update readme

Author: sozohoy

README.md

@@ -1 +1,159 @@
-# PhotoConcurrencyManager
+# PhotoConcurrencyManager
+
+A concurrent photo loading and caching manager for iOS that provides efficient photo asset handling with support for both high and low-quality image loading states.
+
+## Features
+
+- ✨ Concurrent photo loading with async/await support
+- 🎯 Multiple image quality delivery modes (low/high quality)
+- 💾 Built-in memory caching
+- 🔄 Prefetching support for smooth scrolling
+- 📱 iCloud photo access handling
+- 🎨 Flexible image loading configurations
+- 🏃‍♂️ Performance optimized for scrolling
+
+## Installation
+
+### Swift Package Manager
+
+Add the following to your `Package.swift` file:
+
+```swift
+dependencies: [
+    .package(url: "https://github.com/sozohoy/PhotoConcurrencyManager", from: "1.0.0")
+]
+```
+
+## Usage
+
+### Basic Usage
+
+```swift
+let manager = PhotoConcurrencyManager()
+
+// Request photo library authorization
+let isAuthorized = await manager.requestAuthorization()
+
+// Load an image
+let stream = manager.loadImage(
+    asset: photoAsset,
+    targetSize: CGSize(width: 300, height: 300),
+    contentMode: .aspectFill,
+    configuration: .thumbnail
+)
+
+for try await quality in stream {
+    switch quality {
+    case .low(let image):
+        // Handle low quality image (e.g., show as placeholder)
+    case .high(let image):
+        // Handle high quality image
+    }
+}
+```
+
+### Prefetching Images
+
+```swift
+// Start prefetching
+manager.prefetchImages(
+    for: assets,
+    targetSize: CGSize(width: 300, height: 300),
+    contentMode: .aspectFill,
+    configuration: .scrolling
+)
+
+// Cancel prefetching when needed
+manager.cancelPrefetching(
+    for: assets,
+    targetSize: CGSize(width: 300, height: 300),
+    contentMode: .aspectFill,
+    configuration: .scrolling
+)
+```
+
+### Loading Images While Scrolling
+
+```swift
+let image = try await manager.loadImageWhenScrolling(
+    asset: asset,
+    targetSize: CGSize(width: 300, height: 300),
+    contentMode: .aspectFill,
+    configuration: .scrolling
+)
+```
+
+## Configuration Options
+
+### Image Quality Configuration
+
+The library provides several preset configurations:
+
+```swift
+// Default configuration for optimal quality/performance balance
+.opportunisticFit
+
+// High quality synchronous loading
+.highQualitySync
+
+// Fast loading for thumbnails
+.thumbnail
+
+// Optimized for scroll performance
+.scrolling
+```
+
+### Custom Configuration
+
+Create custom configurations by specifying:
+- Synchronous/Asynchronous loading
+- Delivery mode (fast/opportunistic/high quality)
+- Content mode (aspect fit/fill)
+- iCloud access mode
+- Resize mode
+- Version requirements
+
+```swift
+let customConfig = PhotoImageOptions.Configuration(
+    synchronousMode: .async,
+    deliveryMode: .highQuality,
+    contentMode: .aspectFill,
+    iCloudAccessMode: .allowed,
+    resizeMode: .exact,
+    version: .current
+)
+```
+
+## Error Handling
+
+The library provides detailed error cases:
+
+```swift
+public enum ImageLoadingError: Error {
+    case loadingFailed(Error)
+    case cancelled
+    case noImage
+    case unauthorized
+}
+```
+
+## Performance Considerations
+
+- Built-in memory cache management with configurable size limits
+- Automatic cache cleanup
+- Optimized for scroll performance with dedicated configurations
+- Prefetching support for smooth scrolling experiences
+
+## Requirements
+
+- iOS 16.0+
+- Swift 6.0+
+- Xcode 14.0+
+
+## License
+
+This library is released under the MIT license. See [LICENSE](https://github.com/sozohoy/PhotoConcurrencyManager/blob/main/LICENSE) for details.
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.