@spec parse(Plug.Conn.headers(), %{required(binary()) => RemoteIp.Parser.t()}) :: [
  :inet.ip_address()
]

Parses IP addresses out of the given headers.

For each header name/value pair, the value is parsed for zero or more IP addresses by the parser corresponding to the name. If no such parser exists in the given map, we fall back to RemoteIp.Parsers.Generic.

The IPs are concatenated together into a single flat list. Note that the relative order is preserved. That is, each header produce multiple IPs that are kept in the order given by that specific header. Then, in the case of multiple headers, the concatenated list maintains the same order as the headers appeared in the original name/value list.

Due to the error-safe nature of the RemoteIp.Parser behaviour, headers that do not actually contain valid IP addresses should be safely ignored.

Examples

iex> [{"x-one", "1.2.3.4, 2.3.4.5"}, {"x-two", "3.4.5.6, 4.5.6.7"}]
...> |> RemoteIp.Headers.parse()
[{1, 2, 3, 4}, {2, 3, 4, 5}, {3, 4, 5, 6}, {4, 5, 6, 7}]

iex> [{"forwarded", "for=1.2.3.4"}, {"x-forwarded-for", "2.3.4.5"}]
...> |> RemoteIp.Headers.parse()
[{1, 2, 3, 4}, {2, 3, 4, 5}]

iex> [{"accept", "*/*"}, {"user-agent", "ua"}, {"x-real-ip", "1.2.3.4"}]
...> |> RemoteIp.Headers.parse()
[{1, 2, 3, 4}]

@spec take(Plug.Conn.headers(), [binary()]) :: Plug.Conn.headers()

Extracts all headers with the given names.

Note that Plug.Conn headers are assumed to have been normalized to lowercase, so the names you give should be in lowercase as well.

Examples

iex> [{"x-foo", "foo"}, {"x-bar", "bar"}, {"x-baz", "baz"}]
...> |> RemoteIp.Headers.take(["x-foo", "x-baz", "x-qux"])
[{"x-foo", "foo"}, {"x-baz", "baz"}]

iex> [{"x-dup", "foo"}, {"x-dup", "bar"}, {"x-dup", "baz"}]
...> |> RemoteIp.Headers.take(["x-dup"])
[{"x-dup", "foo"}, {"x-dup", "bar"}, {"x-dup", "baz"}]