Scheduler

An Android productivity application designed for event scheduling, hierarchical collection management, and automated notifications. Built with Kotlin, Jetpack Compose, and Room Database, Scheduler implements MVVM architecture to provide an offline-first scheduling experience.

Key Features

• Hierarchical Organization: Create individual events or group them into "Collections" for major projects or travel itineraries.
• Chronological Filtering: Filter schedules through "Today," "This Week," and "This Month" views bounded by calendar logic.
• Real-Time Search: Query events and collections with direct navigation to search results.
• Automated SMS Alerts: Scheduled background notification monitoring triggers SMS alerts 30 minutes prior to event start times.
• Secure Persistence: Local SQLite persistence for user profiles, events, and collection relationships.

Security & Privacy

• Credential Hashing: User passwords are stored as salted PBKDF2 hashes using PBKDF2WithHmacSHA256 (10,000 iterations, unique per-user salt).
• Least Privilege Permissions: SMS permission (SEND_SMS) is requested dynamically only when SMS alerts are enabled by the user.

Technical Stack

• Language: Kotlin
• UI Framework: Jetpack Compose (Material 3)
• Database: Room Persistence Library (SQLite)
• Architecture: MVVM with Kotlin Coroutines and StateFlow
• Annotation Processing: KSP (Kotlin Symbol Processing)
• Dependency Management: Gradle Version Catalog (libs.versions.toml)

Getting Started

1. Clone the Repository:

   git clone https://github.com/mbayers/Scheduler.git

2. Open in Android Studio: Open the root project directory in Android Studio (Ladybug or newer).
3. Build and Run: Build and launch on an Android emulator or physical device running API level 24 or higher.

Permissions

• android.permission.SEND_SMS: Required for automated 30-minute event notification alerts.

Project Architecture & Reflection

1. Requirements & User Needs

Scheduler addresses offline time management requirements by offering user authentication, relational event persistence, and automated event notifications.

2. User-Centered Design

The interface incorporates high-contrast dark theme styling, structured dashboards, hierarchical collection detail views, and expandable cards to present event information without clutter.

3. Architecture & Code Organization

The application adheres to MVVM principles. Jetpack Compose delivers a declarative UI layer powered by StateFlow streams from Room DAO queries, maintaining clean separation of concerns across UI, Domain, and Data layers.

4. Testing & Verification

Verified via JUnit unit tests and Room instrumented migration tests (DatabaseMigrationTest) on connected Android emulators, ensuring database schema transitions and foreign key integrity.

5. Collection Content Management

Implements a unified selector pattern for managing collection items, allowing users to reassign or associate events across collections in a single workflow.

6. Data & Security Layer

Combines Room foreign key constraints (ON DELETE CASCADE) with industry-standard PBKDF2 password hashing to maintain database referential integrity and credential security.