csv2

#!/usr/bin/env ruby

require "csv"
require "json"
require "yaml"

def help(msg = "")
  puts msg
  puts <<-EOF
csv2 something converter
  csv2 FORMAT FILEPATH

Supported formats are:
#{supported_formats.map { |i| " - #{i}" }.join("\n")}
EOF
  true
end

def supported_formats
  formats = []
  Object.private_instance_methods(false).each do |method|
    match = /convert_(\w+)/.match(method.to_s)
    formats << match[1] if match
  end
  formats
end

def convert_yaml(data)
  YAML.dump(data)
end

def convert_json(data)
  JSON.dump(data)
end

def convert(format, path)
  data = []
  CSV.open(path, headers: true, return_headers: true) do |csv|
    csv.each { |row| data << row.to_hash }
  end
  __send__ "convert_#{format}".to_sym, data
end

def main
  help && exit(1) if ARGV.size < 2
  to, path = ARGV[0], ARGV[1]
  help("Unsupported format") && exit(1) unless supported_formats.include?(to)
  help("No such file: #{path}") && exit(1) unless FileTest.exist?(path)
  puts convert(to, path)
end

main