#!/usr/bin/env -S bun --no-env-file --config=/dev/null
/**
 * gstack-state-matrix — the round-trip matrix for proposal, hold and approval state machines (field list 2, W3).
 *
 *   gstack-state-matrix detect [--base <ref>] [--diff-base <sha>]
 *   gstack-state-matrix check <specialist-output|-> [--repo <dir>] [--expect <expectation.json>] [--json]
 *   gstack-state-matrix outfile
 *   gstack-state-matrix findings <reviewer-output|->
 *
 * `detect` prints `SCOPE_STATE_MACHINE=true|false` (shell-safe for
 * `source <(...)`, with `# state-machine:` comment lines naming the hits) from
 * the lines the branch adds since its merge base with origin/<base>.
 * `check` reads the state-machines specialist's output and prints
 * `STATE_MATRIX_GAP:` per gap and `STATE_MATRIX_CHECK: ok | incomplete gaps=<n>`
 * last; exit 0 ok, 1 incomplete (STATE_MATRIX_INCOMPLETE). `outfile` creates and
 * prints a new empty 0600 file in the repo's private `.gstack/tmp/` (0700, kept
 * out of git through info/exclude) for the specialist's output, so a later
 * review never checks or commits an earlier run's file. `findings` prints the
 * output for Step 9.3's merge with each untested cell mapped below the floor
 * (lib/review-scope.ts mapStateMatrixOutput) and `STATE_MATRIX_FINDINGS:` on
 * stderr. Logic: lib/state-matrix.ts.
 */
import { spawnSync } from 'node:child_process';
import { randomBytes } from 'node:crypto';
import * as fs from 'node:fs';
import * as path from 'node:path';
import { addedLines } from '../lib/banned-terms';
import { EXIT, exitTableHelp } from '../lib/headless-artifacts';
import { resultLine } from '../lib/result-codes';
import { resolveBaseBranch } from '../lib/ship-policy';
import { mapStateMatrixOutput } from '../lib/review-scope';
import { checkStateMatrix, detectStateMachine, renderStateMatrixCheck, type Expectation } from '../lib/state-matrix';

const HELP = `gstack-state-matrix — kind × owner action × resulting row for proposal, hold and approval state machines

  detect [--base <ref>] [--diff-base <sha>]   SCOPE_STATE_MACHINE=true|false for the branch's added code lines
  check <file|-> [--repo <dir>] [--expect <json>] [--json]
                                             gaps in the state-machines specialist's output (review/specialists/state-machines.md)
  outfile                                    print a new empty private file for that output
  findings <file|->                          that output for the Step 9.3 merge, each untested cell mapped below the floor

${exitTableHelp()}`;

function flag(args: string[], name: string): string | undefined {
  const i = args.indexOf(name);
  return i >= 0 ? args[i + 1] : undefined;
}
function git(args: string[], cwd?: string): { ok: boolean; out: string } {
  const r = spawnSync('git', args, { cwd, encoding: 'utf8', timeout: 120_000, maxBuffer: 256 * 1024 * 1024 });
  return { ok: r.status === 0, out: r.stdout ?? '' };
}

function detect(rest: string[]): number {
  const root = git(['rev-parse', '--show-toplevel']);
  if (!root.ok) { process.stdout.write('SCOPE_STATE_MACHINE=false\n# not inside a git repository\n'); return EXIT.usage; }
  const repoRoot = root.out.trim();
  const base = resolveBaseBranch(repoRoot, flag(rest, '--base'));
  const mb = flag(rest, '--diff-base') ?? git(['merge-base', `origin/${base}`, 'HEAD'], repoRoot).out.trim();
  const diff = mb ? git(['-c', 'core.quotePath=false', 'diff', '--no-ext-diff', '--no-textconv', '--unified=0', '--no-color', mb], repoRoot) : { ok: false, out: '' };
  if (!diff.ok) { process.stdout.write(`SCOPE_STATE_MACHINE=false\n# no merge base with origin/${base}; run: git fetch origin ${base}\n`); return EXIT.usage; }
  const { detected, hits } = detectStateMachine(addedLines(diff.out));
  const lines = [`SCOPE_STATE_MACHINE=${detected}`, ...hits.slice(0, 12).map(h => `# state-machine: ${h.file}:${h.line} ${[...h.subject, ...h.action].join(',')}`)];
  process.stdout.write(lines.join('\n') + '\n');
  return EXIT.ok;
}

function check(rest: string[]): number {
  const input = rest.find((a, i) => !a.startsWith('--') && !['--repo', '--expect'].includes(rest[i - 1] ?? ''));
  if (!input) { process.stderr.write(`gstack-state-matrix check: a specialist output file (or -) is required\n${HELP}\n`); return EXIT.usage; }
  const text = input === '-' ? fs.readFileSync(0, 'utf8') : fs.readFileSync(input, 'utf8');
  const repoRoot = flag(rest, '--repo') ?? (git(['rev-parse', '--show-toplevel']).out.trim() || process.cwd());
  const expectFile = flag(rest, '--expect');
  const expect = expectFile ? JSON.parse(fs.readFileSync(expectFile, 'utf8')) as Expectation : undefined;
  const result = checkStateMatrix(text, repoRoot, expect);
  process.stdout.write(rest.includes('--json') ? JSON.stringify(result) + '\n' : renderStateMatrixCheck(result));
  if (result.gaps.length) { process.stderr.write(resultLine('gstack-state-matrix check', 'STATE_MATRIX_INCOMPLETE', `${result.gaps.length} gap(s)`) + '\n'); return EXIT.fail; }
  return EXIT.ok;
}

function findings(rest: string[]): number {
  const input = rest.find(a => !a.startsWith('--'));
  if (!input) { process.stderr.write(`gstack-state-matrix findings: a reviewer output file (or -) is required\n${HELP}\n`); return EXIT.usage; }
  const r = mapStateMatrixOutput(input === '-' ? fs.readFileSync(0, 'utf8') : fs.readFileSync(input, 'utf8'));
  process.stdout.write(r.text.endsWith('\n') ? r.text : `${r.text}\n`);
  process.stderr.write(`STATE_MATRIX_FINDINGS: mapped=${r.mapped} (untested cells below the floor; docs/review-policy.md test gap)\n`);
  return EXIT.ok;
}

function outfile(): number {
  const root = git(['rev-parse', '--show-toplevel']);
  const exclude = git(['rev-parse', '--git-path', 'info/exclude']);
  if (!root.ok || !exclude.ok) { process.stderr.write('gstack-state-matrix outfile: not inside a git repository\n'); return EXIT.usage; }
  const dir = path.join(root.out.trim(), '.gstack', 'tmp');
  fs.mkdirSync(dir, { recursive: true, mode: 0o700 });
  fs.chmodSync(dir, 0o700);
  const excludeFile = path.resolve(exclude.out.trim());
  fs.mkdirSync(path.dirname(excludeFile), { recursive: true });
  const excluded = fs.existsSync(excludeFile) ? fs.readFileSync(excludeFile, 'utf8') : '';
  if (!excluded.split('\n').includes('/.gstack/tmp/')) fs.appendFileSync(excludeFile, `${excluded && !excluded.endsWith('\n') ? '\n' : ''}/.gstack/tmp/\n`);
  const file = path.join(dir, `state-machines.${randomBytes(6).toString('hex')}.md`);
  fs.closeSync(fs.openSync(file, 'wx', 0o600));
  process.stdout.write(file + '\n');
  return EXIT.ok;
}

function main(argv: string[]): number {
  const [cmd, ...rest] = argv;
  if (!cmd || cmd === '--help' || cmd === '-h') { process.stdout.write(HELP + '\n'); return cmd ? EXIT.ok : EXIT.usage; }
  if (cmd === 'detect') return detect(rest);
  if (cmd === 'check') return check(rest);
  if (cmd === 'outfile') return outfile();
  if (cmd === 'findings') return findings(rest);
  process.stderr.write(`gstack-state-matrix: unknown command ${cmd}\n${HELP}\n`);
  return EXIT.usage;
}

process.exitCode = main(process.argv.slice(2));