export const CORE_SCENARIO_IDS = Object.freeze([
  'REL-01',
  'REL-02',
  'REL-04',
  'REL-05',
  'REL-06',
  'REL-09',
  'REL-11',
  'AUTH-01',
  'AUTH-05',
  'CHAT-01',
  'CHAT-06',
  'CHAT-07',
  'AGENT-01',
  'AGENT-03',
  'MS-01',
  'COMP-09',
]);

const CRITICAL_IMPACT_RULES = Object.freeze([
  {
    groups: ['AGENT', 'CFG', 'UI'],
    pattern: /^(?:(?:package|npm-shrinkwrap).*\.json|pnpm-lock\.yaml|yarn\.lock)$/i,
  },
  {
    groups: ['AGENT', 'AUTH', 'CFG', 'CHAT', 'DATA'],
    pattern: /^(?:server\.mjs|schema\.sql|(?:migrations?|database)\/)/i,
  },
  {
    groups: ['CFG', 'REL'],
    pattern: /^(?:release-gate\/|scripts\/(?:build-portal-runtime|check-release-ready|release-|run-release-gate|verify-release-gate|verify-canary-))/i,
  },
  {
    groups: ['AGENT', 'CFG', 'REL'],
    pattern: /^scripts\/(?:run-memind-portal-prod|run-memind-portal-candidate|goosed.*compose)/i,
  },
  {
    groups: ['CFG', 'REL'],
    pattern: /^(?:docs\/(?:production-release-guardian|release-gate-automation|release-canary-103)\.md|(?:PRODUCTION_RELEASE_RULES|ENGINEERING_WORKFLOW_RULES)\.md|\.github\/workflows\/)/i,
  },
  {
    groups: ['AGENT', 'AUTH', 'CFG', 'CHAT', 'WX'],
    pattern: /^server\/portal-/i,
  },
  {
    groups: ['AUTH', 'CFG', 'UI'],
    pattern: /^src\/(?:api\/core|config)\.[cm]?[jt]sx?$/i,
  },
  {
    groups: ['AGENT', 'CFG', 'CHAT'],
    pattern: /^(?:tkmind-proxy|session-stream|session-stream-store|deepseek-no-think-proxy)\.mjs$/i,
  },
]);

const NON_RUNTIME_PATHS = Object.freeze([
  /^(?:AGENTS|README|CHANGELOG)\.md$/i,
  /^\.runtime\//i,
  /^docs\//i,
  /^\.cursor\//i,
  /^\.codex\//i,
  /^scripts\/dev(?:-|\.|\/)/i,
  /^scripts\/.*(?:test|fixture|mock).*\.[cm]?[jt]s$/i,
  /\.(?:test|spec)\.[cm]?[jt]sx?$/i,
  /^(?:eslint|prettier|tsconfig|components)\..*$/i,
  /^openapi\.json$/i,
]);

const IMPACT_RULES = Object.freeze([
  { groups: ['MEM'], pattern: /(?:^|\/)(?:memory|episodic)[^/]*|memory-v2/i },
  { groups: ['DATA'], pattern: /(?:page-data|dataset|page-policy)/i },
  { groups: ['WX'], pattern: /(?:wechat|weixin|wx-)/i },
  { groups: ['BILL'], pattern: /(?:billing|payment|charge|balance|subscription)/i },
  { groups: ['PLAZA'], pattern: /(?:^|\/)plaza/i },
  { groups: ['SCHED'], pattern: /(?:schedule|scheduler|reminder|cron)/i },
  { groups: ['SEARCH'], pattern: /(?:search|weather|market|news-provider)/i },
  { groups: ['XLS'], pattern: /(?:excel|xlsx|spreadsheet)/i },
  { groups: ['IMGPG'], pattern: /(?:image|thumbnail|cover|imgproxy)/i },
  { groups: ['FILE'], pattern: /(?:file|attachment|upload|document|pdf|docx|csv)/i },
  { groups: ['MS'], pattern: /mindspace/i },
  { groups: ['PAGE'], pattern: /(?:public-(?:page|finish)|published-page|publication|page-delivery|mindspace-public)/i },
  { groups: ['AGENT'], pattern: /(?:agent|capabilit|goosed|worker|aider|mcp)/i },
  { groups: ['CHAT'], pattern: /(?:chat|conversation|message|reply|session|sse|routing|intent)/i },
  { groups: ['AUTH'], pattern: /(?:auth|access-policy|account|user-permission)/i },
  { groups: ['CFG'], pattern: /(?:config|provider|model-catalog|orchestrator|analytics|disclosure)/i },
  { groups: ['CFG'], pattern: /(?:^|\/)\.env(?:\.example)?$/i },
  { groups: ['UI'], pattern: /^(?:src\/|public\/)|\.(?:css|scss|tsx|vue)$/i },
]);

const GROUP_DEPENDENCIES = Object.freeze({
  MEM: ['CHAT'],
  DATA: ['AUTH', 'PAGE', 'MS'],
  WX: ['AUTH', 'CHAT'],
  BILL: ['AUTH', 'CHAT'],
  PLAZA: ['AUTH'],
  SEARCH: ['CHAT'],
  XLS: ['FILE'],
  IMGPG: ['FILE', 'PAGE'],
  FILE: ['AUTH', 'CHAT'],
  MS: ['PAGE'],
  PAGE: ['FILE', 'MS'],
  AGENT: ['CHAT', 'CFG'],
});

function normalizePaths(paths) {
  return [...new Set(paths.map((item) => String(item).replaceAll('\\', '/')).filter(Boolean))].sort();
}

function matchesAny(patterns, relativePath) {
  return patterns.some((pattern) => pattern.test(relativePath));
}

function closeGroupDependencies(initialGroups) {
  const groups = new Set(initialGroups);
  const pending = [...groups];
  while (pending.length > 0) {
    const group = pending.shift();
    for (const dependency of GROUP_DEPENDENCIES[group] ?? []) {
      if (groups.has(dependency)) continue;
      groups.add(dependency);
      pending.push(dependency);
    }
  }
  return [...groups].sort();
}

export function selectImpactScenarios({
  catalog,
  changedPaths,
  blockingReasons = [],
}) {
  const normalizedPaths = normalizePaths(changedPaths);
  const catalogIds = new Set(catalog.map((scenario) => scenario.id));
  const missingCore = CORE_SCENARIO_IDS.filter((id) => !catalogIds.has(id));
  if (missingCore.length > 0) {
    throw new Error(`Core release scenarios are missing from the catalog: ${missingCore.join(',')}`);
  }

  if (blockingReasons.length > 0) {
    throw new Error(`Impact selection is blocked: ${blockingReasons.join(',')}`);
  }
  const directGroups = new Set();
  const unmappedPaths = [];

  for (const relativePath of normalizedPaths) {
    let matched = false;
    for (const rule of CRITICAL_IMPACT_RULES) {
      if (!rule.pattern.test(relativePath)) continue;
      matched = true;
      for (const group of rule.groups) directGroups.add(group);
    }
    if (matchesAny(NON_RUNTIME_PATHS, relativePath)) continue;

    for (const rule of IMPACT_RULES) {
      if (!rule.pattern.test(relativePath)) continue;
      matched = true;
      for (const group of rule.groups) directGroups.add(group);
    }
    if (matched) continue;

    unmappedPaths.push(relativePath);
  }

  if (unmappedPaths.length > 0) {
    throw new Error(
      `Impact selection has unmapped runtime paths: ${unmappedPaths.join(',')}`,
    );
  }
  const impactGroups = closeGroupDependencies(directGroups);
  const strategy = impactGroups.length > 0 ? 'impact' : 'core';
  const selected = new Set(CORE_SCENARIO_IDS);

  for (const scenario of catalog) {
    if (impactGroups.includes(scenario.group)) selected.add(scenario.id);
  }

  const selectedIds = catalog
    .map((scenario) => scenario.id)
    .filter((id) => selected.has(id));

  return {
    policy_version: 2,
    strategy,
    catalog_total: catalog.length,
    core_ids: [...CORE_SCENARIO_IDS],
    impact_groups: impactGroups,
    changed_paths: normalizedPaths,
    unmapped_paths: unmappedPaths,
    full_gate_reasons: [],
    selected_ids: selectedIds,
    selected_total: selectedIds.length,
  };
}