From 3e7def3a26eed5d44fab1d13ea222dabddee5c0e Mon Sep 17 00:00:00 2001
From: Elizabeth Hunt <elizabeth@simponic.xyz>
Date: Tue, 6 Aug 2024 23:56:14 -0700
Subject: [PATCH] scheduler pt 1

---
 src/util/scheduler.ts | 94 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 81 insertions(+), 13 deletions(-)

diff --git a/src/util/scheduler.ts b/src/util/scheduler.ts
index 9f9f594..3265c7c 100644
--- a/src/util/scheduler.ts
+++ b/src/util/scheduler.ts
@@ -1,25 +1,93 @@
 import * as TE from "fp-ts/lib/TaskEither";
-import { pipe } from "fp-ts/lib/function";
+import * as IO from "fp-ts/lib/IO";
+import * as RA from "fp-ts/lib/ReadonlyArray";
+import * as RM from "fp-ts/lib/ReadonlyMap";
+import * as T from "fp-ts/Task";
+import * as S from "fp-ts/string";
+import { contramap, type Eq } from "fp-ts/Eq";
+import { pipe, identity } from "fp-ts/lib/function";
 import type { Schedule } from "../canary";
+import { ConsoleLogger, type Logger } from "./logger";
+import type { Separated } from "fp-ts/lib/Separated";
+import type { Magma } from "fp-ts/lib/Magma";
+import { intercalate } from "fp-ts/lib/Foldable";
+
+interface Unit {}
+const Unit: Unit = {};
 
 interface ScheduledJob {
   id: string;
-  execute: TE.TaskEither<Error, boolean>;
+  execute: <TResult>() => TE.TaskEither<Error, TResult>;
   at: Date;
   schedule: Schedule;
 }
 
 type SchedulerState = ReadonlyArray<ScheduledJob>;
 
-export const schedulerLoop =
-  (state: SchedulerState): TE.TaskEither<Error, void> =>
-  () => {
-    const loop = (currentState: SchedulerState): TE.TaskEither<Error, void> =>
-      pipe(
-        executeDueJobs(currentState),
-        delay(1000), // Delay for 1 second
-        map((newState) => loop(newState)),
-      );
+const logState = (
+  state: SchedulerState,
+  now: Date,
+  logger: Logger = ConsoleLogger,
+) => {
+  const ids = pipe(
+    state,
+    RA.map(({ id }) => id),
+    (ids) => intercalate(S.Monoid, RA.Foldable)("|", ids),
+  );
+  return logger.log(`Executing ${ids} at ${now.toUTCString()}`);
+};
 
-    return loop(state)();
-  };
+const executeDueJobs = <TResult>(
+  state: SchedulerState,
+): IO.IO<
+  T.Task<
+    Separated<ReadonlyArray<[string, Error]>, ReadonlyArray<[string, TResult]>>
+  >
+> =>
+  pipe(
+    IO.of(state),
+    IO.bindTo("state"),
+    IO.bind("now", () => () => new Date()),
+    IO.bind("toExecute", ({ now, state }) =>
+      pipe(IO.of(state), IO.map(RA.filter(({ at }) => at <= now))),
+    ),
+    IO.flatMap(({ state, now }) =>
+      pipe(
+        IO.of(state),
+        IO.tap((state) => logState(state, now)),
+        IO.map((state) =>
+          pipe(
+            state,
+            RA.map(({ execute, id }) =>
+              pipe(
+                execute(),
+                TE.bimap(
+                  (error) => [id, error] as [string, Error],
+                  (result) => [id, result] as [string, TResult],
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    ),
+    IO.map((jobs) => pipe(jobs, RA.wilt(T.ApplicativePar)(identity))),
+  );
+
+const jobEq: Eq<ScheduledJob> = pipe(
+  S.Eq,
+  contramap(({ id }) => id),
+);
+const jobMagma: Magma<ScheduledJob> = {
+  concat: (a: ScheduledJob, b: ScheduledJob): ScheduledJob => ({
+    ...a,
+    ...b,
+  }),
+};
+
+export const schedulerLoop = (jobs: ReadonlyArray<ScheduledJob>) => {
+  const jobsTable: Map<
+    string,
+    { retries: number; specification: ScheduledJob }
+  > = pipe(jobs, RM.fromFoldable(jobEq, jobMagma, RA.Foldable));
+};