Concurrent Record Edit

"use client";

import { OccupancyBanner } from "@/components/f-ui/occupancy-banner/occupancy-banner";

export function OccupancyBannerDemo() {
  return (
    <OccupancyBanner
      currentUserId="you"
      occupants={[
        { id: "ada", kind: "edit", displayName: "Ada Chen" },
        { id: "you", kind: "edit", displayName: "You" },
      ]}
    />
  );
}

"use client";

import { useCallback, useEffect, useMemo, useRef, useState } from "react";

import { Button } from "@/components/f-ui/button/button";
import { OccupancyBanner } from "@/components/f-ui/occupancy-banner/occupancy-banner";
import type { Occupant } from "@/components/f-ui/occupancy-banner/occupancy-message";
import { isStaleVersionProblem } from "@/components/f-ui/stale-save-dialog/is-stale-version-problem";
import { StaleSaveDialog } from "@/components/f-ui/stale-save-dialog/stale-save-dialog";
import { StaleVersionBanner } from "@/components/f-ui/stale-save-dialog/stale-version-banner";
import { Textarea } from "@/components/ui/textarea";

type Ticket = {
  notes: string;
  version: string;
  modifiedBy?: { displayName: string };
};

type Presence = Occupant & { expiresAt: number };

const TTL_MS = 8000;

function bumpVersion(version: string): string {
  const n = Number.parseInt(version, 10);
  return String(Number.isFinite(n) ? n + 1 : 1);
}

function saveTicket(ticket: Ticket, clientVersion: string, notes: string, actor: string): Ticket {
  if (clientVersion !== ticket.version) {
    throw {
      status: 412,
      code: "object.stale_version",
      modifiedBy: ticket.modifiedBy,
    };
  }
  return {
    notes,
    version: bumpVersion(ticket.version),
    modifiedBy: { displayName: actor },
  };
}

function SessionPane({
  actorId,
  actorName,
  ticket,
  presence,
  onHeartbeat,
  onSave,
  onReload,
}: {
  actorId: string;
  actorName: string;
  ticket: Ticket;
  presence: Presence[];
  onHeartbeat: (occupant: Occupant) => void;
  onSave: (clientVersion: string, notes: string) => Ticket;
  onReload: () => Ticket;
}) {
  const [notes, setNotes] = useState(ticket.notes);
  const [version, setVersion] = useState(ticket.version);
  const [open, setOpen] = useState(false);
  const [behind, setBehind] = useState(false);
  const [modifiedBy, setModifiedBy] = useState<{ displayName?: string }>();
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    onHeartbeat({ id: actorId, kind: "edit", displayName: actorName });
    const id = window.setInterval(() => {
      onHeartbeat({ id: actorId, kind: "edit", displayName: actorName });
    }, 2000);
    return () => window.clearInterval(id);
  }, [actorId, actorName, onHeartbeat]);

  const occupants = useMemo(
    () => presence.filter((row) => row.id !== actorId),
    [presence, actorId],
  );

  const handleReload = () => {
    const next = onReload();
    setNotes(next.notes);
    setVersion(next.version);
    setOpen(false);
    setBehind(false);
  };

  return (
    <div className="flex min-w-0 flex-1 flex-col gap-3 rounded-xl border bg-card p-4">
      <p className="text-sm font-medium">{actorName}</p>
      {behind && !open ? (
        <StaleVersionBanner modifiedBy={modifiedBy} onReload={handleReload} />
      ) : null}
      <OccupancyBanner currentUserId={actorId} occupants={occupants} />
      <label className="flex flex-col gap-1.5 text-sm">
        Notes
        <Textarea value={notes} onChange={(e) => setNotes(e.target.value)} rows={4} />
      </label>
      <p className="text-muted-foreground text-xs">Loaded version {version}</p>
      {error ? <p className="text-destructive text-sm">{error}</p> : null}
      <Button
        type="button"
        onClick={() => {
          setError(null);
          try {
            const next = onSave(version, notes);
            setVersion(next.version);
            setBehind(false);
          } catch (err) {
            if (isStaleVersionProblem(err)) {
              const problem = err as { modifiedBy?: { displayName?: string } };
              setModifiedBy(problem.modifiedBy);
              setOpen(true);
              return;
            }
            setError("Could not save.");
          }
        }}
      >
        Save
      </Button>
      <StaleSaveDialog
        open={open}
        onOpenChange={setOpen}
        modifiedBy={modifiedBy}
        draftText={notes}
        changedFields={[{ label: "Notes", local: notes, server: ticket.notes }]}
        onReload={handleReload}
        onKeepEditing={() => {
          setOpen(false);
          setBehind(true);
        }}
      />
    </div>
  );
}

export function StaleSaveDialogTwoSessionDemo() {
  const [ticket, setTicket] = useState<Ticket>({
    notes: "Kickoff notes for the Q3 order.",
    version: "1",
  });
  const ticketRef = useRef(ticket);
  ticketRef.current = ticket;
  const [presence, setPresence] = useState<Presence[]>([]);
  const [, setTick] = useState(0);

  useEffect(() => {
    const id = window.setInterval(() => setTick((n) => n + 1), 1000);
    return () => window.clearInterval(id);
  }, []);

  const onHeartbeat = useCallback((occupant: Occupant) => {
    setPresence((rows) => {
      const next = rows.filter((row) => row.id !== occupant.id);
      next.push({ ...occupant, expiresAt: Date.now() + TTL_MS });
      return next;
    });
  }, []);

  const livePresence = presence.filter((row) => row.expiresAt > Date.now());

  return (
    <div className="flex flex-col gap-3 sm:flex-row">
      <SessionPane
        actorId="ada"
        actorName="Ada Chen"
        ticket={ticket}
        presence={livePresence}
        onHeartbeat={onHeartbeat}
        onSave={(clientVersion, notes) => {
          const next = saveTicket(ticketRef.current, clientVersion, notes, "Ada Chen");
          setTicket(next);
          return next;
        }}
        onReload={() => ticketRef.current}
      />
      <SessionPane
        actorId="ben"
        actorName="Ben Park"
        ticket={ticket}
        presence={livePresence}
        onHeartbeat={onHeartbeat}
        onSave={(clientVersion, notes) => {
          const next = saveTicket(ticketRef.current, clientVersion, notes, "Ben Park");
          setTicket(next);
          return next;
        }}
        onReload={() => ticketRef.current}
      />
    </div>
  );
}