import { describe, expect, it } from "vitest";

import {
  activeProductFeatureIds,
  resolveProductFeatures,
  selectCompiledProductFeatures,
} from "../../src/contracts/product-features.ts";
import { runtimeConfigV2ArtifactSchema } from "../../src/contracts/release-artifacts.ts";
import {
  COMPILED_PRODUCT_FEATURE_IDS,
  INSTALLED_PRODUCT_FEATURE_IDS,
} from "../../src/features/installed-product-manifest.ts";
import {
  ROUTE_FEATURE_OWNER,
  ROUTE_REGISTRY,
} from "../../src/features/installed-feature-contracts.ts";

const COMPILED = Object.freeze([
  Object.freeze({ featureId: "reference-feature" }),
  Object.freeze({ featureId: "billing" }),
]);

describe("build-time product selection", () => {
  it("keeps everything when nothing is declared", () => {
    for (const declared of [undefined, "", "   "]) {
      expect(
        selectCompiledProductFeatures(COMPILED, declared).map((f) => f.featureId),
        String(declared),
      ).toEqual(["reference-feature", "billing"]);
    }
  });

  it("narrows to the declared subset", () => {
    expect(
      selectCompiledProductFeatures(COMPILED, "billing").map((f) => f.featureId),
    ).toEqual(["billing"]);
    expect(
      selectCompiledProductFeatures(COMPILED, " billing , reference-feature ").map(
        (f) => f.featureId,
      ),
    ).toEqual(["reference-feature", "billing"]);
  });

  it("selects nothing only when asked explicitly", () => {
    // A blank value keeps everything on purpose: an unset CI variable expands
    // to a blank string, and that must not be how a build ships no features.
    expect(selectCompiledProductFeatures(COMPILED, "none")).toEqual([]);
    expect(selectCompiledProductFeatures(COMPILED, " none ")).toEqual([]);
    expect(selectCompiledProductFeatures(COMPILED, "").length).toBe(2);
    // A value that parses to no names at all is a typo, not an instruction.
    expect(() => selectCompiledProductFeatures(COMPILED, ",")).toThrow(
      /names no feature/u,
    );
  });

  it("refuses to name a feature this build does not contain", () => {
    // The whole point of the direction rule: an environment value can subtract
    // from the source tree and must never be able to add to it. Accepting an
    // unknown id silently would let a deployment believe it had switched on
    // something that is not in the bundle.
    expect(() => selectCompiledProductFeatures(COMPILED, "analytics")).toThrow(
      /does not contain: analytics/u,
    );
    expect(() =>
      selectCompiledProductFeatures(COMPILED, "billing,analytics"),
    ).toThrow(/analytics/u);
  });

  it("refuses a duplicated feature id in the manifest", () => {
    expect(() =>
      selectCompiledProductFeatures(
        [{ featureId: "a" }, { featureId: "a" }],
        undefined,
      ),
    ).toThrow(/duplicate product feature id/u);
  });
});

describe("runtime product feature resolution", () => {
  it("reports active, disabled and not-installed distinctly", () => {
    const statuses = resolveProductFeatures(
      ["reference-feature", "billing"],
      ["reference-feature"],
      { "reference-feature": "DISABLED" },
    );
    expect(statuses).toEqual([
      { featureId: "billing", state: "NOT_INSTALLED" },
      { featureId: "reference-feature", state: "DISABLED_BY_CONFIG" },
    ]);
    expect(activeProductFeatureIds(statuses)).toEqual([]);
  });

  it("cannot switch on a feature the build left out", () => {
    // `DEFAULT` on an uninstalled feature is not an instruction to install it.
    const statuses = resolveProductFeatures(["billing"], [], {
      billing: "DEFAULT",
    });
    expect(statuses).toEqual([{ featureId: "billing", state: "NOT_INSTALLED" }]);
    expect(activeProductFeatureIds(statuses)).toEqual([]);
  });

  it("ignores an override naming a feature this build never declared", () => {
    // A shared runtime document may cover several builds, so a stale key is
    // inert rather than fatal.
    const statuses = resolveProductFeatures(
      ["reference-feature"],
      ["reference-feature"],
      { analytics: "DISABLED" },
    );
    expect(activeProductFeatureIds(statuses)).toEqual(["reference-feature"]);
  });

  it("leaves an installed feature active without an override", () => {
    const statuses = resolveProductFeatures(
      COMPILED_PRODUCT_FEATURE_IDS,
      INSTALLED_PRODUCT_FEATURE_IDS,
    );
    expect(activeProductFeatureIds(statuses)).toEqual([
      ...INSTALLED_PRODUCT_FEATURE_IDS,
    ]);
  });
});

describe("runtime config carries the switch", () => {
  const base = {
    APP_ENV: "local" as const,
    API_BASE_URL: "http://localhost:8080/",
    TELEMETRY_ENABLED: false,
    AUTH_MODE: "demo" as const,
    CONFIG_SCHEMA_VERSION: "2.0" as const,
    RELEASE_MANIFEST_URL: "/release-manifest.json",
  };

  it("defaults to disabling nothing", () => {
    const parsed = runtimeConfigV2ArtifactSchema.parse(base);
    expect(parsed.FEATURE_OVERRIDES).toEqual({});
  });

  it("accepts only DEFAULT or DISABLED", () => {
    expect(
      runtimeConfigV2ArtifactSchema.parse({
        ...base,
        FEATURE_OVERRIDES: { "reference-feature": "DISABLED" },
      }).FEATURE_OVERRIDES,
    ).toEqual({ "reference-feature": "DISABLED" });
    // There is no "ENABLED": the vocabulary itself is what makes the rule
    // unbreakable, not a check somewhere downstream.
    expect(
      runtimeConfigV2ArtifactSchema.safeParse({
        ...base,
        FEATURE_OVERRIDES: { "reference-feature": "ENABLED" },
      }).success,
    ).toBe(false);
  });

  it("refuses a malformed feature id", () => {
    for (const featureId of ["Reference", "reference_feature", "", "-x"]) {
      expect(
        runtimeConfigV2ArtifactSchema.safeParse({
          ...base,
          FEATURE_OVERRIDES: { [featureId]: "DISABLED" },
        }).success,
        featureId,
      ).toBe(false);
    }
  });
});

describe("every installed registry consults the manifest", () => {
  /**
   * The manifest only means something if each registry actually asks it. A new
   * registry that spreads a feature in directly would reintroduce exactly the
   * coupling this file exists to remove, and nothing else would notice.
   */
  it("gates every feature contribution on the selection", async () => {
    const { readdir, readFile } = await import("node:fs/promises");
    const nodePath = (await import("node:path")).default;
    const root = "src/features";
    const registries = (await readdir(root)).filter((entry) =>
      /^installed-.*\.tsx?$/u.test(entry),
    );
    expect(registries.length).toBeGreaterThan(3);
    const exempt = new Set([
      // The manifest is the selection.
      "installed-product-manifest.ts",
      // Capabilities have their own §3.5 selection file and override vocabulary.
      "installed-runtime-capabilities.ts",
      // Message keys stay total on purpose; see the file for why.
      "installed-feature-messages.ts",
    ]);
    for (const registry of registries) {
      if (exempt.has(registry)) continue;
      const source = await readFile(nodePath.join(root, registry), "utf8");
      expect(
        /INSTALLED_PRODUCT_FEATURE(S|_IDS)/u.test(source),
        `${registry} must compose from the product manifest`,
      ).toBe(true);
    }
  });
});

describe("route ownership", () => {
  it("attributes every feature route to its feature and no platform route", () => {
    for (const featureId of INSTALLED_PRODUCT_FEATURE_IDS) {
      expect(Object.values(ROUTE_FEATURE_OWNER)).toContain(featureId);
    }
    // Platform routes have no owner, so disabling a feature can never withdraw
    // the shell's own navigation.
    for (const routeId of ["APP_HOME", "NOT_FOUND", "EXAMPLES_PLATFORM"]) {
      expect(ROUTE_FEATURE_OWNER[routeId], routeId).toBeUndefined();
      expect(Object.keys(ROUTE_REGISTRY)).toContain(routeId);
    }
  });

  it("owns exactly the routes the registry received from features", () => {
    const owned = Object.keys(ROUTE_FEATURE_OWNER);
    expect(owned.length).toBeGreaterThan(0);
    for (const routeId of owned) {
      expect(Object.keys(ROUTE_REGISTRY), routeId).toContain(routeId);
    }
  });
});