class Rack::QueryParser

# File lib/rack/query_parser.rb, line 36
def self.make_default(param_depth_limit, **options)
  new(Params, param_depth_limit, **options)
end

# File lib/rack/query_parser.rb, line 62
def initialize(params_class, param_depth_limit, bytesize_limit: BYTESIZE_LIMIT, params_limit: PARAMS_LIMIT)
  @params_class = params_class
  @param_depth_limit = param_depth_limit
  @bytesize_limit = bytesize_limit
  @params_limit = params_limit
end

# File lib/rack/query_parser.rb, line 196
def make_params
  @params_class.new
end

# File lib/rack/query_parser.rb, line 200
def new_depth_limit(param_depth_limit)
  self.class.new @params_class, param_depth_limit
end

# File lib/rack/query_parser.rb, line 124
def normalize_params(params, name, v, _depth=nil)
  _normalize_params(params, name, v, 0)
end

# File lib/rack/query_parser.rb, line 109
def parse_nested_query(qs, separator = nil)
  params = make_params

  each_query_pair(qs, separator) do |k, v|
    _normalize_params(params, k, v, 0)
  end

  return params.to_h
end

# File lib/rack/query_parser.rb, line 73
def parse_query(qs, separator = nil, &unescaper)
  params = make_params

  each_query_pair(qs, separator, unescaper) do |k, v|
    if cur = params[k]
      if cur.class == Array
        params[k] << v
      else
        params[k] = [cur, v]
      end
    else
      params[k] = v
    end
  end

  return params.to_h
end

# File lib/rack/query_parser.rb, line 94
def parse_query_pairs(qs, separator = nil)
  pairs = []

  each_query_pair(qs, separator) do |k, v|
    pairs << [k, v]
  end

  pairs
end

# File lib/rack/query_parser.rb, line 128
        def _normalize_params(params, name, v, depth)
  raise ParamsTooDeepError if depth >= param_depth_limit

  if !name
    # nil name, treat same as empty string (required by tests)
    k = after = ''
  elsif depth == 0
    # Start of parsing, don't treat [] or [ at start of string specially
    if start = name.index('[', 1)
      # Start of parameter nesting, use part before brackets as key
      k = name[0, start]
      after = name[start, name.length]
    else
      # Plain parameter with no nesting
      k = name
      after = ''
    end
  elsif name.start_with?('[]')
    # Array nesting
    k = '[]'
    after = name[2, name.length]
  elsif name.start_with?('[') && (start = name.index(']', 1))
    # Hash nesting, use the part inside brackets as the key
    k = name[1, start-1]
    after = name[start+1, name.length]
  else
    # Probably malformed input, nested but not starting with [
    # treat full name as key for backwards compatibility.
    k = name
    after = ''
  end

  return if k.empty?

  if after == ''
    if k == '[]' && depth != 0
      return [v]
    else
      params[k] = v
    end
  elsif after == "["
    params[name] = v
  elsif after == "[]"
    params[k] ||= []
    raise ParameterTypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    params[k] << v
  elsif after.start_with?('[]')
    # Recognize x[][y] (hash inside array) parameters
    unless after[2] == '[' && after.end_with?(']') && (child_key = after[3, after.length-4]) && !child_key.empty? && !child_key.index('[') && !child_key.index(']')
      # Handle other nested array parameters
      child_key = after[2, after.length]
    end
    params[k] ||= []
    raise ParameterTypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    if params_hash_type?(params[k].last) && !params_hash_has_key?(params[k].last, child_key)
      _normalize_params(params[k].last, child_key, v, depth + 1)
    else
      params[k] << _normalize_params(make_params, child_key, v, depth + 1)
    end
  else
    params[k] ||= make_params
    raise ParameterTypeError, "expected Hash (got #{params[k].class.name}) for param `#{k}'" unless params_hash_type?(params[k])
    params[k] = _normalize_params(params[k], after, v, depth + 1)
  end

  params
end

# File lib/rack/query_parser.rb, line 222
def each_query_pair(qs, separator, unescaper = nil)
  return if !qs || qs.empty?

  if qs.bytesize > @bytesize_limit
    raise QueryLimitError, "total query size exceeds limit (#{@bytesize_limit})"
  end

  pairs = qs.split(separator ? (COMMON_SEP[separator] || /[#{separator}] */n) : DEFAULT_SEP, @params_limit + 1)

  if pairs.size > @params_limit
    param_count = pairs.size + pairs.last.count(separator || "&")
    raise QueryLimitError, "total number of query parameters (#{param_count}) exceeds limit (#{@params_limit})"
  end

  if unescaper
    pairs.each do |p|
      next if p.empty?
      k, v = p.split('=', 2).map!(&unescaper)
      yield k, v
    end
  else
    pairs.each do |p|
      next if p.empty?
      k, v = p.split('=', 2).map! { |s| unescape(s) }
      yield k, v
    end
  end
rescue ArgumentError => e
  raise InvalidParameterError, e.message, e.backtrace
end

# File lib/rack/query_parser.rb, line 210
def params_hash_has_key?(hash, key)
  return false if /\[\]/.match?(key)

  key.split(/[\[\]]+/).inject(hash) do |h, part|
    next h if part == ''
    return false unless params_hash_type?(h) && h.key?(part)
    h[part]
  end

  true
end

# File lib/rack/query_parser.rb, line 206
def params_hash_type?(obj)
  obj.kind_of?(@params_class)
end

# File lib/rack/query_parser.rb, line 253
def unescape(string, encoding = Encoding::UTF_8)
  URI.decode_www_form_component(string, encoding)
end