import {
  type ModuleConfigurationDeclarationInput,
  type ModuleSecretSource,
  parseModuleManifest,
} from "@ekklesia/contracts";
import { describe, expect, it } from "vitest";
import type { DiscoveredModule } from "../src/modules/discovery.js";
import { resolveModuleEligibility, resolveModuleLifecycleView } from "../src/modules/lifecycle.js";

/** A minimal in-memory `DiscoveredModule`, built through `parseModuleManifest` so a fixture real
 * discovery would reject can never stand in for one it would accept. */
function fakeModule(
  id: string,
  options: {
    readonly configuration?: readonly ModuleConfigurationDeclarationInput[];
    readonly dependencies?: Record<string, unknown>;
  } = {},
): DiscoveredModule {
  const manifest = parseModuleManifest({
    manifestVersion: 5,
    id,
    name: `${id} module`,
    version: "1.0.0",
    compatibility: { platform: "^0.1.0", moduleSdk: "^0.1.0" },
    configuration: options.configuration ?? [],
    ...(options.dependencies ? { dependencies: options.dependencies } : {}),
    entrypoints: { server: "./dist/does-not-exist/index.js" },
  });
  return {
    directory: `/modules/${id}`,
    entrypoints: { server: `/modules/${id}/dist/does-not-exist/index.js` },
    manifest,
    manifestPath: `/modules/${id}/ekklesia.module.json`,
    packageName: `@test/${id}`,
  };
}

function enablement(...records: readonly (readonly [string, boolean])[]) {
  return { modules: records.map(([moduleId, enabled]) => ({ moduleId, enabled })) };
}

function settings(...records: readonly (readonly [string, string, string])[]) {
  return {
    records: records.map(([moduleId, key, value]) => ({ key, moduleId, value })),
  };
}

function secretsFor(
  map: Readonly<Record<string, Readonly<Record<string, string>>>>,
): ModuleSecretSource {
  return { get: (moduleId, key) => map[moduleId]?.[key] };
}

function ids(modules: readonly DiscoveredModule[]): readonly string[] {
  return modules.map((module) => module.manifest.id);
}

function entry(
  resolution: ReturnType<typeof resolveModuleEligibility>,
  moduleId: string,
): ReturnType<typeof resolveModuleEligibility>["entries"][number] {
  const found = resolution.entries.find((candidate) => candidate.moduleId === moduleId);
  if (!found) {
    throw new Error(`No eligibility entry for ${moduleId}.`);
  }
  return found;
}

describe("configuration decides eligibility, through the existing lifecycle resolver", () => {
  it("keeps a module with satisfied configuration eligible, and hands it a snapshot", () => {
    const resolution = resolveModuleEligibility(
      [
        fakeModule("announcements", {
          configuration: [{ key: "bucket", type: "string", required: true }],
        }),
      ],
      enablement(),
      { settings: settings(["announcements", "bucket", "announcements"]) },
    );

    expect(ids(resolution.eligibleModules)).toEqual(["announcements"]);
    expect(entry(resolution, "announcements").blocked).toBeUndefined();
    // The same pass that decided eligibility produced the snapshot, so the configuration that made
    // the module eligible is the identical object it will receive.
    expect(resolution.configurations.get("announcements")?.getString("bucket")).toBe(
      "announcements",
    );
  });

  it("blocks an enabled module whose required configuration is missing, naming the key", () => {
    const resolution = resolveModuleEligibility(
      [
        fakeModule("announcements", {
          configuration: [{ key: "bucket", type: "string", required: true }],
        }),
      ],
      enablement(),
      { settings: settings() },
    );

    expect(resolution.eligibleModules).toEqual([]);
    expect(entry(resolution, "announcements").blocked).toEqual({
      configurationKey: "bucket",
      reason: "configuration_missing",
    });
    // No snapshot for a module that is not going to start.
    expect(resolution.configurations.has("announcements")).toBe(false);
  });

  it("blocks on an invalid stored value rather than starting on a default nobody chose", () => {
    const resolution = resolveModuleEligibility(
      [
        fakeModule("announcements", {
          configuration: [{ key: "slideSeconds", type: "integer", default: 7, maximum: 600 }],
        }),
      ],
      enablement(),
      { settings: settings(["announcements", "slideSeconds", "100000"]) },
    );

    expect(entry(resolution, "announcements").blocked).toEqual({
      configurationKey: "slideSeconds",
      reason: "configuration_invalid",
    });
  });

  it("blocks on a missing required secret, distinctly from a missing ordinary value", () => {
    const resolution = resolveModuleEligibility(
      [
        fakeModule("announcements", {
          configuration: [{ key: "storageCredential", type: "secret", required: true }],
        }),
      ],
      enablement(),
      { settings: settings() },
    );

    // A different reason because it has a different fix: set an environment variable on the
    // deployment, not a value in the database.
    expect(entry(resolution, "announcements").blocked).toEqual({
      configurationKey: "storageCredential",
      reason: "secret_missing",
    });
  });

  it("becomes eligible once the deployment supplies the secret, with no stored value involved", () => {
    const module = fakeModule("announcements", {
      configuration: [{ key: "storageCredential", type: "secret", required: true }],
    });

    expect(
      resolveModuleEligibility([module], enablement(), { settings: settings() }).eligibleModules,
    ).toEqual([]);
    expect(
      ids(
        resolveModuleEligibility([module], enablement(), {
          secrets: secretsFor({ announcements: { storageCredential: "s3cret" } }),
          settings: settings(),
        }).eligibleModules,
      ),
    ).toEqual(["announcements"]);
  });

  it("does not evaluate a disabled module's configuration at all", () => {
    const resolution = resolveModuleEligibility(
      [
        fakeModule("announcements", {
          configuration: [{ key: "bucket", type: "string", required: true }],
        }),
      ],
      enablement(["announcements", false]),
      { settings: settings() },
    );

    // Disabled is not blocked: it is doing what it was told, and reporting a configuration problem
    // for something nobody asked to run would be noise.
    expect(entry(resolution, "announcements").blocked).toBeUndefined();
    expect(entry(resolution, "announcements").configured.enabled).toBe(false);
  });

  it("leaves a module declaring no configuration exactly as it was", () => {
    const resolution = resolveModuleEligibility([fakeModule("calendar")], enablement(), {
      settings: settings(),
    });

    expect(ids(resolution.eligibleModules)).toEqual(["calendar"]);
    expect(resolution.configurations.get("calendar")?.keys()).toEqual([]);
  });

  it("resolves identically when no configuration input is supplied at all", () => {
    // The third argument is optional, so every pre-existing caller keeps its exact behaviour.
    const withoutInput = resolveModuleEligibility([fakeModule("calendar")], enablement());
    const withEmptyInput = resolveModuleEligibility([fakeModule("calendar")], enablement(), {
      settings: settings(),
    });

    expect(withoutInput.entries).toEqual(withEmptyInput.entries);
    expect(ids(withoutInput.eligibleModules)).toEqual(["calendar"]);
  });
});

describe("configuration blocking propagates through the dependency graph", () => {
  const graph = [
    fakeModule("storage", {
      configuration: [{ key: "bucket", type: "string", required: true }],
    }),
    fakeModule("media", { dependencies: { modules: { required: { storage: "^1.0.0" } } } }),
    fakeModule("announcements", { dependencies: { modules: { required: { media: "^1.0.0" } } } }),
  ];

  it("blocks required dependents of a configuration-blocked module, transitively", () => {
    const resolution = resolveModuleEligibility(graph, enablement(), { settings: settings() });

    expect(resolution.eligibleModules).toEqual([]);
    // The chain terminates at the module whose own configuration is at fault, exactly as it
    // terminates at a disabled module — one mechanism, not two.
    expect(entry(resolution, "storage").blocked).toEqual({
      configurationKey: "bucket",
      reason: "configuration_missing",
    });
    expect(entry(resolution, "media").blocked).toEqual({
      dependency: { kind: "module", moduleId: "storage" },
      reason: "required_dependency_blocked",
    });
    expect(entry(resolution, "announcements").blocked).toEqual({
      dependency: { kind: "module", moduleId: "media" },
      reason: "required_dependency_blocked",
    });
  });

  it("unblocks the whole chain once the configuration is supplied", () => {
    const resolution = resolveModuleEligibility(graph, enablement(), {
      settings: settings(["storage", "bucket", "media-objects"]),
    });

    expect(ids(resolution.eligibleModules)).toEqual(["storage", "media", "announcements"]);
  });

  it("never blocks an unrelated module because of another module's configuration", () => {
    const resolution = resolveModuleEligibility([...graph, fakeModule("calendar")], enablement(), {
      settings: settings(),
    });

    expect(ids(resolution.eligibleModules)).toEqual(["calendar"]);
    expect(entry(resolution, "calendar").blocked).toBeUndefined();
  });

  it("drops the snapshot of a module that resolved its own configuration but lost eligibility", () => {
    const resolution = resolveModuleEligibility(
      [
        fakeModule("storage"),
        fakeModule("announcements", {
          configuration: [{ key: "bucket", type: "string", default: "b" }],
          dependencies: { modules: { required: { storage: "^1.0.0" } } },
        }),
      ],
      enablement(["storage", false]),
      { settings: settings() },
    );

    // Its own configuration was fine; it is blocked by its dependency. The map must still contain
    // exactly the modules that are going to start.
    expect(entry(resolution, "announcements").blocked?.reason).toBe("required_dependency_disabled");
    expect(resolution.configurations.has("announcements")).toBe(false);
    expect([...resolution.configurations.keys()]).toEqual([]);
  });
});

describe("configuration changes are restart-required, and reported honestly", () => {
  const module = fakeModule("announcements", {
    configuration: [{ key: "slideSeconds", type: "integer", default: 7, minimum: 1, maximum: 600 }],
  });
  const discoveredModules = [module];

  function bootSnapshot(bootSettings: ReturnType<typeof settings>) {
    const resolution = resolveModuleEligibility(discoveredModules, enablement(), {
      settings: bootSettings,
    });
    return {
      discoveredModules,
      eligibility: resolution.entries,
      startedModuleIds: resolution.eligibleModules.map((entry) => entry.manifest.id),
    };
  }

  it("does not claim a running module changed when only stored configuration did", () => {
    const view = resolveModuleLifecycleView(bootSnapshot(settings()), enablement(), {
      settings: settings(["announcements", "slideSeconds", "12"]),
    });

    // The module really is still running with 7; a configuration change is applied by the next
    // restart, and this reports exactly that rather than pretending the value took effect.
    expect(view[0]?.runtime).toEqual({ state: "running" });
    expect(view[0]?.restartRequired).toBe(false);
  });

  it("reports a pending restart when new configuration would change whether the module runs", () => {
    // Boot with a value that blocked the module, then correct it.
    const blocked = resolveModuleEligibility(discoveredModules, enablement(), {
      settings: settings(["announcements", "slideSeconds", "0"]),
    });
    expect(blocked.eligibleModules).toEqual([]);

    const view = resolveModuleLifecycleView(
      {
        discoveredModules,
        eligibility: blocked.entries,
        startedModuleIds: [],
      },
      enablement(),
      { settings: settings(["announcements", "slideSeconds", "12"]) },
    );

    // Correcting the value must show as restart-pending: the next boot really will start it.
    expect(view[0]?.runtime).toEqual({
      configurationKey: "slideSeconds",
      reason: "configuration_invalid",
      state: "blocked",
    });
    expect(view[0]?.restartRequired).toBe(true);
  });

  it("reports the boot-time configuration reason, not a recomputed one", () => {
    const blocked = resolveModuleEligibility(discoveredModules, enablement(), {
      settings: settings(["announcements", "slideSeconds", "0"]),
    });
    const view = resolveModuleLifecycleView(
      { discoveredModules, eligibility: blocked.entries, startedModuleIds: [] },
      enablement(),
      { settings: settings(["announcements", "slideSeconds", "0"]) },
    );

    expect(view[0]?.runtime).toEqual({
      configurationKey: "slideSeconds",
      reason: "configuration_invalid",
      state: "blocked",
    });
    expect(view[0]?.restartRequired).toBe(false);
  });

  it("never puts a configuration value into the lifecycle view, only the key", () => {
    const blocked = resolveModuleEligibility(discoveredModules, enablement(), {
      settings: settings(["announcements", "slideSeconds", "0"]),
    });
    const view = resolveModuleLifecycleView(
      { discoveredModules, eligibility: blocked.entries, startedModuleIds: [] },
      enablement(),
      { settings: settings(["announcements", "slideSeconds", "0"]) },
    );

    expect(JSON.stringify(view)).toContain("slideSeconds");
    expect(JSON.stringify(view)).not.toContain('"0"');
  });
});