#!/usr/bin/env node

/**
 * campaign-export-cli — export a tracked repo's action plan into that repo's own `docs/`
 * (v5.7 Fase 2, Block 4c).
 *
 * Block 4b built the cross-repo prioritized backlog; this is the "plan export" half of Block 4c.
 * Given a repo tracked in the campaign ledger, it resolves the repo's linked config-audit
 * session, reads that session's `action-plan.md`, and assembles (via the pure
 * `campaign-export` lib) a `docs/config-audit-plan-<sessionId>.md` document carrying a
 * provenance header + the verbatim plan ("planer følger arbeidsstedet").
 *
 * Read-only by DEFAULT (a dry-run preview that returns the assembled `document` + `targetPath`
 * so the command can show the user what will be written). The actual write happens ONLY under
 * the opt-in `--write` flag — which the `/config-audit campaign` command invokes solely after
 * explicit human approval (Verifiseringsplikt — nothing auto-written). Writing the file
 * faithfully (a byte-exact copy of the assembled document) is the CLI's job, not the LLM's, so
 * a 200-line plan is never re-typed and cannot drift.
 *
 * Execution is NOT here: Block 4c reuses the existing `/config-audit implement` (backup +
 * apply + verify) + `/config-audit rollback`. This CLI only exports the durable record.
 *
 * Naming: `-cli` suffix → NOT an orchestrated scanner, so the scanner count is unchanged and
 * the snapshot suite stays byte-stable.
 *
 * Usage:
 *   node campaign-export-cli.mjs --repo <path> [--write]
 *        [--ledger-file <p>] [--sessions-dir <p>] [--reference-date <YYYY-MM-DD>] [--output-file <p>]
 *
 * Exit codes: 0 = exportable (preview ready, or written under --write),
 *             1 = advisory: repo tracked but not exportable yet (no linked session / no plan),
 *             3 = error (missing --repo, untracked repo, no/corrupt ledger, unreadable plan).
 */

import { resolve, join, dirname } from 'node:path';
import { homedir } from 'node:os';
import { readFile, writeFile, mkdir } from 'node:fs/promises';
import {
  loadLedger,
  validateLedger,
  defaultLedgerPath,
} from './lib/campaign-ledger.mjs';
import { planExportPath, buildPlanExportDocument } from './lib/campaign-export.mjs';

const DATE_RE = /^\d{4}-\d{2}-\d{2}$/;

function fail(message) {
  process.stderr.write(`Error: ${message}\n`);
  process.exit(3);
}

/** Default session store: next to the ledger, OUTSIDE the plugin dir. */
function defaultSessionsDir() {
  return join(homedir(), '.claude', 'config-audit', 'sessions');
}

function parseArgs(argv) {
  const flags = { repo: null, ledgerFile: null, sessionsDir: null, referenceDate: null, outputFile: null, write: false };
  for (let i = 0; i < argv.length; i++) {
    const a = argv[i];
    if (a === '--repo' && argv[i + 1] !== undefined) flags.repo = argv[++i];
    else if (a === '--ledger-file' && argv[i + 1] !== undefined) flags.ledgerFile = argv[++i];
    else if (a === '--sessions-dir' && argv[i + 1] !== undefined) flags.sessionsDir = argv[++i];
    else if (a === '--reference-date' && argv[i + 1] !== undefined) flags.referenceDate = argv[++i];
    else if (a === '--output-file' && argv[i + 1] !== undefined) flags.outputFile = argv[++i];
    else if (a === '--write') flags.write = true;
    else if (a.startsWith('--')) fail(`unknown flag "${a}"`);
    else fail(`unexpected argument "${a}"`);
  }
  return flags;
}

async function emit(payload, outputFile, exitCode) {
  const json = JSON.stringify(payload, null, 2);
  if (outputFile) await writeFile(outputFile, json, 'utf-8');
  else process.stdout.write(json + '\n');
  process.exit(exitCode);
}

async function main() {
  const flags = parseArgs(process.argv.slice(2));
  if (!flags.repo) fail('--repo <path> is required');
  if (flags.referenceDate && !DATE_RE.test(flags.referenceDate)) fail('--reference-date must be YYYY-MM-DD');

  const ledgerPath = resolve(flags.ledgerFile || defaultLedgerPath());
  const sessionsDir = resolve(flags.sessionsDir || defaultSessionsDir());
  const repoPath = resolve(flags.repo);
  // The clock is read here ONLY — passed to the pure lib as the injected `now`.
  const now = flags.referenceDate || new Date().toISOString().slice(0, 10);

  let ledger;
  try {
    ledger = await loadLedger(ledgerPath);
  } catch (err) {
    fail(`could not read ledger at ${ledgerPath}: ${err.message}`);
  }
  if (ledger === null) fail(`no campaign ledger at ${ledgerPath} — run "/config-audit campaign init" first`);

  const { valid, errors } = validateLedger(ledger);
  if (!valid) fail(`ledger at ${ledgerPath} is invalid:\n  - ${errors.join('\n  - ')}`);

  const repo = ledger.repos.find((r) => r.path === repoPath);
  if (!repo) fail(`repo "${repoPath}" is not tracked in the campaign — add it first`);

  const repoInfo = { path: repo.path, name: repo.name, status: repo.status, sessionId: repo.sessionId ?? null };

  // Gate 1: the repo must have a linked session (set via `set-status … --session <id>`).
  if (typeof repo.sessionId !== 'string' || repo.sessionId.trim() === '') {
    return emit(
      { status: 'ok', action: 'export', repo: repoInfo, exportable: false, problems: ['no-session-linked'],
        written: false, targetPath: null, document: null },
      flags.outputFile,
      1,
    );
  }

  // Gate 2: that session must carry an action-plan.md (i.e. `/config-audit plan` has run).
  const sourcePlanPath = join(sessionsDir, repo.sessionId, 'action-plan.md');
  let planMarkdown;
  try {
    planMarkdown = await readFile(sourcePlanPath, 'utf-8');
  } catch (err) {
    if (err && err.code === 'ENOENT') {
      return emit(
        { status: 'ok', action: 'export', repo: repoInfo, sessionId: repo.sessionId, sourcePlanPath,
          exportable: false, problems: ['no-action-plan'], written: false, targetPath: null, document: null },
        flags.outputFile,
        1,
      );
    }
    fail(`could not read action plan at ${sourcePlanPath}: ${err.message}`);
  }

  const targetPath = planExportPath(repo.path, repo.sessionId);
  const document = buildPlanExportDocument({
    repoName: repo.name,
    repoPath: repo.path,
    sessionId: repo.sessionId,
    planMarkdown,
    now,
  });

  let written = false;
  if (flags.write) {
    await mkdir(dirname(targetPath), { recursive: true });
    await writeFile(targetPath, document, 'utf-8');
    written = true;
  }

  return emit(
    { status: 'ok', action: 'export', repo: repoInfo, sessionId: repo.sessionId, sourcePlanPath,
      exportable: true, problems: [], written, targetPath, document },
    flags.outputFile,
    0,
  );
}

const isDirectRun =
  process.argv[1] && resolve(process.argv[1]) === resolve(new URL(import.meta.url).pathname);
if (isDirectRun) {
  main().catch((err) => {
    process.stderr.write(`Fatal: ${err.message}\n`);
    process.exit(3);
  });
}