onyx-tasks/PLAN.md

Bevy Tasks - Project Plan

Vision

A local-first, cross-platform tasks application inspired by Google Tasks, built with Bevy for high performance and future game-like UX polish. The application will launch near-instantly on all platforms and support both local file storage and WebDAV synchronization.

Core Principles

1. Local-First: All data is stored locally by default, with optional sync
2. Performance: Sub-second cold start time on all platforms
3. Cross-Platform: Native support for Windows, Linux, macOS, iOS, and Android
4. Privacy: User data stays on their devices and chosen storage locations
5. Future-Proof: Built on Bevy to enable advanced UI/UX features later

Target Platforms

• Desktop: Windows, Linux, macOS
• Mobile: iOS, Android

Technology Stack

Project Structure: Workspace with Backend/Frontend Separation

The project is organized as a Cargo workspace with three main crates:

1. bevy-tasks-core (Library): Pure Rust business logic, no UI dependencies
2. bevy-tasks-cli (Binary): Command-line interface for power users and testing
3. bevy-tasks-gui (Binary): Graphical frontend (framework TBD - see Frontend Comparison)

This separation provides:

• Clean architecture with testable core logic
• Multiple interfaces to the same backend
• Ability to develop and validate backend before frontend work
• CLI tool useful for automation, scripting, and CI/CD

Backend/Core Library

• serde: Serialization/deserialization
• pulldown-cmark or markdown: Markdown parsing
• serde_yaml: YAML frontmatter parsing (Obsidian-style metadata)
• directories: Cross-platform path handling
• tokio: Async runtime for I/O operations
• reqwest + dav-client: WebDAV support
• uuid: Unique identifiers for tasks
• chrono: Date/time handling
• anyhow: Error handling

CLI Frontend

• clap: Command-line argument parsing
• colored: Terminal colors for better UX
• indicatif: Progress bars for sync operations

GUI Frontend

See "Frontend Framework Comparison" section below for detailed options.

Performance Optimization

• Lazy loading: Load only visible data
• Minimal dependencies: Keep binary size small
• Release optimizations: LTO, strip symbols
• Backend separation: Core logic has zero UI overhead

Architecture

Data Model

Tasks are stored as individual .md (Markdown) files, with metadata in YAML frontmatter (Obsidian-compatible format).

Task File Format (my-task-name.md):
---
id: 550e8400-e29b-41d4-a716-446655440000
status: in-progress
due: 2025-11-15T14:00:00Z
created: 2025-10-26T10:00:00Z
updated: 2025-10-26T12:30:00Z
parent: 550e8400-e29b-41d4-a716-446655440001
position: 1
tags: [work, urgent]
---

Task description and notes go here in **markdown** format.

- Can include lists
- Rich formatting
- Links, etc.

In-Memory Model:

Task {
    id: Uuid,
    title: String,              // Derived from filename
    notes: String,              // Markdown content
    status: TaskStatus,         // From frontmatter
    due_date: Option<DateTime>, // From frontmatter
    created_at: DateTime,       // From frontmatter
    updated_at: DateTime,       // From frontmatter
    parent_id: Option<Uuid>,    // From frontmatter
    position: i32,              // From frontmatter
    tags: Vec<String>,          // From frontmatter
}

TaskList {
    id: Uuid,
    title: String,              // Derived from folder name
    tasks: Vec<Task>,
    created_at: DateTime,
    updated_at: DateTime,
    position: i32,
}

AppConfig {
    storage_type: StorageType,  // Local or WebDAV
    local_path: Option<PathBuf>,
    webdav_url: Option<String>,
    webdav_credentials: Option<Credentials>,
    theme: Theme,
    last_sync: Option<DateTime>,
}

Workspace Structure

bevy-tasks/
├── Cargo.toml                    # Workspace definition
├── PLAN.md
├── README.md
│
├── crates/
│   ├── bevy-tasks-core/          # Core library (backend)
│   │   ├── Cargo.toml
│   │   ├── src/
│   │   │   ├── lib.rs
│   │   │   ├── task.rs           # Task model
│   │   │   ├── task_list.rs      # TaskList model
│   │   │   ├── config.rs         # AppConfig
│   │   │   ├── repository.rs     # High-level API
│   │   │   ├── storage/
│   │   │   │   ├── mod.rs
│   │   │   │   ├── local.rs      # Local file I/O
│   │   │   │   ├── markdown.rs   # Markdown parser
│   │   │   │   └── webdav.rs     # WebDAV sync
│   │   │   └── error.rs          # Error types
│   │   └── tests/
│   │       ├── integration.rs
│   │       └── fixtures/
│   │
│   ├── bevy-tasks-cli/           # CLI frontend
│   │   ├── Cargo.toml
│   │   ├── src/
│   │   │   ├── main.rs
│   │   │   ├── commands/
│   │   │   │   ├── mod.rs
│   │   │   │   ├── add.rs
│   │   │   │   ├── list.rs
│   │   │   │   ├── complete.rs
│   │   │   │   ├── sync.rs
│   │   │   │   └── init.rs
│   │   │   └── ui.rs             # Terminal formatting
│   │   └── README.md
│   │
│   └── bevy-tasks-gui/           # GUI frontend
│       ├── Cargo.toml
│       ├── src/
│       │   ├── main.rs           # App entry point
│       │   ├── app.rs            # Framework setup
│       │   ├── ui/
│       │   │   ├── mod.rs
│       │   │   ├── screens/
│       │   │   │   ├── task_list.rs
│       │   │   │   ├── task_detail.rs
│       │   │   │   └── settings.rs
│       │   │   └── components/
│       │   │       ├── task_item.rs
│       │   │       ├── task_input.rs
│       │   │       └── list_selector.rs
│       │   └── state.rs          # UI state management
│       ├── assets/
│       │   ├── fonts/
│       │   └── icons/
│       └── README.md
│
└── docs/
    ├── API.md
    ├── CLI.md
    └── DEVELOPMENT.md

Core Library API Design

The bevy-tasks-core library will expose a clean, high-level API:

// Main repository interface
pub struct TaskRepository {
    storage: Box<dyn Storage>,
}

impl TaskRepository {
    pub fn new(config: Config) -> Result<Self>;
    pub fn init(path: PathBuf) -> Result<Self>;

    // Task operations
    pub fn create_task(&mut self, list_id: Uuid, task: Task) -> Result<Task>;
    pub fn get_task(&self, id: Uuid) -> Result<Task>;
    pub fn update_task(&mut self, task: Task) -> Result<()>;
    pub fn delete_task(&mut self, id: Uuid) -> Result<()>;
    pub fn list_tasks(&self, list_id: Uuid) -> Result<Vec<Task>>;

    // List operations
    pub fn create_list(&mut self, name: String) -> Result<TaskList>;
    pub fn get_lists(&self) -> Result<Vec<TaskList>>;
    pub fn delete_list(&mut self, id: Uuid) -> Result<()>;

    // Sync operations
    pub fn sync_push(&mut self) -> Result<SyncResult>;
    pub fn sync_pull(&mut self) -> Result<SyncResult>;
    pub fn sync_status(&self) -> Result<SyncStatus>;
}

// Storage trait for local and WebDAV implementations
pub trait Storage {
    fn read_task(&self, list_id: Uuid, task_id: Uuid) -> Result<Task>;
    fn write_task(&mut self, list_id: Uuid, task: &Task) -> Result<()>;
    // ... more methods
}

Storage Strategy

Local Storage

• Location: User-selectable folder OR platform-specific app data directory
  • Windows: %APPDATA%/bevy-tasks/ (default)
  • Linux: ~/.local/share/bevy-tasks/ (default)
  • macOS: ~/Library/Application Support/bevy-tasks/ (default)
  • iOS: App sandbox documents directory
  • Android: Internal storage app directory
  • User can select any folder with read/write permissions
• Format: Markdown files with YAML frontmatter (Obsidian-compatible)
• Structure:

  data/
  ├── .bevy-tasks/
  │   ├── config.json          # App configuration
  │   └── metadata.json        # List ordering, sync state
  ├── My Tasks/                # Task list folder
  │   ├── Buy groceries.md
  │   ├── Call dentist.md
  │   └── Project X/           # Subtask folder (optional)
  │       └── Design mockup.md
  └── Work/                    # Another task list
      ├── Review PRs.md
      └── Team meeting prep.md
  

Benefits of Markdown Format:

• Human-readable and editable in any text editor
• Compatible with Obsidian, Logseq, and other markdown tools
• Easy to version control (git-friendly)
• Future-proof format
• Enables external editing and scripting
• Natural organization with folders

WebDAV Sync

• Conflict Resolution: Last-write-wins with timestamp
• Sync Strategy:
  • On app start (if connected)
  • On background timer (every 5 minutes when active)
  • On task modification (debounced)
• Offline Support: All operations work offline, sync when online

Performance Strategy

Fast Startup Requirements

1. Minimal initialization: Load only essential systems
2. Lazy data loading: Load visible tasks first
3. Background operations: Non-critical data and sync after first render
4. Efficient file I/O: Stream large markdown files
5. Small binary size: Minimal dependencies in core library

Startup Sequence (egui GUI)

1. Initialize eframe window (< 50ms)
2. Load config from disk (< 20ms)
3. Render empty UI (first frame < 100ms)
4. Load current task list in background
5. Update UI as tasks load (incremental rendering)
6. Start WebDAV sync in background (if configured)

Target: < 200ms cold start on desktop

Memory Optimization

• Use Vec instead of HashMap for small collections
• Limit rendered tasks to visible viewport
• Lazy load task lists (only load selected list)
• Stream markdown parsing for large files

Feature Roadmap

Phase 1: Core Library & CLI MVP

Goal: Build and validate the backend with a functional CLI

Features:

• Project workspace setup (bevy-tasks-core, bevy-tasks-cli, bevy-tasks-gui)
• Data models (Task, TaskList, AppConfig)
• Markdown file I/O with YAML frontmatter parsing
• Local storage implementation
• Repository pattern and public API
• CLI: init, add, list, complete, delete, edit commands
• CLI: Basic task listing and formatting
• Comprehensive unit and integration tests

Deliverables:

• bevy-tasks-core library with stable API
• Functional CLI that can manage tasks via command line
• Data persists as Obsidian-compatible .md files
• Well-tested backend (>80% coverage)

CLI Example:

bevy-tasks init ~/my-tasks
bevy-tasks add "Buy groceries" --list "Personal"
bevy-tasks list
bevy-tasks complete <task-id>

Phase 2: WebDAV Sync (Backend + CLI)

Goal: Enable cross-device synchronization via CLI

Features:

• WebDAV client implementation in core library
• Credential storage (platform keychain)
• Bi-directional sync (push/pull/auto)
• Conflict resolution (last-write-wins)
• Offline queue for pending operations
• CLI: sync setup, push, pull, status commands
• CLI: Progress indicators for sync operations

Deliverables:

• Working WebDAV sync in backend
• CLI can sync with remote WebDAV server
• Reliable conflict resolution tested with real servers (Nextcloud, ownCloud)

CLI Example:

bevy-tasks sync --setup
bevy-tasks sync --push
bevy-tasks sync --pull
bevy-tasks sync --status

Phase 3: GUI MVP (Desktop)

Goal: Build graphical interface on desktop platforms

Frontend Decision: Choose frontend framework (see Frontend Comparison section)

Features:

• GUI framework integration
• Basic task list view
• Create/edit/delete tasks
• Mark tasks complete
• Settings screen (storage location, WebDAV config)
• Desktop support (Windows, Linux, macOS)
• Sync status indicators

Deliverables:

• Functional desktop GUI app
• Sub-second startup time
• Clean, minimal UI
• Feature parity with CLI

Phase 4: GUI Advanced Features (Desktop)

Goal: Feature parity with Google Tasks

Features:

• Multiple task lists (folders)
• Switch between lists
• Subtasks support
• Due dates with date picker
• Rich markdown editor for task notes
• Drag & drop reordering
• Move tasks between lists
• Folder picker for custom storage
• Keyboard shortcuts
• Search functionality

Deliverables:

• Full-featured desktop task manager
• Polished UX
• Keyboard-driven workflow

Phase 5: Mobile Support

Goal: Deploy to iOS and Android

Features:

• Touch-optimized UI
• iOS build pipeline
• Android build pipeline
• Mobile-specific UX (swipe gestures, pull-to-refresh)
• Background sync on mobile
• Mobile file system integration
• Share extension (share to tasks)
• Native mobile feel

Deliverables:

• Working iOS app
• Working Android app
• Consistent UX across mobile and desktop

Phase 6: Polish & Advanced Features

Goal: Differentiate from Google Tasks, add unique features

Features:

• Themes and customization
• Advanced animations and transitions (if using Bevy)
• Full-text search across tasks
• Filters and smart lists
• Task templates
• Recurring tasks
• Statistics and insights
• Export/import (backup)
• Plugin system for extensions (optional)
• Game-like achievements (optional, if using Bevy)

Deliverables:

• Polished, delightful UX
• Unique features not in Google Tasks
• Distribution to all app stores

Development Guidelines

Performance Budgets

• Cold start: < 500ms on desktop, < 1s on mobile
• First render: < 100ms
• Task creation: < 50ms
• Sync operation: < 2s for typical dataset (< 1000 tasks)
• Memory usage: < 50MB on mobile, < 100MB on desktop

Testing Strategy

• Unit tests: Data models and business logic
• Integration tests: Storage layer operations
• E2E tests: Critical user flows
• Performance tests: Startup time, large datasets
• Platform tests: Verify each platform build

Build & Release

• CI/CD: GitHub Actions for all platforms
• Initial Distribution:
  • Desktop: Direct downloads and sideloading
    • Linux: AppImage, .tar.gz
    • macOS: DMG
    • Windows: MSI, portable .exe
  • Mobile: Sideloading only
    • iOS: .ipa for TestFlight/direct install
    • Android: .apk
• Future Distribution Channels (Phase 5+):
  • F-Droid: FOSS Android app store
  • Flathub: Linux Flatpak repository
  • Google Play Store: Android
  • Apple App Store: iOS and macOS
  • Microsoft Store: Windows
• Version scheme: Semantic versioning (0.1.0 → 1.0.0)
• Release notes: Auto-generated from commits

Technical Challenges & Solutions

Challenge 1: Fast Startup with GUI

Problem: UI initialization can add overhead

Solutions (egui):

• Use eframe with minimal features
• Defer loading of non-visible data
• Initialize window before loading tasks
• Profile startup and optimize hot paths
• Keep core library dependency-light

Challenge 2: Mobile Platform Support

Problem: iOS and Android have different requirements

Solutions:

• Use conditional compilation for platform-specific code
• Test early and often on real devices
• Follow platform guidelines (iOS HIG, Material Design)
• Use platform-specific file pickers and sharing

Challenge 3: WebDAV Reliability

Problem: Network can be unreliable, auth can be complex

Solutions:

• Implement robust retry logic with exponential backoff
• Cache credentials securely (see Authentication Options below)
• Queue operations when offline
• Provide clear sync status to user
• Support multiple WebDAV servers (Nextcloud, ownCloud, etc.)

Challenge 4: Data Migration

Problem: Schema changes need to preserve user data

Solutions:

• Version frontmatter schema from day one
• Write migration scripts for each version bump
• Markdown format is naturally forward/backward compatible
• Users handle their own backups (external to app)
• Migration can be done in-place by updating frontmatter

Frontend Framework Decision

Decision Made: Hybrid approach with egui for Phase 3, optional Bevy migration in Phase 6.

Phase 3-5: egui (Immediate Mode GUI)

Why egui for MVP?

• ✅ Fast development with rich built-in widgets
• ✅ Excellent text editing and form support out of the box
• ✅ Small binary size (~2-3MB stripped)
• ✅ Fast startup time (100-200ms)
• ✅ Mature and stable
• ✅ Simple immediate-mode API
• ✅ Cross-platform (desktop primary, mobile possible)
• ✅ Easy integration with bevy-tasks-core

Trade-offs:

• ⚠️ Less flexibility for custom animations
• ⚠️ Mobile support less mature (but improving)
• ⚠️ Not as "game-like" polish potential

Phase 6 (Optional): Migration to Bevy

If you want game-like polish later:

• ✅ Full control over animations and rendering
• ✅ Unique, polished look beyond standard apps
• ✅ Better mobile support (iOS/Android)
• ✅ ECS architecture for complex interactions
• ✅ Backend stays identical (clean separation!)

Why this works: The bevy-tasks-core library is UI-framework agnostic, so switching from egui to Bevy only requires rewriting the bevy-tasks-gui crate. All business logic, file I/O, sync, and testing remains unchanged.

This approach de-risks the project: validate the concept with egui, then optionally invest in custom polish with Bevy if the app takes off.

Dependencies

Workspace Structure (Cargo.toml)

[workspace]
members = [
    "crates/bevy-tasks-core",
    "crates/bevy-tasks-cli",
    "crates/bevy-tasks-gui",
]
resolver = "2"

[workspace.dependencies]
# Shared dependencies
serde = { version = "1.0", features = ["derive"] }
uuid = { version = "1.0", features = ["serde", "v4"] }
chrono = { version = "0.4", features = ["serde"] }
anyhow = "1.0"
tokio = { version = "1.40", features = ["full"] }

Core Library (bevy-tasks-core/Cargo.toml)

[package]
name = "bevy-tasks-core"
version = "0.1.0"
edition = "2024"

[dependencies]
serde = { workspace = true }
serde_json = "1.0"
serde_yaml = "0.9"  # YAML frontmatter parsing
pulldown-cmark = "0.12"  # Markdown parsing
uuid = { workspace = true }
chrono = { workspace = true }
directories = "5.0"  # Cross-platform paths
tokio = { workspace = true }
anyhow = { workspace = true }

# WebDAV support
reqwest = { version = "0.12", features = ["json", "rustls-tls"] }
# TODO: Evaluate dav-client or implement custom WebDAV

# Credential storage
keyring = "3.0"  # Cross-platform keychain

[dev-dependencies]
tempfile = "3.0"  # For testing file operations

CLI (bevy-tasks-cli/Cargo.toml)

[package]
name = "bevy-tasks-cli"
version = "0.1.0"
edition = "2024"

[[bin]]
name = "bevy-tasks"
path = "src/main.rs"

[dependencies]
bevy-tasks-core = { path = "../bevy-tasks-core" }
clap = { version = "4.5", features = ["derive", "env"] }
colored = "2.0"  # Terminal colors
indicatif = "0.17"  # Progress bars
anyhow = { workspace = true }
tokio = { workspace = true }

GUI (bevy-tasks-gui/Cargo.toml)

[package]
name = "bevy-tasks-gui"
version = "0.1.0"
edition = "2024"

[dependencies]
bevy-tasks-core = { path = "../bevy-tasks-core" }
anyhow = { workspace = true }

# egui for Phase 3-5
eframe = "0.31"  # egui framework with native windowing
egui = "0.31"    # Core egui library

# TODO Phase 6: Consider migration to Bevy for game-like polish
# bevy = { version = "0.16", default-features = false, features = ["bevy_ui", "bevy_render", "bevy_winit"] }

# Platform-specific
[target.'cfg(target_os = "android")'.dependencies]
# Android-specific deps (Phase 5)

[target.'cfg(target_os = "ios")'.dependencies]
# iOS-specific deps (Phase 5)

Getting Started

Prerequisites

• Rust 1.75+ (2024 edition)
• Platform-specific tools (for mobile builds later):
  • iOS: macOS + Xcode
  • Android: Android SDK + NDK

Development Setup

# Clone repository
git clone <repository-url>
cd bevy-tasks

# Build all workspace members
cargo build

# Run tests for core library
cargo test -p bevy-tasks-core

# Run CLI
cargo run -p bevy-tasks-cli -- --help
cargo run -p bevy-tasks-cli -- init ~/test-tasks

# Run GUI (once implemented)
cargo run -p bevy-tasks-gui

# Build for release
cargo build --release -p bevy-tasks-cli
cargo build --release -p bevy-tasks-gui

# Run all tests
cargo test --workspace

Development Workflow (Phase 1)

1. Start with Core Library:

cd crates/bevy-tasks-core
cargo test --watch  # with cargo-watch

2. Build CLI to test backend:

cd crates/bevy-tasks-cli
cargo run -- init ~/my-tasks
cargo run -- add "Test task"
cargo run -- list

3. Iterate on API:

• Add features to core library
• Test via CLI
• Write integration tests
• Document public API

4. Add GUI later (Phase 3):

cd crates/bevy-tasks-gui
cargo run

Questions & Decisions

1. Authentication for WebDAV Sync

Option A: Platform Keychain/Keyring

Implementation: Use keyring crate for cross-platform credential storage

Pros:

• Most secure option
• OS-managed encryption
• Follows platform security best practices
• Auto-locks with system
• Works on all platforms:
  • Windows: Credential Manager
  • macOS: Keychain
  • Linux: Secret Service API (gnome-keyring/kwallet)
  • iOS: Keychain
  • Android: Keystore

Cons:

• Requires user to unlock keychain
• May prompt for permissions
• Linux requires D-Bus and secret service

Security: ⭐⭐⭐⭐⭐

Option B: Encrypted Local Storage

Implementation: Encrypt credentials in config file using a master password or device key

Pros:

• Works offline always
• No external dependencies
• Full control over encryption

Cons:

• Need to manage encryption keys
• Vulnerable if key is compromised
• Need to prompt user for password
• Harder to implement correctly

Security: ⭐⭐⭐ (if done right)

Option C: App-Generated Token + Keychain

Implementation: User authenticates once via OAuth/app-specific password, store token in keychain

Pros:

• More secure than passwords
• Supports modern auth flows
• Can revoke tokens
• Works with Nextcloud, ownCloud app passwords

Cons:

• Requires OAuth flow implementation
• More complex initial setup
• Depends on server support

Security: ⭐⭐⭐⭐⭐

Option D: Store Username + Prompt for Password

Implementation: Store username in config, prompt for password on each sync

Pros:

• Simple implementation
• No credential storage
• Maximum security

Cons:

• Terrible UX
• Not practical for background sync
• Users will hate it

Security: ⭐⭐⭐⭐⭐ (but unusable)

Recommendation

Primary: Option A (Platform Keychain) using the keyring crate

• Store WebDAV username + password in system keychain
• Key: com.bevy-tasks.webdav.{server-domain}
• Graceful fallback if keychain is unavailable

Fallback: Option B (Encrypted storage) for platforms where keychain fails

• Use ChaCha20-Poly1305 for encryption
• Derive key from device identifier + app secret

Future: Option C (Token-based) for servers that support it

• Implement OAuth flow for Nextcloud/ownCloud
• Store tokens in keychain

---

3. Backup Strategy

Decision: User-managed backups via external tools

Rationale:

• Markdown format is already backup-friendly
• Users can use existing tools:
  • Git for version control
  • Dropbox/Google Drive/OneDrive for cloud backup
  • Time Machine (macOS) / File History (Windows)
  • rsync, rclone, etc.
• WebDAV itself serves as a backup when enabled
• Keeps app simple and focused

App Responsibilities:

• Don't corrupt data
• Write atomically (temp file + rename)
• Graceful handling of sync conflicts
• Clear documentation on backup best practices

Optional Future Feature:

• Export all tasks to single file (.zip of markdown)
• Import from backup
• Git integration for automatic versioning

Resources

• Bevy Documentation
• Bevy Mobile Examples
• WebDAV RFC 4918
• Google Tasks API (for feature reference)

License

To be determined.

---

Last Updated: 2025-10-27 Document Version: 2.1 Status: Ready to Implement - egui Hybrid Approach Confirmed