# Phase 2: Infrastructure — Storage

**Status:** ⬜ Not Started
**Parent plan:** [PLAN.md](./PLAN.md)
**Domain:** backend

## Objective

Implement persistent storage: EF Core + SQLite (WAL) with migrations, repository
implementations of the Application layer's interfaces, and a ClosedXML-based Excel
exporter that produces files matching the customer's wide-column spec with date-range
filenames.

## Tasks

- [ ] Add packages to `Marathon.Infrastructure` (via `Directory.Packages.props`):
  - `Microsoft.EntityFrameworkCore`
  - `Microsoft.EntityFrameworkCore.Sqlite`
  - `Microsoft.EntityFrameworkCore.Design`
  - `ClosedXML`
- [ ] Add Application-layer abstractions in `Marathon.Application/Abstractions/`:
  - `IRepository<TKey, TEntity>` — generic CRUD: `GetAsync`, `ListAsync`,
    `AddAsync`, `UpdateAsync`, `DeleteAsync`, `SaveChangesAsync`
  - `IEventRepository : IRepository<EventId, Event>` — adds `ListByDateRangeAsync`,
    `ListBySportAsync`
  - `ISnapshotRepository : IRepository<Guid, OddsSnapshot>` — adds
    `ListByEventAsync(EventId, DateTimeOffset from, DateTimeOffset to)`
  - `IResultRepository : IRepository<EventId, EventResult>`
  - `IAnomalyRepository : IRepository<Guid, Anomaly>`
  - `IExcelExporter` — `ExportAsync(DateRange range, ExportKind kind, string outputPath)`
    where `ExportKind = PreMatch | Live | Combined`
- [ ] Implement `MarathonDbContext` in `Marathon.Infrastructure/Persistence/`:
  - `DbSet<EventEntity>`, `DbSet<SnapshotEntity>`, `DbSet<BetEntity>`,
    `DbSet<EventResultEntity>`, `DbSet<AnomalyEntity>`, `DbSet<SportEntity>`,
    `DbSet<LeagueEntity>`
  - Configure SQLite with WAL via connection string
  - Use `EntityTypeConfiguration<T>` classes (one per entity in `Configurations/`)
  - Map domain types ↔ EF entities via mapping helpers (don't pollute domain)
  - Indexes: `(EventId)` on `Snapshots` and `Bets`; `(Sport, ScheduledAt)` on `Events`
- [ ] Implement `Migrations/InitialCreate` migration (EF Core CLI):
  ```
  dotnet ef migrations add InitialCreate --project src/Marathon.Infrastructure
  ```
- [ ] Implement repositories in `Marathon.Infrastructure/Persistence/Repositories/`:
  - `EventRepository`, `SnapshotRepository`, `ResultRepository`, `AnomalyRepository`
  - Each maps EF entity ↔ domain type at the boundary
- [ ] Implement `ExcelExporter` in `Marathon.Infrastructure/Export/`:
  - Uses ClosedXML
  - Output filename: `Marathon_<from yyyy-MM-dd>_to_<to yyyy-MM-dd>.xlsx`
  - Two sheets: `PreMatch` and `Live` (or only the selected one based on `ExportKind`)
  - Wide columns matching customer spec exactly:
    - Event metadata: `RowNum`, `SportCode`, `Sport`, `Country`, `League`, `Category`,
      `DateFull`, `Day`, `Month`, `Year`, `Time`, `EventId`
    - Match-level bets: `Bet_Match_Win_1`, `Bet_Match_Draw`, `Bet_Match_Win_2`,
      `Bet_Match_Win_Fora_1_Value`, `Bet_Match_Win_Fora_1_Rate`, etc.
    - Period-N bets: dynamically generated for max periods seen (`Bet_Period-1_Win_1`, ...)
    - For Live export, prefix with `Live_` instead of `Bet_`
    - Final column: `WinnerSide` (1 or 2 based on lowest pre-match Win rate, per spec
      §1.2.4 / §2.2.4)
  - Implement a `BetRowDenormalizer` helper that takes a `List<Bet>` and produces a
    flat `Dictionary<string, object?>` keyed by spec column names.
- [ ] Add a DI extension `AddMarathonInfrastructure(IServiceCollection, IConfiguration)`
  in `Marathon.Infrastructure/DependencyInjection.cs` that wires up DbContext +
  repositories + exporter using `IConfiguration` for `Storage:DatabasePath` and
  `Storage:ExportDirectory`.
- [ ] Tests in `Marathon.Infrastructure.Tests`:
  - In-memory SQLite (`Microsoft.Data.Sqlite` with `Mode=Memory;Cache=Shared`)
  - Test: insert + retrieve `Event`, `OddsSnapshot`, `Anomaly` round-trip preserves all
    domain fields
  - Test: `ExcelExporter` generates a workbook with the expected sheet names, headers
    matching spec, and row count matching event count
  - Test: filename pattern matches `Marathon_yyyy-MM-dd_to_yyyy-MM-dd.xlsx`
  - Test: WAL mode is enabled after open

## Files to Modify/Create

- `src/Marathon.Application/Abstractions/I*.cs` — repository interfaces
- `src/Marathon.Application/ExportKind.cs`, `DateRange.cs`
- `src/Marathon.Infrastructure/Persistence/MarathonDbContext.cs`
- `src/Marathon.Infrastructure/Persistence/Entities/*.cs`
- `src/Marathon.Infrastructure/Persistence/Configurations/*Configuration.cs`
- `src/Marathon.Infrastructure/Persistence/Repositories/*Repository.cs`
- `src/Marathon.Infrastructure/Persistence/Mapping.cs` — entity ↔ domain
- `src/Marathon.Infrastructure/Export/ExcelExporter.cs`
- `src/Marathon.Infrastructure/Export/BetRowDenormalizer.cs`
- `src/Marathon.Infrastructure/Migrations/*` — EF migrations
- `src/Marathon.Infrastructure/DependencyInjection.cs`
- `tests/Marathon.Infrastructure.Tests/**`

## Acceptance Criteria

- All Infrastructure code compiles (Big Bang: compile-only smoke check OK).
- DbContext + repositories cover all domain types.
- Excel exporter output matches customer spec column names exactly (no typos in
  `Bet_Match_Win_Fora_1_Value`, hyphens in `Period-1`, etc.).
- Filename includes inclusive date range from event scheduling.

## Notes

- This phase is parallelizable with Phase 3 (Scraping) — they touch disjoint files.
- `ExcelExporter` uses normalized DB data and produces wide columns — DO NOT store
  data in wide format in SQLite.
- Big Bang: do NOT run full test suite. A `dotnet build` smoke check is acceptable.

## Review Checklist

- [ ] Solution builds (compile-only)
- [ ] Excel column names match customer spec exactly (cross-check against TZ §1.2 / §2.2)
- [ ] Filename pattern matches `Marathon_yyyy-MM-dd_to_yyyy-MM-dd.xlsx`
- [ ] No domain types polluted with EF attributes — mapping is in `Configurations/`
- [ ] WAL mode enabled in connection string

## Handoff to Next Phase

<!-- Filled by Phase 2 implementer. -->