import fs from 'node:fs/promises';
import path from 'node:path';

const REPOSITORY_CHECK_IDS = new Set(['REL-01', 'REL-02', 'REL-04']);

export function commandFilesForSuite(suite) {
  return (suite.command ?? [])
    .slice(1)
    .filter((arg) => typeof arg === 'string' && !arg.startsWith('-'))
    .map((arg) => arg.replaceAll('\\', '/'));
}

export function suiteInvalidatedByChanges(suite, changedPaths) {
  const normalized = new Set((changedPaths ?? []).map((item) => String(item).replaceAll('\\', '/')));
  if (normalized.has('release-gate/coverage.mjs')) return true;
  return commandFilesForSuite(suite).some((filePath) => normalized.has(filePath));
}

export function previousScenarioMap(report) {
  return new Map((report?.scenarios ?? []).map((scenario) => [scenario.id, scenario]));
}

export function shouldRerunImpactSuite({
  suite,
  selectedIds,
  previousReport,
  artifactSha256,
  commitSha,
  changedPathsSincePrevious = [],
}) {
  const selectedInSuite = suite.scenarios.filter((scenarioId) => selectedIds.has(scenarioId));
  if (selectedInSuite.length === 0) return false;
  if (!previousReport || previousReport.artifact_sha256 !== artifactSha256) return true;
  if (suiteInvalidatedByChanges(suite, changedPathsSincePrevious)) return true;
  if (suite.mode === 'scenarios' && previousReport.commit_sha !== commitSha) return true;

  const previous = previousScenarioMap(previousReport);
  return selectedInSuite.some((scenarioId) => previous.get(scenarioId)?.status !== 'passed');
}

export function carryForwardScenario(previousScenario) {
  return {
    ...previousScenario,
    evidence: [
      ...(previousScenario.evidence ?? []),
      'carried_forward=true',
    ],
  };
}

export async function findImpactResumeReport({
  reportRoot,
  artifactSha256,
  commitSha,
}) {
  let entries = [];
  try {
    entries = await fs.readdir(reportRoot, { withFileTypes: true });
  } catch (error) {
    if (error.code === 'ENOENT') return null;
    throw error;
  }

  const candidates = [];
  for (const entry of entries) {
    if (!entry.isDirectory() || entry.name === 'local') continue;
    const reportPath = path.join(reportRoot, entry.name, 'report.json');
    try {
      const report = JSON.parse(await fs.readFile(reportPath, 'utf8'));
      if (report?.mode !== 'impact') continue;
      if (report.artifact_sha256 !== artifactSha256) continue;
      if (!Array.isArray(report.scenarios)) continue;
      candidates.push({ report, reportPath, commitSha: report.commit_sha });
    } catch {
      // ignore unreadable reports
    }
  }
  if (candidates.length === 0) return null;

  const sameCommit = candidates.find((candidate) => candidate.commitSha === commitSha);
  if (sameCommit) return sameCommit;
  candidates.sort((left, right) => (
    Date.parse(right.report.completed_at ?? 0) - Date.parse(left.report.completed_at ?? 0)
  ));
  return candidates[0];
}

export { REPOSITORY_CHECK_IDS };