class ActionDispatch::ContentSecurityPolicy

def apply_mapping(source)
  MAPPINGS.fetch(source) do
    raise ArgumentError, "Unknown content security policy source mapping: #{source.inspect}"
  end
end

def apply_mappings(sources)
  sources.map do |source|
    case source
    when Symbol
      apply_mapping(source)
    when String, Proc
      source
    else
      raise ArgumentError, "Invalid content security policy source: #{source.inspect}"
    end
  end
end

def block_all_mixed_content(enabled = true)
  if enabled
    @directives["block-all-mixed-content"] = true
  else
    @directives.delete("block-all-mixed-content")
  end
end

def build(context = nil, nonce = nil)
  build_directives(context, nonce).compact.join("; ")
end

def build_directive(sources, context)
  sources.map { |source| resolve_source(source, context) }
end

def build_directives(context, nonce)
  @directives.map do |directive, sources|
    if sources.is_a?(Array)
      if nonce && nonce_directive?(directive)
        "#{directive} #{build_directive(sources, context).join(' ')} 'nonce-#{nonce}'"
      else
        "#{directive} #{build_directive(sources, context).join(' ')}"
      end
    elsif sources
      directive
    else
      nil
    end
  end
end

def initialize
  @directives = {}
  yield self if block_given?
end

def initialize_copy(other)
  @directives = other.directives.deep_dup
end

def nonce_directive?(directive)
  NONCE_DIRECTIVES.include?(directive)
end

def plugin_types(*types)
  if types.first
    @directives["plugin-types"] = types
  else
    @directives.delete("plugin-types")
  end
end

def report_uri(uri)
  @directives["report-uri"] = [uri]
end

def require_sri_for(*types)
  if types.first
    @directives["require-sri-for"] = types
  else
    @directives.delete("require-sri-for")
  end
end

def resolve_source(source, context)
  case source
  when String
    source
  when Symbol
    source.to_s
  when Proc
    if context.nil?
      raise RuntimeError, "Missing context for the dynamic content security policy source: #{source.inspect}"
    else
      resolved = context.instance_exec(&source)
      resolved.is_a?(Symbol) ? apply_mapping(resolved) : resolved
    end
  else
    raise RuntimeError, "Unexpected content security policy source: #{source.inspect}"
  end
end

def sandbox(*values)
  if values.empty?
    @directives["sandbox"] = true
  elsif values.first
    @directives["sandbox"] = values
  else
    @directives.delete("sandbox")
  end
end

def upgrade_insecure_requests(enabled = true)
  if enabled
    @directives["upgrade-insecure-requests"] = true
  else
    @directives.delete("upgrade-insecure-requests")
  end
end