open Syntax
open Db

type t =
  { user_id : string
  ; nick : string
  ; password : string
  ; email : string
  ; bio : string
  ; avatar : string
  ; metadata : (string * string) list
  }

module Q = struct
  let create_user_table =
    Caqti_request.exec Caqti_type.unit
      "CREATE TABLE IF NOT EXISTS user (user_id TEXT, nick TEXT, password \
       TEXT, email TEXT, bio TEXT, avatar BLOB, PRIMARY KEY(user_id));"

  let create_banished_table =
    Caqti_request.exec Caqti_type.unit
      "CREATE TABLE IF NOT EXISTS banished (nick TEXT, email TEXT);"

  let create_metadata_table =
    Caqti_request.exec Caqti_type.unit
      "CREATE TABLE IF NOT EXISTS user_metadata (user_id TEXT, metadata TEXT, \
       FOREIGN KEY(user_id) REFERENCES user(user_id) ON DELETE CASCADE);"

  let get_metadata =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT metadata FROM user_metadata WHERE user_id=?;"

  let upload_metadata =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "INSERT INTO user_metadata VALUES (?, ?);"

  let delete_metadata =
    Caqti_request.exec Caqti_type.string
      "DELETE FROM user_metadata WHERE user_id=?;"

  let get_user_id_from_nick =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT user_id FROM user WHERE nick=?;"

  let get_user_id_from_email =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT user_id FROM user WHERE email=?;"

  let get_password =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT password FROM user WHERE user_id=?;"

  let is_already_user =
    Caqti_request.find
      Caqti_type.(tup2 string string)
      Caqti_type.int
      "SELECT EXISTS(SELECT 1 FROM user WHERE nick=? OR email=?);"

  let upload_user =
    Caqti_request.exec
      Caqti_type.(
        tup4 string string string Caqti_type.(tup3 string string string))
      "INSERT INTO user VALUES (?, ?, ?, ?, ?, ?);"

  let list_nicks =
    Caqti_request.collect Caqti_type.unit Caqti_type.string
      "SELECT nick FROM user;"

  let get_user =
    Caqti_request.find Caqti_type.string
      (* there is no "tup6" *)
      Caqti_type.(
        tup4 string string string Caqti_type.(tup3 string string string))
      "SELECT * FROM user WHERE user_id=?;"

  let update_bio =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "UPDATE user SET bio=? WHERE user_id=?;"

  let update_nick =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "UPDATE user SET nick=? WHERE user_id=?;"

  let update_email =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "UPDATE user SET email=? WHERE user_id=?;"

  let update_password =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "UPDATE user SET password=? WHERE user_id=?;"

  let get_nick =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT nick FROM user WHERE user_id=?;"

  let get_bio =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT bio FROM user WHERE user_id=?;"

  let get_email =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT email FROM user WHERE user_id=?;"

  let get_avatar =
    Caqti_request.find Caqti_type.string Caqti_type.string
      "SELECT avatar FROM user WHERE user_id=?;"

  let upload_avatar =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "UPDATE user SET avatar=? WHERE user_id=?;"

  let delete_user =
    Caqti_request.exec Caqti_type.string "DELETE FROM user WHERE user_id=?;"

  let upload_banished =
    Caqti_request.exec
      Caqti_type.(tup2 string string)
      "INSERT INTO banished VALUES (?,?);"

  let get_banished =
    Caqti_request.find
      Caqti_type.(tup2 string string)
      Caqti_type.(tup2 string string)
      "SELECT * FROM banished WHERE nick=? OR email=?;"
end

let () =
  let tables =
    [| Q.create_user_table; Q.create_banished_table; Q.create_metadata_table |]
  in
  if
    Array.exists Result.is_error
      (Array.map (fun query -> Db.exec query ()) tables)
  then Dream.error (fun log -> log "can't create user tables")

let exist_nick nick = Result.is_ok (Db.find Q.get_user_id_from_nick nick)

let exist_email email = Result.is_ok (Db.find Q.get_user_id_from_email email)

let get_metadata nick =
  let^ metadata = Db.find Q.get_metadata nick in
  let metadata : (string * string) list = Marshal.from_string metadata 0 in
  Ok metadata

let get_user_id_from_nick nick =
  let^ user_id = Db.find Q.get_user_id_from_nick nick in
  Ok user_id

let get_user user_id =
  let^? user_id, nick, password, (email, bio, avatar) =
    Db.find_opt Q.get_user user_id
  in
  let* metadata = get_metadata user_id in
  Ok { user_id; nick; password; email; bio; avatar; metadata }

let is_banished login = Result.is_ok (Db.find Q.get_banished (login, login))

let get_nick user_id =
  let^ nick = Db.find Q.get_nick user_id in
  Ok nick

let login ~login ~password request =
  let try_password user_id =
    let^ good_password = Db.find Q.get_password user_id in
    if Bcrypt.verify password (Bcrypt.hash_of_string good_password) then
      let _unit_lwt = Dream.invalidate_session request in
      let _unit_lwt = Dream.put_session "user_id" user_id request in
      let* nick = get_nick user_id in
      let _unit_lwt = Dream.put_session "nick" nick request in
      Ok ()
    else if is_banished login then Error "YOU ARE BANISHED"
    else Error "wrong password"
  in

  let^ id_from_nick = Db.find_opt Q.get_user_id_from_nick login in
  let^ id_from_email = Db.find_opt Q.get_user_id_from_email login in
  let user_id_list = List.filter_map Fun.id [ id_from_nick; id_from_email ] in
  match user_id_list with
  | [] -> Error "Invalid login"
  | [ id ] -> try_password id
  | [ id_1; id_2 ] -> (
    match try_password id_1 with
    | Ok () -> Ok ()
    | Error _e -> try_password id_2 )
  | _to_many_ids -> assert false

let valid_nick nick =
  String.length nick < 64
  && String.length nick > 0
  && Dream.html_escape nick = nick

let valid_password password =
  String.length password < 128 && String.length password > 0

let valid_email email = Result.is_ok @@ Emile.of_string email

let register ~email ~nick ~password =
  let valid = valid_nick nick && valid_email email && valid_password password in

  let password = Bcrypt.hash password in
  let password = Bcrypt.string_of_hash password in

  if not valid then Error "Something is wrong"
  else
    let^ nb = Db.find Q.is_already_user (nick, email) in
    if nb = 0 then
      let user_id = Uuidm.to_string (Uuidm.v4_gen random_state ()) in
      let^ () =
        Db.exec Q.upload_user (user_id, nick, password, (email, "", ""))
      in
      let^ () = Db.exec Q.upload_metadata (user_id, Marshal.to_string [] []) in
      Ok ()
    else Error "nick or email already exists"

let list () =
  let^ users = Db.collect_list Q.list_nicks () in
  Ok
    (Format.asprintf "<ul>%a</ul>"
       (Format.pp_print_list (fun fmt -> function
          | s -> Format.fprintf fmt {|<li><a href="/user/%s">%s</a></li>|} s s )
       )
       users )

let profile request =
  match Dream.session "nick" request with
  | None -> "not logged in"
  | Some nick -> Format.sprintf "Hello %s !" nick

let update_bio bio user_id =
  let bio = Dream.html_escape bio in
  let valid = String.length bio < 10000 in
  if not valid then Error "Not biologic"
  else
    let^ () = Db.exec Q.update_bio (bio, user_id) in
    Ok ()

let get_bio user_id =
  let^ bio = Db.find Q.get_bio user_id in
  Ok bio

let get_email user_id =
  let^ email = Db.find Q.get_email user_id in
  Ok email

let get_avatar user_id =
  let^ avatar = Db.find Q.get_avatar user_id in
  if String.length avatar = 0 then Ok None else Ok (Some avatar)

let upload_avatar files user_id =
  match files with
  | [] -> Error "No file provided"
  | [ (name_opt, content) ] ->
    let* _name, _alt, content = clean_image (name_opt, "avatar", content) in
    let^ () = Db.exec Q.upload_avatar (content, user_id) in
    Ok ()
  | _files -> Error "More than one file provided"

let is_admin user_id =
  match get_nick user_id with
  | Error _e -> false
  | Ok nick -> List.mem nick App.admins

let banish user_id =
  let* nick = get_nick user_id in
  let* email = get_email user_id in
  let^ () = Db.exec Q.delete_user user_id in
  let^ () = Db.exec Q.upload_banished (nick, email) in
  Ok ()

let delete_user user_id =
  let^ () = Db.exec Q.delete_user user_id in
  Ok ()

let update_nick nick user_id =
  if valid_nick nick then
    if not (exist_nick nick) then
      let^ () = Db.exec Q.update_nick (nick, user_id) in
      Ok ()
    else Error "nick already taken"
  else Error "invalid nick"

let update_email email user_id =
  if valid_email email then
    if not (exist_email email) then
      let^ () = Db.exec Q.update_email (email, user_id) in
      Ok ()
    else Error "email already taken"
  else Error "invalid email"

let update_password password user_id =
  if valid_password password then
    let password = Bcrypt.hash password in
    let password = Bcrypt.string_of_hash password in
    let^ () = Db.exec Q.update_password (password, user_id) in
    Ok ()
  else Error "invalid password"

let update_metadata count label content user_id =
  let label = Dream.html_escape label in
  let content = Dream.html_escape content in
  if String.length label > 200 || String.length content > 400 then
    Error "label or content is too long"
  else
    let* metadata = get_metadata user_id in
    let length = List.length metadata in
    if count < 0 || count > length then Error "invalid count"
    else
      let n = max (count + 1) @@ length in
      let metadata = Array.of_list metadata in
      let metadata =
        List.init n (fun i ->
            if i = count then (label, content) else metadata.(i) )
      in
      let metadata =
        List.filter (fun (l, c) -> not (l = "" && c = "")) metadata
      in
      if List.length metadata >= 42 then Error "to many metadata"
      else
        let s = Marshal.to_string metadata [] in
        let^ () = Db.exec Q.delete_metadata user_id in
        let^ () = Db.exec Q.upload_metadata (user_id, s) in
        Ok ()

let pp_metadata fmt (label, content) =
  Format.fprintf fmt
    {|
<div class="row">
    <div class="col metadata-label">%s</div>
    <div class="col metadata-content">%s</div>
</div>
    |}
    label content

let pp_metadata_form fmt is_last count (label, content) request =
  let form_tag = Dream.form_tag ~action:"/profile" request in
  let button_text = if is_last then "Add" else "Save" in
  Format.fprintf fmt
    {|
<div class="row">
    %s
        <input name="label" class="metadata-label" value="%s"/>
        <input name="content" class="metadata-content" value="%s"/>
    <button name="count" value="%d" type="submit" class="btn btn-primary">%s</button>
    </form>
</div>
    |}
    form_tag label content count button_text

let pp_metadata_table fmt metadata =
  Format.fprintf fmt
    {|
<div class="metadata-table">
    %a
</div>
|}
    (Format.pp_print_list ~pp_sep:Format.pp_print_space pp_metadata)
    metadata

let pp_metadata_table_form fmt metadata request =
  let l = List.mapi (fun i e -> (i, e)) metadata in
  Format.fprintf fmt
    {|
<div class="metadata-form-table">
    %a
    %a
</div>
|}
    (Format.pp_print_list ~pp_sep:Format.pp_print_space
       (fun fmt (count, metadata) ->
         pp_metadata_form fmt false count metadata request ) )
    l
    (fun fmt (count, metadata) ->
      pp_metadata_form fmt true count metadata request )
    (List.length l, ("", ""))

let public_profile user_id =
  let* user = get_user user_id in
  let user_info =
    Format.asprintf
      {|
    <h1>%s</h1>
    <br />
    <div class="row">
      <div class="col-md-6">
        <blockquote>%s</blockquote>
      </div>
      <div class="col-md-6">
        <img src="/user/%s/avatar" class="img-thumbnail" alt="Your avatar picture">
      </div>
      <a href="/discuss/%s">Speak to me !</a>
      <div class="col-md-6">
        %a
      </div>
    </div>
|}
      user.nick user.bio user.nick user_id pp_metadata_table user.metadata
  in
  Ok user_info