/**
 * Human-readable Czech descriptions for work-plan audit-log rows.
 *
 * The audit log table ("Popis" column) shows only the `description` string,
 * so it must be self-contained: who, when, what. Previously the plan routes
 * left `description` undefined for normal edits, which rendered as "-" and
 * made the audit rows useless. These helpers build a readable subject line
 * such as: `Jan Novák · 08.06.2026 – 12.06.2026 · Práce · Projekt ABC`.
 *
 * Everything here is pure (no Prisma, no Date.now) so it is trivially unit
 * testable. The service layer resolves user/project names and feeds plain
 * strings in.
 */

/** Czech labels for the `plan_category` enum. Mirrors the frontend
 * PlanCellModal options so the audit log reads the same as the UI. */
export const PLAN_CATEGORY_LABELS_CS: Record<string, string> = {
  work: "Práce",
  preparation: "Příprava",
  travel: "Cesta / Montáž",
  leave: "Dovolená",
  sick: "Nemoc",
  training: "Školení",
  other: "Jiné",
};

/** Translate a plan category to its Czech label, falling back to the raw
 * value for unknown categories so nothing is ever silently dropped. */
export function planCategoryLabel(category: string): string {
  return PLAN_CATEGORY_LABELS_CS[category] ?? category;
}

/**
 * Format a `YYYY-MM-DD` string as Czech `DD.MM.YYYY`.
 *
 * Takes a string (not a Date) on purpose: work-plan dates live in `@db.Date`
 * columns and the service derives the ISO day via `toISOString().slice(0,10)`,
 * so there is no timezone ambiguity to reintroduce here. Matches the
 * `localDateCzStr` style in `src/utils/date.ts`.
 */
export function formatPlanDate(iso: string): string {
  const [y, m, d] = iso.split("-");
  if (!y || !m || !d) return iso;
  return `${d}.${m}.${y}`;
}

export interface PlanAuditDescriptionInput {
  /** Employee the plan row belongs to (display name). */
  userName: string;
  /** Already-resolved Czech category label (resolved from plan_categories). */
  categoryLabel: string;
  /** Resolved project name, or null when the row has no project. */
  projectName?: string | null;
  /** Range start (YYYY-MM-DD). For overrides, pass the shift date here. */
  dateFrom: string;
  /** Range end (YYYY-MM-DD). For overrides/single days, equals `dateFrom`. */
  dateTo: string;
  /** Append "nouzová úprava" when the change bypassed the past-date lock. */
  force?: boolean;
  /** Extra Czech note appended at the end (e.g. "nahrazeno novým záznamem"). */
  suffix?: string;
}

/**
 * Build a Czech audit description: a `·`-separated subject line. The action
 * (create/update/delete) and entity type are shown in their own audit-table
 * columns, so the description carries only the subject — never the verb.
 */
export function buildPlanAuditDescription(
  opts: PlanAuditDescriptionInput,
): string {
  const dateLabel =
    opts.dateFrom === opts.dateTo
      ? formatPlanDate(opts.dateFrom)
      : `${formatPlanDate(opts.dateFrom)} – ${formatPlanDate(opts.dateTo)}`;

  const parts: string[] = [opts.userName, dateLabel, opts.categoryLabel];

  if (opts.projectName && opts.projectName.trim()) {
    parts.push(opts.projectName.trim());
  }
  if (opts.suffix && opts.suffix.trim()) {
    parts.push(opts.suffix.trim());
  }
  if (opts.force) {
    parts.push("nouzová úprava");
  }

  return parts.join(" · ");
}