/**
 * earth-now.co
 * Author:  Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 * File:    apps/web/test/tiers.test.ts
 * Purpose: Display-tier classification — fast tickers lead, slow stocks land in the reference strip, RT and countries route to their sections
 */

import { describe, expect, it } from "vitest";
import type { CounterModel } from "@earth-now/counter";
import type { MetricSummary } from "../lib/api";
import { secondsPerVisibleTick, tierFor, LIVE_TICK_THRESHOLD_S } from "../lib/tiers";

const T = Date.parse("2026-08-09T12:00:00Z");

function model(perSecond: number): CounterModel {
  return {
    metricId: "m",
    anchorValue: 0,
    anchorTime: "2026-01-01T00:00:00.000Z",
    rateFn: { kind: "linear", perSecond },
    observedAt: "2026-01-01T00:00:00.000Z",
    sourceId: "s",
    modelVersion: "test-v1",
    displayHints: { decimals: 0, unit: "u" },
  };
}

function metric(over: Partial<MetricSummary>): MetricSummary {
  return {
    id: "some_metric",
    name: { fr: "x", en: "x" },
    domain: "population",
    priority: "mvp",
    kind: "cumulative",
    level: 1,
    model: "seasonal-ytd-v1",
    unit: "people",
    sources: [],
    display: { decimals: 0, unit: { fr: "u", en: "u" } },
    windows: ["ytd"],
    stale: false,
    ...over,
  };
}

describe("secondsPerVisibleTick", () => {
  it("computes the visible tick interval from rate, decimals and display scale", () => {
    // 4 units/s at 0 decimals → last digit changes every 0.25 s.
    expect(secondsPerVisibleTick(model(4), { decimals: 0 }, T)).toBeCloseTo(0.25, 9);
    // 1027 MWh/s displayed in TWh (scale 1e-6) with 2 decimals → 0.01 TWh per tick.
    expect(secondsPerVisibleTick(model(1027), { decimals: 2, scale: 1e-6 }, T)).toBeCloseTo(
      0.01 / (1027e-6),
      6,
    );
    expect(secondsPerVisibleTick(model(0), { decimals: 0 }, T)).toBe(Infinity);
  });
});

describe("tierFor", () => {
  it("fast tickers are live, slow stocks are reference", () => {
    expect(tierFor(metric({}), model(4.2), T)).toBe("live");
    // CO₂ ppm style: 2.6 ppm/yr, 2 decimals → hours per tick → reference.
    expect(
      tierFor(
        metric({ id: "co2_ppm", kind: "stock", display: { decimals: 2, unit: { fr: "ppm", en: "ppm" } } }),
        model(2.6 / 31_556_952),
        T,
      ),
    ).toBe("reference");
  });

  it("routes hero, countries and RT metrics to their sections regardless of rate", () => {
    expect(tierFor(metric({ id: "world_population" }), model(2.2), T)).toBe("hero");
    expect(tierFor(metric({ id: "country_population_india" }), model(0.37), T)).toBe("country");
    expect(tierFor(metric({ id: "earthquakes_24h", level: "rt" }), model(0), T)).toBe("realtime");
  });

  it("rate-of and depletion displays read as static → reference", () => {
    const rateOf = metric({
      id: "co2_rate",
      kind: "derived",
      derived: { op: "rate-of", inputs: [{ id: "co2_emissions_ytd", weight: 1 }] },
    });
    expect(tierFor(rateOf, model(1200), T)).toBe("reference");
  });

  it("no model → reference (stale metrics never fake liveness)", () => {
    expect(tierFor(metric({}), undefined, T)).toBe("reference");
  });

  it("threshold boundary respects LIVE_TICK_THRESHOLD_S", () => {
    const boundaryRate = 1 / LIVE_TICK_THRESHOLD_S;
    expect(tierFor(metric({}), model(boundaryRate * 1.01), T)).toBe("live");
    expect(tierFor(metric({}), model(boundaryRate * 0.99), T)).toBe("reference");
  });
});