#!/usr/bin/env ruby

# == Summary
#   Generates a exifs.csv file from JPEGs in a directory
#   and subdirectories.
#
# == Usage
#   ./exif2csv.rb [path_to_images]
#
#   If [path_to_images] is not entered, program will browse
#   subfolders.
#
# == Version History
#   v0.0.2 - current
#   v0.0.1 - 2010/08/27
#
# == Issues
#   - Includes empty lines for JPEGs with no exifs

require 'csv'
require 'rubygems'
require 'mini_exiftool'

class Exif2CSV
  @@header = ['FocalLength', 'Aperture', 'ExposureTime', 'ISO', 'Lens']

  def self.generate_csv(directory)
    CSV.open('exifs.csv', 'wb') do |csv|
      csv << @@header 
      Exif2CSV.get_images(directory).each do |image|
        csv << Exif2CSV.read_exifs(image)
      end
    end
  end

  private
  def self.get_images(directory)
    Dir.glob(File.join(directory,'**','*.jpg'), File::FNM_CASEFOLD)
  end
  def self.read_exifs(photo)
    exifs = MiniExiftool.new photo
    exifs.to_hash.values_at(*@@header)
  end
end

if ARGV.empty?
  Exif2CSV.generate_csv '.'
else
  Exif2CSV.generate_csv ARGV[0]
end