrors`.

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## Navigation Modes

Three modes are selectable in Settings → Appearance (`NavCustomization.kt:10-12`):

### Drawer (default) — `NAV_MODE_DRAWER`

A slide-out navigation drawer containing all configurable nav items. The hamburger icon in the toolbar opens it.

### Bottom Navigation — `NAV_MODE_BOTTOM`

A bottom bar with **3** configurable slots plus a fixed **Dashboard** tab (always leftmost) and a **More** tab (always rightmost). Tapping **More** opens `NavMoreSheetFragment` — a bottom sheet listing all items not assigned to the visible slots.

### Circular — `NAV_MODE_CIRCULAR`

A radial wheel UI with 4 customisable wheel slots + a lock-icon centre — see [Circular Nav](26-circular-nav.md).

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## Navigation Slots

`NavCustomization.ALL_SWAPPABLE` enumerates every reorderable destination. Quick actions and bottom-bar slots persist as individual `SharedPreferences` keys (`NavCustomization.kt:52-93`).

| Destination | Nav ID |
|---|---|
| Accounts | `nav_accounts` |
| Contacts | `nav_contacts` |
| Transfer | `nav_transfer` |
| PayMV QR | `nav_pay_mv_qr` |
| Activities | `nav_activities` |
| Transfer History | `nav_transfer_history` |
| Financing | `nav_finances` |
| Cards | `nav_pay_with_card` |
| OTP | `nav_otp` |
| Settings | `nav_settings` |

Defaults:

| Slot set | Defaults |
|---|---|
| Bottom-bar (3 slots) | Accounts, Contacts, Transfer |
| Circular wheel (4 slots) | Transfer, Cards, Contacts, Accounts |
| Quick actions (2 FAB slots on dashboard) | Transfer, PayMV QR |

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## Autolock

Autolock fires after a configurable period of user inactivity. Any touch event resets the timer.

| Timeout option |
|---|
| 30 seconds |
| 1 minute (default) |
| 3 minutes |
| 5 minutes |

There is no "Never" option (`SettingsSecurityFragment.kt:81-86`) — auto-lock cannot be disabled.

When the timeout expires a 10-second countdown warning dialog appears. If dismissed, the timer resets. If ignored, the app calls `LockActivity` and clears `app.isUnlocked`.

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## Global State — `BasedBankApp`

`BasedBankApp` holds all in-memory session data (`BasedBankApp.kt:27-49`). Nothing is stored to disk except encrypted credentials.

| Field | Description |
|---|---|
| `isUnlocked` | Set to `true` after successful lock-screen auth; guards against process-restart bypass |
| `accounts: List<BankAccount>` | Combined view of every visible account across all banks |
| `fullName: String` | Account holder name (best available across logins) |
| `mibSessions` | Map of MIB loginId → active session (cookies + DH key) |
| `mibProfilesMap` | Per-loginId list of MIB CIF profiles |
| `mibLoginFlows` | Active `MibLoginFlow` instances per login |
| `mibAccounts: List<BankAccount>` | MIB-only slice of `accounts` |
| `bmlSessions` | Map of BML profileId → OAuth tokens |
| `bmlProfilesMap` | Per-loginId list of `BmlProfile` |
| `bmlLoginFlows` | Active `BmlLoginFlow` instances per login (holds web session cookies for activation) |
| `bmlAccounts: List<BankAccount>` | BML-only slice |
| `fahipaySessions` | Map of Fahipay loginId → authID + session cookie |
| `fahipayAccounts: List<BankAccount>` | Fahipay-only slice |
| `mibMutex` | Coroutine mutex — serializes all MIB profile-switch + request sequences |

### Profile Visibility

Each stored profile has a visibility flag. Hidden profiles are excluded from the accounts list and from all API refresh cycles until re-enabled in Settings → Logins.

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## MIB Session KeepAlive

MIB web sessions expire after approximately 30 seconds of inactivity. `HomeActivity` schedules a coroutine that calls the MIB keepAlive endpoint every 25 seconds for each active MIB session while the app is in the foreground.

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