MediathekNext

Self-hosted web app to browse and download content from German public TV (ARD, ZDF). Built on .NET 10, Blazor Server, SQLite (swappable), and .NET Aspire.

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Prerequisites

```bash dotnet workload install aspire brew install ffmpeg ```

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Running locally (standalone — everything in one process)

```bash dotnet restore cd src/MediathekNext.AppHost dotnet run ```

Aspire dashboard at http://localhost:15000. The app defaults to role=standalone.

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Role system

The same binary (MediathekNext.Worker) runs in three roles. Role is resolved in priority order — first match wins:

Priority	Method	Example
1	CLI argument	dotnet run -- --role worker
2	Environment variable	MEDIATHEK_ROLE=worker
3	appsettings.json	"Role": "worker"
4	Default	standalone

Role	Does
standalone	Everything: migrations, catalog, API, downloads
core	DB owner, catalog refresh, API — no downloads
worker	Download execution only — scalable horizontally

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Scaling with Docker Compose

```bash

Standalone (single machine, simple)

docker compose --profile standalone up

Scaled out (core + multiple workers)

docker compose --profile distributed up docker compose --profile distributed up --scale worker=3

With observability

docker compose --profile distributed --profile observability up ```

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Swapping the database

Change two config values — no code changes required:

```json { "Database": { "Provider": "postgres", "ConnectionString": "Host=localhost;Database=mediathek;Username=app;Password=secret" } } ```

Supported providers: sqlite (default), postgres, mssql

Uncomment the corresponding package in MediathekNext.Worker.csproj and MediathekNext.Infrastructure.csproj.

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EF Core migrations

```bash cd src/MediathekNext.Worker

dotnet ef migrations add
--project ../MediathekNext.Infrastructure
--startup-project .

dotnet ef database update
--project ../MediathekNext.Infrastructure
--startup-project . ```

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Architecture

``` src/ Domain — Entities, interfaces, enums (zero deps) Application — Use cases, handlers, validators Infrastructure — EF Core, repos, ffmpeg, MediathekView parser, polling service Api — ASP.NET Core 10 Minimal API endpoints Web — Blazor Server frontend Worker — Single binary, role-switchable (standalone/core/worker) Roles/ StandaloneRole.cs CoreRole.cs WorkerRole.cs AppHost — .NET Aspire orchestration ServiceDefaults — OTEL, health checks, service discovery ```

How job dispatch works (no message broker)

1. POST /api/downloads → StartDownloadHandler inserts a DownloadJob row with Status=Queued
2. DownloadPollingService (running in worker or standalone role) polls every 5 seconds
3. Worker claims a job by calling job.MarkClaiming(workerId) and calling SaveChanges()
4. EF Core includes the RowVersion concurrency token in the WHERE clause automatically
5. If two workers race, one gets DbUpdateConcurrencyException and moves on — no locks, no broker, works on any SQL database

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API

``` GET /api/catalog/search?q= GET /api/catalog/episodes/{id} GET /api/catalog/shows GET /api/catalog/shows/{showId}/episodes GET /api/catalog/channels/{channelId}?contentType= GET /api/catalog/type/{contentType}?channelId=

POST /api/downloads GET /api/downloads GET /api/downloads/{id} DELETE /api/downloads/{id} POST /api/downloads/{id}/retry

GET /api/settings PUT /api/settings ```

OpenAPI: /openapi/v1.json