(** JMAP JSON Parser Utilities

    This module provides helper functions for parsing JMAP objects using jsonm/ezjsonm.

    All parsing functions should reference specific test files for expected JSON format.
*)

(** Helper functions for working with ezjsonm values *)
module Helpers = struct
  (** Expect a JSON object and return field list *)
  let expect_object = function
    | `O fields -> fields
    | _ -> raise (Jmap_error.Parse_error "Expected JSON object")

  (** Expect a JSON array and return element list *)
  let expect_array = function
    | `A items -> items
    | _ -> raise (Jmap_error.Parse_error "Expected JSON array")

  (** Expect a JSON string *)
  let expect_string = function
    | `String s -> s
    | _ -> raise (Jmap_error.Parse_error "Expected JSON string")

  (** Expect a JSON integer *)
  let expect_int = function
    | `Float f -> int_of_float f
    | _ -> raise (Jmap_error.Parse_error "Expected JSON number")

  (** Expect a JSON boolean *)
  let expect_bool = function
    | `Bool b -> b
    | _ -> raise (Jmap_error.Parse_error "Expected JSON boolean")

  (** Find optional field in object *)
  let find_field name fields =
    List.assoc_opt name fields

  (** Require field to be present *)
  let require_field name fields =
    match find_field name fields with
    | Some v -> v
    | None -> raise (Jmap_error.Parse_error (Printf.sprintf "Missing required field: %s" name))

  (** Get optional string field *)
  let get_string_opt name fields =
    match find_field name fields with
    | Some (`String s) -> Some s
    | Some _ -> raise (Jmap_error.Parse_error (Printf.sprintf "Field %s must be a string" name))
    | None -> None

  (** Get required string field *)
  let get_string name fields =
    match require_field name fields with
    | `String s -> s
    | _ -> raise (Jmap_error.Parse_error (Printf.sprintf "Field %s must be a string" name))

  (** Get optional boolean field with default *)
  let get_bool_opt name fields default =
    match find_field name fields with
    | Some (`Bool b) -> b
    | Some _ -> raise (Jmap_error.Parse_error (Printf.sprintf "Field %s must be a boolean" name))
    | None -> default

  (** Get required boolean field *)
  let get_bool name fields =
    match require_field name fields with
    | `Bool b -> b
    | _ -> raise (Jmap_error.Parse_error (Printf.sprintf "Field %s must be a boolean" name))

  (** Get optional int field *)
  let get_int_opt name fields =
    match find_field name fields with
    | Some (`Float f) -> Some (int_of_float f)
    | Some _ -> raise (Jmap_error.Parse_error (Printf.sprintf "Field %s must be a number" name))
    | None -> None

  (** Get required int field *)
  let get_int name fields =
    match require_field name fields with
    | `Float f -> int_of_float f
    | _ -> raise (Jmap_error.Parse_error (Printf.sprintf "Field %s must be a number" name))

  (** Parse a map with string keys *)
  let parse_map parse_value = function
    | `O fields ->
        List.map (fun (k, v) -> (k, parse_value v)) fields
    | _ -> raise (Jmap_error.Parse_error "Expected JSON object for map")

  (** Parse an array *)
  let parse_array parse_elem = function
    | `A items -> List.map parse_elem items
    | `Null -> []
    | _ -> raise (Jmap_error.Parse_error "Expected JSON array")

  (** Parse optional array (null or array) *)
  let parse_array_opt parse_elem = function
    | `Null -> None
    | `A items -> Some (List.map parse_elem items)
    | _ -> raise (Jmap_error.Parse_error "Expected JSON array or null")
end

(** TODO: Implement specific parsers for each JMAP type.
    Each parser should reference its corresponding test file. *)

(** Parse JMAP Request
    Test files: test/data/core/request_*.json *)
let parse_request json =
  Jmap_request.Parser.of_json json

(** Parse JMAP Response
    Test files: test/data/core/response_*.json *)
let parse_response json =
  Jmap_response.Parser.of_json json

(** Parse JMAP Session
    Test files: test/data/core/session.json *)
let parse_session json =
  Jmap_session.Parser.of_json json