#!/usr/bin/env node
/**
 * pnpm conformance — cross-feature drift gate.
 *
 * Walks every `packages/*\/src/feature.manifest.ts`, reuses the AST parser
 * from `@repo/core-eslint` to extract per-use-case publishes/consumes,
 * builds global publish + consume sets across all features, and fails on:
 *
 *   - Orphan consumer: a feature declares `consumes: ["X"]` but no
 *     feature publishes "X".
 *
 * Exits 0 on success, 1 on any violation. Prints a tabular summary of
 * the event graph for transparency.
 */
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { parseManifestUseCases } from "../packages/core-eslint/rules/_manifest-ast.js";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const REPO_ROOT = path.resolve(__dirname, "..");

export function findAllManifests(repoRoot = REPO_ROOT) {
  const packagesDir = path.join(repoRoot, "packages");
  if (!fs.existsSync(packagesDir)) return [];
  const out = [];
  for (const entry of fs.readdirSync(packagesDir)) {
    const manifestPath = path.join(packagesDir, entry, "src", "feature.manifest.ts");
    if (fs.existsSync(manifestPath)) {
      out.push({ feature: entry, path: manifestPath });
    }
  }
  return out;
}

export function buildEventGraph(manifests) {
  const graph = new Map();
  for (const { feature, path: manifestPath } of manifests) {
    const useCases = parseManifestUseCases(manifestPath);
    if (!useCases) continue;
    for (const [useCase, entry] of Object.entries(useCases)) {
      for (const event of entry.publishes) {
        if (!graph.has(event)) graph.set(event, { publishers: [], consumers: [] });
        graph.get(event).publishers.push({ feature, useCase });
      }
      for (const event of entry.consumes) {
        if (!graph.has(event)) graph.set(event, { publishers: [], consumers: [] });
        graph.get(event).consumers.push({ feature, useCase });
      }
    }
  }
  return graph;
}

export function findOrphanConsumers(graph) {
  const orphans = [];
  for (const [event, { publishers, consumers }] of graph.entries()) {
    if (consumers.length > 0 && publishers.length === 0) {
      orphans.push({ event, consumers });
    }
  }
  return orphans;
}

function main() {
  const manifests = findAllManifests();
  console.log(`Found ${manifests.length} feature manifest(s):`);
  for (const { feature } of manifests) console.log(`  - ${feature}`);
  console.log();

  const graph = buildEventGraph(manifests);
  if (graph.size === 0) {
    console.log("No cross-feature events declared yet — nothing to check.");
    process.exit(0);
  }

  console.log(`Event graph (${graph.size} event(s)):`);
  for (const [event, { publishers, consumers }] of graph.entries()) {
    console.log(`  ${event}`);
    console.log(`    publishers: ${publishers.length === 0 ? "(none)" : publishers.map((p) => `${p.feature}.${p.useCase}`).join(", ")}`);
    console.log(`    consumers:  ${consumers.length === 0 ? "(none)" : consumers.map((c) => `${c.feature}.${c.useCase}`).join(", ")}`);
  }
  console.log();

  const orphans = findOrphanConsumers(graph);
  if (orphans.length === 0) {
    console.log("✓ pnpm conformance — passed");
    process.exit(0);
  }
  console.error(`✗ pnpm conformance — ${orphans.length} orphan consumer(s):`);
  for (const { event, consumers } of orphans) {
    console.error(`  ${event}`);
    for (const c of consumers) {
      console.error(`    consumed by ${c.feature}.${c.useCase}, but no feature publishes it`);
    }
  }
  process.exit(1);
}

if (import.meta.url === `file://${process.argv[1]}`) {
  main();
}