let new_version = 15L and old_version = 14L
and identifier = "2021-11-05"
and migrate_doc = "add platform to build"
and rollback_doc = "remove platform from build"

open Grej.Syntax

let new_build =
  Caqti_request.exec
    Caqti_type.unit
    {| CREATE TABLE new_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_code INTEGER NOT NULL,
         result_msg TEXT,
         console TEXT NOT NULL,
         script TEXT NOT NULL,
         platform TEXT NOT NULL,
         main_binary INTEGER,
         user INTEGER NOT NULL,
         job INTEGER NOT NULL,
         input_id BLOB, -- sha256 (sha256<opam-switch> || sha256<build-environment> || sha256<system-packages>)

         FOREIGN KEY(main_binary) REFERENCES build_artifact(id) DEFERRABLE INITIALLY DEFERRED,
         FOREIGN KEY(user) REFERENCES user(id),
         FOREIGN KEY(job) REFERENCES job(id)
       )
    |}

let old_build =
  Caqti_request.exec
    Caqti_type.unit
    {| CREATE TABLE new_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_code INTEGER NOT NULL,
         result_msg TEXT,
         console TEXT NOT NULL,
         script TEXT NOT NULL,
         main_binary INTEGER,
         user INTEGER NOT NULL,
         job INTEGER NOT NULL,
         input_id BLOB, -- sha256 (sha256<opam-switch> || sha256<build-environment> || sha256<system-packages>)

         FOREIGN KEY(main_binary) REFERENCES build_artifact(id) DEFERRABLE INITIALLY DEFERRED,
         FOREIGN KEY(user) REFERENCES user(id),
         FOREIGN KEY(job) REFERENCES job(id)
       )
    |}

let copy_from_old_build =
  Caqti_request.exec
    Caqti_type.unit
    {| INSERT INTO new_build(id, uuid, start_d, start_ps, finish_d, finish_ps,
         result_code, result_msg, console, script, platform, main_binary, user, job, input_id)
       SELECT id, uuid, start_d, start_ps, finish_d, finish_ps, result_code, result_msg,
         console, script, 'PLACEHOLDER-PLATFORM', main_binary, user, job, input_id
       FROM build
    |}

let copy_from_new_build =
  Caqti_request.exec
    Caqti_type.unit
    {| INSERT INTO new_build(id, uuid, start_d, start_ps, finish_d, finish_ps,
         result_code, result_msg, console, script, main_binary, user, job, input_id)
       SELECT id, uuid, start_d, start_ps, finish_d, finish_ps, result_code, result_msg,
         console, script, main_binary, user, job, input_id
       FROM build
    |}

let build_id_and_user =
  Caqti_request.collect
    Caqti_type.unit
    Caqti_type.(tup2 (Builder_db.Rep.id (`build : [ `build ])) int64)
    "SELECT id, user FROM build"

let update_new_build_platform =
  Caqti_request.exec
    Caqti_type.(tup2 (Builder_db.Rep.id (`build : [ `build ])) string)
    "UPDATE new_build SET platform = ?2 WHERE id = ?1"

let drop_build =
  Caqti_request.exec
    Caqti_type.unit
    "DROP TABLE build"

let rename_build =
  Caqti_request.exec
    Caqti_type.unit
    "ALTER TABLE new_build RENAME TO build"

(*
1|reynir
2|freebsd-builder
3|ubuntu-builder
5|nologin
6|reynir-solsort
7|reynir-spurv
*)
let platform_of_user_id = function
  | 1L -> assert false
  | 2L -> "freebsd-12"
  | 3L -> "ubuntu-20.04"
  | 5L -> assert false
  | 6L -> "debian-10"
  | 7L -> "debian-11"
  | _ -> assert false

let migrate _datadir (module Db : Caqti_blocking.CONNECTION) =
  let* () = Grej.check_version ~user_version:old_version (module Db) in
  let* () = Db.exec new_build () in
  let* () = Db.exec copy_from_old_build () in
  let* builds = Db.collect_list build_id_and_user () in
  let* () =
    Grej.list_iter_result (fun (id, user) ->
        let platform = platform_of_user_id user in
        Db.exec update_new_build_platform (id, platform))
      builds
  in
  let* () = Db.exec drop_build () in
  let* () = Db.exec rename_build () in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_job_start ON build(job, start_d DESC, start_ps DESC)")
      ()
  in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_failed ON build(job, start_d DESC, start_ps DESC) WHERE result_code <> 0")
      ()
  in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_input_id ON build(input_id)")
      ()
  in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_main_binary ON build(main_binary)")
      ()
  in
  Db.exec (Grej.set_version new_version) ()

let rollback _datadir (module Db : Caqti_blocking.CONNECTION) =
  let* () = Grej.check_version ~user_version:new_version (module Db) in
  let* () = Db.exec old_build () in
  let* () = Db.exec copy_from_new_build () in
  let* () = Db.exec drop_build () in
  let* () = Db.exec rename_build () in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_job_start ON build(job, start_d DESC, start_ps DESC)")
      ()
  in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_failed ON build(job, start_d DESC, start_ps DESC) WHERE result_code <> 0")
      ()
  in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_input_id ON build(input_id)")
      ()
  in
  let* () =
    Db.exec (Caqti_request.exec Caqti_type.unit
        "CREATE INDEX idx_build_main_binary ON build(main_binary)")
      ()
  in
  Db.exec (Grej.set_version old_version) ()