📸 Flickr Search App

A Kotlin Multiplatform (KMP) application that allows users to search for photos using the Flickr API. The app follows modern development practices, including Jetpack Compose, MVVM architecture, and unit testing.

🚀 Features

• Search for Photos: Search for photos using the Flickr API with various search terms.
• Grid Display: Display search results in an aesthetically pleasing grid format.
• Search History: Save and access your search history for quick re-access.
• Unit Tested: Core components, including the repository, database, and utility functions, are thoroughly unit tested.

🛠️ Tech Stack

• Kotlin Multiplatform (KMP): Shared logic across Android and other platforms.
• Jetpack Compose: UI Toolkit for building native UI.
• Retrofit: For networking and API calls.
• SQLDelight: For local database storage.
• Kotlin Coroutines & Flow: For asynchronous operations.
• Mokkery: For unit testing.
• Kotlinx DateTime: For date and time formatting.

🏛️ Architecture: MVVM with Clean Architecture

This application is built using a combination of the MVVM (Model-View-ViewModel) architectural pattern and Clean Architecture principles to create a robust, testable, and maintainable codebase. This approach ensures a clear separation of concerns and promotes a modular design.

Core Principles

• Separation of Concerns: Each part of the application has a specific responsibility, making the code easier to understand and modify.
• Testability: The architecture facilitates unit testing of individual components in isolation.
• Maintainability: The modular design makes it easier to update or replace parts of the application without affecting other parts.
• Independence: The core business logic is independent of the UI and data sources.

Layers

The application is divided into three main layers:

1. Domain Layer

• Responsibilities: Contains the core business logic and use cases of the application. It's the heart of the app and is independent of any external frameworks or UI.
• Components:
  • Entities: Represent the core business objects (e.g., Photo, SearchQuery).
  • Use Cases: Define the specific actions that can be performed in the application (e.g., SearchPhotosUseCase, GetAllSearchHistoryUseCase). Use cases encapsulate the business rules.
  • Interfaces (Repositories): Define contracts for interacting with the Data layer (e.g., SearchRepository).
• Benefits:
  • Testability: Business logic can be tested in isolation.
  • Flexibility: Changes in the outer layers don't affect the core business logic.
  • Reusability: Use cases can be reused by different parts of the application.

2. Presentation Layer (MVVM)

• Responsibilities: Handles the UI logic and user interactions. It's responsible for displaying data and responding to user events. This layer implements the MVVM pattern.
• Components:
  • ViewModels: Prepare data from the Domain layer (Use Cases) for the View and handle user input. They expose data streams (using Kotlin Flows) to the View.
  • UI (Jetpack Compose): The actual UI components that display data and handle user interactions. The View observes data streams from the ViewModels and updates accordingly.
• Interactions:
  • ViewModels interact with Use Cases from the Domain layer to perform actions.
  • The UI observes data streams from the ViewModels and updates accordingly.
• MVVM:
  • Model: The data and business logic provided by the Domain Layer.
  • View: The UI built with Jetpack Compose.
  • ViewModel: The intermediary between the View and the Model, preparing data and handling user input.

3. Data Layer

• Responsibilities: Handles data retrieval and storage, both from local and remote sources.
• Components:
  • Repositories: Implement the interfaces defined in the Domain layer. They abstract the data sources.
  • Data Sources: Handle interactions with specific data sources (e.g., Retrofit for the Flickr API, SQLDelight for the local database).
  • Data Models: Represent the data structures used by the data sources (e.g., API responses, database tables).
• Interactions:
  • Repositories interact with data sources to fetch or store data.
  • The Domain layer interacts with Repositories to access data.

🖼️ Screenshots

Android

📦 Compiled APK

For those who want to quickly try out the app without building it from source, a pre-compiled APK is available:

• Download Flickr Search APK

Note:

• You may need to enable "Install from Unknown Sources" in your Android device's settings to install the APK.
• This APK is for testing purposes only.

🔧 Setup & Installation

1. Clone the Repository

bash git clone https://github.com/DasJhaman/Flicker-Image-Search.git.

2. Open in Android Studio

• Open Android Studio.
• Select "Open" and navigate to the flickr-search directory you just cloned.
• Wait for Gradle to sync and download all necessary dependencies. This might take a few minutes.

3. Configure API Keys

• Create a file named local.properties in the root directory of your project (the same level as build.gradle.kts).
• Add the following lines to local.properties, replacing value with your actual API key and parameters:

SEARCH_METHOD=flickr.photos.search

API_KEY=value

API_BASE_URL=https://api.flickr.com/services/rest/

Note: You'll need to obtain a Flickr API key from the Flickr website to use the API.

4. Run the App

• Connect an Android emulator or a physical Android device to your computer.
• In Android Studio, select the androidApp configuration.
• Click the "Run" button (green play icon) to build and run the app on your selected device.

🧪 Unit Tests

The project includes unit tests for core functionalities:

✅ Repository Tests

• SearchRepositoryTest: Tests API calls and search history storage.

✅ Utility Function Tests

• DateTimeFormatterTest: Validates date formatting logic.

✅ Database Tests

• SearchHistoryTableQueriesTest: Tests queries for storing and retrieving search history.

✅ UI Tests

• DashboardScreenTest: Tests for UI screen. Run By using ./gradlew connectedDebugAndroidTest

How to Run Tests

• Open the terminal in Android Studio.
• Navigate to the root directory of the project.
• Run the following command: bash ./gradlew testDebugUnitTest

📜 License

This project is licensed under the MIT License.

🤝 Contribution

Contributions are welcome!

• Feel free to open an issue to report bugs or suggest new features.
• If you'd like to contribute code, please submit a pull request.
• Make sure to update tests as appropriate when making changes.

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