#!/usr/bin/env node

/**
 * campaign-cli — read-only reporter for the durable machine-wide campaign ledger
 * (v5.7 Fase 2, Block 3b).
 *
 * Mirrors the knowledge-refresh-cli precedent: it is the DETERMINISTIC, READ-ONLY half
 * of the hybrid motor. It loads the campaign ledger (the durable file that sits ABOVE
 * individual config-audit sessions), validates it, and emits the repo list + a
 * machine-wide roll-up as JSON. It NEVER writes the ledger — initialization and every
 * status transition belong to the command layer (Block 3c `/config-audit campaign`),
 * which calls the lib's pure transforms + saveLedger only on explicit, human-approved
 * action. A missing ledger file is reported gracefully (initialized:false), NEVER created.
 *
 * Naming: `-cli` suffix → NOT an orchestrated scanner (the scan-orchestrator only loads
 * scanner modules), so the scanner count is unchanged and the snapshot suite stays
 * byte-stable.
 *
 * Usage:
 *   node campaign-cli.mjs [--ledger-file <path>] [--output-file <path>]
 *
 * Exit codes: 0 = initialized & valid, 1 = not initialized yet (advisory), 3 = error.
 */

import { resolve } from 'node:path';
import { writeOutputFile } from './lib/write-output.mjs';
import {
  loadLedger,
  validateLedger,
  rollUp,
  buildBacklog,
  defaultLedgerPath,
} from './lib/campaign-ledger.mjs';

/**
 * Usage error. Throws rather than calling process.exit(): exit() discards
 * unflushed stdout when stdout is a pipe. The top-level catch prints the same
 * `Error: ` text and sets the same exit code 3, so callers see no difference.
 */
class CliUsageError extends Error {}

function fail(message) {
  throw new CliUsageError(message);
}

async function main() {
  const args = process.argv.slice(2);
  let ledgerFile = null;
  let outputFile = null;

  for (let i = 0; i < args.length; i++) {
    const a = args[i];
    if (a === '--ledger-file' && args[i + 1]) ledgerFile = args[++i];
    else if (a === '--output-file' && args[i + 1]) outputFile = args[++i];
    // A flag we do not understand must fail loudly. Silently dropping it lets a
    // caller-side mistake — a typo'd `--ledger-file`, or a shell that did not
    // word-split "--flag value" into two argv entries — produce a confident
    // report about the wrong ledger.
    else if (a.startsWith('--')) fail(`unknown flag "${a}"`);
  }

  const ledgerPath = resolve(ledgerFile || defaultLedgerPath());

  let ledger;
  try {
    // loadLedger returns null on ENOENT (graceful first run) and throws on parse error.
    ledger = await loadLedger(ledgerPath);
  } catch (err) {
    fail(`could not read ledger at ${ledgerPath}: ${err.message}`);
  }

  let payload;
  let exitCode;

  if (ledger === null) {
    // Graceful first run — the ledger does not exist yet. We DO NOT create it; that is
    // the command layer's job (Block 3c), on explicit human-approved action.
    payload = {
      status: 'ok',
      initialized: false,
      ledgerPath,
      schemaVersion: null,
      createdDate: null,
      updatedDate: null,
      repos: [],
      rollUp: rollUp({ repos: [] }),
      backlog: buildBacklog({ repos: [] }),
    };
    exitCode = 1; // advisory: there is no campaign to report yet
  } else {
    const { valid, errors } = validateLedger(ledger);
    if (!valid) {
      fail(`ledger at ${ledgerPath} is invalid:\n  - ${errors.join('\n  - ')}`);
    }
    payload = {
      status: 'ok',
      initialized: true,
      ledgerPath,
      schemaVersion: ledger.schemaVersion,
      createdDate: ledger.createdDate,
      updatedDate: ledger.updatedDate,
      repos: ledger.repos,
      rollUp: rollUp(ledger),
      backlog: buildBacklog(ledger),
    };
    exitCode = 0;
  }

  const json = JSON.stringify(payload, null, 2);
  if (outputFile) await writeOutputFile(outputFile, json, 'utf-8');
  else process.stdout.write(json + '\n');

  process.exitCode = exitCode;
}

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