git-contribution-graph/README.md

# git-contribution-graph

A self-hosted Symfony service that merges contribution data from **GitHub**, **GitLab** and **Gitea** into a single GitHub-style heatmap SVG you can embed anywhere.

```
https://your-host/graph.svg?theme=dark
```

![Example graph](https://gitgraph.arthurerlich.de/graph.svg)

---

## Features

- **Three platforms** — GitHub, GitLab (cloud or self-hosted), Gitea (self-hosted)
- **Merged heatmap** — contributions from all sources are summed per day
- **GitHub colour palette** — exact dark/light theme tokens
- **Embeddable** — returns `image/svg+xml`, works in any `<img>` tag or Markdown
- **Cached** — responses cached for 1 hour, safe to embed in public READMEs
- **Graceful degradation** — if one platform fails, the others still render

---

## Deploy

### Requirements

- Docker + Docker Compose

### 1. Create a `docker-compose.yml`

Use the pre-built image — no need to clone the repo:

```yaml
services:
  graph:
    image: git.arthurerlich.de/haylan/git-contribution-graph:latest
    ports:
      - "8080:8080"
    env_file:
      - .env.local
    volumes:
      - cache:/var/www/html/var/cache

volumes:
  cache:
```

The image is published to the Gitea container registry. Pull it manually with:

```bash
docker pull git.arthurerlich.de/haylan/git-contribution-graph:latest
```

Semver tags are published (`0`, `0.0`, `0.0.1`) alongside `latest` — see the [container registry](https://git.arthurerlich.de/haylan/-/packages/container/git-contribution-graph/latest) for all available tags.

### 2. Configure

Create a `.env.local` file next to your `docker-compose.yml`:

```dotenv
APP_SECRET=<generate with: openssl rand -hex 16>

# GitHub
GITHUB_USER=your-github-username
GITHUB_TOKEN=ghp_…

# GitLab (omit GITLAB_URL to use gitlab.com)
GITLAB_USER=your-gitlab-username
GITLAB_TOKEN=glpat-…
GITLAB_URL=

# Gitea
GITEA_USER=your-gitea-username
GITEA_TOKEN=…
GITEA_URL=https://git.example.com

# Optional: restrict to specific hostnames (comma-separated), leave empty to allow all
ALLOWED_HOSTS=
```

Only configure the platforms you use — unused ones are silently skipped.

### 3. Start

```bash
docker compose up -d
```

The service listens on **port 8080** by default. Put Traefik or nginx in front of it for HTTPS.

### 4. Verify

```bash
curl http://localhost:8080/health
# {"status":"ok"}
```

---

## API

### `GET /graph.svg`

| Parameter | Required | Description |
|---|---|---|
| `theme` | ✗ | `dark` (default) or `light` |

All credentials are configured via environment variables — see [Deploy](#deploy).

---

## Embedding in a README

```markdown
<!-- Dark theme (default) -->
![Contribution Graph](https://your-host/graph.svg)

<!-- Light theme -->
![Contribution Graph](https://your-host/graph.svg?theme=light)
```

---

## Token setup

### GitHub

**Fine-grained token (recommended):**
1. Go to **Settings → Developer settings → Personal access tokens → Fine-grained tokens**
2. Set **Resource owner** to your account
3. Under **Permissions → Account permissions**, set **Contribution activity** → Read-only
4. Generate and copy the token

**Classic token:** create a token with the `read:user` scope.

### GitLab

1. Go to **User Settings → Access Tokens**
2. Add a token with scopes: `read_user`, `read_api`
3. Generate and copy the token

### Gitea

1. Go to **Settings → Applications → Manage Access Tokens**
2. Add a token with permission: **user** → Read
3. Generate and copy the token

---

## Development

### Local (PHP)

```bash
# Install deps
composer install

# Run dev server
APP_ENV=dev php -S localhost:8080 -t public

# Test endpoint
curl "http://localhost:8080/graph.svg" -o graph.svg
```

### Docker (recommended)

`docker-compose.override.yml` is picked up automatically and targets the `dev` stage (Xdebug enabled, source mounted).

```bash
# Start dev container
docker compose up -d --build

# Shell into the container
docker compose exec graph sh

# Run tests inside the container
docker compose exec graph php bin/phpunit

# Disable Xdebug for faster test runs
XDEBUG_MODE=off docker compose up -d
```

Xdebug listens on port **9003**. On Linux, `host.docker.internal` is resolved via `host-gateway`.

To run with production config only (no override):

```bash
docker compose -f docker-compose.yml up -d --build
```

---

## Testing

```bash
# Run full suite
php bin/phpunit

# Human-readable output
php bin/phpunit --testdox

# Single file
php bin/phpunit tests/Unit/Service/SvgRendererTest.php

# Filter by name
php bin/phpunit --filter it_renders
```

---

## Architecture

```
GET /graph.svg?theme=dark|light
  └─ GraphController
       ├─ host check (ALLOWED_HOSTS env, optional)
       ├─ cache lookup (filesystem, 1h TTL, key = "graph_{theme}")
       │    └─ on miss:
       │         ├─ GitHubProvider  → GitHub GraphQL API (contributionCalendar)
       │         ├─ GitLabProvider  → GitLab REST API    (/users/:id/events, paginated)
       │         └─ GiteaProvider   → Gitea REST API     (/users/:user/heatmap)
       │              each returns array<string, int>  (Y-m-d => count)
       │              failures are caught and logged; remaining providers still render
       │         └─ merge by date (sum counts across providers)
       │         └─ SvgRenderer::render()
       └─ Response: image/svg+xml, Cache-Control: public max-age=3600
```

**Provider activation:** a provider only runs when its env vars are non-empty. GitHub and GitLab require `_USER` + `_TOKEN`; Gitea additionally requires `_URL`. GitLab resolves a numeric user ID from the username via a `/api/v4/users?username=` lookup before fetching events.

**SvgRenderer:** builds a 53-column × 7-row grid aligned so the last column always ends on the Saturday of the current week. Five intensity levels (0 → level 0, 1–3 → 1, 4–6 → 2, 7–9 → 3, 10+ → 4) mapped to GitHub's colour tokens. No external assets — the SVG is fully self-contained.

**Cache:** filesystem adapter (`var/cache/`), mounted as a Docker volume to survive container restarts. Theme is part of the cache key so dark and light are cached independently.

---

## License

MIT