dougyouch/schema

#!/usr/bin/env ruby

require 'schema-model'
require 'csv'
require 'json'
require 'optparse'

options = {
  json_file: nil,
  require_file: nil,
  csv_file: nil,
  schema_class_name: nil
}

OptionParser.new do |opts|
  opts.banner = "Usage: " + File.basename(__FILE__)

  opts.on('--json JSON_FILE', 'JSON data') do |v|
    options[:json_file] = v
  end

  opts.on('-r', '--require FILE', 'File with schema model') do |v|
    options[:require_file] = v
  end

  opts.on('--csv CSV_FILE', 'File to output csv data') do |v|
    options[:csv_file] = v
  end

  opts.on('--schema SCHEMA_CLASS_NAME', 'Name of the schema to apply to the json data') do |v|
    options[:schema_class_name] = v
  end
end.parse!

raise('no filed required') unless options[:require_file]
raise('no schema specified') unless options[:schema_class_name]

$LOAD_PATH << '.'
raise("file #{options[:require_file]} not found") unless require(options[:require_file])

raise("schema #{options[:schema_class_name]} not found") unless Object.const_defined?(options[:schema_class_name])

schema_class = Object.const_get(options[:schema_class_name])
schema_class.schema_include Schema::Arrays

json_data =
  if options[:json_file]
    raise("json file #{options[:json_file]} not found") unless File.exist?(options[:json_file])
    File.read(options[:json_file])
  elsif ARGV.last == '-'
    ARGF.read
  else
    raise('no json data specified')
  end

def output_csv(schema, io)
  str = CSV.generate do |csv|
    csv << schema.to_a.flatten
  end

  io.print str
end

io =
  if file = options[:csv_file]
    if File.exist?(file)
      File.open(options[:csv_file], 'ab')
    else
      headers = CSV.generate do |csv|
        csv << schema_class.to_headers
      end
      f = File.open(options[:csv_file], 'wb')
      f.print headers
      f
    end
  else
    $stdout
  end

json_data = JSON.parse(json_data)
json_data = [json_data] unless json_data.is_a?(Array)

json_data.each do |data|
  output_csv(schema_class.from_hash(data), io)
end