#!/usr/bin/env ruby

cams = { "SIGMA DP2 Merrill" => "dp2m", "FP2" => "fp2", "Canon EOS 1000D" => "1000d", "iPad Air" => "ipadair", "iPhone 5" => "iphone5", "iPhone SE" => "iphonese", "IQ180" => "iq180" }
cams.default = "default"

file_ext = ARGV[0]
if !file_ext
  file_ext = "jpg"
end

ids = []
while line = STDIN.gets # list of files
  a = line.split('.')
  a.pop
  ids << a.join('.')
end

used_prefixes = {} # prefix -> 0..N

ids.each do |i|
  exif = `exiftool #{i}.#{file_ext} 2>/dev/null`
  a = exif.split "\n"
  timestamp = nil
  timestamp_bak = nil
  cam = nil
  cam_bak = nil
  a.each { |j|
    if j.start_with? "Camera Model Name"
      cam = j
    elsif j.start_with? "Model"
      cam_bak = j
    elsif j.start_with? "Date/Time Original"
      timestamp = j
    elsif j.start_with? "File Modification Date/Time"
      if not timestamp_bak
        timestamp_bak = j
      end
    elsif j.start_with? "Creation Date"
      timestamp_bak = j
    else
      next
    end
  }
  skip = false
  t = ""
  c = ""
  new_prefix = ""
  add = 0
  begin
    if timestamp
      t = timestamp.split(':',2)[1].strip.gsub(/(:|\ )/, '-')
    end
    if timestamp_bak
      t_bak = timestamp_bak.split(':',2)[1].strip.gsub(/(:|\ )/, '-')
    end
    if cam
      c = cams[cam.split(':',2)[1].strip]
    elsif cam_bak
      c = cams[cam_bak.split(':',2)[1].strip]
    else
      c = "unknown-device"
    end
    if t.split('-').first.to_i < 2000
      t = t_bak
      if not t or t.split('-').first.to_i < 2000
        puts "metadata unreasonable for #{i}, skipping!"
        skip = true
      end
    end
    new_prefix = "#{t}-#{c}"
    add = 1
  rescue
    puts "Can't find metadata for #{i}, skipping!"
    skip = true
  end
  next if skip
  while used_prefixes.has_key? new_prefix
    new_prefix = "#{t}-#{add}-#{c}"
    add += 1
  end
  used_prefixes[new_prefix] = true

  Dir.glob("#{i}*").each { |f|
    ext = f.gsub(/^#{i}/,"")
    if File.exists? "#{new_prefix}#{ext}"
      puts "File exists: #{new_prefix}#{ext} (#{i})!"
      exit
    else
      `mv #{i}#{ext} #{new_prefix}#{ext}`
    end
  }
end