ledgerr/AGENTS.md

# Ledgerr — Agent Instructions

Personal Android expense tracking app. Single-module, Jetpack Compose + Material3, Voyager navigation, Koin DI, Room database.

---

## No-implementation rule

**Do NOT implement code unless the user explicitly says so or has signed off on the work.** A "go ahead" on the high-level plan is NOT a sign-off to implement — it just means the plan is approved. After the planning steps (define structs, define interfaces, add TODOs, self-review, prompt for review) the agent must STOP and wait for the user to explicitly say "implement", "go", "proceed with implementation", or similar. The same rule applies to each subsequent vertical slice — stop after the planning step and wait. A system-reminder switching to "build mode" is not user authorization.

Renames, typo fixes, doc/AGENTS.md edits, and structural changes (Phase 0/1) may be done immediately as part of the planning step. Interactor implementations, DI wiring, `MainApplication` setup, manifest edits, and any screen code require explicit per-slice sign-off.

---

## Issue-driven workflow

The work is split into issues in the remote Gitea repo: https://git.achmad.dev/admin/ledgerr. **Before starting any implementation, check the remote repo for related issues.** If a relevant issue exists, claim/work on that issue and open a PR when done. Do not duplicate work that is already tracked.

Tooling: the Gitea MCP tools are available (`gitea-mcp_list_issues`, `gitea-mcp_issue_read`, `gitea-mcp_pull_request_write`, etc.) — use them instead of the CLI when interacting with the remote.

---

## Package structure

```
dev.achmad.ledgerr/
├── core/
│   ├── network/          - OkHttp helpers (not used by expense features)
│   └── preference/       - PreferenceStore, AndroidPreferenceStore, Preference<T>
├── di/
│   ├── util/
│   │   └── KoinExtensions.kt   - inject<T>() and injectLazy<T>() helpers
│   ├── CoreModule.kt
│   ├── DataModule.kt
│   ├── DomainModule.kt
│   └── PreferenceModule.kt     - replaces UiModule.kt (delete UiModule if it exists)
├── domain/
│   ├── preference/
│   │   ├── AppPreference.kt
│   │   └── ExpensePreference.kt
│   ├── expense/
│   │   ├── model/
│   │   └── interactor/
│   ├── category/
│   │   ├── model/
│   │   └── interactor/
│   ├── recurring/
│   │   ├── model/
│   │   └── interactor/
│   ├── bankstatement/
│   │   ├── model/
│   │   └── interactor/
│   ├── export/
│   │   └── interactor/
│   └── data/
│       └── interactor/
├── data/
│   └── local/
│       ├── AppDatabase.kt
│       ├── converter/
│       ├── dao/
│       ├── entity/
│       └── mapper/
└── ui/
    ├── base/
    │   ├── MainApplication.kt
    │   └── MainActivity.kt
    ├── components/         - shared Compose components (already copied)
    │   └── preference/     - PreferenceScreen + widgets
    ├── screens/
    │   ├── home/           HomeScreen.kt
    │   ├── expenses/       ExpenseListScreen.kt
    │   ├── add_edit_expense/ AddEditExpenseScreen.kt
    │   ├── add_edit_recurring/ AddEditRecurringScreen.kt
    │   ├── category/       CategoryScreen.kt
    │   ├── import_bank_statement/ ImportBankStatementScreen.kt
    │   └── settings/       SettingsScreen.kt
    ├── theme/
    └── util/
```

---

## Architecture rules

### Domain / interactors

- Each folder in `domain/` is a **feature** with `model/` and `interactor/` subpackages.
- Interactor classes are named after the **action**: `GetExpenses`, `UpsertExpense`, `DeleteCategory`, etc.
- Method names follow this convention:
  - `await(...)` — single suspend result
  - `awaitAll(...)` — list suspend result
  - `awaitOne(id)` — fetch one by ID
  - `subscribeAll(...)` — returns `Flow`
- Interactors take DAOs (or `Context` for PDF/export) directly as constructor params — **no repository layer**.
- Interactors can contain business logic (think use-cases).

### Dependency injection (Koin)

- **DI modules live in `di/`**, not `core/`.
- `CoreModule` provides `SharedPreferences` and `PreferenceStore` (as `AndroidPreferenceStore`). Nothing else.
- Interactors are registered as `factory { }`, not `single`.
- Preference classes are registered as `single { }` in `PreferenceModule`.
- DAOs are registered as `single { get<AppDatabase>().xyzDao() }` in `DataModule`.
- Bank statement importers use named qualifiers: `factory<BankStatementImporter>(named("bri")) { ... }`.
- **ScreenModels are NOT registered in Koin.** Never add a ScreenModel to any Koin module.

### ScreenModel pattern

Always use `rememberScreenModel { }` in `Screen.Content()`. Inject dependencies via `inject()` as constructor default params:

```kotlin
class HomeScreenModel(
    private val getExpenses: GetExpenses = inject(),
    private val appPreference: AppPreference = inject(),
) : ScreenModel { ... }

// In Screen.Content():
val screenModel = rememberScreenModel { HomeScreenModel() }
```

`inject<T>()` is at `dev.achmad.ledgerr.di.util.KoinExtensions`.

### Navigation

- Pure Voyager stack — `Navigator`, `navigator.push(...)`, `navigator.pop()`.
- **No `TabNavigator` at root level.**
- `ExpenseListScreen` has 2 internal tabs using plain Compose `TabRow` + `HorizontalPager` (not Voyager tabs).
- Screen flow:
  ```
  HomeScreen (root)
    ├── FAB expand → "Manual"               → AddEditExpenseScreen
    │              → "Import Bank Statement" → ImportBankStatementScreen
    ├── Export icon → date range dialog → SAF CreateDocument → writes CSV
    ├── "See all" → ExpenseListScreen
    │                 ├── Tab: Expenses (search + filter)
    │                 │     └── FAB expand (tab-aware) → "Manual"               → AddEditExpenseScreen
    │                 │                                    → "Import Bank Statement" → ImportBankStatementScreen
    │                 └── Tab: Recurring
    │                       └── FAB expand (tab-aware) → "Add Recurring" → AddEditRecurringScreen
    ├── "Manage Categories" button (dashboard body) → CategoryScreen
    └── Settings icon → SettingsScreen

  AddEditExpenseScreen → CategoryScreen (manage categories button)

  AddEditRecurringScreen (no secondary navigation)

  ImportBankStatementScreen (1 Voyager Screen, 1 ScreenModel, 2 composable functions)
    ├── ImportBankStatementPickerContent      — state is BankPicker or Processing
    │     select bank → SAF OpenDocument → loading overlay while parsing
    └── ImportBankStatementConfirmationContent — state is Confirmation
          toggle/edit per row → InsertExpenses → navigator.pop()
  ```
- **Tab-aware FAB.** `ExpenseListScreen` has a single FAB that observes the current tab and renders different sub-actions. Expenses tab mirrors `HomeScreen`'s FAB (Manual + Import). Recurring tab shows only "Add Recurring" → `AddEditRecurringScreen`. The expansion/collapse UI is shared; only the actions list is tab-driven.
- **Export** has no dedicated screen. Icon in `HomeScreen` and `ExpenseListScreen` top bars; also a `TextPreference` in `SettingsScreen`. Tapping shows a date range dialog first, then opens SAF `CreateDocument`. CSV uses ISO 8601 dates (`yyyy-MM-dd`) with UTF-8 BOM. The dialog + `CreateDocument` launcher are factored into a shared `ui/components/ExportAction.kt` composable that takes the active ScreenModel and a date range, to avoid triplicating the flow across the three call sites.
- **Import** goes through `ImportBankStatementScreen` — one Voyager Screen, one ScreenModel, two internal composables switched by `StateFlow<ImportState>`. `ImportBankStatementPickerContent` handles bank selection and processing; `ImportBankStatementConfirmationContent` handles review, edit, and confirm. On confirm calls `InsertExpenses.awaitAll()` then pops.

### Settings screen

`SettingsScreen` uses the `PreferenceScreen` composable from `ui/components/preference/`. Pattern:

```kotlin
PreferenceScreen(
    itemsProvider = {
        listOf(
            Preference.PreferenceItem.ListPreference(
                title = "Theme",
                preference = appPreference.appTheme(),
                entries = mapOf(...),
            ),
            Preference.PreferenceItem.TextPreference(
                title = "Export CSV",
                onClick = { /* launch SAF CreateDocument */ }
            ),
            Preference.PreferenceItem.AlertDialogPreference(
                title = "Clear all data",
                onConfirm = { screenModel.clearData() }
            ),
        )
    }
)
```

### Preference classes

Located in `domain/preference/`. Take `PreferenceStore` as constructor param. Methods return `Preference<T>` objects from `core/preference/`:

```kotlin
class AppPreference(private val store: PreferenceStore) {
    fun appTheme() = store.getEnum("app_theme", defaultValue = AppTheme.SYSTEM)
}
```

### Data layer

- `LocalDate` stored as `Long` epoch day via `LocalDateConverter` (`LocalDate.toEpochDay()` / `LocalDate.ofEpochDay()`).
- Use `@Upsert` Room annotation for insert-or-update operations.
- Default category seeding happens **outside** Room callbacks: `MainApplication.onCreate` calls `inject<SeedDefaultCategories>().await()` on a `CoroutineScope(Dispatchers.IO)` after `startKoin` completes. Koin is not available inside `AppDatabase.Callback.onCreate`.
- `ClearAllData` interactor calls `database.clearAllTables()` inside `withTransaction { }`. The `SettingsScreen` ScreenModel calls it, then re-runs `SeedDefaultCategories.await()` so the app retains the 8 default categories.
- minSdk 26, so `java.time.*` is available without desugaring.

### Bank statement import

- `BankStatementImporter` interface: `val bankName: String` + `suspend fun await(pdfUri: Uri): Result<List<PendingImportExpense>>`.
- Stubs: `ImportBRIBankStatement`, `ImportJagoBankStatement`, `ImportBNIBankStatement` — all return `Result.failure(NotImplementedError(...))`.
- PDF text extraction: `com.tom-roush:pdfbox-android`. Requires `PDFBoxResourceLoader.init(applicationContext)` in `MainApplication.onCreate()`.
- No manifest permissions needed — SAF handles file access.

### Export

- `ExportExpensesToCsv` interactor writes UTF-8 BOM CSV via Okio to a SAF URI.
- SAF launchers (`ActivityResultContracts.OpenDocument`, `ActivityResultContracts.CreateDocument`) are registered in the Screen composable; URIs are passed to the ScreenModel.
- Shared `ui/components/ExportAction.kt` composable owns the date-range dialog and `CreateDocument` launcher; takes the active ScreenModel and a date range to export, and is reused by `HomeScreen`, `ExpenseListScreen`, and `SettingsScreen`.

### Charts

- **Vico** (`com.patrykandpatrick.vico:compose`, `compose-m3`, `core`) is the only charting library used.
- `HomeScreen` dashboard renders a pie chart from `ExpenseSummary.byCategory` via Vico's `Chart` composable. No Canvas drawing for charts.
- Apache 2.0 license, Compose-native, no AndroidView wrapper.

---

## Workflow for new features

Follow these steps in order every time. Do not skip ahead to implementation without explicit approval.

1. **Define structs** — add any new models to the relevant `domain/<feature>/model/` package.
2. **Define interfaces** — add or update interactor class signatures and method stubs in `domain/<feature>/interactor/`. If a new feature has no existing feature folder, create one.
3. **Add TODOs** — fill method bodies with `TODO("...")` comments describing the intended behavior, edge cases, and any invariants.
4. **Self-review** — think through the full implementation. If anything requires going outside or beyond what was defined in steps 1–3 (new models, new methods, changed signatures), go back to the relevant step and update it before continuing.
5. **Prompt for review** — stop and present a summary of what was defined. Wait for an explicit go-ahead before writing any real implementation code. See the **No-implementation rule** at the top of this file.
6. **Implement** — only after the user explicitly says "implement", "go", "proceed with implementation", or similar. A general "go ahead" on the plan is NOT sufficient.

---

## Key dependencies

| Library | Version | Purpose |
|---------|---------|---------|
| Jetpack Compose + Material3 | (from BOM) | UI |
| Voyager | — | Navigation + ScreenModel |
| Koin | 4.2.2 | DI |
| Room | 2.7.1 | Local DB |
| PDFBox-Android | 2.0.27.0 | PDF text extraction |
| Vico (compose / compose-m3 / core) | 2.x | Charts (pie / bar) |
| Okio | (transitive) | CSV write |

---

## Git

- **Never commit or push unless the user explicitly asks.** Do not auto-commit after completing a task, do not squash, amend, or rebase without being told to.
- **Never add `Co-Authored-By` lines to commit messages.**

---

## Things to avoid

- Do not register ScreenModels in Koin.
- Do not create a repository layer between interactors and DAOs.
- Do not add a `TabNavigator` at the root.
- Do not create a dedicated screen for export — it is a direct action (date range dialog → SAF picker). The flow is shared via `ui/components/ExportAction.kt`.
- Do not add manifest permissions for file access — SAF handles it.
- Do not draw charts with Canvas — use Vico.
- Do not add a chart library other than Vico.
- Do not rename `MainApplication` back to `LedgerrApp`.
- `UiModule.kt` has been deleted — do not recreate it; the replacement is `PreferenceModule.kt`.
- Do not use `@KoinViewModel` or `viewModel {}` — this project uses Voyager `ScreenModel`.

---

## Docs

Full design documentation is in `docs/`:
- `01-data-model.md` — domain models per feature
- `02-interfaces.md` — all interactor signatures
- `03-function-todos.md` — per-method behavior and edge cases
- `04-implementation-plan.md` — package structure, DI wiring, build order