#!/usr/bin/env swift
// Print the size of every item in my Photos Library.
// See https://alexwlchan.net/2023/finding-big-photos/

import Photos

struct AssetData: Codable {
  var localIdentifier: String
  var originalFilename: String
  var fileSize: Int64
}

/// Returns a list of assets in the Photos Library.
///
/// The list is sorted by file size, from largest to smallest.
func getAssetsBySize() -> [AssetData] {
  var allAssets: [AssetData] = []

  let options: PHFetchOptions? = nil

  PHAsset.fetchAssets(with: options)
    .enumerateObjects({ (asset, _, _) in
      let resource = PHAssetResource.assetResources(for: asset)[0]

      let data = AssetData(
        localIdentifier: asset.localIdentifier,
        originalFilename: resource.originalFilename,
        fileSize: resource.value(forKey: "fileSize") as! Int64
      )

      allAssets.append(data)
    })

  allAssets.sort { $0.fileSize > $1.fileSize }

  return allAssets
}

/// Quick extension to allow left-padding a string in Swift
///
/// By user2878850 on Stack Overflow:
/// https://stackoverflow.com/a/69859859/1558022
extension String {
  func leftPadding(toLength: Int, withPad: String) -> String {
    String(
      String(reversed())
        .padding(toLength: toLength, withPad: withPad, startingAt: 0)
        .reversed()
    )
  }
}

let bcf = ByteCountFormatter()

for photo in getAssetsBySize() {
  let size =
    bcf
      .string(fromByteCount: photo.fileSize)
      .leftPadding(toLength: 8, withPad: " ")
  print("\(size)  \(photo.originalFilename)")
}