"use client";

import { useMemo, useState } from "react";
import { useRouter } from "next/navigation";
import { hireEmployee } from "@/actions/employees";
import { deleteHireDraft, saveHireDraft } from "@/actions/hireDrafts";
import { Button } from "@/components/ui/Button";
import { Modal } from "@/components/ui/Modal";
import { useToast } from "@/components/ui/Toast";
import type { OpenPositionResolved } from "@/lib/positions";
import { isValidSvnr, requiresAustrianSvnr } from "@/lib/svnr";
import { StepPerson } from "./StepPerson";
import { StepPosition } from "./StepPosition";
import { StepSummary } from "./StepSummary";
import { StepVertrag } from "./StepVertrag";
import { EMPTY_HIRE_DRAFT, type HireDraftData } from "./types";

const STEP_LABELS = ["Person", "Position", "Vertrag", "Zusammenfassung"];

type HireWizardProps = {
  open: boolean;
  onClose: () => void;
  openPositions: OpenPositionResolved[];
  locations: { id: string; name: string; country: string }[];
  resumeDraft: { id: string; step: number; payload: Record<string, unknown> } | null;
  initialPositionId?: string;
};

export function HireWizard({ open, onClose, openPositions, locations, resumeDraft, initialPositionId }: HireWizardProps) {
  const { showToast } = useToast();
  const router = useRouter();
  // The parent remounts this component (via a changing `key`) each time it's
  // freshly opened, so these initializers — reading resumeDraft/
  // initialPositionId once at mount — are the reset, no effect needed.
  const [step, setStep] = useState(() => resumeDraft?.step ?? 0);
  const [draft, setDraft] = useState<HireDraftData>(() =>
    resumeDraft
      ? { ...EMPTY_HIRE_DRAFT, ...(resumeDraft.payload as Partial<HireDraftData>) }
      : { ...EMPTY_HIRE_DRAFT, positionId: initialPositionId ?? "" }
  );
  const [draftId] = useState<string | undefined>(() => resumeDraft?.id);
  const [submitting, setSubmitting] = useState(false);

  const selectedPosition = useMemo(
    () => openPositions.find((p) => p.id === draft.positionId) ?? null,
    [openPositions, draft.positionId]
  );

  function update(patch: Partial<HireDraftData>) {
    setDraft((prev) => ({ ...prev, ...patch }));
  }

  // Blocks step 1 rather than letting the hire fail at the RPC: the SVNR
  // trigger rejects a bad number, and by then the user is three steps on.
  const svNummerOk =
    !draft.svNummer.trim() ||
    !requiresAustrianSvnr(locations.find((l) => l.id === draft.locationId)?.country) ||
    isValidSvnr(draft.svNummer, draft.birthDate || null);

  const stepValid = [
    // E-Mail gehört zu den Pflichtfeldern, weil die Spalte NOT NULL ist. Ohne
    // die Prüfung hier bricht erst die Datenbank ab — am Ende des vierten
    // Schritts, nach allen Eingaben.
    Boolean(draft.firstName && draft.lastName && draft.birthDate && draft.locationId && draft.email.trim()) &&
      svNummerOk,
    Boolean(draft.positionId && draft.besetzung),
    Boolean(draft.entryDate && draft.workDays.length > 0),
    true,
  ][step];

  async function handleSaveDraft() {
    const result = await saveHireDraft({ id: draftId, step, data: draft });
    if (result.success) {
      showToast("Entwurf gespeichert.");
      router.refresh();
      onClose();
    } else {
      showToast(result.error ?? "Fehler beim Speichern.", "error");
    }
  }

  async function handleSubmit() {
    if (!selectedPosition || !draft.besetzung) return;
    setSubmitting(true);
    const result = await hireEmployee({
      first_name: draft.firstName,
      last_name: draft.lastName,
      title_prefix: draft.titlePrefix,
      title_suffix: draft.titleSuffix,
      gender: draft.gender,
      birth_date: draft.birthDate,
      sv_nummer: draft.svNummer || undefined,
      email: draft.email.trim(),
      phone: draft.phone || undefined,
      position_id: draft.positionId,
      location_id: draft.locationId,
      entry_date: draft.entryDate,
      contract_type: draft.contractType,
      contract_end_date: draft.contractType === "befristet" ? draft.contractEndDate : undefined,
      employment_type: draft.employmentType,
      weekly_hours: Number(draft.weeklyHours),
      paygrade: draft.paygrade,
      source: draft.besetzung,
      worker_type: draft.workerType,
      collective_agreement: draft.collectiveAgreement,
      work_days: draft.workDays,
      is_betriebsrat: draft.isBetriebsrat,
      has_dienstwagen: draft.hasDienstwagen,
      is_laterale_fuehrung: draft.isLateraleFuehrung,
      is_c_level: draft.isCLevel,
    });
    setSubmitting(false);
    if (result.success) {
      showToast(`${draft.firstName} ${draft.lastName} wurde eingestellt.`);
      if (draftId) await deleteHireDraft(draftId);
      router.refresh();
      onClose();
    } else {
      showToast(result.error ?? "Fehler beim Anlegen.", "error");
    }
  }

  return (
    <Modal
      open={open}
      onClose={onClose}
      title="Neueinstellung"
      widthClassName="max-w-2xl"
      footer={
        <div className="flex w-full items-center justify-between">
          <div className="flex gap-2">
            <Button variant="ghost" onClick={onClose}>
              Abbrechen
            </Button>
            <Button variant="ghost" onClick={handleSaveDraft}>
              Als Entwurf speichern
            </Button>
          </div>
          <div className="flex gap-2">
            {step > 0 && (
              <Button variant="secondary" onClick={() => setStep((s) => s - 1)}>
                Zurück
              </Button>
            )}
            {step < 3 && (
              <Button onClick={() => setStep((s) => s + 1)} disabled={!stepValid}>
                Weiter
              </Button>
            )}
            {step === 3 && (
              <Button onClick={handleSubmit} pending={submitting}>
                Anlegen
              </Button>
            )}
          </div>
        </div>
      }
    >
      {/* A progress trail, not navigation: only completed steps are
          reachable, so the rest are genuinely disabled rather than inert
          buttons that silently swallow a click. */}
      <div className="mb-6 flex items-center justify-center gap-3">
        {STEP_LABELS.map((label, i) => (
          <button
            key={label}
            type="button"
            disabled={i >= step}
            aria-current={i === step ? "step" : undefined}
            onClick={() => i < step && setStep(i)}
            className={`flex items-center gap-2 rounded text-xs font-semibold focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-brand-500 disabled:cursor-default ${
              i === step ? "text-brand-700" : i < step ? "text-ink-body" : "text-ink-muted"
            }`}
          >
            <span className={`flex h-6 w-6 items-center justify-center rounded-full ${i <= step ? "bg-brand-500 text-white" : "bg-surface text-ink-muted"}`}>
              {i + 1}
            </span>
            {label}
          </button>
        ))}
      </div>

      {step === 0 && <StepPerson draft={draft} update={update} locations={locations} />}
      {step === 1 && <StepPosition draft={draft} update={update} openPositions={openPositions} />}
      {step === 2 && <StepVertrag draft={draft} update={update} />}
      {step === 3 && <StepSummary draft={draft} selectedPosition={selectedPosition} locations={locations} />}
    </Modal>
  );
}