(** Implementation of JMAP SearchSnippet objects (RFC 8621 Section 5) *)

type t = {
  email_id : Jmap.Id.t;
  subject : string option;
  preview : string option;
}

(** {1 SearchSnippet Construction} *)

let create ~email_id ?subject ?preview () = {
  email_id;
  subject;
  preview;
}

(** {1 Field Access} *)

let email_id t = t.email_id
let subject t = t.subject  
let preview t = t.preview

(** {1 JSON Serialization} *)

let to_json t =
  let json_fields = [
    ("emailId", `String (Jmap.Id.to_string t.email_id));
  ] in
  let json_fields = match t.subject with
    | Some s -> ("subject", `String s) :: json_fields
    | None -> ("subject", `Null) :: json_fields
  in
  let json_fields = match t.preview with
    | Some p -> ("preview", `String p) :: json_fields
    | None -> ("preview", `Null) :: json_fields
  in
  `Assoc (List.rev json_fields)

let of_json json =
  try
    let open Yojson.Safe.Util in
    let email_id_str = json |> member "emailId" |> to_string in
    let email_id = match Jmap.Id.of_string email_id_str with
      | Ok id -> id
      | Error _ -> failwith ("Invalid emailId: " ^ email_id_str)
    in
    let subject = json |> member "subject" |> to_string_option in
    let preview = json |> member "preview" |> to_string_option in
    Ok (create ~email_id ?subject ?preview ())
  with
  | exn -> Error ("Failed to parse SearchSnippet: " ^ Printexc.to_string exn)



(** {1 SearchSnippet/get Method Support} *)

module Get_args = struct
  type t = {
    account_id : string;
    filter : Yojson.Safe.t;  (* Use raw JSON for now since Filter module doesn't have of_json *)
    email_ids : Jmap.Id.t list;
  }
  
  let create ~account_id ~filter ~email_ids () = {
    account_id;
    filter;
    email_ids;
  }
  
  let account_id t = t.account_id
  let filter t = t.filter
  let email_ids t = t.email_ids
  
  let to_json t =
    `Assoc [
      ("accountId", `String t.account_id);
      ("filter", t.filter);
      ("emailIds", `List (List.map (fun id -> `String (Jmap.Id.to_string id)) t.email_ids));
    ]
  
  let of_json json =
    try
      let open Yojson.Safe.Util in
      let account_id = json |> member "accountId" |> to_string in
      let filter = json |> member "filter" in
      let email_ids_json = json |> member "emailIds" |> to_list in
      let email_ids = List.map (fun id_json ->
        let id_str = to_string id_json in
        match Jmap.Id.of_string id_str with
        | Ok id -> id
        | Error _ -> failwith ("Invalid email ID: " ^ id_str)
      ) email_ids_json in
      Ok (create ~account_id ~filter ~email_ids ())
    with
    | exn -> Error ("Failed to parse SearchSnippet/get args: " ^ Printexc.to_string exn)
  
  
  end

module Get_response = struct
  type snippet = t  (* Reference to the outer SearchSnippet.t *)
  
  type response = {
    account_id : string;
    list : snippet list;
    not_found : Jmap.Id.t list;
  }
  
  let create ~account_id ~list ?(not_found=[]) () = {
    account_id;
    list;
    not_found;
  }
  
  let account_id t = t.account_id
  let list t = t.list
  let not_found t = t.not_found
  
  let to_json t =
    `Assoc [
      ("accountId", `String t.account_id);
      ("list", `List (List.map to_json t.list));
      ("notFound", match t.not_found with
        | [] -> `Null
        | ids -> `List (List.map (fun id -> `String (Jmap.Id.to_string id)) ids));
    ]
  
  let of_json json =
    try
      let open Yojson.Safe.Util in
      let account_id = json |> member "accountId" |> to_string in
      let list_json = json |> member "list" |> to_list in
      let list = List.map (fun snippet_json ->
        match of_json snippet_json with
        | Ok snippet -> snippet
        | Error err -> failwith err
      ) list_json in
      let not_found = match json |> member "notFound" with
        | `Null -> []
        | `List ids -> List.map (fun id_json ->
            let id_str = to_string id_json in
            match Jmap.Id.of_string id_str with
            | Ok id -> id
            | Error _ -> failwith ("Invalid not found ID: " ^ id_str)
          ) ids
        | _ -> failwith "notFound must be null or array"
      in
      Ok (create ~account_id ~list ~not_found ())
    with
    | exn -> Error ("Failed to parse SearchSnippet/get response: " ^ Printexc.to_string exn)
  
  
  end