#!/usr/bin/env node
// build-rollup-register.mjs — the state roll-up register builder (STEG 0 wiring).
//
// WHY THIS EXISTS: cross-repo sessions each keep a LOCAL-ONLY STATE.md whose flush-left
// marker lines ("topic: status — prose") are the single source of truth for where each
// shared topic stands. This builder assembles those into two DISTINCT outputs, never
// conflating marker *durability* with *publicity* (the root cause of AS#5):
//
//   - Output A = rich LOCAL roll-up: full "topic: status — prose" grepped from every
//     ~/repos/*/STATE.md. For the operator, locally. NEVER published.
//   - Output B = optional PUBLIC status-token index: "topic: status" ALONE, projected
//     from A and filtered to repos that opted in via a committed .rollup-carrier.
//
// Contract source (ratified): ~/.claude/coord/register.md (framework-neutral contract
// authored commons-side @ c66ccc3; status vocab @ fe6b998). Catalog owns the builder
// wiring + the adversarial axes; commons owns the framework-neutral contract.
//
// Three builder modes, tolerating absence (no repo is ever forced to commit a carrier):
//   1. absent   — no carrier          -> omitted from B; A covers it fully.
//   2. committed — .rollup-carrier     -> travels with clone/subtree/public mirror -> B.
//   3. private  — .rollup-carrier.local (gitignored side-channel) -> A/private only, never B.
//
// Three gates:
//   V4 (public-safety) — a carrier line must be exactly "topic: <status-token>": no prose,
//                        no em-dash, known token. A violating committed carrier is blocked from B.
//   V5 (drift-warn)    — committed carrier status != STATE marker status -> warn; STATE WINS
//                        (B projects the STATE status, since B is a projection of A).
//   V6 (marker-loss)   — a line that LOOKS like a marker attempt ("topic: <known status>")
//                        but does not parse is REPORTED, never silently dropped. V4/V5 only
//                        ever gated the carrier, so a malformed STATE marker used to vanish
//                        with exit 0 — the loss channel this gate closes.
//
// Pure-function core is covered by build-rollup-register.test.mjs. Zero npm deps.

import { readdirSync, existsSync, readFileSync, statSync } from 'node:fs';
import { join, basename } from 'node:path';
import { homedir } from 'node:os';
import { fileURLToPath } from 'node:url';

const EMDASH = '—';

// The canonical, closed status vocabulary (register.md "Status-vokabular"). "active" was
// folded into in-progress and is invalid; unknown tokens are malformed.
export const STATUS_VOCAB = [
  'planned',
  'in-progress',
  'partial',
  'blocked',
  'deferred',
  'done',
  'not-applicable',
];

const TOPIC = '[a-z0-9][a-z0-9-]*';

// --- Output A source: a STATE.md marker line "topic: status — prose" -----------------
// Returns { topic, status, prose } or null if the line is not a well-formed marker
// (unknown status tokens are treated as "not a marker", so ordinary prose never matches).
export function parseMarkerLine(line) {
  const m = line.match(new RegExp(`^(${TOPIC}):\\s+(\\S+)(?:\\s+${EMDASH}\\s+(.*))?\\s*$`));
  if (!m) return null;
  const [, topic, status, prose] = m;
  if (!STATUS_VOCAB.includes(status)) return null;
  return { topic, status, prose: prose ? prose.trim() : '' };
}

// --- V6 marker-loss gate --------------------------------------------------------------
// parseMarkerLine collapses two DIFFERENT facts into one null: "this is not a marker" and
// "this is a marker that failed to parse". Callers cannot tell them apart, so a malformed
// marker disappeared with no warning and exit 0. A marker ATTEMPT is a line whose topic and
// KNOWN status token are both present — an unknown token stays "not a marker" (that is the
// existing, deliberate rule), which is what keeps ordinary prose out of the loss channel.
// Deliberately a warning, not a failure: a typo in another repo's LOCAL state file must be
// visible, but it is not this builder's business to fail on.
const MARKER_ATTEMPT = new RegExp(`^(${TOPIC}):\\s+(\\S+)`);

// Returns { markers, losses:[{ lineNo, line }] } for one STATE.md text.
export function extractMarkers(stateText) {
  const markers = [];
  const losses = [];
  stateText.split('\n').forEach((line, i) => {
    const m = parseMarkerLine(line);
    if (m) {
      markers.push(m);
      return;
    }
    const attempt = line.match(MARKER_ATTEMPT);
    if (attempt && STATUS_VOCAB.includes(attempt[2])) losses.push({ lineNo: i + 1, line });
  });
  return { markers, losses };
}

// --- Output B source: a bare carrier line "topic: status" (token ALONE) ---------------
// Returns { topic, status } or null. Any prose, em-dash, or unknown token -> null.
export function parseCarrierLine(line) {
  const m = line.match(new RegExp(`^(${TOPIC}):\\s+(\\S+)\\s*$`));
  if (!m) return null;
  const [, topic, status] = m;
  if (!STATUS_VOCAB.includes(status)) return null;
  return { topic, status };
}

// --- V4 public-safety gate ------------------------------------------------------------
// Validate a whole .rollup-carrier file. Blank lines are tolerated. Every other line MUST
// be an exact bare carrier line; otherwise it is a violation with a classified reason:
//   em-dash | prose-after-token | unknown-status | malformed
// Returns { ok, entries, violations:[{ lineNo, line, reason }] }.
export function validateCarrier(text) {
  const entries = [];
  const violations = [];
  text.split('\n').forEach((line, i) => {
    const lineNo = i + 1;
    if (line.trim() === '') return; // blank: tolerated, not a violation
    if (line.includes(EMDASH)) {
      violations.push({ lineNo, line, reason: 'em-dash' });
      return;
    }
    const entry = parseCarrierLine(line);
    if (entry) {
      entries.push(entry);
      return;
    }
    // Not a clean carrier line — classify why so the operator can fix it precisely.
    const shape = line.match(new RegExp(`^(${TOPIC}):\\s+(\\S+)(\\s+.*)?$`));
    if (shape) {
      const status = shape[2];
      const trailing = shape[3];
      if (!STATUS_VOCAB.includes(status)) violations.push({ lineNo, line, reason: 'unknown-status' });
      else if (trailing && trailing.trim() !== '') violations.push({ lineNo, line, reason: 'prose-after-token' });
      else violations.push({ lineNo, line, reason: 'malformed' });
    } else {
      violations.push({ lineNo, line, reason: 'malformed' });
    }
  });
  return { ok: violations.length === 0, entries, violations };
}

// --- V5 drift-warn --------------------------------------------------------------------
// Compare a repo's STATE markers against its carrier entries. Only shared topics are
// compared; a disagreement yields { topic, stateStatus, carrierStatus }. STATE wins.
export function computeDrift(markers, carrierEntries) {
  const stateByTopic = new Map(markers.map((m) => [m.topic, m.status]));
  const drift = [];
  for (const c of carrierEntries) {
    if (stateByTopic.has(c.topic) && stateByTopic.get(c.topic) !== c.status) {
      drift.push({ topic: c.topic, stateStatus: stateByTopic.get(c.topic), carrierStatus: c.status });
    }
  }
  return drift;
}

// --- Orchestrator ---------------------------------------------------------------------
// repos: [{ name, statePath, markers:[{topic,status,prose}], losses, carrier:string|null, carrierMode }]
// Returns:
//   outputA     [{ repo, topic, status, prose }]      — LOCAL roll-up, every repo/mode.
//   outputB     ["topic: status", ...] (sorted)       — PUBLIC index; committed + V4-clean only.
//   drift       [{ repo, topic, stateStatus, carrierStatus }]
//   violations  [{ repo, lineNo, line, reason }]
//   markerLosses[{ repo, statePath, lineNo, line }]   — V6: marker attempts that did not parse.
export function buildRegister({ repos }) {
  const outputA = [];
  const outputBLines = [];
  const drift = [];
  const violations = [];
  const markerLosses = [];

  for (const r of repos) {
    for (const m of r.markers) {
      outputA.push({ repo: r.name, topic: m.topic, status: m.status, prose: m.prose ?? '' });
    }
    for (const l of r.losses ?? []) {
      markerLosses.push({ repo: r.name, statePath: r.statePath ?? null, ...l });
    }
    // Only mode "committed" reaches the public index B.
    if (r.carrierMode !== 'committed' || r.carrier == null) continue;

    const v = validateCarrier(r.carrier);
    if (!v.ok) {
      for (const viol of v.violations) violations.push({ repo: r.name, ...viol });
      continue; // a V4-violating carrier must not pollute the public index
    }

    for (const d of computeDrift(r.markers, v.entries)) drift.push({ repo: r.name, ...d });

    // B is a projection of A: STATE status is authoritative (V5 — STATE wins on drift).
    const stateByTopic = new Map(r.markers.map((m) => [m.topic, m.status]));
    for (const e of v.entries) {
      const status = stateByTopic.has(e.topic) ? stateByTopic.get(e.topic) : e.status;
      outputBLines.push(`${e.topic}: ${status}`);
    }
  }

  outputBLines.sort();
  return { outputA, outputB: outputBLines, drift, violations, markerLosses };
}

// --- Repo discovery: depth 1 + depth 2 under polyrepo containers ----------------------
// Mirrors board.sh:63-89 EXACTLY, and deliberately so: a directory that is itself a git
// repo is one repo and is NOT descended into; a directory that is not a repo but holds
// git repos is a polyrepo container (the plugin marketplace) contributing its children,
// never itself. A depth-1-only glob missed 5 markers across 11 depth-2 STATE.md files.
//
// Identity is the RAW BASENAME (board.sh:100), not "parent/child", so this builder, board.sh
// and the coord mailboxes (~/.claude/coord/<repo>/) all name the same repo the same way.
// Two names for one repo is the AS#5 defect class. Measured today: 0 collisions across 25
// state-bearing directories — a fact, not a guarantee, hence the collision gate below.
//
// Not descending into a git repo also makes the known nested-name trap
// (claude-code-100x/claude-code-100x, both git repos) structurally unreachable rather than
// merely absent.
//
// "Is a repo" tests `.git` for EXISTENCE, not directory-ness: a worktree or submodule has
// `.git` as a FILE. A plain `git worktree add ~/repos/feature-x` lands a depth-1 sibling
// that can carry its own STATE.md, and a directory test dropped it SILENTLY — no warning,
// no count, indistinguishable from a repo with nothing to say. This was pinned rather than
// fixed one-sidedly because diverging would break the very same-name-from-both-readers
// invariant this function exists to hold. board.sh's side is in place — MEASURED, not
// reported: its Discovery block tests `-e`, and has since board.sh was introduced
// (repo-mailbox 61e224c, first released v0.9.0). This is the other half. The two move
// together or not at all — change one, change the other.
function isGitRepo(dir) {
  const dotGit = join(dir, '.git');
  return existsSync(dotGit);
}

function subdirs(dir) {
  try {
    return readdirSync(dir, { withFileTypes: true })
      .filter((e) => e.isDirectory())
      .map((e) => join(dir, e.name));
  } catch {
    return [];
  }
}

// Read one repo dir into a register record, or null when it contributes nothing.
function readRepo(repoDir) {
  const statePath = join(repoDir, 'STATE.md');
  if (!existsSync(statePath) || !statSync(statePath).isFile()) return null;
  const { markers, losses } = extractMarkers(readFileSync(statePath, 'utf8'));
  // A repo with only LOSSES still contributes: dropping it here would re-open the exact
  // silent channel V6 closes.
  if (markers.length === 0 && losses.length === 0) return null;

  const committed = join(repoDir, '.rollup-carrier');
  const priv = join(repoDir, '.rollup-carrier.local');
  let carrier = null;
  let carrierMode = 'absent';
  if (existsSync(committed)) {
    carrier = readFileSync(committed, 'utf8');
    carrierMode = 'committed';
  } else if (existsSync(priv)) {
    carrier = readFileSync(priv, 'utf8');
    carrierMode = 'private';
  }
  return { name: basename(repoDir), statePath, markers, losses, carrier, carrierMode };
}

export function discoverRepos(reposRoot) {
  const repoDirs = [];
  for (const entry of subdirs(reposRoot)) {
    if (isGitRepo(entry)) {
      repoDirs.push(entry);
      continue;
    }
    for (const child of subdirs(entry)) {
      if (isGitRepo(child)) repoDirs.push(child);
    }
  }

  const repos = [];
  const seen = new Map();
  for (const dir of repoDirs) {
    const r = readRepo(dir);
    if (!r) continue; // contributes nothing -> cannot collide with anything
    const prior = seen.get(r.name);
    // Fail HIGH: a silent pick-one would make the register quietly wrong about which repo
    // a marker came from, which is worse than not building at all. Gated on CONTRIBUTING
    // repos only — two same-named directories where just one bears a STATE.md are not
    // ambiguous, so they must not stop the build.
    if (prior) {
      throw new Error(
        `repo name collision: "${r.name}" resolves to two STATE-bearing directories `
        + `(${prior} and ${dir}). The register cannot attribute markers unambiguously.`,
      );
    }
    seen.set(r.name, dir);
    repos.push(r);
  }
  return repos;
}

// --- CLI shell (thin) -----------------------------------------------------------------
// Discovers repos for Output A, detects carrier mode per repo, prints both outputs with
// clear LOCAL/PUBLIC framing plus drift + violation + marker-loss notices. The operator
// redirects; the builder itself commits nothing.

const isMain = process.argv[1] && fileURLToPath(import.meta.url) === process.argv[1];
if (isMain) {
  const reposRoot = process.argv[2] || join(homedir(), 'repos');
  let repos;
  try {
    repos = discoverRepos(reposRoot);
  } catch (err) {
    // A name collision makes every marker's attribution suspect, so emit nothing at all.
    process.stderr.write(`FATAL ${err.message}\n`);
    process.exit(2);
  }
  const { outputA, outputB, drift, violations, markerLosses } = buildRegister({ repos });

  const out = [];
  out.push(`# State roll-up register — source: ${reposRoot}/*/STATE.md + <container>/*/STATE.md`);
  // "discovered", not "with markers": a repo carrying only V6 losses is discovered and
  // reported, but contributes nothing to A.
  out.push(`# repos discovered: ${repos.length}  (` +
    `${repos.filter((r) => r.carrierMode === 'committed').length} committed, ` +
    `${repos.filter((r) => r.carrierMode === 'private').length} private, ` +
    `${repos.filter((r) => r.carrierMode === 'absent').length} absent)`);
  out.push('');
  out.push('## Output A — rich LOCAL roll-up (LOCAL-ONLY, never publish)');
  for (const e of outputA) {
    out.push(`${e.repo.padEnd(28)} ${e.topic}: ${e.status}${e.prose ? ` ${EMDASH} ${e.prose}` : ''}`);
  }
  out.push('');
  out.push(`## Output B — public status-token index (${outputB.length} line(s); publishable)`);
  for (const line of outputB) out.push(line);
  out.push('');

  const notices = [];
  for (const v of violations) {
    notices.push(`V4 VIOLATION  ${v.repo} .rollup-carrier:${v.lineNo} [${v.reason}] ${v.line.trim()}`);
  }
  for (const d of drift) {
    notices.push(`V5 DRIFT-WARN ${d.repo} "${d.topic}": STATE=${d.stateStatus} != carrier=${d.carrierStatus} (STATE wins in B)`);
  }
  for (const l of markerLosses) {
    notices.push(`V6 MARKER-LOSS ${l.statePath ?? l.repo}:${l.lineNo} did not parse as a marker: ${l.line.trim()}`);
  }
  if (notices.length) {
    process.stderr.write(`${notices.join('\n')}\n`);
  }

  process.stdout.write(`${out.join('\n')}\n`);
  process.exit(violations.length === 0 ? 0 : 1);
}