Source file musicProperty.ml

(*****************************************************************************)
(*                                                                           *)
(*  Copyright (C) 2026 Yves Ndiaye                                           *)
(*                                                                           *)
(* This Source Code Form is subject to the terms of the Mozilla Public       *)
(* License, v. 2.0. If a copy of the MPL was not distributed with this       *)
(* file, You can obtain one at https://mozilla.org/MPL/2.0/.                 *)
(*                                                                           *)
(*****************************************************************************)

type t = { music_id : Int64.t; key : string; value : string }
[@@deriving yojson]

module Column = struct
  let music_id = "music_id"
  let key = "key"
  let value = "value"
end

let init music_id key value = { music_id; key; value }
let table_name = "music_properties"
let foreign_music_id = Column.music_id
let column_key = Column.key
let column_value = Column.value
let p_music_id = Printf.sprintf "%s.%s" table_name foreign_music_id
let p_key = Printf.sprintf "%s.%s" table_name column_key
let p_value = Printf.sprintf "%s.%s" table_name column_value

let sql_table =
  Printf.sprintf
    {| 
CREATE TABLE IF NOT EXISTS %s (
    %s INTEGER NOT NULL,
    %s TEXT NOT NULL,
    %s TEXT NOT NULL,
    FOREIGN KEY (%s) REFERENCES %s (%s)
      ON UPDATE CASCADE
      ON DELETE CASCADE
);|}
    table_name foreign_music_id column_key column_value foreign_music_id
    MusicFile.table_name MusicFile.primary_key

let columns statement offset =
  let module D = Sqlite3.Data in
  let music_id = Sqlite3.column_int64 statement offset in
  let key = Sqlite3.column_text statement (offset + 1) in
  let value = Sqlite3.column_text statement (offset + 2) in
  ({ music_id; key; value }, offset + 3)

let columns_data data offset =
  let music_id = Sqlite3.Data.to_int64_exn data.(offset) in
  let key = Sqlite3.Data.to_string_exn data.(offset + 1) in
  let value = Sqlite3.Data.to_string_exn data.(offset + 2) in
  ({ music_id; key; value }, offset + 3)

let update_key database music_id key old_value new_value =
  let ( let* ) rc f =
    match rc with
    | Sqlite3.Rc.OK | Sqlite3.Rc.DONE ->
        f ()
    | rc ->
        let message = Sqlite3.errmsg database in
        Error (rc, message)
  in
  let statement =
    Printf.sprintf
      "UPDATE %s SET %s = ?4 WHERE %s = ?1 AND %s = ?2 AND %s = ?3;" table_name
      column_value foreign_music_id column_key column_value
  in
  let statement = Sqlite3.prepare database statement in
  let* () = Sqlite3.bind_int64 statement 1 music_id in
  let* () = Sqlite3.bind_text statement 2 key in
  let* () = Sqlite3.bind_text statement 3 old_value in
  let* () = Sqlite3.bind_text statement 4 new_value in
  let* () = Sqlite3.step statement in
  let* () = Sqlite3.finalize statement in
  Ok ()

let remove_key database t =
  let ( let* ) rc f =
    match rc with
    | Sqlite3.Rc.OK | Sqlite3.Rc.DONE ->
        f ()
    | rc ->
        let message = Sqlite3.errmsg database in
        Error (rc, message)
  in
  let { music_id; key; value = _ } = t in
  let statement =
    Printf.sprintf "DELETE FROM %s WHERE %s = ? AND key = ?;" table_name
      foreign_music_id
  in
  let statement = Sqlite3.prepare database statement in
  let* () = Sqlite3.bind_int64 statement 1 music_id in
  let* () = Sqlite3.bind_text statement 2 key in
  let* () = Sqlite3.step statement in
  let* () = Sqlite3.finalize statement in
  Ok ()

let insert database t =
  let ( let* ) rc f =
    match rc with
    | Sqlite3.Rc.OK | Sqlite3.Rc.DONE | Sqlite3.Rc.CONSTRAINT ->
        f ()
    | rc ->
        let message = Sqlite3.errmsg database in
        Error (rc, message)
  in
  let statement =
    Printf.sprintf "INSERT INTO %s (%s, %s, %s) VALUES (?, ?, ?);" table_name
      foreign_music_id column_key column_value
  in
  let statement = Sqlite3.prepare database statement in

  let* () = Sqlite3.bind_int64 statement 1 t.music_id in
  let* () = Sqlite3.bind_text statement 2 t.key in
  let* () = Sqlite3.bind_text statement 3 t.value in
  let* () = Sqlite3.step statement in
  let* () = Sqlite3.finalize statement in
  Ok ()

let properties database music_id =
  let module P = SkhcMetadata.Metadata.Properties in
  let module V = SkhcMetadata.Metadata.Values in
  let ( let* ) rc f =
    match rc with
    | Sqlite3.Rc.OK | Sqlite3.Rc.DONE ->
        f ()
    | rc ->
        let message = Sqlite3.errmsg database in
        Error (rc, message)
  in
  let statement =
    Printf.sprintf "SELECT * from %s WHERE %s = ?;" table_name foreign_music_id
  in
  let statement = Sqlite3.prepare database statement in
  let* () = Sqlite3.bind_int64 statement 1 music_id in
  let _, properties =
    Sqlite3.fold ~init:P.empty
      ~f:(fun properties data ->
        let { key; value; music_id = _ }, _ = columns_data data 0 in
        P.update key
          (function
            | None -> Some (V.singleton value) | Some v -> Some (V.add value v)
            )
          properties
      )
      statement
  in
  Ok properties

let music_id s = s.music_id
let key s = s.key
let value s = s.value

(* Test *)
let equal : t -> t -> bool = ( = )
let compare : t -> t -> int = Stdlib.compare