// scripts/bakeoff-armA-merge.mjs
// NW2 bake-off — Arm A (prose path) merge step.
//
// Arm A is the CURRENT /trekreview Phase 5–6 substrate: main spawns the two
// reviewers FOREGROUND (Agent tool), each emits a trailing fenced ```json block
// of findings (the prose contract), and main hand-validates + dedups before
// spawning the coordinator. This script is that hand-validate + dedup, made
// reproducible:
//
//   for each reviewer raw-output file:
//     validateReviewerOutput()  (NW1 — extract last json fence, parse, schema-check)
//   collect findings from VALID reviewers
//   triplet-dedup by (file,line,rule_key)   [SAME logic as Arm B's dedupByTriplet,
//                                             so the two arms dedup identically —
//                                             triplet-only, no jaccard pass-2]
//   → emit { merged, validation, raw_finding_count, deduped_count }
//
// The merged findings are then handed to the review-coordinator (spawned by main),
// mirroring Arm B's coordinatorPrompt input. JSON-robustness metric = the
// `validation` report (parse/schema failures + which codes).
//
// Usage:
//   node scripts/bakeoff-armA-merge.mjs [--json] <reviewerA.txt> <reviewerB.txt> ...
//   → stdout: merged findings JSON (or full report with --json). Exit 0 always
//     (validation failures are reported in-band, not as a nonzero exit).

import { readFileSync, existsSync } from 'node:fs';
import { validateReviewerOutput } from '../lib/review/findings-schema.mjs';

// Triplet dedup — byte-for-byte the same key + first-wins policy as
// scripts/trekreview-armB.workflow.mjs `dedupByTriplet`, so neither arm gets a
// dedup advantage. Triplet-only (file,line,rule_key); NO jaccard pass-2.
export function dedupByTriplet(findings) {
  const seen = new Map();
  for (const f of findings) {
    const key = `${f.file} ${f.line} ${f.rule_key}`;
    if (!seen.has(key)) seen.set(key, f);
  }
  return [...seen.values()];
}

/**
 * Merge an array of reviewer raw-output texts into the coordinator's input.
 * @param {Array<{label?: string, text: string}>} reviewerOutputs
 * @returns {{ merged, validation, raw_finding_count, deduped_count }}
 */
export function mergeArmA(reviewerOutputs) {
  const validation = [];
  const allFindings = [];
  for (const { label, text } of reviewerOutputs) {
    const r = validateReviewerOutput(text);
    validation.push({
      label: label || null,
      valid: r.valid,
      finding_count: Array.isArray(r.parsed?.findings) ? r.parsed.findings.length : 0,
      error_codes: (r.errors || []).map((e) => e.code),
      warning_codes: (r.warnings || []).map((w) => w.code),
    });
    // Mirror Phase 5: only VALID reviewer output flows to the coordinator.
    if (r.valid && Array.isArray(r.parsed?.findings)) {
      allFindings.push(...r.parsed.findings);
    }
  }
  const merged = dedupByTriplet(allFindings);
  return {
    merged,
    validation,
    raw_finding_count: allFindings.length,
    deduped_count: merged.length,
  };
}

// ---- CLI shim ----------------------------------------------------------------

if (import.meta.url === `file://${process.argv[1]}`) {
  const argv = process.argv.slice(2);
  const asJson = argv.includes('--json');
  const files = argv.filter((a) => !a.startsWith('--'));
  if (files.length === 0) {
    process.stderr.write('Usage: bakeoff-armA-merge.mjs [--json] <reviewer-output> ...\n');
    process.exit(2);
  }
  const outputs = files.map((f) => {
    if (!existsSync(f)) {
      process.stderr.write(`bakeoff-armA-merge: file not found: ${f}\n`);
      process.exit(2);
    }
    return { label: f, text: readFileSync(f, 'utf-8') };
  });
  const result = mergeArmA(outputs);
  if (asJson) {
    process.stdout.write(JSON.stringify(result, null, 2) + '\n');
  } else {
    process.stdout.write(JSON.stringify(result.merged, null, 2) + '\n');
    process.stderr.write(
      `arm-A merge: ${result.raw_finding_count} raw → ${result.deduped_count} deduped; ` +
      `validation ${result.validation.map((v) => `${v.label}:${v.valid ? 'OK' : v.error_codes.join('/')}`).join(' ')}\n`,
    );
  }
  process.exit(0);
}