Units of Work: Shoe Choo

Decomposition Strategy

Deployment Model: Single monolithic macOS application (.app bundle) Unit Strategy: Logical modules within a single Xcode target, organized by feature domain Rationale: Desktop macOS app has no microservice boundary — units represent development phases aligned with feature priority and dependency order

Unit Definitions

Unit 1: Core Editor Engine

Priority: Critical — Foundation for all other units Scope: Markdown parsing, intermediate model, rendering pipeline, TextKit 2 editor surface

Component	Role in Unit
C-05 MarkdownParser	Parse Markdown to AST
C-06 EditorNodeModel	Intermediate block model
C-07 MarkdownRenderer	AST → NSAttributedString
C-08 WYSIWYGTextView	TextKit 2 editing surface

Deliverables:

Working WYSIWYG editor that renders headings, bold, italic, links, lists, blockquotes, code blocks, tables, task lists, strikethrough, horizontal rules
Paragraph-level delayed rendering (cursor leaves → render, cursor enters → show syntax)
IME support, Undo/Redo, spell check via native TextKit 2
Syntax highlighting for code blocks

Stories: 1.1–1.10 (Epic 1: WYSIWYG Editing)

Unit 2: Document Management

Priority: High — Required for file operations, depends on Unit 1 for editor integration Scope: NSDocument lifecycle, app entry point, editor settings

Component	Role in Unit
C-01 ShoechooApp	App lifecycle, DocumentGroup scene
C-02 MarkdownDocument	NSDocument file I/O, auto-save
C-03 EditorViewModel	Per-document state management
C-04 EditorSettings	App-wide preferences
C-09 EditorView	SwiftUI editor + toolbar composition
C-13 FileService	File utilities

Deliverables:

Xcode project with SwiftUI DocumentGroup scene
NSDocument-based open/save/auto-save/versions
Tabbed windows
Recent files tracking
EditorViewModel orchestrating the rendering pipeline from Unit 1
EditorSettings with font, spacing, appearance preferences

Stories: 3.1–3.5 (Epic 3: Document Management), 8.1 (Epic 8: Typography)

Unit 3: Focus & Immersion

Priority: High — Core differentiator (“集中”), depends on Unit 1 editor surface Scope: Focus mode, typewriter scrolling, full-screen

Component	Role in Unit
C-08 WYSIWYGTextView	Focus dimming + typewriter scroll implementation
C-03 EditorViewModel	Focus/typewriter state management
C-04 EditorSettings	Persistence of preferences

Deliverables:

Focus mode: dim inactive paragraphs, highlight active paragraph
Typewriter scrolling: center active line vertically
Full-screen writing mode with auto-hiding toolbar/sidebar
Preference persistence across app restarts

Stories: 2.1–2.3 (Epic 2: Focus & Typewriter), 7.1 (Epic 7: Full-Screen)

Unit 4: Image & Media

Priority: Medium — Enhances editing experience, depends on Unit 1 + Unit 2 Scope: Image drag & drop, clipboard paste, asset management

Component	Role in Unit
C-12 ImageService	Image import and asset management
C-13 FileService	Assets directory management
C-08 WYSIWYGTextView	Drag & drop handling
C-03 EditorViewModel	Image reference insertion

Deliverables:

Drag & drop images from Finder into editor
Paste images from clipboard
Auto-copy to {filename}.assets/ folder
Relative path Markdown reference insertion
Untitled document save prompt

Stories: 6.1–6.2 (Epic 6: Image Support)

Unit 5: Export & Polish

Priority: Medium — Final MVP features, depends on Unit 1 + Unit 2 Scope: HTML/PDF export, sidebar, dark mode

Component	Role in Unit
C-11 ExportService	HTML and PDF generation
C-10 SidebarView	Recent files sidebar
C-09 EditorView	Dark mode adaptation

Deliverables:

Export to HTML (swift-markdown AST → HTML)
Export to PDF (HTML → macOS native PDF rendering)
Collapsible recent files sidebar
Full dark mode support for all UI elements and editor rendering

Stories: 4.1–4.2 (Epic 4: Export), 5.1 (Epic 5: Sidebar), 7.2 (Epic 7: Dark Mode)

Code Organization

shoechoo/
+-- shoechoo.xcodeproj
+-- shoechoo/
|   +-- App/                          # Unit 2
|   |   +-- ShoechooApp.swift
|   |   +-- MarkdownDocument.swift
|   +-- Models/                        # Unit 1 + Unit 2
|   |   +-- EditorViewModel.swift
|   |   +-- EditorSettings.swift
|   |   +-- EditorNodeModel.swift
|   |   +-- EditorNode.swift
|   +-- Parser/                        # Unit 1
|   |   +-- MarkdownParser.swift
|   +-- Renderer/                      # Unit 1
|   |   +-- MarkdownRenderer.swift
|   +-- Editor/                        # Unit 1 + Unit 3
|   |   +-- WYSIWYGTextView.swift
|   |   +-- ShoechooTextView.swift
|   |   +-- FocusMode.swift
|   |   +-- TypewriterScroll.swift
|   +-- Views/                         # Unit 2 + Unit 5
|   |   +-- EditorView.swift
|   |   +-- SidebarView.swift
|   |   +-- PreferencesView.swift
|   +-- Services/                      # Unit 4 + Unit 5
|   |   +-- ExportService.swift
|   |   +-- ImageService.swift
|   |   +-- FileService.swift
|   +-- Extensions/
|   +-- Resources/
|       +-- Assets.xcassets
+-- shoechooTests/                     # Mirrors source structure
+-- shoechooUITests/
+-- docs/                              # GitHub Pages
+-- aidlc-docs/                        # AI-DLC docs
+-- README.md
+-- README-ja.md

Implementation Order & Timeline

Week 1-2: Unit 1 (Core Editor Engine)
    |
    v
Week 2-3: Unit 2 (Document Management)
    |
    +---> Week 3-4: Unit 3 (Focus & Immersion) [parallel possible]
    |
    +---> Week 4:   Unit 4 (Image & Media)     [parallel possible]
    |
    v
Week 4-5: Unit 5 (Export & Polish)
    |
    v
Week 5:   Integration Testing + Build + Notarization