"use client";

import { useState, useTransition } from "react";
import {
  AlertCircleIcon,
  PlayIcon,
  XIcon,
  Loader2Icon,
} from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  resumeReminderRunAction,
  cancelReminderRunAction,
} from "@/actions/reminders";

interface PausedRunBannerProps {
  runId: string;
  /** Best-effort sent count for the body copy. Falls back to a
   *  generic message when undefined. */
  sent?: number;
  /** Best-effort total target count. */
  total?: number;
  /** Deadline hour the bot stopped at. Shown in the body copy. */
  windowEndHour: number;
  /** Operator timezone (for the deadline label). */
  timezone: string;
}

/**
 * Amber callout shown above the reminder detail view when the most
 * recent run is in 'paused' state. Two interactive choices:
 *   • Resume → re-enqueues the run via the bot.
 *   • Cancel run → stops the run cleanly (remaining pending → skipped).
 *
 * Pause notifications deep-link the operator into this surface.
 */
export function PausedRunBanner({
  runId,
  sent,
  total,
  windowEndHour,
  timezone,
}: PausedRunBannerProps) {
  const [pending, startTransition] = useTransition();
  const [error, setError] = useState<string | null>(null);

  const onResume = () =>
    startTransition(async () => {
      setError(null);
      const r = await resumeReminderRunAction({ runId });
      if (!r.ok) setError(r.error);
    });

  const onCancel = () =>
    startTransition(async () => {
      setError(null);
      const r = await cancelReminderRunAction({ runId });
      if (!r.ok) setError(r.error);
    });

  const remaining =
    typeof sent === "number" && typeof total === "number"
      ? Math.max(0, total - sent)
      : null;

  return (
    <div
      className="rounded-lg border border-amber-500/40 bg-amber-500/5 p-4 space-y-3"
      data-testid="paused-run-banner"
    >
      <div className="flex items-start gap-2">
        <AlertCircleIcon className="size-4 text-amber-600 dark:text-amber-400 mt-0.5 shrink-0" />
        <div className="space-y-1 text-sm">
          <p className="font-medium">Reminder paused</p>
          <p className="text-xs text-muted-foreground">
            {typeof sent === "number" && typeof total === "number"
              ? `${sent} of ${total} groups delivered.`
              : "The delivery window closed before all groups got the message."}{" "}
            The deadline was {windowEndHour}:00 ({timezone}).{" "}
            {remaining !== null && remaining > 0
              ? `Resume to send the remaining ${remaining}, or cancel the run.`
              : "Resume to keep going, or cancel the run."}
          </p>
        </div>
      </div>
      {error && (
        <div className="text-xs text-destructive">{error}</div>
      )}
      <div className="flex gap-2">
        <Button
          size="sm"
          onClick={onResume}
          disabled={pending}
          className="gap-2"
          data-testid="paused-resume"
        >
          {pending ? (
            <Loader2Icon className="size-3.5 animate-spin" />
          ) : (
            <PlayIcon className="size-3.5" />
          )}
          Resume
        </Button>
        <Button
          size="sm"
          variant="outline"
          onClick={onCancel}
          disabled={pending}
          className="gap-2"
          data-testid="paused-cancel"
        >
          <XIcon className="size-3.5" />
          Cancel run
        </Button>
      </div>
    </div>
  );
}