import { createHash, randomUUID } from "node:crypto";
import { createServer } from "node:http";
import { readFile, writeFile, mkdir } from "node:fs/promises";
import { dirname, join } from "node:path";
import { pathToFileURL } from "node:url";

import { exec, json } from "./lib/verify-package-core.mjs";
import { withVerifierCleanup } from "./lib/verifier-cleanup.mjs";

/** Keep the live updater owner and its workspace when process cleanup is unproven. */
export class PackageUpdateCleanupFailure extends AggregateError {
  constructor(primary, cleanupOwner, result, workspace) {
    const cleanup = new Error(result.reason);
    super(
      primary === undefined ? [cleanup] : [primary, cleanup],
      `Package updater cleanup incomplete; retained ${workspace}`,
      { cause: primary },
    );
    this.cleanupOwner = cleanupOwner;
    this.workspace = workspace;
  }
}

/** Own the helper and installer descendants until output and process cleanup finish. */
async function runUpdater({
  harness,
  environment,
  signal,
  workspace,
  retainWorkspace,
}) {
  // Only updater execution needs built process ownership; importing this fixture
  // does not make unrelated source-only verifier helpers depend on dist.
  const { ProviderProcessSupervisor, spawnOwnedProviderProcess } =
    await import("../dist/process/ProviderProcess.js");
  const { cleanupOwnedProcessGroup } =
    await import("../dist/process/ProcessOwnership.js");
  const launch = await spawnOwnedProviderProcess({
    command: process.execPath,
    arguments: [harness],
    expectedCommand: null,
    hostEnvironment: environment,
    cwd: workspace,
    runId: randomUUID(),
    sweepTokenOwnedProcesses: true,
    signal,
  });
  let collectionFailure;
  const supervisor = new ProviderProcessSupervisor(
    {
      ...launch,
      ownsProcessLifetime: true,
      cleanup:
        launch.cleanup ?? (() => cleanupOwnedProcessGroup(launch.ownership)),
    },
    {
      maxDiagnosticBytes: 16 * 1024 * 1024,
      onDiagnostic(event) {
        if (event.type === "output" && event.truncated)
          collectionFailure ??= new Error(
            "Package updater exceeded its diagnostic capacity",
          );
        if (event.type === "error")
          collectionFailure ??= new Error(event.message, {
            cause: event.cause,
          });
      },
    },
  );
  let failure;
  let stdout;
  try {
    while (!(await supervisor.waitForOutputClose(50))) {
      signal.throwIfAborted();
      if (collectionFailure !== undefined) throw collectionFailure;
    }
    signal.throwIfAborted();
    if (collectionFailure !== undefined) throw collectionFailure;
    const snapshot = supervisor.snapshot();
    if (
      snapshot.diagnosticTruncated ||
      snapshot.exitCode !== 0 ||
      snapshot.signal !== null
    )
      throw new Error(
        `Package updater failed: ${snapshot.stdout.text}\n${snapshot.stderr.text}`,
      );
    stdout = snapshot.stdout.text;
  } catch (cause) {
    failure = { cause };
  }
  const stopped = await supervisor.stop();
  if (stopped.status === "incomplete") {
    retainWorkspace?.();
    throw new PackageUpdateCleanupFailure(
      failure?.cause,
      supervisor,
      stopped,
      workspace,
    );
  }
  if (failure !== undefined) throw failure.cause;
  return stdout;
}

/** Exercise the packaged updater with real npm and a local release registry fixture. */
export async function verifyPackageUpdate({
  prefix,
  packageRoot,
  tarball,
  workspace,
  environment,
  retainWorkspace,
}) {
  const metadataPath = join(packageRoot, "package.json");
  const metadata = json(await readFile(metadataPath, "utf8"));
  const archive = await readFile(tarball);
  const entry = join(packageRoot, "scripts", "rea.mjs");
  const home = join(workspace, "update-home");
  const codexPath = join(home, ".codex", "config.toml");
  const originalConfig =
    '[mcp_servers.rea]\ncommand = "npx"\nargs = ["-y", "rea-agents@0.0.0", "mcp"]\n';
  await mkdir(dirname(codexPath), { recursive: true });
  await writeFile(codexPath, originalConfig);
  let fixtureFailure;
  const fixture = new AbortController();
  const server = createServer((request, response) => {
    void serveRegistry(request, response).catch((error) => {
      fixtureFailure ??= error;
      fixture.abort(fixtureFailure);
      if (response.headersSent) {
        response.destroy();
        return;
      }
      response.writeHead(500);
      response.end(String(error));
    });
  });
  let registry;
  async function serveRegistry(request, response) {
    const pathname = new URL(request.url, registry).pathname;
    if (pathname === "/rea-agents") {
      response.setHeader("Content-Type", "application/json");
      response.end(
        JSON.stringify({
          name: metadata.name,
          "dist-tags": { latest: metadata.version },
          versions: {
            [metadata.version]: {
              ...metadata,
              dist: {
                tarball: `${registry}/release.tgz`,
                integrity: `sha512-${createHash("sha512").update(archive).digest("base64")}`,
              },
            },
          },
        }),
      );
    } else if (pathname === "/release.tgz") {
      response.end(archive);
    } else if (request.method === "POST") {
      response.setHeader("Content-Type", "application/json");
      response.end("{}");
    } else {
      const upstream = await fetch(`https://registry.npmjs.org${request.url}`);
      const body = Buffer.from(await upstream.arrayBuffer());
      response.writeHead(upstream.status, {
        "Content-Type":
          upstream.headers.get("content-type") ?? "application/octet-stream",
      });
      response.end(body);
    }
  }
  await new Promise((resolveListen, reject) => {
    server.once("error", reject);
    server.listen(0, "127.0.0.1", resolveListen);
  });
  return withVerifierCleanup(async () => {
    try {
      const address = server.address();
      if (typeof address !== "object" || address === null)
        throw new Error("Registry fixture did not bind");
      registry = `http://127.0.0.1:${address.port}`;
      // Model an older installed release's identity while retaining the new updater
      // under test. The registry supplies the unmodified packed target artifact.
      const generatedPath = join(
        packageRoot,
        "dist",
        "generatedPackageMetadata.js",
      );
      const generated = await readFile(generatedPath, "utf8");
      const previousVersion = "0.0.0";
      const previousGenerated = generated.replace(
        `version: "${metadata.version}"`,
        `version: "${previousVersion}"`,
      );
      if (previousGenerated === generated)
        throw new Error("Could not create previous-release identity fixture");
      await writeFile(generatedPath, previousGenerated);
      await writeFile(
        metadataPath,
        JSON.stringify({ ...metadata, version: previousVersion }),
      );
      const runtimeEnvironment = {
        ...environment,
        HOME: home,
        USERPROFILE: home,
        APPDATA: join(home, "AppData", "Roaming"),
        LOCALAPPDATA: join(home, "AppData", "Local"),
        CLAUDE_CONFIG_DIR: home,
        CODEX_HOME: join(home, ".codex"),
        COPILOT_HOME: join(home, ".copilot"),
        GROK_HOME: join(home, ".grok"),
        SAND_DATA_ROOT: join(home, ".grokbot"),
        OMP_PROFILE: undefined,
        PI_CODING_AGENT_DIR: undefined,
        PI_CONFIG_DIR: undefined,
        PI_PROFILE: undefined,
        XDG_CONFIG_HOME: join(home, ".config"),
        OPENCODE_CONFIG: join(home, ".config", "opencode", "opencode.json"),
        npm_config_prefix: prefix,
        npm_config_registry: registry,
      };
      const previous = (
        await exec(process.execPath, [entry, "--version"], {
          env: runtimeEnvironment,
        })
      ).stdout.trim();
      if (previous !== previousVersion)
        throw new Error(`Previous-release fixture reported ${previous}`);
      const harness = join(workspace, "verify-update.mjs");
      await writeFile(
        harness,
        `
import { runUpdate } from ${JSON.stringify(pathToFileURL(join(packageRoot, "dist/application/Update.js")).href)};
import { systemUpdateHost } from ${JSON.stringify(pathToFileURL(join(packageRoot, "dist/application/UpdateRuntime.js")).href)};
const host = systemUpdateHost(${JSON.stringify(packageRoot)}, ${JSON.stringify(home)});
const result = await runUpdate(${JSON.stringify(previousVersion)}, host, "structured");
process.stdout.write(JSON.stringify(result));
if (result.status === "failed") process.exitCode = 1;
`,
      );
      const result = json(
        await runUpdater({
          harness,
          environment: runtimeEnvironment,
          signal: fixture.signal,
          workspace,
          retainWorkspace,
        }),
      );
      if (
        result.status !== "updated" ||
        result.installedVersion !== metadata.version ||
        result.command.at(-1) !== `${metadata.name}@${metadata.version}` ||
        result.maintenance.status !== "planned" ||
        result.maintenance.scope.clients.join(",") !== "codex" ||
        result.maintenance.scope.skill !== false
      )
        throw new Error(
          `Packaged updater failed its exact-release contract: ${JSON.stringify(result)}`,
        );
      if ((await readFile(codexPath, "utf8")) !== originalConfig)
        throw new Error(
          "Update applied integration maintenance without approval",
        );
      const current = (
        await exec(process.execPath, [entry, "--version"], {
          env: runtimeEnvironment,
        })
      ).stdout.trim();
      if (current !== metadata.version)
        throw new Error(`Updated executable reported ${current}`);
      const help = (
        await exec(process.execPath, [entry, "--help"], {
          env: runtimeEnvironment,
        })
      ).stdout;
      if (!/^\s{2}update\s/mu.test(help) || /^\s{2}upgrade\s/mu.test(help))
        throw new Error(
          "Updated CLI did not expose update as its sole maintenance command",
        );
      if (fixtureFailure !== undefined) throw fixtureFailure;
      return {
        installed_version: result.installedVersion,
        exact_release: true,
        maintenance_read_only: true,
      };
    } catch (error) {
      // A retained process owner takes precedence over its triggering fixture
      // failure; otherwise report the first registry/proxy failure exactly.
      throw error instanceof PackageUpdateCleanupFailure
        ? error
        : (fixtureFailure ?? error);
    }
  }, [
    async () => {
      server.closeAllConnections();
      await new Promise((resolveClose, reject) =>
        server.close((error) =>
          error === undefined ? resolveClose() : reject(error),
        ),
      );
    },
  ]);
}