performance.fs

/// The program is from http://codereview.stackexchange.com/q/20068
module Performance

open System
open System.Drawing
open System.IO
open System.Text
open System.Text.RegularExpressions

let rec getAllFiles baseDir = 
  seq { 
    yield! Directory.EnumerateFiles(baseDir)
    for dir in Directory.EnumerateDirectories(baseDir) do
      yield! getAllFiles dir
  }

let dateTakenFromExif file = 
  let r = new Regex(":")
  use fs = new FileStream(file, FileMode.Open, FileAccess.Read)
  use myImage = Image.FromStream(fs, false, false)
  let propItem = myImage.GetPropertyItem(36867)
  let dateTaken = r.Replace(Encoding.UTF8.GetString(propItem.Value), "-", 2)
  DateTime.Parse(dateTaken)

let getDateTaken file = 
  try 
    dateTakenFromExif file
  with :? Exception -> File.GetLastWriteTime(file) //Use the last write time in the event that the file was moved/copied

let addToFile file n = 
  match n with
  | 2 -> 
    let fileDir = Path.GetDirectoryName(file)
    let nextFile = 
      Path.GetFileNameWithoutExtension(file) + "-" + n.ToString() 
      + Path.GetExtension(file)
    Path.Combine(fileDir, nextFile)
  | _ -> 
    let prev = n - 1
    file.Replace("-" + prev.ToString(), "-" + n.ToString())

let getNewFilename newFilePath = 
  let rec incrementFilename file n = 
    let filenameIncremented = addToFile file n
    match File.Exists(filenameIncremented) with
    | false -> filenameIncremented
    | true -> incrementFilename filenameIncremented (n + 1)
  match File.Exists(newFilePath) with
  | false -> newFilePath
  | true -> incrementFilename newFilePath 2

let move destinationRoot files = 
  let moveHelper file = 
    let dateTaken = getDateTaken file
    let finalPath = 
      Path.Combine
        (destinationRoot, dateTaken.Year.ToString(), 
         dateTaken.ToString("yyyy-MM-dd"))
    if not (Directory.Exists(finalPath)) then 
      Directory.CreateDirectory(finalPath) |> ignore
    let newFile = 
      getNewFilename (Path.Combine(finalPath, Path.GetFileName(file)))
    try 
      File.Copy(file, newFile)
    with :? Exception as e -> 
      failwith (sprintf "error renaming %s to %s\n%s" file newFile e.Message)
  files |> Seq.iter moveHelper

let moveFrom source = 
  getAllFiles source
  |> Seq.filter (fun f -> Path.GetExtension(f).ToLower() <> ".db") //exlcude the thumbs.db files
  |> move """C:\_EXTERNAL_DRIVE\_Camera"""
  printfn "Done"

moveFrom """C:\Users\Mike\Pictures\To Network"""
moveFrom """C:\_EXTERNAL_DRIVE\Camera"""