mceachen/exiftool

# frozen_string_literal: true

require 'json'
require 'shellwords'
require 'exiftool/result'
require 'forwardable'
require 'pathname'

# Exiftool Class
class Exiftool
  class NoSuchFile < StandardError; end

  class NotAFile < StandardError; end

  class ExiftoolNotInstalled < StandardError; end

  class NoDefaultResultWithMultiget < StandardError; end

  class << self
    attr_writer :command
  end

  def self.command
    @command ||= 'exiftool'
  end

  def self.exiftool_installed?
    exiftool_version.to_f.positive?
  end

  # This is a string, not a float, to handle versions like "9.40" properly.
  def self.exiftool_version
    @exiftool_version ||= `#{command} -ver 2> /dev/null`.chomp
  end

  def self.expand_path(filename)
    raise(NoSuchFile, filename) unless File.exist?(filename)

    raise(NotAFile, filename) unless File.file?(filename)

    File.expand_path(filename)
  end

  extend Forwardable

  def_delegators :first_result, :to_hash, :to_display_hash, :symbol_display_hash, :raw, :[]

  def initialize(filenames, exiftool_opts = '')
    @file2result = {}
    filenames = [filenames] if filenames.is_a?(String) || filenames.is_a?(Pathname)
    return if filenames.empty?

    escaped_filenames = filenames.map do |f|
      Shellwords.escape(self.class.expand_path(f.to_s))
    end.join(' ')
    # I'd like to use -dateformat, but it doesn't support timezone offsets properly,
    # nor sub-second timestamps.
    cmd = "#{self.class.command} #{exiftool_opts} -j -coordFormat \"%.8f\" #{escaped_filenames} 2> /dev/null"
    json = `#{cmd}`.chomp
    raise ExiftoolNotInstalled if json == ''

    JSON.parse(json).each do |raw|
      result = Result.new(raw)
      @file2result[result.source_file] = result
    end
  end

  def results(include_results_with_errors: false)
    if include_results_with_errors
      @file2result.values
    else
      @file2result.values.reject(&:errors?)
    end
  end

  def result_for(filename)
    @file2result[self.class.expand_path(filename)]
  end

  def files_with_results
    results.map(&:source_file)
  end

  def errors?
    @file2result.values.any?(&:errors?)
  end

  private

  def first_result
    raise(NoDefaultResultWithMultiget, 'use #result_for when multiple filenames are used') if @file2result.size > 1

    @file2result.values.first
  end
end