class Inspec::Shell

def configure_pry # rubocop:disable Metrics/AbcSize
  # Delete any before_session, before_eval, and after_eval hooks so we can
  # replace them with our own. Pry 0.10 used to have a single method to clear
  # all hooks, but this was removed in Pry 0.11.
  [:before_session, :before_eval, :after_eval].each do |event|
    Pry.hooks.get_hooks(event).keys.map { |hook| Pry.hooks.delete_hook(event, hook) }
  end
  that = self
  # Add the help command
  Pry::Commands.block_command 'help', 'Show examples' do |resource|
    that.help(resource)
  end
  # configure pry shell prompt
  Pry.config.prompt_name = 'inspec'
  Pry.prompt = [proc { "#{readline_ignore("\e[1m\e[32m")}#{Pry.config.prompt_name}> #{readline_ignore("\e[0m")}" }]
  # Add a help menu as the default intro
  Pry.hooks.add_hook(:before_session, 'inspec_intro') do
    intro
    print_target_info
  end
  # Track the rules currently registered and what their merge count is.
  Pry.hooks.add_hook(:before_eval, 'inspec_before_eval') do
    @runner.reset
  end
  # After pry has evaluated a commanding within the binding context of a
  # test file, register all the rules it discovered.
  Pry.hooks.add_hook(:after_eval, 'inspec_after_eval') do
    @runner.load
    @runner.run_tests if !@runner.all_rules.empty?
  end
  # Don't print out control class inspection when the user uses DSL methods.
  # Instead produce a result of evaluating their control.
  Pry.config.print = proc do |_output_, value, pry|
    next if !@runner.all_rules.empty?
    pry.pager.open do |pager|
      pager.print pry.config.output_prefix
      Pry::ColorPrinter.pp(value, pager, Pry::Terminal.width! - 1)
    end
  end
end

def help(topic = nil)
  if topic.nil?
    puts <<~EOF
      Available commands:
          `[resource]` - run resource on target machine
          `help resources` - show all available resources that can be used as commands
          `help [resource]` - information about a specific resource
          `help matchers` - show information about common matchers
          `exit` - exit the InSpec shell
      You can use resources in this environment to test the target machine. For example:
          command('uname -a').stdout
          file('/proc/cpuinfo').content => "value"
      #{print_target_info}
    EOF
  elsif topic == 'resources'
    resources.sort.each do |resource|
      puts " - #{resource}"
    end
  elsif topic == 'matchers'
    print_matchers_help
  elsif !Inspec::Resource.registry[topic].nil?
    topic_info = Inspec::Resource.registry[topic]
    info = "#{mark 'Name:'} #{topic}\n\n"
    unless topic_info.desc.nil?
      info += "#{mark 'Description:'}\n\n"
      info += "#{topic_info.desc}\n\n"
    end
    unless topic_info.example.nil?
      info += "#{mark 'Example:'}\n"
      info += "#{print_example(topic_info.example)}\n\n"
    end
    info += "#{mark 'Web Reference:'}\n\n"
    info += "https://www.inspec.io/docs/reference/resources/#{topic}\n\n"
    puts info
  else
    puts "The resource #{topic} does not exist. For a list of valid resources, type: help resources"
  end
end

def initialize(runner)
  @runner = runner
end

def intro
  puts 'Welcome to the interactive InSpec Shell'
  puts "To find out how to use it, type: #{mark 'help'}"
  puts
end

def mark(x)
  "\e[1m\e[39m#{x}\e[0m"
end

def print_example(example)
  # determine min whitespace that can be removed
  min = nil
  example.lines.each do |line|
    if !line.strip.empty? # ignore empty lines
      line_whitespace = line.length - line.lstrip.length
      min = line_whitespace if min.nil? || line_whitespace < min
    end
  end
  # remove whitespace from each line
  example.gsub(/\n\s{#{min}}/, "\n")
end

def print_matchers_help
  puts <<~EOL
    Matchers are used to compare resource values to expectations. While some
    resources implement their own custom matchers, the following matchers are
    common amongst all resources:
    #{mark 'be'}
    The #{mark 'be'} matcher can be used to compare numeric values.
      its('size') { should be >= 10 }
    #{mark 'cmp'}
    The #{mark 'cmp'} matcher is like #{mark 'eq'} but less restrictive. It will try
    to fit the resource value to the expectation.
    "Protocol" likely returns a string, but cmp will ensure it's a number before
    comparing:
      its('Protocol') { should cmp 2 }
      its('Protocol') { should cmp '2' }
    "users" may return an array, but if it contains only one item, cmp will compare
    it as a string or number as needed:
      its('users') { should cmp 'root' }
    cmp is not case-sensitive:
      its('log_format') { should cmp 'raw' }
      its('log_format') { should cmp 'RAW' }
    #{mark 'eq'}
    The #{mark 'eq'} matcher tests for exact equality of two values. Value type
    (string, number, etc.) is important and must be the same. For a less-restrictive
    comparison matcher, use the #{mark 'cmp'} matcher.
      its('RSAAuthentication') { should_not eq 'no' }
    #{mark 'include'}
    The #{mark 'include'} matcher tests to see if a value is included in a list.
      its('users') { should include 'my_user' }
    #{mark 'match'}
    The #{mark 'match'} matcher can be used to test a string for a match using a
    regular expression.
      its('content') { should_not match /^MyKey:\\s+some value/ }
    For more examples, see: https://www.inspec.io/docs/reference/matchers/
  EOL
end

def print_target_info
  ctx = @runner.backend
  puts <<~EOF
    You are currently running on:
    #{Inspec::BaseCLI.detect(params: ctx.platform.params, indent: 4, color: 39)}
  EOF
end

def readline_ignore(code)
  "\001#{code}\002"
end

def resources
  Inspec::Resource.registry.keys
end

def start
  # This will hold a single evaluation binding context as opened within
  # the instance_eval context of the anonymous class that the profile
  # context creates to evaluate each individual test file. We want to
  # pretend like we are constantly appending to the same file and want
  # to capture the local variable context from inside said class.
  @ctx_binding = @runner.eval_with_virtual_profile('binding')
  configure_pry
  @ctx_binding.pry
end