# IronKanban — Technical Blueprint (Dev Spec)

## 0. Scope

MVP implementation of:

- Git-backed markdown project/task system
- Kanban board UI
- Drag & drop between columns
- Real-time-ish updates (polling → SSE-ready)
- PHP backend + vanilla JS frontend
- No framework (structured, but lightweight)

## 1. System Architecture

### 1.1 High-level flow

```plain
Filesystem (markdown + git)
    ↑ ↓
Repositories (PHP)
    ↑ ↓
Services (business logic)
    ↑ ↓
API Endpoints (public/api/*.php)
    ↑ ↓
Frontend (vanilla JS + SortableJS)
```

### 1.2 Request lifecycle (example: move task)

```plain
Drag card →
JS computes new position →
POST /api/move-task.php →
TaskRepository loads file →
BoardService updates column/order →
TaskRepository writes file →
GitService commits →
RevisionService updates revision →
Response JSON →
UI updates (already optimistic)
```

## 2. Filesystem Contract

### 2.1 Root config

```php
const PROJECT_ROOT = '/data/projects';
```

All file access must resolve within this root.

### 2.2 Project layout

```plain
/data/projects/{projectSlug}/
├── index.md
├── board.md
├── notes/
│   └── *.md
├── tasks/
│   └── *.md
```

## 3. Markdown Contract

### 3.1 Front matter parser contract

```php
class FrontMatterDocument {
  public array $meta;
  public string $body;
}
```

### 3.2 Required keys by type

#### Project (`index.md`)

```yaml
type: project
id: string
title: string
created: ISO8601
updated: ISO8601
```

#### Board (`board.md`)

```yaml
type: board
project_id: string
columns:
  - id: string
    label: string
    order: int
updated: ISO8601
```

#### Task (`tasks/*.md`)

```yaml
type: task
id: string
title: string
project_id: string

column: string
order: int

completed: bool
priority: string
is_active: bool

created: ISO8601
updated: ISO8601
```

Optional (must be preserved if present):

```yaml
status: string|null
status_note: string|null
assignee: string|null
tags: array
section: string   # legacy
```

#### Note (`notes/*.md`)

```yaml
type: note
id: string
title: string
project_id: string
created: ISO8601
updated: ISO8601
```

## 4. Domain Models

### 4.1 Project

```php
class Project {
  public string $id;
  public string $title;
  public string $path;
}
```

### 4.2 Task

```php
class Task {
  public string $id;
  public string $title;
  public string $projectId;

  public string $column;
  public int $order;

  public bool $completed;
  public string $priority;
  public bool $isActive;

  public array $meta;
  public string $body;
}
```

### 4.3 Board

```php
class Board {
  public string $projectId;

  /** @var Column[] */
  public array $columns;
}
```

### 4.4 Column

```php
class Column {
  public string $id;
  public string $label;
  public int $order;
}
```

### 4.5 Note

```php
class Note {
  public string $id;
  public string $title;
  public string $body;
}
```

## 5. Repositories

### 5.1 ProjectRepository

```php
class ProjectRepository {
  public function getAll(): array;
  public function get(string $slug): Project;
}
```

### 5.2 TaskRepository

```php
class TaskRepository {
  public function getAll(string $projectId): array;
  public function get(string $projectId, string $taskId): Task;

  public function save(Task $task): void;
  public function create(array $data): Task;
  public function delete(string $projectId, string $taskId): void;
}
```

#### Responsibilities

- read/write markdown
- preserve unknown front matter keys
- handle file paths
- ensure atomic writes

### 5.3 BoardRepository

```php
class BoardRepository {
  public function get(string $projectId): Board;
  public function save(Board $board): void;
}
```

### 5.4 NoteRepository

```php
class NoteRepository {
  public function getAll(string $projectId): array;
  public function save(Note $note): void;
}
```

## 6. Services

### 6.1 BoardService

```php
class BoardService {
  public function getBoardState(string $projectId): array;

  public function moveTask(
    string $projectId,
    string $taskId,
    string $column,
    int $newOrder
  ): void;
}
```

### 6.2 TaskOrderingService

```php
class TaskOrderingService {
  public function computeOrder(array $tasks, int $targetIndex): int;
  public function rebalance(array $tasks): array;
}
```

#### Rule

- Use gaps: 100, 200, 300
- Insert = midpoint
- Rebalance only if gap < threshold

### 6.3 GitService

```php
class GitService {
  public function commit(string $message): void;
}
```

#### Implementation (MVP)

```bash
git add .
git commit -m "..."
```

#### Future

- scoped add
- branch support

### 6.4 RevisionService

```php
class RevisionService {
  public function get(string $projectId): string;
  public function bump(string $projectId): void;
}
```

#### Storage

```plain
/data/projects/{project}/.revision
```

### 6.5 FileLock

```php
class FileLock {
  public static function run(string $path, callable $callback);
}
```

Uses `flock()`.

## 7. API Specification

All endpoints return JSON.

### 7.1 GET `/api/board-state.php`

#### Query

`?project=personal-projects`

#### Response

```json
{
  "project": {},
  "board": {},
  "columns": [],
  "tasks": [],
  "notes": [],
  "revision": "timestamp"
}
```

### 7.2 POST `/api/move-task.php`

#### Input

```json
{
  "projectId": "personal-projects",
  "taskId": "task-123",
  "column": "doing",
  "index": 2
}
```

#### Flow

```plain
load tasks in column →
compute order →
update task →
save →
git commit →
revision bump
```

### 7.3 POST `/api/create-task.php`

```json
{
  "projectId": "...",
  "title": "...",
  "column": "backlog",
  "body": ""
}
```

### 7.4 POST `/api/save-task.php`

Full update:

```json
{
  "projectId": "...",
  "taskId": "...",
  "title": "...",
  "body": "...",
  "meta": {}
}
```

### 7.5 POST `/api/delete-task.php`

```json
{
  "projectId": "...",
  "taskId": "..."
}
```

### 7.6 POST `/api/create-column.php`

```json
{
  "projectId": "...",
  "label": "Blocked"
}
```

### 7.7 POST `/api/update-board.php`

Reorder / rename columns.

### 7.8 POST `/api/save-note.php`

### 7.9 GET `/api/events.php` (Phase 2)

SSE stream:

```plain
event: boardUpdated
data: { "revision": "..." }
```

## 8. Frontend Spec

### 8.1 Stack

- Vanilla JS
- SortableJS (drag/drop)
- Server-rendered HTML + JS hydration

### 8.2 State model

```javaScript
const state = {
  projectId: null,
  columns: [],
  tasks: [],
  revision: null
};
```

### 8.3 Drag/drop flow

```javaScript
onEnd →
  get taskId
  get new column
  get index
  compute optimistic order
  update DOM
  POST move-task
  if fail → revert
```

### 8.4 Polling loop (MVP)

```javaScript
setInterval(async () => {
  const res = await fetch('/api/board-state?project=...');
  if (res.revision !== state.revision) {
    reloadBoard();
  }
}, 5000);
```

### 8.5 SSE (Phase 2)

```javaScript
const evt = new EventSource('/api/events.php?project=...');
evt.onmessage = () => reloadBoard();
```

## 9. Migration Logic

### 9.1 Missing board.md

```plain
scan tasks →
collect unique section values →
generate columns →
write board.md
```

### 9.2 Missing column

```php
if (!column && section) {
  column = slugify(section);
}
```

### 9.3 Missing order

Assign:

`order = index * 100;`

## 10. File Write Rules

### 10.1 Atomic write

```plain
write temp file →
fsync →
rename →
unlock
```

### 10.2 Preserve unknown metadata

Never discard keys.

### 10.3 Encoding

UTF-8 only.

## 11. Error Handling

### 11.1 API response format

```json
{
  "success": false,
  "error": "message"
}
```

### 11.2 Conflict detection

If revision mismatch:

```json
{
  "success": false,
  "error": "conflict"
}
```

## 12. Security

- No path traversal
- Sanitize projectId
- Whitelist file extensions
- Escape shell commands
- Run git in repo root only

## 13. Performance Considerations

- Cache parsed board in memory per request
- Avoid re-reading unchanged files
- Lazy-load notes if needed
- Debounce save operations (frontend)

## 14. MVP Milestones

### Phase 1

- File parsing
- Board rendering
- Basic UI

### Phase 2

- Drag/drop
- Save APIs

### Phase 3

- Task CRUD
- Column CRUD

### Phase 4

- Git integration
- Revision tracking

### Phase 5

- Polling updates

### Phase 6 (optional)

- SSE

## 15. Out-of-Scope (MVP)

- Auth system
- Multi-repo support
- Comments
- Subtasks
- Attachments
- Permissions
- Websockets

## 16. Build Order (Practical)

I suggest this order:

1. Markdown parser + writer
2. TaskRepository
3. BoardRepository
4. BoardService (read-only)
5. Render board (no JS yet)
6. Add SortableJS
7. Move-task endpoint
8. Create/edit task
9. GitService
10. Revision + polling

## 17. Key Architectural Decisions (Locked)

These are your “don’t rethink this at 2am” decisions:

- ✅ tasks remain flat files in /tasks
- ✅ kanban state = column in front matter
- ✅ board config = board.md
- ✅ ordering = sparse integers
- ✅ git is first-class
- ✅ PHP handles everything server-side
- ✅ SortableJS is allowed
- ❌ no folder-per-column model
- ❌ no heavy framework