#!/usr/bin/env node
/*
FNXC:TestInfrastructure 2026-06-25-00:00:
verify:fast is the opt-in, TEST-FREE verification command. It gives deterministic,
flake-free signal in seconds without running the test suite, by doing exactly:
  1. bootstrap — rebuild missing/stale workspace dist prerequisites used by package builds.
  2. typecheck — scoped to the changed packages (their `typecheck` script, or
     `pnpm --filter <pkg> exec tsc --noEmit -p .` when none exists).
  3. build — scoped to the changed packages, plus the CLI package needed by boot smoke.
  4. boot smoke — once (scripts/boot-smoke.mjs: CLI --help + real serve /api/health).

FNXC:TestInfrastructure 2026-06-26-00:49:
A fresh worktree can have no plugin runtime dist artifacts or `packages/cli/dist/bin.js`.
Since package builds import those plugin artifacts and boot-smoke invokes the
source-checkout CLI wrapper, verify:fast must bootstrap workspace dist artifacts
and always build @runfusion/fusion before the smoke so the command proves a
runnable checkout instead of failing on a missing prerequisite.

Rationale: docs/testing.md observes the broad test gate "caught no recalled real
bugs while consuming ~70% of shipping time in flake triage." typecheck+build+boot
is fast and never flakes, so it is a sound project `testCommand`/verification
command when you want non-test verification. This command changes NO default —
`pnpm test`, the merge gate, and CI are untouched. The full suite stays available
(`pnpm test:full`) and runs non-blocking on push to main.

Change-detection REUSES scripts/test-changed.mjs (getBaseBranch /
detectComparisonBase / changedFilesSince / resolveAffectedPackages / workspace
resolution) so verify:fast scopes to exactly the packages a changed-only test run
would, instead of reinventing git-diff. Each step is bounded by the existing
`runWithWatchdog` (class "changed") so a hung tsc/build/serve fails fast instead
of blocking forever, and we exit nonzero on the first failing step.
*/

import os from "node:os";
import path from "node:path";
import { existsSync, readFileSync } from "node:fs";
import { spawn } from "node:child_process";
import { fileURLToPath } from "node:url";

import {
  getBaseBranch,
  detectComparisonBase,
  changedFilesSince,
  listWorkspacePackageInfos,
  listWorkspacePackages,
  buildPackageDirByName,
  resolveAffectedPackages,
} from "./test-changed.mjs";
import { deriveBudgetMs, runWithWatchdog } from "./lib/run-vitest-watchdog.mjs";

const scriptDir = path.dirname(fileURLToPath(import.meta.url));
const repoRoot = path.resolve(scriptDir, "..");
const bootSmokeScriptPath = path.join(scriptDir, "boot-smoke.mjs");
const artifactBootstrapScriptPath = path.join(scriptDir, "ensure-test-artifacts.mjs");
const packageManifestPath = path.join(repoRoot, "package.json");

/*
FNXC:TestInfrastructure 2026-07-22-12:00:
Cheap policy scanners must fail during the test-free verification path, before
bootstrap or builds can hide a malformed changeset until clean-room merge.
Read the canonical root pretest composition rather than duplicating validator
rules or maintaining a second list; default invocations are read-only and never
use a validator's mutation flags (such as check-routes-modular --update).
*/
export function readPretestStaticCheckScripts(manifestPath = packageManifestPath) {
  const pretest = JSON.parse(readFileSync(manifestPath, "utf8")).scripts?.pretest;
  if (typeof pretest !== "string" || !pretest.trim()) {
    throw new Error("package.json must define a non-empty pretest static-check composition");
  }

  const scripts = pretest.split("&&").map((command) => {
    const match = /^\s*node\s+(scripts\/check-[\w-]+\.mjs)\s*$/.exec(command);
    if (!match) {
      throw new Error(`pretest contains a non-static-check command: ${command.trim()}`);
    }
    return match[1];
  });

  if (scripts.length === 0) {
    throw new Error("package.json pretest must contain at least one static check");
  }
  return scripts;
}

export const PRETEST_STATIC_CHECK_SCRIPTS = Object.freeze(readPretestStaticCheckScripts());

/*
FNXC:TestInfrastructure 2026-06-25-00:00:
@fusion/desktop and @fusion/mobile are excluded from the root `build`/`typecheck`
scripts (heavy native/electron + RN toolchains), so verify:fast mirrors that
policy and skips them with a note rather than failing on an unbuildable filter.
*/
export const VERIFY_EXCLUDED_PACKAGES = new Set(["@fusion/desktop", "@fusion/mobile"]);
export const BOOT_SMOKE_REQUIRED_BUILD_PACKAGES = ["@runfusion/fusion"];

/*
FNXC:TestInfrastructure 2026-08-11-09:38:
verify:fast ran every step strictly serially, so its wall clock was the SUM of steps
that have no ordering relationship. Two groups are independent and now run
concurrently, bounded per group:

  - static checks: ~10 read-only validators, each dominated by node startup rather
    than work (~5.4s serial on this repo, ~1.6s grouped).
  - typechecks: one per changed package, `--noEmit` or the package's own script, so
    no two can collide on an output. This is the dominant cost of a multi-package
    run — dashboard + engine alone were ~65s of a 96.6s run.

Ordering that MATTERS is preserved: bootstrap, builds, and boot smoke stay serial and
in plan order (builds consume bootstrap output; the smoke must run against freshly
built artifacts). Only steps sharing a `parallelGroup` overlap, and a group is a
barrier — the next step never starts before every member settles.

Limits are conservative on purpose: typechecks are memory-hungry (tsc over this
workspace), so oversubscribing trades wall clock for swap. Set FUSION_VERIFY_FAST_SERIAL=1
to force the old fully-serial behavior when interleaved child output makes a failure
hard to read.
*/
const cpuCount = (() => {
  try { return Math.max(1, os.cpus()?.length ?? 1); } catch { return 1; }
})();
export const STATIC_CHECK_PARALLEL_LIMIT = Math.max(2, Math.min(8, cpuCount - 1));
export const TYPECHECK_PARALLEL_LIMIT = Math.max(1, Math.min(4, Math.floor(cpuCount / 2)));

/**
 * Build the scoped typecheck step for a package. Prefers the package's own
 * `typecheck` script (e.g. dashboard runs two tsc passes); falls back to a plain
 * project tsc --noEmit when the package declares no typecheck script.
 *
 * @param {string} pkg  workspace package name (e.g. "@fusion/engine")
 * @param {{ hasTypecheck?: boolean }} [meta]
 * @returns {{ id: string, kind: string, pkg: string, label: string, command: string, args: string[], klass: string }}
 */
export function buildTypecheckStep(pkg, meta = {}) {
  const args = meta.hasTypecheck
    ? ["--filter", pkg, "typecheck"]
    : ["--filter", pkg, "exec", "tsc", "--noEmit", "-p", "."];
  /* Typechecks are per-package and emit nothing (`--noEmit`, or the package's own
     script writing only its own tsbuildinfo), so sibling packages cannot collide.
     They are the dominant cost of a multi-package run — grouping them lets the wall
     clock be the slowest package rather than their sum. */
  return { id: `typecheck:${pkg}`, kind: "typecheck", pkg, label: `typecheck ${pkg}`, command: "pnpm", args, klass: "changed", parallelGroup: "typecheck", parallelLimit: TYPECHECK_PARALLEL_LIMIT };
}

/**
 * Build the scoped build step for a package.
 *
 * @param {string} pkg
 * @returns {{ id: string, kind: string, pkg: string, label: string, command: string, args: string[], klass: string }}
 */
export function buildBuildStep(pkg) {
  return { id: `build:${pkg}`, kind: "build", pkg, label: `build ${pkg}`, command: "pnpm", args: ["--filter", pkg, "build"], klass: "changed" };
}

/**
 * Build the single boot-smoke step (always last, after any builds, so it runs
 * against freshly built artifacts).
 *
 * @param {string} smokeScriptPath
 * @param {string} [nodeBin]
 */
export function buildBootSmokeStep(smokeScriptPath, nodeBin = process.execPath) {
  return {
    id: "boot-smoke",
    kind: "boot-smoke",
    pkg: null,
    label: "boot smoke (CLI --help + real serve /api/health)",
    command: nodeBin,
    args: [smokeScriptPath],
    klass: "changed",
  };
}

/**
 * Build the prerequisite artifact bootstrap step. It is intentionally first so
 * fresh worktrees have the bundled plugin/runtime dist outputs before scoped
 * package builds (especially @runfusion/fusion) import them.
 *
 * @param {string} bootstrapScriptPath
 * @param {string} [nodeBin]
 */
export function buildArtifactBootstrapStep(bootstrapScriptPath, nodeBin = process.execPath) {
  return {
    id: "bootstrap-artifacts",
    kind: "bootstrap-artifacts",
    pkg: null,
    label: "bootstrap workspace dist artifacts",
    command: nodeBin,
    args: [bootstrapScriptPath],
    klass: "changed",
  };
}

/**
 * Build one canonical, read-only root pretest validator invocation.
 *
 * @param {string} checkScript repo-relative check script path
 * @param {string} [root]
 * @param {string} [nodeBin]
 */
export function buildStaticCheckStep(checkScript, root = repoRoot, nodeBin = process.execPath) {
  const name = path.basename(checkScript, ".mjs");
  return {
    id: `static-check:${name}`,
    kind: "static-check",
    pkg: null,
    label: `static check ${name}`,
    command: nodeBin,
    args: [path.join(root, checkScript)],
    klass: "changed",
    /* Canonical static checks are read-only repo validators with no shared writable
       state, so they are safe to run concurrently. Each costs more in node startup
       than in work, which is exactly the shape that wastes wall clock run serially. */
    parallelGroup: "static-checks",
    parallelLimit: STATIC_CHECK_PARALLEL_LIMIT,
  };
}

/**
 * Pure planner: turn canonical static checks and the affected package set into
 * an ordered step list. Static checks → bootstrap missing/stale dist artifacts
 * → typecheck (all eligible) → build (eligible with a build script) → required
 * boot-smoke build prerequisites → boot smoke. With no eligible packages this
 * still builds the source-checkout CLI before the smoke so fresh worktrees have
 * `packages/cli/dist/bin.js`.
 *
 * @param {object} opts
 * @param {string[]} [opts.packages] affected package names
 * @param {Map<string, { dir?: string, hasTypecheck?: boolean, hasTsconfig?: boolean, hasBuild?: boolean }>} [opts.packageMeta]
 * @param {string[]} [opts.staticCheckScripts] repo-relative canonical pretest validator paths
 * @param {string} [opts.staticCheckRoot]
 * @param {string} opts.bootSmokeScriptPath
 * @param {string} [opts.artifactBootstrapScriptPath]
 * @param {string} [opts.nodeBin]
 * @returns {{ eligiblePackages: string[], excludedPackages: string[], requiredBootBuildPackages: string[], steps: object[] }}
 */
export function buildVerifyPlan({ packages = [], packageMeta = new Map(), staticCheckScripts = PRETEST_STATIC_CHECK_SCRIPTS, staticCheckRoot = repoRoot, bootSmokeScriptPath: smokeScriptPath, artifactBootstrapScriptPath: bootstrapScriptPath = artifactBootstrapScriptPath, nodeBin = process.execPath } = {}) {
  const eligiblePackages = packages.filter((pkg) => !VERIFY_EXCLUDED_PACKAGES.has(pkg));
  const excludedPackages = packages.filter((pkg) => VERIFY_EXCLUDED_PACKAGES.has(pkg));

  const steps = staticCheckScripts.map((checkScript) => buildStaticCheckStep(checkScript, staticCheckRoot, nodeBin));
  steps.push(buildArtifactBootstrapStep(bootstrapScriptPath, nodeBin));
  for (const pkg of eligiblePackages) {
    const meta = packageMeta.get(pkg) ?? {};
    /*
    FNXC:TestInfrastructure 2026-07-03-21:54:
    Workspace alias packages such as `runfusion.ai` are publishable JavaScript shims with no tsconfig. verify:fast should not synthesize a `tsc -p .` fallback for those packages; their executable behavior is covered by the required CLI build and boot smoke.
    */
    if (meta.hasTypecheck === false && meta.hasTsconfig === false) continue;
    steps.push(buildTypecheckStep(pkg, meta));
  }

  const builtPackages = new Set();
  for (const pkg of eligiblePackages) {
    const meta = packageMeta.get(pkg) ?? {};
    // Only build packages that declare a build script; pure test/config packages
    // have nothing to emit and a `pnpm --filter <pkg> build` would error.
    if (meta.hasBuild !== false) {
      steps.push(buildBuildStep(pkg));
      builtPackages.add(pkg);
    }
  }

  const requiredBootBuildPackages = [];
  for (const pkg of BOOT_SMOKE_REQUIRED_BUILD_PACKAGES) {
    if (builtPackages.has(pkg) || VERIFY_EXCLUDED_PACKAGES.has(pkg)) continue;
    const meta = packageMeta.get(pkg) ?? { hasBuild: true };
    if (meta.hasBuild === false) continue;
    requiredBootBuildPackages.push(pkg);
    steps.push(buildBuildStep(pkg));
    builtPackages.add(pkg);
  }

  steps.push(buildBootSmokeStep(smokeScriptPath, nodeBin));
  return { eligiblePackages, excludedPackages, requiredBootBuildPackages, steps };
}

/**
 * Read each affected package's package.json to learn which scripts it declares.
 *
 * @param {string[]} packages
 * @param {Map<string, string>} packageDirByName  pkg name → repo-relative dir
 * @param {string} [root]
 * @returns {Map<string, { dir: string, hasTypecheck: boolean, hasTsconfig: boolean, hasBuild: boolean }>}
 */
export function readPackageMeta(packages, packageDirByName, root = repoRoot) {
  const meta = new Map();
  for (const pkg of packages) {
    const dir = packageDirByName.get(pkg);
    let scripts = {};
    if (dir) {
      try {
        const pkgJson = JSON.parse(readFileSync(path.join(root, dir, "package.json"), "utf8"));
        scripts = pkgJson.scripts ?? {};
      } catch {
        // Missing/unreadable package.json: fall back to tsc default + attempt build.
      }
    }
    meta.set(pkg, {
      dir: dir ?? null,
      hasTypecheck: typeof scripts.typecheck === "string",
      hasTsconfig: dir ? existsSync(path.join(root, dir, "tsconfig.json")) : true,
      hasBuild: typeof scripts.build === "string",
    });
  }
  return meta;
}

/**
 * Resolve the affected package set for the current working tree, reusing
 * test-changed's git-diff + workspace resolution. Returns both the package list
 * and a human note describing why the set is what it is (no base, no changes,
 * unmappable path, etc.) so the CLI can explain a boot-smoke-only run.
 *
 * @returns {{ packages: string[], packageDirByName: Map<string,string>, note: string }}
 */
export function resolveAffectedForVerify() {
  const baseBranch = getBaseBranch();
  const comparisonBase = detectComparisonBase(baseBranch);
  const workspacePackages = listWorkspacePackageInfos();
  const packageNameByDir = listWorkspacePackages(workspacePackages);
  const packageDirByName = buildPackageDirByName(workspacePackages);

  if (!comparisonBase) {
    return { packages: [], packageDirByName, note: `could not resolve merge-base with ${baseBranch}; running boot-smoke prerequisite build only` };
  }
  const changedFiles = changedFilesSince(comparisonBase);
  if (changedFiles === null) {
    return { packages: [], packageDirByName, note: "failed to read git diff; running boot-smoke prerequisite build only" };
  }
  if (changedFiles.length === 0) {
    return { packages: [], packageDirByName, note: "no changes detected against base; running boot-smoke prerequisite build only" };
  }
  const affected = resolveAffectedPackages(changedFiles, packageNameByDir);
  if (affected === null) {
    return { packages: [], packageDirByName, note: "changed file did not map to a workspace package; running boot-smoke prerequisite build only" };
  }
  if (affected.length === 0) {
    return { packages: [], packageDirByName, note: "no affected workspace package (root/docs-only changes); running boot-smoke prerequisite build only" };
  }
  return { packages: affected, packageDirByName, note: `affected packages: ${affected.join(", ")}` };
}

/**
 * Run one step under the wall-clock watchdog (class "changed"). Streams the
 * child's output (stdio inherit) and throws with an `.exitCode` on the first
 * failure/timeout/signal so the caller exits nonzero immediately.
 */
export async function runStep(step, { spawnFn = spawn, log = console.log, errLog = console.error, cwd = repoRoot } = {}) {
  const budgetMs = deriveBudgetMs({ klass: step.klass ?? "changed" });
  log(`\n[verify:fast] -> ${step.label}`);
  log(`[verify:fast]    ${step.command} ${step.args.join(" ")}  (budget ${Math.round(budgetMs / 1000)}s)`);
  const startedAt = Date.now();
  const { code, signal, timedOut } = await runWithWatchdog({
    command: step.command,
    args: step.args,
    env: process.env,
    cwd,
    budgetMs,
    label: step.label,
    log: errLog,
    spawn: spawnFn,
  });
  const elapsedS = ((Date.now() - startedAt) / 1000).toFixed(1);
  if (timedOut || signal || code !== 0) {
    const reason = timedOut ? `watchdog timeout (${budgetMs}ms)` : signal ? `signal ${signal}` : `exit code ${code}`;
    const error = new Error(`[verify:fast] FAILED: ${step.label} (${reason}) after ${elapsedS}s`);
    error.exitCode = timedOut ? 124 : signal ? 1 : code ?? 1;
    throw error;
  }
  log(`[verify:fast]    OK ${step.label} (${elapsedS}s)`);
}

/**
 * Split a plan into consecutive runs of steps sharing a `parallelGroup`. Steps with
 * no group (or when serial mode is forced) each become their own single-step batch,
 * which is what keeps bootstrap → build → boot-smoke ordering intact.
 *
 * Grouping is CONSECUTIVE-only: two separated blocks with the same group name stay
 * separate batches, so a planner reordering can never silently hoist a step across
 * an intervening serial dependency.
 *
 * @param {object[]} steps
 * @param {boolean} [serial]
 * @returns {{ group: string|null, limit: number, steps: object[] }[]}
 */
export function batchVerifySteps(steps, serial = false) {
  const batches = [];
  for (const step of steps) {
    const group = serial ? null : step.parallelGroup ?? null;
    const previous = batches[batches.length - 1];
    if (group && previous && previous.group === group) {
      previous.steps.push(step);
      previous.limit = Math.min(previous.limit, step.parallelLimit ?? previous.limit);
      continue;
    }
    batches.push({ group, limit: group ? step.parallelLimit ?? 1 : 1, steps: [step] });
  }
  return batches;
}

/**
 * Run planned steps, stopping at the first failure. Steps sharing a `parallelGroup`
 * run concurrently under that group's limit; every other step runs alone and in order.
 *
 * A failing group still awaits its in-flight siblings before throwing — killing them
 * mid-flight would leave partial tsbuildinfo/dist state behind — and reports the
 * FIRST failure in plan order so the message is stable regardless of which sibling
 * happened to lose the race.
 */
export async function runVerifyPlan(steps, { run = runStep, serial = process.env.FUSION_VERIFY_FAST_SERIAL === "1" } = {}) {
  for (const batch of batchVerifySteps(steps, serial)) {
    if (batch.steps.length === 1) {
      await run(batch.steps[0]);
      continue;
    }

    const failures = new Array(batch.steps.length).fill(null);
    let next = 0;
    const worker = async () => {
      for (;;) {
        const index = next++;
        if (index >= batch.steps.length) return;
        try {
          await run(batch.steps[index]);
        } catch (error) {
          failures[index] = error;
        }
      }
    };
    await Promise.all(
      Array.from({ length: Math.max(1, Math.min(batch.limit, batch.steps.length)) }, worker),
    );

    const firstFailure = failures.find(Boolean);
    if (firstFailure) throw firstFailure;
  }
}

export async function main() {
  const overallStart = Date.now();
  console.log("[verify:fast] test-free verification: scoped typecheck/build + CLI build + boot smoke.");

  const { packages, packageDirByName, note } = resolveAffectedForVerify();
  console.log(`[verify:fast] ${note}`);

  const packageMeta = readPackageMeta([...new Set([...packages, ...BOOT_SMOKE_REQUIRED_BUILD_PACKAGES])], packageDirByName);
  const { eligiblePackages, excludedPackages, requiredBootBuildPackages, steps } = buildVerifyPlan({
    packages,
    packageMeta,
    bootSmokeScriptPath,
    artifactBootstrapScriptPath,
  });

  if (excludedPackages.length > 0) {
    console.log(`[verify:fast] skipping excluded packages (also excluded from root build/typecheck): ${excludedPackages.join(", ")}`);
  }
  if (eligiblePackages.length === 0) {
    console.log("[verify:fast] no scoped packages to verify; running boot-smoke prerequisite build and boot smoke only.");
  } else {
    console.log(`[verify:fast] scoped to: ${eligiblePackages.join(", ")}`);
  }
  if (requiredBootBuildPackages.length > 0) {
    console.log(`[verify:fast] boot-smoke prerequisite build: ${requiredBootBuildPackages.join(", ")}`);
  }
  console.log(`[verify:fast] plan: ${steps.map((s) => s.id).join(" -> ")}`);

  await runVerifyPlan(steps);

  const elapsedS = ((Date.now() - overallStart) / 1000).toFixed(1);
  console.log(`\n[verify:fast] PASS — ${steps.length} step(s) green in ${elapsedS}s (no tests run).`);
}

const currentFilePath = fileURLToPath(import.meta.url);
if (process.argv[1] && path.resolve(process.argv[1]) === currentFilePath) {
  main().catch((error) => {
    if (error?.message) console.error(error.message);
    if (error?.exitCode) process.exit(error.exitCode);
    console.error(error);
    process.exit(1);
  });
}