//
//  LottieBundleImageProvider.swift
//  lottie-swift
//
//  Created by Brandon Withrow on 1/25/19.
//

import Foundation
import CoreGraphics
import UIKit

/**
 An `AnimationImageProvider` that provides images by name from a specific bundle.
 The BundleImageProvider is initialized with a bundle and an optional searchPath.
 */
public class BundleImageProvider: AnimationImageProvider {
  
  let bundle: Bundle
  let searchPath: String?
  
  /**
   Initializes an image provider with a bundle and an optional subpath.
   
   Provides images for an animation from a bundle. Additionally the provider can
   search a specific subpath for the images.
   
   - Parameter bundle: The bundle containing images for the provider.
   - Parameter searchPath: The subpath is a path within the bundle to search for image assets.
   
   */
  public init(bundle: Bundle, searchPath: String?) {
    self.bundle = bundle
    self.searchPath = searchPath
  }
  
  public func imageForAsset(asset: ImageAsset) -> CGImage? {
    
    let imagePath: String?
    /// Try to find the image in the bundle.
    if let searchPath = searchPath {
      /// Search in the provided search path for the image
      var directoryPath = URL(fileURLWithPath: searchPath)
      directoryPath.appendPathComponent(asset.directory)
      
      if let path = bundle.path(forResource: asset.name, ofType: nil, inDirectory: directoryPath.path) {
        /// First search for the image in the asset provided sub directory.
        imagePath = path
      } else if let path = bundle.path(forResource: asset.name, ofType: nil, inDirectory: searchPath) {
        /// Try finding the image in the search path.
        imagePath = path
      } else {
        imagePath = bundle.path(forResource: asset.name, ofType: nil)
      }
    } else {
      if let path = bundle.path(forResource: asset.name, ofType: nil, inDirectory: asset.directory) {
        /// First search for the image in the asset provided sub directory.
        imagePath = path
      } else {
        /// First search for the image in bundle.
        imagePath = bundle.path(forResource: asset.name, ofType: nil)
      }
    }
    
    guard let foundPath = imagePath, let image = UIImage(contentsOfFile: foundPath) else {
      /// No image found.
      return nil
    }
    return image.cgImage
  }
  
}