"use client";

import { useState } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { Badge } from "@/components/ui/badge";
import { AdminDialog } from "@/components/ui/admin-dialog";
import {
  approveSalary,
  returnSalary,
  selectCandidate,
  returnSelection,
  approveInterviewWaiver,
  declineInterviewWaiver,
} from "../crewing/applications/actions";
import { decideLeave } from "../crewing/leave/actions";
import { approveAppraisal } from "../crewing/appraisals/actions";

export type CrewApprovalKind = "SALARY" | "SELECTION" | "WAIVER" | "LEAVE" | "APPRAISAL";

export type CrewApprovalItem = {
  id: string; // applicationId, or leaveRequestId for LEAVE
  kind: CrewApprovalKind;
  candidateName: string;
  rank: string;
  requisitionCode: string;
  detail: string;
  link: string;
};

const KIND_LABEL: Record<CrewApprovalKind, string> = { SALARY: "Salary", SELECTION: "Selection", WAIVER: "Waiver", LEAVE: "Leave", APPRAISAL: "Appraisal" };
const KIND_VARIANT = { SALARY: "warning", SELECTION: "default", WAIVER: "secondary", LEAVE: "warning", APPRAISAL: "default" } as const;

const approveFn: Record<CrewApprovalKind, (id: string) => Promise<{ ok: true } | { error: string }>> = {
  SALARY: approveSalary,
  SELECTION: selectCandidate,
  WAIVER: approveInterviewWaiver,
  LEAVE: (id) => decideLeave(id, true),
  APPRAISAL: (id) => approveAppraisal(id, true),
};
const returnFn: Record<CrewApprovalKind, (id: string, reason: string) => Promise<{ ok: true } | { error: string }>> = {
  SALARY: returnSalary,
  SELECTION: returnSelection,
  WAIVER: declineInterviewWaiver,
  LEAVE: (id, reason) => decideLeave(id, false, reason),
  APPRAISAL: (id, reason) => approveAppraisal(id, false, reason),
};

function Row({ item }: { item: CrewApprovalItem }) {
  const router = useRouter();
  const [pending, setPending] = useState(false);
  const [error, setError] = useState("");
  const [returnOpen, setReturnOpen] = useState(false);
  const [reason, setReason] = useState("");

  async function approve() {
    setPending(true); setError("");
    const res = await approveFn[item.kind](item.id);
    setPending(false);
    if ("error" in res) setError(res.error); else router.refresh();
  }
  async function doReturn(e: React.FormEvent) {
    e.preventDefault();
    setPending(true); setError("");
    const res = await returnFn[item.kind](item.id, reason);
    setPending(false);
    if ("error" in res) setError(res.error); else { setReturnOpen(false); router.refresh(); }
  }

  return (
    <tr className="hover:bg-neutral-50">
      <td className="px-4 py-3"><Badge variant={KIND_VARIANT[item.kind]}>{KIND_LABEL[item.kind]}</Badge></td>
      <td className="px-4 py-3">
        <Link href={item.link} className="font-medium text-neutral-900 hover:text-primary-700">{item.candidateName}</Link>
        <span className="block text-xs text-neutral-500">{item.rank} · <span className="font-mono">{item.requisitionCode}</span></span>
      </td>
      <td className="px-4 py-3 text-sm text-neutral-600">{item.detail}</td>
      <td className="px-4 py-3 text-right">
        <div className="flex justify-end gap-2">
          <button onClick={approve} disabled={pending} className="rounded-md bg-primary-600 px-3 py-1.5 text-xs font-semibold text-white hover:bg-primary-700 disabled:opacity-60">Approve</button>
          <button onClick={() => setReturnOpen(true)} disabled={pending} className="rounded-md border border-neutral-300 px-3 py-1.5 text-xs font-medium text-neutral-700 hover:bg-neutral-50">Return</button>
        </div>
        {error && <p className="text-xs text-danger-700 mt-1">{error}</p>}
        <AdminDialog title={`Return ${KIND_LABEL[item.kind].toLowerCase()}`} open={returnOpen} onClose={() => setReturnOpen(false)}>
          <form onSubmit={doReturn} className="space-y-4 text-left">
            <textarea className="w-full rounded-lg border border-neutral-300 px-3 py-2 text-sm" rows={3} value={reason} onChange={(e) => setReason(e.target.value)} required placeholder="Reason for returning" />
            <div className="flex justify-end gap-3">
              <button type="button" className="rounded-lg border border-neutral-300 px-4 py-2 text-sm font-medium text-neutral-700 hover:bg-neutral-50" onClick={() => setReturnOpen(false)}>Cancel</button>
              <button type="submit" disabled={pending} className="rounded-lg bg-primary-600 px-4 py-2 text-sm font-semibold text-white hover:bg-primary-700 disabled:opacity-60">Return</button>
            </div>
          </form>
        </AdminDialog>
      </td>
    </tr>
  );
}

export function CrewingApprovals({ items }: { items: CrewApprovalItem[] }) {
  return (
    <div className="mt-8">
      <h2 className="text-sm font-semibold text-neutral-900 mb-1">Crewing approvals</h2>
      <p className="text-xs text-neutral-500 mb-3">{items.length} item{items.length === 1 ? "" : "s"} awaiting your decision</p>
      <div className="rounded-lg border border-neutral-200 bg-white overflow-hidden">
        <table className="w-full text-sm">
          <thead className="bg-neutral-50 border-b border-neutral-200">
            <tr>
              <th className="px-4 py-3 text-left font-medium text-neutral-600">Kind</th>
              <th className="px-4 py-3 text-left font-medium text-neutral-600">Candidate</th>
              <th className="px-4 py-3 text-left font-medium text-neutral-600">Detail</th>
              <th className="px-4 py-3"></th>
            </tr>
          </thead>
          <tbody className="divide-y divide-neutral-100">
            {items.map((item) => <Row key={`${item.kind}-${item.id}`} item={item} />)}
          </tbody>
        </table>
      </div>
    </div>
  );
}