class Shoulda::Matchers::ActiveRecord::QueryTheDatabaseMatcher

def failure_message_for_should
  if @options.key?(:expected_query_count)
    "Expected ##{@options[:method_name]} to cause #{@options[:expected_query_count]} database queries but it actually caused #{@queries.length} queries:" + friendly_queries
  else
    "Expected ##{@options[:method_name]} to query the database but it actually caused #{@queries.length} queries:" + friendly_queries
  end
end

def failure_message_for_should_not
  if @options[:expected_query_count]
    "Expected ##{@options[:method_name]} to not cause #{@options[:expected_query_count]} database queries but it actually caused #{@queries.length} queries:" + friendly_queries
  else
    "Expected ##{@options[:method_name]} to not query the database but it actually caused #{@queries.length} queries:" + friendly_queries
  end
end

def filter_query(query)
  query[:name] == 'SCHEMA' || looks_like_schema?(query[:sql])
end

def friendly_queries
  @queries.map do |query|
    "\n  (#{query[:name]}) #{query[:sql]}"
  end.join
end

def initialize(times)
  ActiveSupport::Deprecation.warn 'The query_the_database matcher is deprecated and will be removed in 2.0'
  @queries = []
  @options = {}
  if times.respond_to?(:count)
    @options[:expected_query_count] = times.count
  else
    @options[:expected_query_count] = times
  end
end

def looks_like_schema?(sql)
  schema_terms.any? { |term| sql.include?(term) }
end

def matches?(subject)
  subscriber = ActiveSupport::Notifications.subscribe('sql.active_record') do |name, started, finished, id, payload|
    @queries << payload unless filter_query(payload)
  end
  if @options[:method_arguments]
    subject.send(@options[:method_name], *@options[:method_arguments])
  else
    subject.send(@options[:method_name])
  end
  ActiveSupport::Notifications.unsubscribe(subscriber)
  if @options[:expected_count_is_maximum]
    @queries.length <= @options[:expected_query_count]
  elsif @options[:expected_query_count].present?
    @queries.length == @options[:expected_query_count]
  else
    @queries.length > 0
  end
end

def or_less
  @options[:expected_count_is_maximum] = true
  self
end

def schema_terms
  ['FROM sqlite_master', 'PRAGMA', 'SHOW TABLES', 'SHOW KEYS FROM', 'SHOW FIELDS FROM', 'begin transaction', 'commit transaction']
end

def when_calling(method_name)
  @options[:method_name] = method_name
  self
end

def with(*method_arguments)
  @options[:method_arguments] = method_arguments
  self
end