let new_version = 1L and old_version = 0L
let identifier = "2021-01-26"
let migrate_doc = "add column main_binary to build"
let rollback_doc = "remove column main_binary from build"

open Grej.Infix

let set_application_id =
  Caqti_type.unit ->. Caqti_type.unit @@
  Printf.sprintf "PRAGMA application_id = %ld" Builder_db.application_id

let alter_build =
  Caqti_type.unit ->. Caqti_type.unit @@
  "ALTER TABLE build ADD COLUMN main_binary TEXT"

let all_builds =
  Caqti_type.unit ->* Caqti_type.int64 @@
  "SELECT id FROM build"

let bin_artifact =
  Caqti_type.int64 ->* Caqti_type.(tup2 int64 string) @@
  "SELECT id, filepath FROM build_artifact WHERE build = ? AND filepath LIKE 'bin/%'"

let set_main_binary =
  Caqti_type.(tup2 int64 (option string)) ->. Caqti_type.unit @@
  "UPDATE build SET main_binary = $2 WHERE id = $1"

let migrate _datadir (module Db : Caqti_blocking.CONNECTION) =
  let open Grej.Infix in
  Grej.check_version ~application_id:0l ~user_version:0L (module Db) >>= fun () ->
  Db.exec alter_build () >>= fun () ->
  Db.collect_list all_builds () >>= fun builds ->
  Grej.list_iter_result (fun build ->
      Db.collect_list bin_artifact build >>= function
      | [_id, main_binary] ->
        Db.exec set_main_binary (build, Some main_binary)
      | [] ->
        Logs.debug (fun m -> m "No binaries for build id %Ld" build);
        Ok ()
      | binaries ->
        Logs.warn (fun m -> m "More than one binary for build id %Ld" build);
        Logs.debug (fun m -> m "binaries: [%a]" Fmt.(list ~sep:(any ";") string)
                       (List.map snd binaries));
        Ok ())
    builds >>= fun () ->
  Db.exec Builder_db.set_application_id () >>= fun () ->
  Db.exec (Grej.set_version new_version) ()

let rename_build =
  Caqti_type.unit ->. Caqti_type.unit @@
  "ALTER TABLE build RENAME TO __tmp_build"

let create_build =
  Caqti_type.unit ->. Caqti_type.unit @@
  {| CREATE TABLE build (
       id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
       uuid VARCHAR(36) NOT NULL UNIQUE,
       start_d INTEGER NOT NULL,
       start_ps INTEGER NOT NULL,
       finish_d INTEGER NOT NULL,
       finish_ps INTEGER NOT NULL,
       result_kind TINYINT NOT NULL,
       result_code INTEGER,
       result_msg TEXT,
       console BLOB NOT NULL,
       script TEXT NOT NULL,
       job INTEGER NOT NULL,

       FOREIGN KEY(job) REFERENCES job(id)
     )
  |}

let rollback_data =
  Caqti_type.unit ->. Caqti_type.unit @@
  {| INSERT INTO build
     SELECT id, uuid, start_d, start_ps, finish_d, finish_ps,
       result_kind, result_code, result_msg, console, script, job
     FROM __tmp_build
  |}

let rollback _datadir (module Db : Caqti_blocking.CONNECTION) =
  let open Grej.Infix in
  Grej.check_version ~user_version:new_version (module Db) >>= fun () ->
  Db.exec rename_build () >>= fun () ->
  Db.exec create_build () >>= fun () ->
  Db.exec rollback_data () >>= fun () ->
  Db.exec (Grej.set_version old_version) ()