// Labels and helpers for Source Mesh v2: observation types, comparability classes, roles, coverage tiers.
import type { Comparability, CoverageStatus, CoverageTier, ObservationType } from "./types";

export const OBSERVATION_TYPE_LABEL: Record<ObservationType, string> = {
  TRADE: "Trade",
  MID: "Mid",
  QUOTE: "Quote",
  INDEX_VALUE: "Index value",
  INDICATIVE: "Indicative",
  STABLECOIN_PROXY: "Stablecoin proxy",
  DERIVED: "Derived",
  OFFICIAL_FIX: "Official fix",
  REFERENCE_RATE: "Reference rate",
  SETTLEMENT: "Settlement",
  EOD_CLOSE: "EOD close",
  NAV: "NAV",
};

export const COMPARABILITY_LABEL: Record<Comparability, string> = {
  LIVE: "live market consensus",
  FIX: "official fixing",
  EOD: "end-of-day close",
};

export const COMPARABILITY_OF: Record<ObservationType, Comparability> = {
  TRADE: "LIVE",
  MID: "LIVE",
  QUOTE: "LIVE",
  INDEX_VALUE: "LIVE",
  INDICATIVE: "LIVE",
  STABLECOIN_PROXY: "LIVE",
  DERIVED: "LIVE",
  OFFICIAL_FIX: "FIX",
  REFERENCE_RATE: "FIX",
  SETTLEMENT: "EOD",
  EOD_CLOSE: "EOD",
  NAV: "EOD",
};

export const PROXY_TYPES = new Set<ObservationType>(["STABLECOIN_PROXY", "DERIVED", "INDICATIVE"]);

/** Readable copy for exclusion reasons. `canonical` is the comparability class of the canonical value. */
export function reasonLabel(reason: string | null | undefined, type?: ObservationType, canonical?: Comparability | null): string {
  switch (reason) {
    case "stale":
      return "stale — outside its freshness window";
    case "not_comparable": {
      const own = type ? COMPARABILITY_LABEL[COMPARABILITY_OF[type]] : null;
      const can = canonical ? COMPARABILITY_LABEL[canonical] : null;
      return own && can ? `not comparable: ${own} vs ${can}` : "not comparable with the canonical class";
    }
    case "temporal_mismatch":
      return "temporal mismatch — too far from the freshest observation";
    case "validation_only":
      return "validation only — restricted rights, never votes";
    case "validator_disagrees":
      return "validator disagrees with the consensus";
    case "outlier":
      return "outlier — more than 2 % from the median";
    case "superseded_by_live":
      return "superseded by a live source";
    default:
      return reason ?? "excluded";
  }
}

export type Role = "votes" | "confirms" | "validates" | "excluded";

export function roleOf(c: { included: boolean; reason: string | null; observation_type?: ObservationType; rights_status: string }): Role {
  if (c.included) return c.observation_type && PROXY_TYPES.has(c.observation_type) ? "confirms" : "votes";
  if (c.reason === "validation_only" || c.reason === "validator_disagrees") return "validates";
  return "excluded";
}

export const ROLE_LABEL: Record<Role, string> = { votes: "votes", confirms: "confirms (proxy)", validates: "validates", excluded: "excluded" };

export const TIER_LABEL: Record<CoverageTier, string> = { A: "Tier A · major", B: "Tier B · liquid", C: "Tier C · long tail", D: "Tier D · official reference" };
export const TIER_TARGET: Record<CoverageTier, string> = { A: "≥ 3 independent families, 5 observations", B: "≥ 2 families, 3 observations", C: "1 family, 2 observations", D: "one official source is the truth" };

export const COVERAGE_STATUS_LABEL: Record<CoverageStatus, string> = { COVERED: "covered", UNDERCOVERED: "under-covered", SINGLE_SOURCE: "single source", NO_DATA: "no data" };
export const COVERAGE_STATUS_TONE: Record<CoverageStatus, string> = {
  COVERED: "bg-positive-soft text-positive",
  UNDERCOVERED: "bg-warning-soft text-warning",
  SINGLE_SOURCE: "bg-warning-soft text-warning",
  NO_DATA: "bg-stale-soft text-stale",
};

export function formatDeltaBps(v: number | null | undefined): string {
  if (v == null || !Number.isFinite(v)) return "—";
  const a = Math.abs(v);
  const s = a < 10 ? a.toFixed(2) : a < 100 ? a.toFixed(1) : Math.round(a).toString();
  return `${v > 0 ? "+" : v < 0 ? "−" : ""}${s} bp`;
}

export function deltaTone(v: number | null | undefined): string {
  if (v == null) return "text-ink-3";
  const a = Math.abs(v);
  return a <= 5 ? "text-positive" : a <= 25 ? "text-ink-2" : a <= 100 ? "text-warning" : "text-negative";
}