export type ClockOutOutcome =
  | "linked_to_invoice"
  | "saved_no_invoice"
  | "saved_no_client"
  | "zero_hours";

export const DEFAULT_CLOCK_DESCRIPTION = "Clock In";

/** Stored on entries clocked in before empty descriptions were allowed. */
export const LEGACY_DEFAULT_CLOCK_DESCRIPTION = "Professional services";

export function resolveClockDescription(description: string | null | undefined): string {
  const trimmed = description?.trim();
  return trimmed || DEFAULT_CLOCK_DESCRIPTION;
}

export function formatRunningTimerLabel(description?: string | null): string {
  const trimmed = description?.trim() ?? "";
  if (
    !trimmed ||
    trimmed === DEFAULT_CLOCK_DESCRIPTION ||
    trimmed === LEGACY_DEFAULT_CLOCK_DESCRIPTION
  ) {
    return "Clocked in";
  }
  return trimmed;
}

export function formatElapsedSeconds(seconds: number): string {
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = seconds % 60;
  return [h, m, s].map((v) => String(v).padStart(2, "0")).join(":");
}

/** Hours and minutes only — for Live Activity / compact displays. */
export function formatElapsedHoursMinutes(seconds: number): string {
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  return `${h}:${String(m).padStart(2, "0")}`;
}

export function resolveEffectiveHourlyRate(
  rateText: string,
  clientDefaultRate?: number | null,
): number | null {
  const parsed = rateText.trim() ? Number(rateText) : null;
  if (parsed != null && !Number.isNaN(parsed) && parsed >= 0) return parsed;
  if (clientDefaultRate != null && clientDefaultRate >= 0) return clientDefaultRate;
  return null;
}

export function startedAtFromMinutesAgo(minutes: number): Date {
  return new Date(Date.now() - minutes * 60_000);
}

export function describeClockOutOutcome(input: {
  outcome: ClockOutOutcome;
  hours: number;
  rate: number;
  invoice?: { invoicePrefix: string; invoiceNumber: string } | null;
}): string {
  const amount = input.hours * input.rate;

  switch (input.outcome) {
    case "linked_to_invoice":
      if (input.invoice) {
        const label = `${input.invoice.invoicePrefix}${input.invoice.invoiceNumber}`;
        return `Added ${input.hours}h @ $${input.rate}/hr ($${amount.toFixed(2)}) to ${label}`;
      }
      return `Added ${input.hours}h to invoice`;
    case "saved_no_invoice":
      return `Saved ${input.hours}h — no open invoice for this client.`;
    case "saved_no_client":
      return `Saved ${input.hours}h — pick a client and invoice to bill.`;
    case "zero_hours":
      return "Timer stopped.";
  }
}