import { createHash } from "node:crypto";
import { lstat, mkdir, readdir, readFile, realpath, rename, writeFile } from "node:fs/promises";
import { isBuiltin } from "node:module";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { type ModuleManifest, safeParseModuleManifest } from "@ekklesia/contracts";
import {
  MODULE_PACKAGE_ANY_TARGET,
  MODULE_PACKAGE_FORMAT,
  MODULE_PACKAGE_LICENSE_FILENAME,
  MODULE_PACKAGE_METADATA_FILENAME,
  MODULE_PACKAGE_NOTICES_FILENAME,
  modulePackageArchiveFileName,
  modulePackageRuntimePackage,
  safeParseModulePackageLicenseExpression,
  safeParseModulePackageMetadata,
} from "@ekklesia/contracts/module-package";
import { analyzeModuleUi, ModuleUiBuildError } from "@ekklesia/module-ui-build";
import { build, type Message, type Plugin } from "esbuild";
import { minVersion, satisfies, subset, validRange } from "semver";
import {
  NATIVE_TARGETS,
  NativeError,
  type NativeErrorCode,
  type NativePackage,
  type NativeTarget,
  nativeClosure,
  nativeRuntime,
} from "./native.js";
import { type NoticeComponent, NoticeError, type NoticeUse, thirdPartyNotices } from "./notices.js";
import {
  type BundledPackage,
  BundledPackageIndex,
  isNativeOrPlatformSpecific,
} from "./packages.js";
import { loadLicenseSupplements, SupplementError } from "./supplements.js";
import { deterministicTarGz, TarPathError } from "./tar.js";

/**
 * The canonical Ekklesia module packager (ADR 0049): turns a built module directory into one
 * deterministic Module Package v1 archive and its `.sha256` line.
 *
 * It reads the module directory and the dependencies its workspace installed, and writes only the
 * two output files. It never installs, links, or deploys anything, so the workspace it runs in is
 * left exactly as it was. It produces the portable `any` target, and the native `linux-x64-glibc`
 * target, whose native runtime dependencies are copied rather than bundled (see `./native.ts`).
 */

export type ModulePackErrorCode =
  | NativeErrorCode
  | "MODULE_PACK_BUNDLE_FAILED"
  | "MODULE_PACK_DATABASE_RUNTIME_CONFLICT"
  | "MODULE_PACK_ENTRYPOINT_MISSING"
  | "MODULE_PACK_ENTRYPOINT_UNSUPPORTED"
  | "MODULE_PACK_EXTERNAL_DEPENDENCY"
  | "MODULE_PACK_FORBIDDEN_FILE"
  | "MODULE_PACK_IDENTITY_MISMATCH"
  | "MODULE_PACK_INCORPORATED_CONFLICT"
  | "MODULE_PACK_LAYOUT_CONFLICT"
  | "MODULE_PACK_MODULE_LICENSE_FILE_INVALID"
  | "MODULE_PACK_MODULE_LICENSE_INVALID"
  | "MODULE_PACK_LICENCE_SUPPLEMENT_INVALID"
  | "MODULE_PACK_LICENCE_SUPPLEMENT_MISMATCH"
  | "MODULE_PACK_LICENCE_TEXT_MISSING"
  | "MODULE_PACK_LICENCE_UNKNOWN"
  | "MODULE_PACK_MANIFEST_INVALID"
  | "MODULE_PACK_METADATA_INVALID"
  | "MODULE_PACK_MIGRATIONS_INVALID"
  | "MODULE_PACK_NATIVE_DEPENDENCY"
  | "MODULE_PACK_NATIVE_NODE_INCOMPATIBLE"
  | "MODULE_PACK_NATIVE_TARGET_UNNEEDED"
  | "MODULE_PACK_OUTPUT_FAILED"
  | "MODULE_PACK_PATH_UNSUPPORTED"
  | "MODULE_PACK_REVISION_INVALID"
  | "MODULE_PACK_RUNTIME_UNKNOWN"
  | "MODULE_PACK_SDK_INCOMPATIBLE"
  | "MODULE_PACK_TARGET_UNSUPPORTED"
  | "MODULE_PACK_UI_STALE";

const messages: Readonly<Record<ModulePackErrorCode, string>> = Object.freeze({
  MODULE_PACK_BUNDLE_FAILED:
    "The backend could not be bundled into self-contained files. Every import must resolve and bundle cleanly.",
  MODULE_PACK_DATABASE_RUNTIME_CONFLICT: "The backend bundles more than one Drizzle version.",
  MODULE_PACK_ENTRYPOINT_MISSING:
    "A declared backend entrypoint does not exist. Build the module before packaging it.",
  MODULE_PACK_ENTRYPOINT_UNSUPPORTED:
    "Backend entrypoints must be compiled .js files to be bundled into a Module Package v1.",
  MODULE_PACK_EXTERNAL_DEPENDENCY:
    "The backend bundle would import a dependency at run time; an any-target package bundles everything.",
  MODULE_PACK_FORBIDDEN_FILE:
    "The package would contain a source, test, declaration, source-map, or dependency file.",
  MODULE_PACK_IDENTITY_MISMATCH:
    "package.json must declare a name and the same version as ekklesia.module.json.",
  MODULE_PACK_INCORPORATED_CONFLICT:
    "The package bundles more than one version of an Ekklesia package.",
  MODULE_PACK_LAYOUT_CONFLICT: "Two package files would have the same path.",
  MODULE_PACK_MODULE_LICENSE_FILE_INVALID:
    "The module license text must be supplied as an explicit, non-empty, readable regular file.",
  MODULE_PACK_MODULE_LICENSE_INVALID:
    "The source package.json must declare a valid SPDX license expression as a string.",
  MODULE_PACK_LICENCE_SUPPLEMENT_INVALID:
    "A reviewed license supplement is malformed or does not match its reviewed files.",
  MODULE_PACK_LICENCE_SUPPLEMENT_MISMATCH:
    "A license supplement names this package, but not its exact version, content digest, and declared licence.",
  MODULE_PACK_LICENCE_TEXT_MISSING:
    "A bundled package ships no licence text, and its licence has no complete standard text to supply.",
  MODULE_PACK_LICENCE_UNKNOWN: "A bundled package declares no licence that permits redistribution.",
  MODULE_PACK_MANIFEST_INVALID: "ekklesia.module.json is missing or invalid.",
  MODULE_PACK_METADATA_INVALID: "The generated package metadata failed its own contract.",
  MODULE_PACK_MIGRATIONS_INVALID:
    "The migrations directory must hold only regular files and directories.",
  MODULE_PACK_NATIVE_DEPENDENCY:
    "The backend bundles a native or platform-specific dependency, which an any-target package cannot contain.",
  MODULE_PACK_NATIVE_DEPENDENCY_MISSING:
    "A native runtime dependency requires a package that is not installed.",
  MODULE_PACK_NATIVE_LAYOUT_CONFLICT:
    "Two versions of one package would share the native node_modules layout.",
  MODULE_PACK_NATIVE_NODE_INCOMPATIBLE:
    "A native runtime dependency does not support every Node.js version the package targets.",
  MODULE_PACK_NATIVE_PACKAGE_INVALID:
    "A native runtime dependency could not be read, or contains a link or special file.",
  MODULE_PACK_NATIVE_RUNTIME_UNKNOWN:
    "A native addon's Node.js interface could not be established exactly.",
  MODULE_PACK_NATIVE_TARGET_MISMATCH:
    "A native runtime dependency, or a file in one, is not built for the package's target.",
  MODULE_PACK_NATIVE_TARGET_UNNEEDED:
    "A native target needs a native addon; a package without one uses the any target.",
  MODULE_PACK_OUTPUT_FAILED: "The package could not be written to the output directory.",
  MODULE_PACK_PATH_UNSUPPORTED:
    "A package path is not portable printable ASCII that fits the archive format.",
  MODULE_PACK_REVISION_INVALID: "The source revision must be a full 40- or 64-character commit id.",
  MODULE_PACK_RUNTIME_UNKNOWN:
    "The module's package.json must declare the Node.js versions it supports in engines.node.",
  MODULE_PACK_SDK_INCOMPATIBLE:
    "The bundled Module SDK is outside the manifest's own compatibility.moduleSdk range.",
  MODULE_PACK_TARGET_UNSUPPORTED:
    "This packager produces the any and linux-x64-glibc targets only.",
  MODULE_PACK_UI_STALE:
    "A declared browser artifact is missing or out of date. Build the module before packaging it.",
});

export class ModulePackError extends Error {
  readonly code: ModulePackErrorCode;
  /** The package or path the failure concerns, when there is one. A module author's own build
   * input, never a secret. */
  readonly detail?: string;
  /** esbuild's structured diagnostics, for a command line to print. */
  readonly diagnostics: readonly Message[];

  constructor(code: ModulePackErrorCode, detail?: string, diagnostics: readonly Message[] = []) {
    super(detail === undefined ? messages[code] : `${messages[code]} (${detail})`);
    this.name = "ModulePackError";
    this.code = code;
    if (detail !== undefined) {
      this.detail = detail;
    }
    this.diagnostics = diagnostics;
  }
}

export interface PackModuleOptions {
  /** A built module directory: its manifest, package.json, and compiled entrypoints. */
  readonly moduleDirectory: string;
  /** Explicit license-text input. Its bytes are copied unchanged to the package root as LICENSE. */
  readonly licenseFile: string;
  /** `any`, or a native target this packager supports (`linux-x64-glibc`). */
  readonly target: string;
  readonly outDirectory: string;
  /** The full commit id the module was built from. */
  readonly sourceRevision: string;
  /** Informational only; recorded as given. */
  readonly repository?: string;
  /** The Node.js range the package is built for. Defaults to the module's own `engines.node`. */
  readonly nodeRange?: string;
  /** Reviewed license supplements (ADR 0052). Defaults to the ones this packager ships. */
  readonly supplementsDirectory?: string;
}

export interface ModulePackResult {
  readonly archivePath: string;
  readonly sha256Path: string;
  readonly sha256: string;
  readonly archiveBytes: number;
  readonly moduleId: string;
  readonly version: string;
  readonly target: string;
  /** Payload files, the metadata file not included. */
  readonly fileCount: number;
}

const NATIVE_GUARD = "ekklesia-native-addon-guard";

/** Refuses a compiled addon the moment the bundle reaches one. */
const nativeAddonGuard: Plugin = {
  name: NATIVE_GUARD,
  setup(pluginBuild) {
    pluginBuild.onLoad({ filter: /\.node$/i }, () => ({
      errors: [{ text: "A compiled Node.js addon cannot be bundled into an any-target package." }],
    }));
  },
};

/** Bundled CommonJS code that requires a Node built-in needs a `require` in module scope. Nothing
 * else can be required at run time: every other dependency is inside the bundle, and the packager
 * refuses a bundle that would import anything but a built-in. */
const REQUIRE_BANNER =
  'import { createRequire as __ekklesiaCreateRequire } from "node:module";\nconst require = __ekklesiaCreateRequire(import.meta.url);';

function compare(left: string, right: string): number {
  return left < right ? -1 : left > right ? 1 : 0;
}

function sha256(data: Uint8Array): string {
  return createHash("sha256").update(data).digest("hex");
}

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

async function readJson(file: string): Promise<unknown> {
  return JSON.parse(await readFile(file, "utf8")) as unknown;
}

const ownManifestPath = path.resolve(
  path.dirname(fileURLToPath(import.meta.url)),
  "..",
  "package.json",
);

async function packagerIdentity(): Promise<{ readonly name: string; readonly version: string }> {
  const manifest = (await readJson(ownManifestPath)) as Record<string, unknown>;
  return { name: String(manifest.name), version: String(manifest.version) };
}

/** The Node.js range a module declares for itself, in its own package.json `engines.node` (ADR
 * 0053). Read from the module, never from an enclosing workspace: a standalone module repository has
 * none. */
function moduleNodeRange(developmentPackage: Readonly<Record<string, unknown>>): string {
  const engines = developmentPackage.engines;
  const range = isRecord(engines) ? engines.node : undefined;
  if (typeof range !== "string" || range.trim() === "") {
    throw new ModulePackError("MODULE_PACK_RUNTIME_UNKNOWN");
  }
  return range;
}

/** `./dist/server/index.js` → `dist/server/index.js`, inside the module directory. */
function moduleRelative(declared: string): string {
  return path.posix.normalize(declared.replace(/^\.\//u, ""));
}

function portable(relative: string): boolean {
  const segments = relative.split("/");
  return (
    /^[\x20-\x7e]+$/u.test(relative) &&
    !relative.includes("\\") &&
    segments.every((segment) => segment !== "" && segment !== "." && segment !== "..")
  );
}

function forbidden(relative: string): boolean {
  return (
    /(^|\/)(src|tests?|node_modules)\//u.test(relative) ||
    /\.(map|d\.ts|d\.mts|d\.cts)$/u.test(relative)
  );
}

async function readTree(root: string, relative: string, files: Map<string, Buffer>): Promise<void> {
  const directory = path.join(root, relative);
  for (const entry of (await readdir(directory, { withFileTypes: true })).sort((left, right) =>
    compare(left.name, right.name),
  )) {
    const childRelative = `${relative}/${entry.name}`;
    const stats = await lstat(path.join(directory, entry.name));
    if (stats.isDirectory()) {
      await readTree(root, childRelative, files);
    } else if (stats.isFile()) {
      files.set(childRelative, await readFile(path.join(directory, entry.name)));
    } else {
      throw new ModulePackError("MODULE_PACK_MIGRATIONS_INVALID", childRelative);
    }
  }
}

/** The files redistributed for a component, relative to its root: what it copies, or the source
 * files of it that were bundled. The content digest a license supplement names is over these. */
async function redistributedFiles(component: {
  readonly bundled: BundledPackage;
  readonly files: ReadonlySet<string>;
  readonly copied?: ReadonlyMap<string, Buffer>;
}): Promise<ReadonlyMap<string, Uint8Array>> {
  if (component.copied !== undefined) {
    return component.copied;
  }
  const files = new Map<string, Uint8Array>();
  for (const file of component.files) {
    const real = await realpath(file).catch(() => file);
    files.set(
      path.relative(component.bundled.root, real).split(path.sep).join("/"),
      await readFile(real),
    );
  }
  return files;
}

interface BackendBundle {
  readonly outputs: ReadonlyMap<string, Buffer>;
  readonly inputs: readonly string[];
}

const NATIVE_EXTERNALS = "ekklesia-native-externals";

/** The bare specifier's package name: `sharp/x` → `sharp`, `@scope/name/x` → `@scope/name`. */
function specifierPackage(specifier: string): string {
  const segments = specifier.split("/");
  return specifier.startsWith("@") ? segments.slice(0, 2).join("/") : (segments[0] ?? "");
}

/**
 * For a native target: keeps every native or platform-specific third-party package out of the
 * bundle, as an import of the package itself, and records it as a root of the copied runtime
 * closure. Decided per resolved package, by the same rule that refuses one in an `any` package.
 */
function nativeExternals(
  index: BundledPackageIndex,
  externals: Map<string, BundledPackage>,
): Plugin {
  return {
    name: NATIVE_EXTERNALS,
    setup(pluginBuild) {
      pluginBuild.onResolve({ filter: /^[^./]/ }, async (args) => {
        if (
          (args.pluginData as { ekklesiaNative?: boolean } | undefined)?.ekklesiaNative ||
          isBuiltin(args.path)
        ) {
          return undefined;
        }
        const resolved = await pluginBuild.resolve(args.path, {
          importer: args.importer,
          kind: args.kind,
          pluginData: { ekklesiaNative: true },
          resolveDir: args.resolveDir,
        });
        if (resolved.errors.length > 0 || resolved.external || resolved.path === "") {
          return undefined;
        }
        const owner = await index.packageOf(resolved.path);
        if (
          owner === undefined ||
          !owner.thirdParty ||
          !(await isNativeOrPlatformSpecific(owner))
        ) {
          return undefined;
        }
        if (specifierPackage(args.path) !== owner.name) {
          return {
            errors: [{ text: "A native package must be imported by its own package name." }],
          };
        }
        externals.set(owner.name, owner);
        return { external: true, path: args.path };
      });
    },
  };
}

async function bundleBackend(
  moduleDirectory: string,
  manifest: ModuleManifest,
  nodeRange: string,
  native?: { readonly index: BundledPackageIndex; readonly externals: Map<string, BundledPackage> },
): Promise<BackendBundle> {
  const declared = [
    manifest.entrypoints.server,
    manifest.entrypoints.schema,
    manifest.entrypoints.jobs,
  ].filter((entrypoint): entrypoint is string => entrypoint !== undefined);
  const entryPoints: { in: string; out: string }[] = [];
  for (const entrypoint of declared) {
    const relative = moduleRelative(entrypoint);
    if (!relative.endsWith(".js")) {
      throw new ModulePackError("MODULE_PACK_ENTRYPOINT_UNSUPPORTED", relative);
    }
    try {
      if (!(await lstat(path.join(moduleDirectory, relative))).isFile()) {
        throw new Error("not a file");
      }
    } catch {
      throw new ModulePackError("MODULE_PACK_ENTRYPOINT_MISSING", relative);
    }
    entryPoints.push({ in: `./${relative}`, out: relative.slice(0, -".js".length) });
  }

  const minimum = minVersion(nodeRange);
  let result: Awaited<ReturnType<typeof build>>;
  try {
    result = await build({
      absWorkingDir: moduleDirectory,
      banner: { js: REQUIRE_BANNER },
      bundle: true,
      chunkNames: "dist/chunks/[name]-[hash]",
      entryPoints,
      format: "esm",
      // Licence comments stay in the code as well; THIRD_PARTY_NOTICES is what satisfies the
      // licences, never these comments alone.
      legalComments: "eof",
      logLevel: "silent",
      metafile: true,
      minify: false,
      outdir: moduleDirectory,
      platform: "node",
      plugins:
        native === undefined
          ? [nativeAddonGuard]
          : [nativeExternals(native.index, native.externals), nativeAddonGuard],
      sourcemap: false,
      splitting: true,
      target: `node${minimum?.version ?? "24"}`,
      write: false,
    });
  } catch (error) {
    const errors =
      isRecord(error) && Array.isArray(error.errors) ? (error.errors as Message[]) : [];
    const native = errors.some((message) => message.pluginName === NATIVE_GUARD);
    throw new ModulePackError(
      native ? "MODULE_PACK_NATIVE_DEPENDENCY" : "MODULE_PACK_BUNDLE_FAILED",
      undefined,
      errors,
    );
  }
  // A warning is a bundle that might not run: a require it could not follow, an import it could
  // not see. An installed module has nothing to fall back on, so a warning fails packaging.
  if (result.warnings.length > 0) {
    throw new ModulePackError("MODULE_PACK_BUNDLE_FAILED", undefined, result.warnings);
  }
  const { metafile, outputFiles } = result;
  if (metafile === undefined || outputFiles === undefined) {
    throw new ModulePackError("MODULE_PACK_BUNDLE_FAILED");
  }
  for (const output of Object.values(metafile.outputs)) {
    for (const imported of output.imports) {
      if (
        imported.external &&
        !isBuiltin(imported.path) &&
        !native?.externals.has(specifierPackage(imported.path))
      ) {
        throw new ModulePackError("MODULE_PACK_EXTERNAL_DEPENDENCY", imported.path);
      }
    }
  }
  const outputs = new Map<string, Buffer>();
  for (const outputFile of outputFiles) {
    outputs.set(
      path.relative(moduleDirectory, outputFile.path).split(path.sep).join("/"),
      Buffer.from(outputFile.contents),
    );
  }
  return {
    inputs: Object.keys(metafile.inputs).map((input) => path.resolve(moduleDirectory, input)),
    outputs,
  };
}

export async function packModule(options: PackModuleOptions): Promise<ModulePackResult> {
  const nativeTarget: NativeTarget | undefined = NATIVE_TARGETS.get(options.target);
  if (options.target !== MODULE_PACKAGE_ANY_TARGET && nativeTarget === undefined) {
    throw new ModulePackError("MODULE_PACK_TARGET_UNSUPPORTED", options.target);
  }
  const target = options.target;
  if (!/^(?:[0-9a-f]{40}|[0-9a-f]{64})$/u.test(options.sourceRevision)) {
    throw new ModulePackError("MODULE_PACK_REVISION_INVALID");
  }
  const moduleDirectory = await realpath(path.resolve(options.moduleDirectory)).catch(() => {
    throw new ModulePackError("MODULE_PACK_MANIFEST_INVALID");
  });

  const manifestBytes = await readFile(path.join(moduleDirectory, "ekklesia.module.json")).catch(
    () => {
      throw new ModulePackError("MODULE_PACK_MANIFEST_INVALID");
    },
  );
  let manifestInput: unknown;
  try {
    manifestInput = JSON.parse(manifestBytes.toString("utf8"));
  } catch {
    throw new ModulePackError("MODULE_PACK_MANIFEST_INVALID");
  }
  const parsedManifest = safeParseModuleManifest(manifestInput);
  if (!parsedManifest.success) {
    throw new ModulePackError("MODULE_PACK_MANIFEST_INVALID");
  }
  const manifest = parsedManifest.data;
  const developmentPackage = await readJson(path.join(moduleDirectory, "package.json")).catch(
    () => undefined,
  );
  if (
    !isRecord(developmentPackage) ||
    typeof developmentPackage.name !== "string" ||
    developmentPackage.name === "" ||
    developmentPackage.version !== manifest.version
  ) {
    throw new ModulePackError("MODULE_PACK_IDENTITY_MISMATCH");
  }
  const parsedLicense = safeParseModulePackageLicenseExpression(developmentPackage.license);
  if (!parsedLicense.success) {
    throw new ModulePackError("MODULE_PACK_MODULE_LICENSE_INVALID");
  }
  const license = parsedLicense.data;
  let licenseBytes: Buffer;
  try {
    if (
      typeof options.licenseFile !== "string" ||
      options.licenseFile === "" ||
      !(await lstat(path.resolve(options.licenseFile))).isFile()
    ) {
      throw new Error("not a regular file");
    }
    licenseBytes = await readFile(path.resolve(options.licenseFile));
    if (licenseBytes.length === 0) {
      // An empty file would satisfy the inventory while carrying no license material at all.
      throw new Error("empty");
    }
  } catch {
    throw new ModulePackError("MODULE_PACK_MODULE_LICENSE_FILE_INVALID");
  }

  const nodeRange = options.nodeRange ?? moduleNodeRange(developmentPackage);
  if (validRange(nodeRange) === null) {
    throw new ModulePackError("MODULE_PACK_RUNTIME_UNKNOWN");
  }

  let supplements: Awaited<ReturnType<typeof loadLicenseSupplements>>;
  try {
    supplements = await loadLicenseSupplements(options.supplementsDirectory);
  } catch (error) {
    throw new ModulePackError(
      "MODULE_PACK_LICENCE_SUPPLEMENT_INVALID",
      error instanceof SupplementError ? error.supplement : undefined,
    );
  }

  // 1. The backend, bundled with every pure-JavaScript dependency it uses. For a native target,
  //    native packages stay outside the bundle and are copied with their runtime closure instead.
  const index = new BundledPackageIndex();
  const externals = new Map<string, BundledPackage>();
  const backend = await bundleBackend(
    moduleDirectory,
    manifest,
    nodeRange,
    nativeTarget === undefined ? undefined : { externals, index },
  );
  let nativePackages: readonly NativePackage[] = [];
  let runtimeRequirements: Record<string, unknown> = {};
  if (nativeTarget !== undefined) {
    try {
      nativePackages = await nativeClosure([...externals.values()], nativeTarget);
      const { addons, ...requirements } = nativeRuntime(nativePackages, nativeTarget);
      if (addons === 0) {
        throw new ModulePackError("MODULE_PACK_NATIVE_TARGET_UNNEEDED", options.target);
      }
      runtimeRequirements = requirements;
    } catch (error) {
      if (error instanceof NativeError) {
        throw new ModulePackError(error.code, error.detail);
      }
      throw error;
    }
    for (const nativePackage of nativePackages) {
      const engines = nativePackage.manifest.engines;
      const engine = isRecord(engines) ? engines.node : undefined;
      if (typeof engine === "string" && !subset(nodeRange, engine)) {
        throw new ModulePackError(
          "MODULE_PACK_NATIVE_NODE_INCOMPATIBLE",
          `${nativePackage.name}@${nativePackage.version}`,
        );
      }
    }
  }

  // 2. The browser artifacts, exactly as built, with what went into each.
  let ui: Awaited<ReturnType<typeof analyzeModuleUi>>;
  try {
    ui = await analyzeModuleUi({ moduleDirectory });
  } catch (error) {
    throw new ModulePackError(
      "MODULE_PACK_UI_STALE",
      error instanceof ModuleUiBuildError ? error.code : undefined,
    );
  }

  // 3. Every bundled source file traced to its package, and every copied package.
  const components = new Map<
    string,
    {
      bundled: BundledPackage;
      uses: Set<NoticeUse>;
      files: Set<string>;
      copied?: ReadonlyMap<string, Buffer>;
    }
  >();
  const incorporates = new Map<string, string>();
  const drizzleVersions = new Set<string>();
  const sources: { readonly file: string; readonly use: NoticeUse }[] = [
    ...backend.inputs.map((file) => ({ file, use: "backend" as const })),
    ...ui.artifacts.flatMap((artifact) =>
      artifact.inputs.map((file) => ({ file, use: "browser" as const })),
    ),
  ];
  for (const { file, use } of sources) {
    const bundled = await index.packageOf(file);
    if (bundled === undefined || bundled.root === moduleDirectory) {
      continue;
    }
    if (bundled.ekklesiaOwned) {
      // An Ekklesia module-development package, recognized by its identity, not by where it was
      // installed (ADR 0053): recorded under incorporates, never credited as third-party software.
      const known = incorporates.get(bundled.name);
      if (known !== undefined && known !== bundled.version) {
        throw new ModulePackError("MODULE_PACK_INCORPORATED_CONFLICT", bundled.name);
      }
      incorporates.set(bundled.name, bundled.version);
      continue;
    }
    if (!bundled.thirdParty) {
      continue;
    }
    if (use === "backend" && bundled.name === "drizzle-orm") {
      drizzleVersions.add(bundled.version);
    }
    const key = `${bundled.name}@${bundled.version}`;
    const existing = components.get(key);
    if (existing) {
      existing.uses.add(use);
      existing.files.add(file);
    } else {
      if (use === "backend" && (await isNativeOrPlatformSpecific(bundled))) {
        throw new ModulePackError("MODULE_PACK_NATIVE_DEPENDENCY", key);
      }
      components.set(key, { bundled, files: new Set([file]), uses: new Set([use]) });
    }
  }
  for (const nativePackage of nativePackages) {
    const key = `${nativePackage.name}@${nativePackage.version}`;
    const existing = components.get(key);
    const entry = existing ?? {
      bundled: {
        manifest: nativePackage.manifest,
        name: nativePackage.name,
        root: nativePackage.root,
        ekklesiaOwned: false,
        thirdParty: true,
        version: nativePackage.version,
      },
      files: new Set<string>(),
      uses: new Set<NoticeUse>(),
    };
    entry.uses.add("node_modules");
    entry.copied = nativePackage.files;
    components.set(key, entry);
  }
  const usesDatabaseAbi = manifest.database?.abi === 1;
  if (!usesDatabaseAbi && drizzleVersions.size > 1) {
    throw new ModulePackError("MODULE_PACK_DATABASE_RUNTIME_CONFLICT");
  }
  const sdk = incorporates.get("@ekklesia/module-sdk");
  if (sdk !== undefined && !satisfies(sdk, manifest.compatibility.moduleSdk)) {
    throw new ModulePackError("MODULE_PACK_SDK_INCOMPATIBLE", sdk);
  }

  // 4. The payload.
  const files = new Map<string, Buffer>();
  const add = (relative: string, data: Buffer, copied = false): void => {
    if (!portable(relative)) {
      throw new ModulePackError("MODULE_PACK_PATH_UNSUPPORTED", relative);
    }
    if (!copied && forbidden(relative)) {
      throw new ModulePackError("MODULE_PACK_FORBIDDEN_FILE", relative);
    }
    if (files.has(relative) || relative === MODULE_PACKAGE_METADATA_FILENAME) {
      throw new ModulePackError("MODULE_PACK_LAYOUT_CONFLICT", relative);
    }
    files.set(relative, data);
  };
  for (const [relative, data] of backend.outputs) {
    add(relative, data);
  }
  for (const artifact of ui.artifacts) {
    if (!artifact.builtArtifactCurrent) {
      throw new ModulePackError(
        "MODULE_PACK_UI_STALE",
        path.relative(moduleDirectory, artifact.outputFile),
      );
    }
    add(
      path.relative(moduleDirectory, artifact.outputFile).split(path.sep).join("/"),
      await readFile(artifact.outputFile),
    );
  }
  if (manifest.entrypoints.migrations !== undefined) {
    const migrations = new Map<string, Buffer>();
    try {
      await readTree(moduleDirectory, moduleRelative(manifest.entrypoints.migrations), migrations);
    } catch (error) {
      if (error instanceof ModulePackError) {
        throw error;
      }
      throw new ModulePackError("MODULE_PACK_MIGRATIONS_INVALID");
    }
    for (const [relative, data] of migrations) {
      add(relative, data);
    }
  }
  // A native target's runtime dependencies, as real files, flat under node_modules/<name>. They are
  // third-party packages carried as published, so the module's own source and test path rules do
  // not apply to their contents; declarations and source maps were already left out.
  for (const nativePackage of nativePackages) {
    for (const [relative, data] of nativePackage.files) {
      add(`node_modules/${nativePackage.name}/${relative}`, data, true);
    }
  }
  add("ekklesia.module.json", manifestBytes);
  add(MODULE_PACKAGE_LICENSE_FILENAME, licenseBytes);
  add(
    "package.json",
    Buffer.from(
      `${JSON.stringify(
        modulePackageRuntimePackage({ name: developmentPackage.name, version: manifest.version }),
        null,
        2,
      )}\n`,
    ),
  );
  try {
    add(
      MODULE_PACKAGE_NOTICES_FILENAME,
      Buffer.from(
        await thirdPartyNotices(
          new Map(
            [...components].map(([key, component]): [string, NoticeComponent] => [
              key,
              {
                bundled: component.bundled,
                redistributedFiles: () => redistributedFiles(component),
                uses: component.uses,
              },
            ]),
          ),
          supplements,
        ),
      ),
    );
  } catch (error) {
    if (error instanceof NoticeError) {
      throw new ModulePackError(error.code, error.component);
    }
    throw error;
  }

  // 5. The metadata, checked against its own contract before anything is written.
  const listed = [...files.entries()]
    .sort(([left], [right]) => compare(left, right))
    .map(([relative, data]) => ({ path: relative, sha256: sha256(data), size: data.length }));
  const metadata = {
    packageFormat: MODULE_PACKAGE_FORMAT,
    module: { id: manifest.id, version: manifest.version },
    license,
    target,
    runtime: { node: nodeRange, ...runtimeRequirements },
    provenance: {
      revision: options.sourceRevision,
      ...(options.repository === undefined ? {} : { repository: options.repository }),
      packager: await packagerIdentity(),
    },
    incorporates: Object.fromEntries(
      [...incorporates].sort(([left], [right]) => compare(left, right)),
    ),
    ...(!usesDatabaseAbi && drizzleVersions.size === 1
      ? { transitional: { databaseRuntime: { "drizzle-orm": [...drizzleVersions][0] } } }
      : {}),
    files: listed.map((file) => ({ path: file.path, size: file.size, sha256: file.sha256 })),
  };
  if (!safeParseModulePackageMetadata(metadata).success) {
    throw new ModulePackError("MODULE_PACK_METADATA_INVALID");
  }
  const payload = new Map(files);
  payload.set(
    MODULE_PACKAGE_METADATA_FILENAME,
    Buffer.from(`${JSON.stringify(metadata, null, 2)}\n`),
  );

  // 6. The archive and its digest.
  let archive: Buffer;
  try {
    archive = deterministicTarGz(manifest.id, payload);
  } catch (error) {
    if (error instanceof TarPathError) {
      throw new ModulePackError("MODULE_PACK_PATH_UNSUPPORTED", error.path);
    }
    throw error;
  }
  const digest = sha256(archive);
  const fileName = modulePackageArchiveFileName(manifest.id, manifest.version, target);
  const outDirectory = path.resolve(options.outDirectory);
  const archivePath = path.join(outDirectory, fileName);
  const sha256Path = `${archivePath}.sha256`;
  try {
    await mkdir(outDirectory, { recursive: true });
    const staging = `${archivePath}.partial-${process.pid}`;
    await writeFile(staging, archive);
    await rename(staging, archivePath);
    await writeFile(`${sha256Path}.partial-${process.pid}`, `${digest}  ${fileName}\n`);
    await rename(`${sha256Path}.partial-${process.pid}`, sha256Path);
  } catch {
    throw new ModulePackError("MODULE_PACK_OUTPUT_FAILED");
  }

  return Object.freeze({
    archiveBytes: archive.length,
    archivePath,
    fileCount: listed.length,
    moduleId: manifest.id,
    sha256: digest,
    sha256Path,
    target,
    version: manifest.version,
  });
}