#!/usr/bin/env node
/* global process, console */
// Runs dependency-cruiser per workspace package to find circular imports, and fails only on
// cycles that are not already recorded in the baseline file. Run with --update-baseline to
// regenerate the baseline from the current state (e.g. after fixing a cycle).
//
// Exits 0 when the tree matches the baseline, 1 when a new cycle appeared, and 2 when the
// baseline is merely stale. CI distinguishes the last two when reporting.
import { execFileSync } from 'node:child_process';
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..', '..');
// Resolve dependency-cruiser's own entry point rather than the `.bin` shim, and run it with the
// current Node binary. On Windows the shim is split into an extensionless shell script (which
// `execFileSync` cannot launch) and a `.cmd` (which Node >=18 refuses to spawn without a shell,
// see CVE-2024-27980), so going through `.bin` makes this script POSIX-only for no benefit.
const depcruiseBin = path.join(repoRoot, 'node_modules', 'dependency-cruiser', 'bin', 'dependency-cruise.mjs');
const configPath = path.join(path.dirname(fileURLToPath(import.meta.url)), 'dependency-cruiser.json');
const baselinePath = path.join(path.dirname(fileURLToPath(import.meta.url)), 'known-violations.json');

/** A cycle exists that the baseline does not record — a regression. */
const EXIT_NEW_CYCLES = 1;
/** The baseline records cycles that no longer exist — it just needs regenerating. */
const EXIT_BASELINE_DRIFT = 2;

// Same scope as `npm run lint`/`type-check`/`test` (--workspaces --if-present): the packages
// actually declared as npm workspaces, not every directory under packages/ (e.g.
// insomnia-component-docs is intentionally excluded and its deps aren't installed at the root).
const rootPackageJson = JSON.parse(fs.readFileSync(path.join(repoRoot, 'package.json'), 'utf8'));
const packageDirs = rootPackageJson.workspaces
  .map(workspace => ({ name: path.basename(workspace), dir: path.join(repoRoot, workspace) }))
  .sort((a, b) => a.name.localeCompare(b.name));
const packageNames = packageDirs.map(({ name }) => name);

function packageForAbsPath(absPath) {
  const found = packageDirs.find(({ dir }) => absPath === dir || absPath.startsWith(dir + path.sep));
  return found ? found.name : null;
}

// Rotates a cycle's node list to start at its lexicographically smallest entry, so the same
// logical cycle reported starting from different nodes (which dependency-cruiser does) collapses
// to one canonical key.
function canonicalize(repoRelNodes) {
  let minIndex = 0;
  for (let i = 1; i < repoRelNodes.length; i++) {
    if (repoRelNodes[i] < repoRelNodes[minIndex]) minIndex = i;
  }
  return [...repoRelNodes.slice(minIndex), ...repoRelNodes.slice(0, minIndex)].join(' -> ');
}

function cruisePackage({ name, dir }) {
  const tsconfigPath = path.join(dir, 'tsconfig.json');
  const args = ['--config', configPath];
  if (fs.existsSync(tsconfigPath)) args.push('--ts-config', 'tsconfig.json');
  // Exclude node_modules and any local build/dist output (untracked, non-reproducible artifacts
  // from a prior local build) at any depth, e.g. packages/insomnia/build/.
  args.push('-x', 'node_modules|(^|/)(build|dist)(/|$)', '--output-type', 'json', '.');

  let stdout;
  try {
    stdout = execFileSync(process.execPath, [depcruiseBin, ...args], {
      cwd: dir,
      encoding: 'utf8',
      maxBuffer: 1024 * 1024 * 100,
    });
  } catch (error) {
    if (error?.status !== 1 || !error.stdout) throw error;
    // dependency-cruiser exits with status 1 when forbidden violations are found. Parse its JSON
    // output so the baseline comparison can decide whether those cycles are new.
    stdout = error.stdout;
  }
  const result = JSON.parse(stdout);

  // key: canonical signature -> Set of packages it touches
  const cycles = new Map();
  for (const violation of result.summary.violations) {
    if (violation.type !== 'cycle') continue;
    // A cycle needs >=2 distinct modules; length-1 "cycles" are resolver artifacts (e.g. a bare
    // specifier like `esbuild` misresolved to a same-named local file `esbuild.ts`), not real
    // circular dependencies.
    if (violation.cycle.length <= 1) continue;
    const repoRelNodes = violation.cycle.map(node => {
      const abs = path.resolve(dir, node.name);
      return path.relative(repoRoot, abs).split(path.sep).join('/');
    });
    const key = canonicalize(repoRelNodes);
    if (cycles.has(key)) continue;
    const attributed = new Set(repoRelNodes.map(p => packageForAbsPath(path.resolve(repoRoot, p))).filter(Boolean));
    cycles.set(key, attributed);
  }
  return cycles;
}

function cruiseAll() {
  // packageName -> Set<canonical key>
  const byPackage = new Map(packageNames.map(name => [name, new Set()]));
  for (const pkg of packageDirs) {
    const cycles = cruisePackage(pkg);
    for (const [key, attributed] of cycles) {
      for (const pkgName of attributed) {
        byPackage.get(pkgName).add(key);
      }
    }
  }
  return byPackage;
}

function readBaseline() {
  if (!fs.existsSync(baselinePath)) return new Map();
  const raw = JSON.parse(fs.readFileSync(baselinePath, 'utf8'));
  return new Map(Object.entries(raw).map(([name, keys]) => [name, new Set(keys)]));
}

function writeBaseline(byPackage) {
  const raw = {};
  for (const name of packageNames) {
    raw[name] = [...byPackage.get(name)].sort();
  }
  fs.writeFileSync(baselinePath, JSON.stringify(raw, null, 2) + '\n');
}

function main() {
  const updateBaseline = process.argv.includes('--update-baseline');
  const current = cruiseAll();

  if (updateBaseline) {
    writeBaseline(current);
    const total = [...current.values()].reduce((sum, set) => sum + set.size, 0);
    console.log(
      `Baseline updated: ${baselinePath} (${total} cycle attributions across ${packageNames.length} packages)`,
    );
    return;
  }

  const baseline = readBaseline();
  let hasNew = false;
  let hasDrift = false;
  for (const name of packageNames) {
    const currentKeys = current.get(name);
    const baselineKeys = baseline.get(name) || new Set();
    const newKeys = [...currentKeys].filter(key => !baselineKeys.has(key));
    const removedKeys = [...baselineKeys].filter(key => !currentKeys.has(key));
    console.log(
      `${name}: ${currentKeys.size} cycle(s)${newKeys.length ? `, ${newKeys.length} NEW` : ''}${removedKeys.length ? `, ${removedKeys.length} REMOVED` : ''}`,
    );
    if (newKeys.length) {
      hasNew = true;
      for (const key of newKeys) console.log(`  NEW: ${key}`);
    }
    if (removedKeys.length) {
      hasDrift = true;
      for (const key of removedKeys) console.log(`  REMOVED FROM BASELINE: ${key}`);
    }
  }

  if (hasNew || hasDrift) {
    if (hasNew) console.log('\nNew circular dependencies detected that are not in the baseline.');
    if (hasDrift) console.log('\nBaseline contains circular dependencies no longer present in the current tree.');
    console.log(`Run "npm run check-cycle-references:baseline" and commit the updated ${path.basename(baselinePath)}.`);
    // Both cases need the baseline regenerated, but they mean opposite things — a new cycle is a
    // regression, while drift alone means cycles were fixed and the baseline was left behind.
    // Exit 1 vs 2 so CI can say which happened instead of reporting every failure as "new".
    process.exit(hasNew ? EXIT_NEW_CYCLES : EXIT_BASELINE_DRIFT);
  }
  console.log('\nNo new circular dependencies.');
}

main();