#!/usr/bin/env node

/**
 * Config-Audit Drift CLI
 * Compare current configuration against a saved baseline.
 * Usage:
 *   node drift-cli.mjs <path> --save [--name my-baseline]
 *   node drift-cli.mjs <path> [--baseline my-baseline] [--json] [--output-file path]
 *   node drift-cli.mjs --list
 * Unknown options and value-less --name/--baseline/--output-file exit 3.
 * Zero external dependencies.
 */

import { resolve } from 'node:path';
import { writeFile } from 'node:fs/promises';
import { runAllScanners } from './scan-orchestrator.mjs';
import { diffEnvelopes, formatDiffReport } from './lib/diff-engine.mjs';
import { saveBaseline, loadBaseline, listBaselines } from './lib/baseline.mjs';
import { humanizeFindings } from './lib/humanizer.mjs';

const BOOL_FLAGS = ['--save', '--list', '--json', '--raw', '--global'];
const VALUE_FLAGS = ['--name', '--baseline', '--output-file'];

async function main() {
  const args = process.argv.slice(2);
  let targetPath = '.';
  let baselineName = 'default';
  let save = false;
  let list = false;
  let jsonMode = false;
  let rawMode = false;
  let includeGlobal = false;
  let outputFile = null;

  // M-BUG-21: this loop used to end in `else if (!arg.startsWith('-')) targetPath = arg`,
  // with no unknown-flag branch. An unrecognised flag was dropped silently and its
  // VALUE fell through to targetPath — so `--output-file /tmp/x.json` scanned
  // /tmp/x.json, a path that does not exist, yielding a near-empty scan and
  // therefore permanent phantom drift. A missing value for --name was equally
  // silent and destructive: it left baselineName at 'default' and OVERWROTE the
  // default baseline. Both now fail loudly (exit 3) instead.
  for (let i = 0; i < args.length; i++) {
    const arg = args[i];

    if (BOOL_FLAGS.includes(arg)) {
      if (arg === '--save') save = true;
      else if (arg === '--list') list = true;
      else if (arg === '--json') jsonMode = true;
      else if (arg === '--raw') rawMode = true;
      else if (arg === '--global') includeGlobal = true;
    } else if (VALUE_FLAGS.includes(arg)) {
      const value = args[i + 1];
      if (value === undefined || value.startsWith('-')) {
        throw new Error(`Option ${arg} requires a value.`);
      }
      if (arg === '--name' || arg === '--baseline') baselineName = value;
      else outputFile = value;
      i++;
    } else if (arg.startsWith('-')) {
      throw new Error(
        `Unknown option: ${arg}\n` +
        `Valid options: ${[...BOOL_FLAGS, ...VALUE_FLAGS].join(' ')}`
      );
    } else {
      targetPath = arg;
    }
  }

  // --- List mode ---
  if (list) {
    const result = await listBaselines();
    // commands/drift.md runs this with `2>/dev/null` (ux-rules rule 2). The
    // human listing below goes to stderr, so without --output-file the command
    // received 0 bytes and could render nothing. The flag was already accepted
    // by the arg parser; only list mode ignored it.
    if (outputFile) await writeFile(outputFile, JSON.stringify(result, null, 2) + '\n', 'utf-8');
    if (jsonMode || rawMode) {
      process.stdout.write(JSON.stringify(result, null, 2) + '\n');
    } else {
      if (result.baselines.length === 0) {
        process.stderr.write('No baselines saved.\n');
        process.stderr.write('Save one with: node drift-cli.mjs <path> --save\n');
      } else {
        process.stderr.write('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n');
        process.stderr.write(' Saved Baselines\n');
        process.stderr.write('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n\n');
        for (const b of result.baselines) {
          process.stderr.write(` ${b.name.padEnd(20)} ${b.findingCount} findings  ${b.savedAt}\n`);
        }
        process.stderr.write('\n━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n');
      }
    }
    return;
  }

  // --- Save mode ---
  if (save) {
    if (!jsonMode && !rawMode) {
      process.stderr.write(`Config-Audit Drift CLI v2.1.0\n`);
      process.stderr.write(`Saving baseline "${baselineName}" for ${resolve(targetPath)}\n\n`);
    }

    const envelope = await runAllScanners(targetPath, { includeGlobal, humanizedProgress: !jsonMode && !rawMode });
    const result = await saveBaseline(envelope, baselineName);

    if (jsonMode || rawMode) {
      process.stdout.write(JSON.stringify({ saved: true, name: result.name, path: result.path }, null, 2) + '\n');
    } else {
      process.stderr.write(`\nBaseline "${result.name}" saved to ${result.path}\n`);
      process.stderr.write(`Findings: ${envelope.aggregate.total_findings}\n`);
    }
    return;
  }

  // --- Drift mode (default) ---
  if (!jsonMode && !rawMode) {
    process.stderr.write(`Config-Audit Drift CLI v2.1.0\n`);
    process.stderr.write(`Target: ${resolve(targetPath)}\n`);
    process.stderr.write(`Baseline: ${baselineName}\n\n`);
  }

  // Load baseline
  const baseline = await loadBaseline(baselineName);
  if (!baseline) {
    if (jsonMode || rawMode) {
      process.stdout.write(JSON.stringify({ error: `Baseline "${baselineName}" not found. Save one with --save.` }, null, 2) + '\n');
    } else {
      process.stderr.write(`Baseline "${baselineName}" not found.\n`);
      process.stderr.write(`Save one first: node drift-cli.mjs <path> --save\n`);
    }
    process.exitCode = 1;
    return;
  }

  // M-BUG-27: a baseline carries the path it was saved from, but nothing ever
  // compared it against the current target. Diffing a repo against a baseline
  // anchored elsewhere produced 100% phantom drift — every baseline finding
  // "resolved", every current finding "new" — and reported it as trend
  // "improving": a reassuring and entirely false signal, on the DEFAULT
  // baseline. The warning goes to stderr in every mode; stdout stays
  // byte-identical to the frozen v5.0.0 shape.
  const baselineTarget = baseline._baseline?.target_path || '';
  const currentTarget = resolve(targetPath);
  const anchorMatches = !baselineTarget || baselineTarget === currentTarget;
  if (baselineTarget && baselineTarget !== currentTarget) {
    process.stderr.write(
      `\nWarning: baseline "${baselineName}" was saved from a different target path.\n` +
      `  baseline: ${baselineTarget}\n` +
      `  current:  ${currentTarget}\n` +
      `  The two scans cover different trees, so this diff is not a drift signal.\n` +
      `  Re-anchor with: drift-cli.mjs ${currentTarget} --save --name ${baselineName}\n\n`
    );
  }

  // Run current scan
  const current = await runAllScanners(targetPath, {
    includeGlobal,
    humanizedProgress: !jsonMode && !rawMode,
  });

  // Diff
  const diff = diffEnvelopes(baseline, current);

  // Default mode: humanize finding-bearing diff fields before report rendering.
  // `_baselineAnchor` rides here and NOT in the raw shape: commands/drift.md runs
  // the CLI under `2>/dev/null`, so the stderr warning above never reaches the
  // caller that has to act on it. --json/--raw stay v5.0.0-shaped.
  const humanizedDiff = {
    ...diff,
    _baselineAnchor: { matches: anchorMatches, baselineTarget, currentTarget },
    newFindings: humanizeFindings(diff.newFindings || []),
    resolvedFindings: humanizeFindings(diff.resolvedFindings || []),
    unchangedFindings: humanizeFindings(diff.unchangedFindings || []),
    movedFindings: humanizeFindings(diff.movedFindings || []),
  };

  if (jsonMode || rawMode) {
    // --json and --raw both write the raw v5.0.0-shape diff (byte-identical).
    process.stdout.write(JSON.stringify(diff, null, 2) + '\n');
  } else {
    const report = formatDiffReport(humanizedDiff);
    process.stderr.write('\n' + report + '\n');
  }

  // ux-rules rule 2: every scanner Bash call uses `--output-file <path>` and the
  // command reads the file with the Read tool. drift-cli had no such flag, and
  // its default-mode report goes to stderr — which commands/drift.md discarded
  // via `2>/dev/null` while instructing the agent to "read stdout". The command
  // captured nothing. Matches posture.mjs: raw diff in --json/--raw, humanized
  // otherwise; stdout is unaffected.
  if (outputFile) {
    const fileDiff = (jsonMode || rawMode) ? diff : humanizedDiff;
    await writeFile(outputFile, JSON.stringify(fileDiff, null, 2), 'utf-8');
    process.stderr.write(`\nResults written to ${outputFile}\n`);
  }

  // Exit code: 0=stable/improving, 1=degrading
  process.exitCode = diff.summary.trend === 'degrading' ? 1 : 0;
}

// Only run CLI if invoked directly
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.exitCode = 3;
  });
}