People actions

"use server"

import { db, type Leave, type Result } from "@/lib/sample-data"

/**
 * The People dashboard's shared server actions: what more than one of its
 * pages does to the same rows. The overview's leave queue and the leave page
 * both decide a request, so the decision lives here, once, and both import
 * it — one action name, one behaviour, everywhere the dashboard offers it.
 *
 * Installed as `@lib/dashboards/people/actions.ts` by the `actions-people`
 * item, which every page that imports it lists in its registry dependencies,
 * so installing the dashboard installs it too. Every answer is a `Result`,
 * and the name in it is read off the rows the action looked up.
 */

export type LeaveDecision = Extract<Leave["status"], "approved" | "declined">

export type DecidedLeave = { id: string; status: LeaveDecision; employeeName: string; kind: Leave["kind"] }

/**
 * Grants or refuses a request. Only a pending one can be decided: a request
 * that was already approved or declined is refused with the decision it got,
 * because a manager pressing the other button a second time — or a second
 * manager on another page — is the race this guards against. The employee is
 * read off the row, never the form.
 */
export async function decideLeave(id: string, decision: LeaveDecision): Promise<Result<DecidedLeave>> {
  // The type is erased at the action boundary; only the two words a page offers may be written.
  if (decision !== "approved" && decision !== "declined") {
    return { ok: false, error: { code: "invalid", message: `"${String(decision)}" is not a decision a request can take.` } }
  }

  const leave = await db.leaves.get(id)
  if (!leave) {
    return { ok: false, error: { code: "not_found", message: `No leave request with id "${id}".` } }
  }
  const employee = await db.employees.get(leave.employeeId)
  const name = employee?.name ?? "That colleague"

  if (leave.status !== "pending") {
    return {
      ok: false,
      error: { code: "conflict", message: `${name}'s ${leave.kind} leave was already ${leave.status}.` },
    }
  }

  const updated = await db.leaves.update(id, { status: decision })
  if (!updated.ok) return updated
  return { ok: true, data: { id, status: decision, employeeName: name, kind: leave.kind } }
}