"use client";

import { useActionState } from "react";
import type { SyncSchedulerSettings } from "yt-dlp-transcript-common/lib/settings";
import {
  saveSchedulerSettingsAction,
  type SaveResult,
} from "../../../scheduler/actions";
import {
  SYNC_INTERVAL_MAX_MINUTES,
  SYNC_INTERVAL_MIN_MINUTES,
} from "yt-dlp-transcript-common/lib/channelConfig";
import { DurationField } from "../../../components/DurationField";
import { Field } from "../../../components/forms/Field";
import { seedChecked } from "../../../lib/formState";
import { FULL_SWEEP_PRESETS } from "../../../scheduler/intervalPresets";

// THE SYNC OPERATION'S SETTINGS BLOCK, whole. It is the form the descriptor's
// `settingsBlock: "syncScheduler"` selects, drawn below the schedule on
// /operations/sync.
//
// It was half a form here and a fieldset on /settings, which meant TWO writers
// of one block — and the only thing keeping them from clobbering each other was
// that both remembered to preserve the fields their own render did not show.
// One block, one page, one writer (saveSchedulerSettingsAction); /settings
// preserves it the way it preserves digest, diarization and the lane.
//
// `heartbeatSeconds` is the live EFFECTIVE value passed from the page
// (resolveHeartbeatSeconds), not the stored one: SYNC_HEARTBEAT_SECONDS
// overrides the setting, and a field showing the stored number beside a server
// running a different cadence is a lie the operator cannot see.
export function SchedulerSettingsForm({
  scheduler,
  heartbeatSeconds,
}: {
  scheduler: SyncSchedulerSettings;
  heartbeatSeconds: number;
}) {
  const [state, formAction, pending] = useActionState<
    SaveResult | undefined,
    FormData
  >(saveSchedulerSettingsAction, undefined);

  return (
    <form
      action={formAction}
      data-settings-block="syncScheduler"
      className="flex flex-col gap-3 border border-border rounded p-3"
    >
      <h2 className="text-sm font-semibold">Sync scheduler</h2>
      <label className="flex items-start gap-2 text-sm">
        <input
          type="checkbox"
          name="syncSchedulerEnabled"
          defaultChecked={seedChecked(
            state,
            "syncSchedulerEnabled",
            scheduler.enabled,
          )}
          className="mt-1"
        />
        <span className="flex flex-col gap-0.5">
          <span className="font-medium">Enable scheduled auto-sync</span>
          <span className="text-xs text-muted-foreground">
            Master switch. When off, ticks are no-ops and only manual syncs run.
          </span>
        </span>
      </label>
      <div className="flex flex-wrap gap-4">
        <DurationField
          label="Default interval"
          name="syncSchedulerDefaultIntervalMinutes"
          baseUnit="minutes"
          units={["minutes", "hours", "days"]}
          value={scheduler.defaultIntervalMinutes}
          min={1}
          max={44640}
          rate={{ noun: "check", per: "channel" }}
          hint="Auto-sync cadence for channels left on “Default”."
          className="max-w-sm"
        />
        <DurationField
          label="Default full sweep interval"
          name="syncSchedulerFullSweepIntervalMinutes"
          baseUnit="minutes"
          units={["hours", "days"]}
          value={scheduler.fullSweepIntervalMinutes}
          presets={FULL_SWEEP_PRESETS}
          allowOff
          offLabel="Off (never sweep)"
          min={1}
          max={44640}
          rate={{
            noun: "full listing fetch",
            pluralNoun: "full listing fetches",
            per: "channel",
          }}
          hint="How often a sync re-reads a channel's whole listing to refresh it and flag missing videos. Channels can override this."
          className="max-w-sm"
        />
        <DurationField
          label="Internal heartbeat"
          name="syncSchedulerHeartbeatSeconds"
          baseUnit="seconds"
          units={["seconds", "minutes"]}
          value={heartbeatSeconds}
          allowOff
          offLabel="Off (external cron)"
          min={15}
          max={3600}
          hint="When off, drive ticks with an external cron heartbeat. Clamped to 15–3600s; turning it on from off needs a server restart."
          className="max-w-sm"
        />
      </div>
      <div className="flex flex-wrap gap-4">
        <Field
          label="Full-sweep auto-confirm cap"
          name="syncSchedulerFullSweepConfirmMaxSuspects"
          state={state}
          defaultValue={String(scheduler.fullSweepConfirmMaxSuspects)}
          type="number"
          hint="When a sweep finds at most this many videos missing from the listing, it probes each one upstream to confirm; above the cap it only flags them and leaves the probing to 'Check maybe-missing'. 0 = never auto-confirm. This is a count of videos, not a duration."
        />
        <Field
          label="Full-sweep shrink guard"
          name="syncSchedulerFullSweepShrinkGuardPercent"
          state={state}
          defaultValue={String(scheduler.fullSweepShrinkGuardPercent)}
          type="number"
          hint="If a fresh listing comes back smaller than the stored one by more than this percentage (and by more than 25 entries), it is treated as suspect: the stored video list and the missing-video flags are left alone and the sweep is retried on the next sync rather than after the full cadence. A second enumeration reporting a similar count confirms it and is accepted, so a genuine mass deletion still lands. 0 = off; an empty listing is always refused. This is a percentage, not a duration."
        />
        <Field
          label="Max concurrent syncs"
          name="syncSchedulerMaxConcurrentSyncs"
          state={state}
          defaultValue={String(scheduler.maxConcurrentSyncs)}
          type="number"
          hint="A tick queues at most (this − already-running) channels, most-overdue first; the rest roll to the next tick. Bounds load and staggers big batches."
        />
        <DurationField
          label="Keep-latest check interval"
          name="syncSchedulerKeepLatestCheckIntervalMinutes"
          baseUnit="minutes"
          units={["hours", "days"]}
          value={scheduler.keepLatestCheckIntervalMinutes}
          min={SYNC_INTERVAL_MIN_MINUTES}
          max={SYNC_INTERVAL_MAX_MINUTES}
          hint="A Storage chore on the sync heartbeat, not sync: how often channels with a keep-latest limit are re-checked so old videos get pruned even when nothing new arrived."
          className="max-w-sm"
        />
      </div>
      <div className="flex gap-3">
        <Field
          label="Quiet hours start (0–23)"
          name="syncSchedulerQuietHoursStart"
          state={state}
          defaultValue={
            scheduler.quietHoursStart != null
              ? String(scheduler.quietHoursStart)
              : ""
          }
          type="number"
        />
        <Field
          label="Quiet hours end (0–23)"
          name="syncSchedulerQuietHoursEnd"
          state={state}
          defaultValue={
            scheduler.quietHoursEnd != null
              ? String(scheduler.quietHoursEnd)
              : ""
          }
          type="number"
        />
      </div>
      <p className="text-xs text-muted-foreground -mt-1">
        Optional local-clock window when auto-sync is suppressed (may wrap past
        midnight, e.g. 22 → 6). Leave both blank to always allow.
      </p>
      <div className="flex flex-wrap gap-3">
        <DurationField
          label="Backoff base"
          name="syncSchedulerBackoffBaseMinutes"
          baseUnit="minutes"
          units={["minutes", "hours"]}
          value={scheduler.backoffBaseMinutes}
          min={SYNC_INTERVAL_MIN_MINUTES}
          max={SYNC_INTERVAL_MAX_MINUTES}
        />
        <DurationField
          label="Backoff max"
          name="syncSchedulerBackoffMaxMinutes"
          baseUnit="minutes"
          units={["minutes", "hours", "days"]}
          value={scheduler.backoffMaxMinutes}
          min={SYNC_INTERVAL_MIN_MINUTES}
          max={SYNC_INTERVAL_MAX_MINUTES}
        />
      </div>
      <p className="text-xs text-muted-foreground -mt-1">
        After N consecutive failed syncs a channel waits base·2^(N-1) minutes
        (capped at max) before retrying.
      </p>
      <div className="flex items-center gap-3">
        <button
          type="submit"
          disabled={pending}
          className="px-3 py-1.5 rounded-md bg-primary text-primary-foreground text-sm font-medium hover:opacity-90 disabled:opacity-50"
        >
          {pending ? "Saving…" : "Save controls"}
        </button>
        {state?.ok === true && (
          <span role="status" className="text-sm text-success">
            Saved.
          </span>
        )}
        {state?.ok === false && (
          <span role="alert" className="text-sm text-destructive">
            {state.error}
          </span>
        )}
      </div>
    </form>
  );
}