class RuboCop::Cop::Performance::Detect


[].reverse.detect { |item| true }
[].detect { |item| true }
# good
[].filter { |item| true }[-1]
[].filter { |item| true }[0]
[].filter { |item| true }.last
[].filter { |item| true }.first
[].find_all { |item| true }.last
[].find_all { |item| true }.first
[].select { |item| true }.last
[].select { |item| true }.first
# bad
@example
if the receiver is a ‘Hash`, it may report a false positive.
`Array` or equivalent, but can’t reliably detect it. For example,
This cop is unsafe because it assumes that the receiver is an
@safety
`detect` instead.
chained to ‘select`, `find_all` or `filter` and change them to use
Identifies usages of `first`, `last`, `[0]` or `[-1]`

def accept_first_call?(receiver, body) 

def accept_first_call?(receiver, body)
  caller, _first_method, args = *receiver
  # check that we have usual block or block pass
  return true if body.nil? && (args.nil? || !args.block_pass_type?)
  lazy?(caller)
end

def autocorrect(corrector, node, replacement) 

def autocorrect(corrector, node, replacement)
  receiver, _first_method = *node
  first_range = receiver.source_range.end.join(node.loc.selector)
  receiver, _args, _body = *receiver if receiver.block_type?
  corrector.remove(first_range)
  corrector.replace(receiver.loc.selector, replacement)
end

def lazy?(node) 

def lazy?(node)
  return false unless node
  receiver, method, _args = *node
  method == :lazy && !receiver.nil?
end

def message_for_method(method, index) 

def message_for_method(method, index)
  case method
  when :[]
    index == -1 ? INDEX_REVERSE_MSG : INDEX_MSG
  when :last
    REVERSE_MSG
  else
    MSG
  end
end

def on_send(node) 

def on_send(node)
  detect_candidate?(node) do |receiver, second_method, args|
    if second_method == :[]
      index = args
      args = {}
    end
    return unless args.empty?
    return unless receiver
    receiver, _args, body = *receiver if receiver.block_type?
    return if accept_first_call?(receiver, body)
    register_offense(node, receiver, second_method, index)
  end
end

def preferred_method 

def preferred_method
  config.for_cop('Style/CollectionMethods')['PreferredMethods']['detect'] || 'detect'
end

def register_offense(node, receiver, second_method, index) 

def register_offense(node, receiver, second_method, index)
  _caller, first_method, _args = *receiver
  range = receiver.loc.selector.join(node.loc.selector)
  message = message_for_method(second_method, index)
  formatted_message = format(message, prefer: preferred_method,
                                      first_method: first_method,
                                      second_method: second_method,
                                      index: index)
  add_offense(range, message: formatted_message) do |corrector|
    autocorrect(corrector, node, replacement(second_method, index))
  end
end

def replacement(method, index) 

def replacement(method, index)
  if method == :last || (method == :[] && index == -1)
    "reverse.#{preferred_method}"
  else
    preferred_method
  end
end