open Printf
open Nethttp_client
open Nethtml
open Netencoding;;


Nettls_gnutls.init();;

let extract_string_value document =
  match document with
  | Data(s) -> Some s
  | _ -> None


let find_string_value = function
  | Some s -> true
  | None -> false


let rec get_title_element_from_list doc_list =

  try
    List.find find_string_value (List.map get_title_element doc_list)
  with
    Not_found -> None

and get_title_element document =

  match document with
  | Element("title", args, sub) ->
      (
        let title_candidates = List.map extract_string_value sub in
        try
          List.find find_string_value title_candidates
        with
          Not_found -> None
      )
  | Element(e, args, sub) -> get_title_element_from_list sub
  | Data(s) -> None


let rec print_document document =
  match document with
  | Element(e, args, sub) ->
      printf "Element: %s\n" e;
      List.iter print_document sub
  | Data(s) -> printf "Data: %s\n" s


let get_http_document body_str =
  let ch = new Netchannels.input_string body_str in
  Nethtml.parse ch

let decode_esc_char str =
  Html.decode ~in_enc:`Enc_utf8
              ~out_enc:`Enc_utf8
              ~entity_base:`Html () str

let get_http_title body =
  let ch = new Netchannels.input_string body in
  let doc = Nethtml.parse ch in
  let title = get_title_element_from_list doc in
  match title with
  | Some s -> Some (decode_esc_char s)
  | None -> None


(* TODO: Log errors *)
let get_body url =
  try Convenience.http_get url with
  | Http_error e -> "http error /o\\"
  | Failure f -> "http fail lol"