maraphon-app/plans/initial-implementation/CONTEXT.md

Feature Context: Initial Implementation

Configuration

• Development mode: Automated
• Execution mode: Orchestrator
• Strategy: Big Bang
• Build: dotnet build Marathon.sln
• Test: dotnet test Marathon.sln
• Lint: dotnet format Marathon.sln --verify-no-changes
• Run: dotnet run --project src/Marathon.Hosts.WpfBlazor
• Implementer models: Sonnet 4.6 (backend), Opus (frontend)
• Reviewer model: Sonnet 4.6

Customer Constraints

• Source: marathonbet.by — anonymous scraping (no login). ToS risk acknowledged by customer.
• Output: Excel files matching customer's wide-column spec (Bet_Match_Win_1, Bet_Period-1_Win_Fora_2_Value, etc.) with date-range filenames.
• Storage: customer accepted SQLite-with-Excel-export instead of Excel-as-database (decided 2026-05-05).
• UI tech: Blazor Hybrid (changed from initial WPF assumption — better for web migration).
• Locale: RU + EN.
• Scope: analyze-only initially; design IBetPlacer extension point for future betting.
• Configurability: every variable parameter (polling, concurrency, retry, UA, retention, thresholds, locale) goes in appsettings.json + Settings UI page.

Current State

Repo just initialized. Single main commit with .gitignore + README.md + CLAUDE.md. Working on feature/initial-implementation branch. No source code yet — Phase 0 starts with scraping research, no implementation.

Temporary Workarounds

(none yet)

Cross-Phase Dependencies

• Phase 1 (Domain) is the foundation; all later phases reference domain types.
• Phase 2 (Storage) & Phase 3 (Scraping) depend only on Phase 1 — can run in parallel.
• Phase 4 (Application + Workers) depends on Phase 2 + Phase 3.
• Phase 5 (UI Shell) depends on Phase 1 only — can run in parallel with 2/3.
• Phase 6 (Event Browsing UI) depends on Phase 4 + Phase 5.
• Phase 7 (Anomaly) depends on Phase 4 (snapshot storage) + Phase 6 (UI patterns).
• Phase 8 (Results) depends on Phase 6.
• Phase 9 (Packaging) is final — runs full build + test suite.

Deferred Work

• Bet placing (explicit out-of-scope; design extension point only).
• Authenticated scraping (anonymous now; IOddsScraper impl is swappable).
• Multi-bookmaker support (only marathonbet.by; abstraction allows future expansion).
• PostgreSQL backend (SQLite for now; IRepository<T> abstraction allows swap).

Failed Approaches

• Public results / archive endpoint — does NOT exist. Tested https://www.marathonbet.by/su/results, /su/results/, /su/results.htm — all return HTTP 404. No /archive, /history links anywhere in the public HTML either. Phase 8 deviation: the Results loader cannot back-fill from an archive — it must poll each event detail page until eventJsonInfo.matchIsComplete=true and snapshot resultDescription at that moment. Phase 8 implementer must revise the subplan accordingly.
• JSONP /su/liveupdate/popular/ endpoint — exposes only refresh signals ({"modified":[{"type":"refreshPage"}],"updated":<ts>}), not actual odds. Cannot be used as a JSON odds source. Use it only as a "something changed" hint to trigger a full event-detail re-scrape.
• Anonymous WebSocket (STOMP) at /su/websocket/endpoint is documented in initData.stomp but appears to require an authenticated session (PUNTER-SESSION-HASH cookie); we did not test it but the customer's anonymous scraping constraint makes it unsuitable anyway.

Review Findings Log

(populated by reviewers)

Phase Execution Log

Phase	Agent	Model	Test Writer	Parallel	Notes
Phase 0	phase-implementer	Opus	⏭️ Skipped (research only)	—	✅ Done 2026-05-05. Outputs: spike/SCRAPE_FINDINGS.md + spike/SCHEMA_DRAFT.md + 7 local fixtures. Anonymous scraping confirmed feasible; HttpClient+AngleSharp recommended; no Playwright needed; no public results page found (Phase 8 deviation noted).
Phase 1	phase-implementer	Sonnet 4.6	⏭️ Skipped (Big Bang)	—	✅ Done 2026-05-05. 9 projects (5 src + 4 test). 96 domain tests passed. Key decisions: BetScope sealed hierarchy, ScheduledAt=UTC+3 (Moscow), OddsValue rejects zero. Deviations: slnx auto-created alongside sln, WPF App.xaml.cs needs FQ Application type.
Phase 2	phase-implementer	Sonnet 4.6	⏭️ Skipped (Big Bang)	✅ With 3 + 5	—
Phase 3	phase-implementer	Sonnet 4.6	⏭️ Skipped (Big Bang)	✅ With 2 + 5	—
Phase 4	phase-implementer	Sonnet 4.6	⏭️ Skipped (Big Bang)	—	✅ Done 2026-05-05. 4 use cases, 3 BackgroundService pollers, InfrastructureModule, ApplicationModule, reflection wiring removed. 202/202 tests green (+17 new).
Phase 5	phase-implementer-frontend	Opus	⏭️ Skipped (Big Bang)	✅ With 2 + 3	Uses frontend-design skill
Phase 6	phase-implementer-frontend	Opus	⏭️ Skipped (Big Bang)	—	✅ Done 2026-05-05. PreMatch + Live + Events/Detail pages, EventListShell, SportIcon, OddsCell, OddsTimeline (Plotly.Blazor wrap), ExportDialog. EventBrowsingState + IEventBrowsingService facade. RU+EN strings under PreMatch.* / Live.* / Detail.* / Export.* / Sport.*. 228/228 tests green (+26 new bUnit).
Phase 7	phase-implementer (split if needed)	Sonnet/Opus	⏭️ Skipped (Big Bang)	—	UI portion uses Opus
Phase 8	phase-implementer (split if needed)	Sonnet/Opus	⏭️ Skipped (Big Bang)	—	UI portion uses Opus
Phase 9	phase-implementer	Sonnet 4.6	✅ Final phase tests	—	Full build + test enforced

Environment & Runtime Notes

• Windows 10, PowerShell 5.1 default shell, Bash also available.
• git configured globally; remote origin = https://git.dolgolyov-family.by/alexei.dolgolyov/maraphon-app.git.
• Note: home directory (C:\Users\Alexei) is itself a git repo (likely accidental). The maraphon-app local .git overrides it for this directory tree.
• .NET SDK assumed installed; if Phase 1 fails on dotnet --version, install or document in CONTEXT.md.

Implementation Notes

Phase 7 Backend (Anomaly detection, 2026-05-05)

• AnomalyDetector is pure domain — no I/O, no DI. Constructor takes three ints/decimals from AnomalyOptions; the caller (use case) materialises it per cycle. The UI evidence panel can reconstruct the same probabilities from EvidenceJson without needing to re-invoke the detector.
• Implied probability formula: p_i = 1 / rate_i, then normalise so all p_i sum to 1 (divorcé of the bookmaker's margin). This is the standard European odds conversion.
• Flip score = max(|p_post[i] − p_pre[i]|) over Match-Win sides (p1, pDraw?, p2). Score is clamped to [0, 1] before constructing Anomaly (domain invariant enforces ≤1).
• Two-part gate — an anomaly requires BOTH: (a) flipScore ≥ OddsFlipThreshold AND (b) argmax(p_pre) != argmax(p_post). This prevents spurious detections when one side's probability shifts a lot but it was never the favourite.
• Tennis / 2-way markets — pDraw is null when no BetType.Draw bet is present. The detector and EvidenceJson gracefully handle this (JSON field is omitted when null via DefaultIgnoreCondition.WhenWritingNull).
• EvidenceJson uses System.Text.Json with custom JsonPropertyName attributes on sealed nested records (EvidencePayload, SnapshotEvidence). Source generation was not used at this scale — the payload is small and created infrequently.
• DetectAnomaliesUseCase loads all events + last-24-h live snapshots per cycle. This is a deliberate simplification; a future optimisation is to track last_run_at per event. Documented as 🟡 in the handoff.
• Dedup strategy: two anomalies are considered duplicates if they share EventId, Kind, and their DetectedAt values fall within a 1-minute window. This prevents the same suspension triggering re-insertion on consecutive detection cycles while the gap snapshot pair remains in the 24-hour window.
• AnomalyOptions placed in Marathon.Application/Configuration/ (not Infrastructure). The AnomalyDetector itself is in Marathon.Domain/AnomalyDetection/ but requires no options binding — it takes plain constructor parameters.
• AnomalyDetectionPoller reads IOptionsMonitor<AnomalyOptions> per cycle so that hot-reload of DetectionIntervalSeconds takes effect without a restart. Same pattern as LiveOddsPoller reading WorkerOptions.
• Workers:AnomalyDetectionEnabled added to WorkerOptions (default true) and appsettings.json. UI agent must add a Settings toggle for this flag.
• New test count: +17 (13 domain + 4 application). Total: 245/245 passing.
• Test note: rates 1.5/2.5 produce a flip score of ~0.25 — BELOW the 0.30 threshold. Always use 1.3/4.0 (flip score ~0.51) or steeper to guarantee detection in tests.

Phase 6 (Event browsing UI, 2026-05-05)

• Plotly.Blazor pinned to 5.4.1. v7.x exists but introduces breaking changes; 5.4.1 is the latest on the .NET 8 line and works with our existing MudBlazor 7.15.0 / .NET 8.0.12 stack. The Plotly.Blazor.LayoutLib.Margin type clashes with MudBlazor.Margin — fully qualify the layout-side type.
• Razor source generator does NOT accept C# 11 raw string literals ("""…""") inside @code blocks. The parser sees the leading """ as the start of a normal string and never finds the close, producing an "Unterminated string literal" RZ1000. Use concatenated single-quoted attribute strings instead (see SportIcon.razor SVG constants).
• Razor reserves the identifier code. A @foreach (var code in ...) loop is parsed as the @code directive, not as iteration. Use any other identifier (var sportCode in ...).
• MudBlazor.DateRange shadows Marathon.Application.Storage.DateRange in any file whose _Imports.razor brings both namespaces in. Add using AppDateRange = Marathon.Application.Storage.DateRange; per-file where the application's DateRange is constructed (already done in ExportDialog.razor and ExportDialogTests.cs).
• EventBrowsingService is Scoped, EventBrowsingState is Singleton. The service captures the per-circuit DI scope so EF Core's DbContext lifetime works correctly; the state object holds the per-page filter records and fires OnChange only when the new value !equals the old one. This split matches Phase 5's split between ThemeState (singleton) and per-circuit data services.
• View-models, not domain entities, cross the UI boundary. Pages bind to EventListItem / EventDetail / BetRow / OddsTimelinePoint records (defined in Marathon.UI.Services). Repositories are not exposed to Razor components. This keeps the UI free of EF tracked graphs and preserves Phase 5's "RCL is host-agnostic" invariant.
• Live page reads polling cadence from IOptionsMonitor<ScrapingSettingsForm>. Phase 4's WorkerOptions.LivePollIntervalSeconds (drives the poller) is a separate setting from the UI's display refresh; the latter intentionally follows Scraping:PollingIntervalSeconds per the Phase 6 subplan.
• Plotly chart memoization. Computed signature = (count, first ticks, last ticks, first/last rate triples). Sufficient to invalidate the trace list on any meaningful change while staying cheap during live polling.
• bUnit shared MarathonTestContext now registers the fake browsing service and the browsing state. Phase 7 tests can extend it directly or follow the same pattern. Support/TestData.MoscowToday(int hour) produces correctly-offset DateTimeOffset values — domain Event.ScheduledAt will reject any other offset.

Phase 1 (Solution skeleton + Domain model, 2026-05-05)

• .NET 10 SDK creates .slnx by default. dotnet new sln produces Marathon.slnx (new XML format), not Marathon.sln. A hand-crafted Marathon.sln was added alongside it so that dotnet build Marathon.sln works as specified in the plan. Both files are kept; prefer Marathon.sln for CLI commands.
• BetScope is a sealed record hierarchy: abstract record BetScope with sealed record MatchScope : BetScope (singleton Instance) and sealed record PeriodScope(int Number) : BetScope. Use pattern matching, not an enum+nullable approach.
• Event.ScheduledAt must be UTC+3 (Moscow), not UTC. The domain enforces Offset == TimeSpan.FromHours(3). Phase 3 must construct DateTimeOffset with +03:00 before passing to Event; do NOT convert to UTC first.
• Directory.Build.props must NOT set TargetFramework — WpfBlazor needs net8.0-windows while all other projects use net8.0. Each csproj owns its TFM.
• Marathon.Application namespace conflicts with System.Windows.Application in WPF App.xaml.cs. Fix: use System.Windows.Application fully qualified. Phase 5 must keep this qualification.
• Central package management: all PackageReference elements in test csproj files must NOT include Version=. Versions live exclusively in Directory.Packages.props.
• 96 domain tests, 0 failures. All invariants covered: SportCode, EventId, OddsRate, OddsValue, BetScope, Bet (all 4 type combinations), OddsSnapshot, Event (ScheduledAt offset), Anomaly.

Phase 0 (Scraping spike, 2026-05-05)

• Anonymous scraping is feasible from a non-Belarus IP. No Cloudflare, no JS challenge, no UA filtering observed. Server: nginx. Standard cookies only.
• Site is fully SSR. All needed data (event grid, full odds, breadcrumbs, period markets) is in the raw HTML. No SPA hydration required.
• Recommended scraper stack: HttpClient + AngleSharp + Polly v8. Playwright is not required for read-only scraping — keep it as an optional fallback flag (Scraping:UsePlaywright) for future-proofing only.
• Polling cadence: site itself polls live updates every 3 s; for our analyzer, pre-match 30 s and live 5–10 s is sufficient.
• Rate-limit: 5 sequential requests at 1 req/s pacing all returned 200 in <1 s, no throttling. Recommend default RequestsPerSecond=1, MaxConcurrent=4.
• Sport ID semantics: customer's "Sport_Code = 6" (Basketball) maps to data-sport-treeId="6" in the breadcrumb-canonical sport listing (/su/betting/Basketball+-+6). Some sports also have a separate "category tree ID" used inside the live grouping (e.g., 45356 for Basketball-live) — ignore those, use only the canonical breadcrumb ID.
• Selection key format: <eventId>@<MarketName>{LineIndex?}.<Outcome>. The market name is sport-specific (Match_Result, 1st_Half_Result, Total_Goals, Total_Points, Total_Games, To_Win_Match_With_Handicap, etc.). Total thresholds are encoded in the outcome (Under_3.5, Over_213.5). Handicap values are NOT in the key — they're in <span class="middle-simple"> text.
• Tennis has no Draw outcome — domain Bet_Match_Draw must be nullable.
• Date display ambiguity: listing shows HH:MM (today) or DD <ru-month> HH:MM (future). Anchor the parser on initData.serverTime (Moscow TZ, format YYYY,MM,DD,HH,MM,SS).
• No public results page (/su/results → 404). Final scores are exposed only on the event detail page itself via eventJsonInfo JSON (matchIsComplete, resultDescription). Phase 8 must poll until completion; cannot back-fill from an archive endpoint.
• Probe environment: Windows 10 + curl, geo-routed as Poland (countryCode: PL). Customer in Belarus may see slightly different KYC overlays — parser must be defensive (treat missing markets as null, never throw).
• Captures saved locally at spike/captures/*.html (gitignored): 7 fixtures for offline parser development in Phase 3.