import { z } from 'zod';

/**
 * The VS-NfD hardening-profile mode and the machine-readable configuration
 * catalog (issue #243, ADR 0027).
 *
 * The deployment declares through `VS_NFD_MODE` how the application treats
 * configuration options that violate the VS-NfD reference profile
 * (docs/vs-nfd/50-haertungsleitfaden.md):
 *
 * - `off`      — VS-NfD is not a topic; no marking anywhere (the default).
 * - `marked`   — options stay available, violations are marked (#244).
 * - `hidden`   — violating options disappear, the hiding is marked (#245).
 * - `enforced` — violating writes are rejected server-side (#246).
 *
 * Deploy-level (env) on purpose, like BACKUP_ALLOWED_TARGETS (#192): a
 * compromised Site Admin must not be able to widen the mode at runtime.
 *
 * The catalog below is the single source of truth for "profile-relevant":
 * every entry names the setting, the machine-checkable compliant value and
 * the hardening-guide section it comes from. A fence test keeps catalog
 * and guide from drifting (vs-nfd-profile-catalogue.test.ts, pattern
 * #201): every switch listed in the guide is either here or in the
 * explicit advisory list — never silently absent.
 */
export const VS_NFD_MODES = ['off', 'marked', 'hidden', 'enforced'] as const;
export type VsNfdMode = (typeof VS_NFD_MODES)[number];
export const vsNfdModeSchema = z.enum(VS_NFD_MODES);

/**
 * The decidable compliance predicates. Deliberately tiny: a catalog entry
 * must be checkable without prose interpretation, or it belongs in the
 * advisory list instead.
 */
export type VsNfdCompliance =
  | { kind: 'equals'; value: boolean | string }
  | { kind: 'maxNumber'; value: number }
  | { kind: 'nonEmpty' };

export interface VsNfdProfileEntry {
  /** `instance` = instance_settings key; `deploy` = env variable. */
  scope: 'instance' | 'deploy';
  key: string;
  compliance: VsNfdCompliance;
  /** Section of docs/vs-nfd/50-haertungsleitfaden.md the value comes from. */
  hardeningRef: '1.1' | '1.2';
}

/**
 * Profile entries with a machine-checkable compliant value. Order mirrors
 * the hardening guide. Pond-level opt-ins (`apiEnabled`, `mcpEnabled`)
 * are deliberately absent: their instance master switches govern, so a
 * pond opt-in cannot violate the profile on its own (ADR 0027).
 */
export const VS_NFD_PROFILE: readonly VsNfdProfileEntry[] = [
  {
    scope: 'instance',
    key: 'auth.registrationMode',
    compliance: { kind: 'equals', value: 'closed' },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'api.enabled',
    compliance: { kind: 'equals', value: false },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'mcp.enabled',
    compliance: { kind: 'equals', value: false },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'feeds.enabled',
    compliance: { kind: 'equals', value: false },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'plugins.enabled',
    compliance: { kind: 'equals', value: false },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'classification.newPageDefault',
    compliance: { kind: 'equals', value: 'vs_nfd' },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'classification.uploadPolicy',
    compliance: { kind: 'equals', value: 'block' },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'upload.svgPolicy',
    compliance: { kind: 'equals', value: 'reject' },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'backup.nextcloud.enabled',
    compliance: { kind: 'equals', value: false },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'readTrail.enabled',
    compliance: { kind: 'equals', value: true },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'legal.imprint',
    compliance: { kind: 'nonEmpty' },
    hardeningRef: '1.1',
  },
  {
    scope: 'instance',
    key: 'legal.privacyPolicy',
    compliance: { kind: 'nonEmpty' },
    hardeningRef: '1.1',
  },
  {
    scope: 'deploy',
    key: 'SESSION_ABSOLUTE_HOURS',
    compliance: { kind: 'maxNumber', value: 12 },
    hardeningRef: '1.2',
  },
  {
    scope: 'deploy',
    key: 'SESSION_IDLE_HOURS',
    compliance: { kind: 'maxNumber', value: 2 },
    hardeningRef: '1.2',
  },
  {
    scope: 'deploy',
    key: 'LOG_LEVEL',
    compliance: { kind: 'equals', value: 'info' },
    hardeningRef: '1.2',
  },
  {
    scope: 'deploy',
    key: 'AUTH_LOCAL_ENABLED',
    compliance: { kind: 'equals', value: false },
    hardeningRef: '1.2',
  },
] as const;

/**
 * Guide entries whose reference value is a judgement call ("only what the
 * service needs", "configure the agency IdP", "leave unset or one host") —
 * profile-relevant, but not machine-checkable. Listed explicitly so the
 * fence test still notices when the guide gains a switch nobody triaged.
 */
export const VS_NFD_PROFILE_ADVISORY: readonly { scope: 'instance' | 'deploy'; key: string }[] = [
  { scope: 'instance', key: 'upload.allowedExtensions' },
  { scope: 'instance', key: 'plugins.allowlist' },
  { scope: 'instance', key: 'trash.retentionDays' },
  { scope: 'instance', key: 'audit.retentionDays' },
  { scope: 'instance', key: 'conversion.payloadRetentionDays' },
  { scope: 'instance', key: 'mail.outboxRetentionDays' },
  { scope: 'instance', key: 'readTrail.dedupWindowMinutes' },
  { scope: 'instance', key: 'readTrail.retentionDays' },
  { scope: 'instance', key: 'idpMapping.rules' },
  { scope: 'deploy', key: 'VS_NFD_MODE' },
  { scope: 'deploy', key: 'BACKUP_ALLOWED_TARGETS' },
  { scope: 'deploy', key: 'SMTP_HOST' },
  { scope: 'deploy', key: 'WEB_PORT' },
  { scope: 'deploy', key: 'API_PORT' },
  { scope: 'deploy', key: 'COLLAB_PORT' },
  { scope: 'deploy', key: 'OIDC_ISSUER' },
  { scope: 'deploy', key: 'OIDC_CLIENT_ID' },
  { scope: 'deploy', key: 'OIDC_CLIENT_SECRET' },
  { scope: 'deploy', key: 'OIDC_SCOPES' },
  { scope: 'deploy', key: 'OIDC_PROVIDER_LABEL' },
  { scope: 'deploy', key: 'AUTH_PROXY_HEADER' },
  { scope: 'deploy', key: 'AUTH_PROXY_TRUSTED_PEERS' },
  { scope: 'deploy', key: 'AUTH_PROXY_MAP' },
  { scope: 'deploy', key: 'AUTH_PROXY_MODE' },
  { scope: 'deploy', key: 'AUTH_PROXY_DN_ATTRIBUTE' },
] as const;

/** True when `value` satisfies the entry's compliance predicate. */
export function isVsNfdCompliant(entry: VsNfdProfileEntry, value: unknown): boolean {
  switch (entry.compliance.kind) {
    case 'equals':
      return value === entry.compliance.value;
    case 'maxNumber':
      return typeof value === 'number' && value <= entry.compliance.value;
    case 'nonEmpty':
      return typeof value === 'string' && value.trim().length > 0;
  }
}

/** One evaluated catalog row, as the admin endpoint reports it (#243). */
export interface VsNfdProfileEntryView {
  scope: 'instance' | 'deploy';
  key: string;
  compliant: boolean;
  /** The compliant value, rendered for display (booleans/numbers stringified). */
  compliantValue: string;
  hardeningRef: '1.1' | '1.2';
}

export interface VsNfdProfileView {
  mode: VsNfdMode;
  entries: VsNfdProfileEntryView[];
  violations: number;
}

/** Display form of a predicate — shared so api and web render it alike. */
export function describeCompliance(compliance: VsNfdCompliance): string {
  switch (compliance.kind) {
    case 'equals':
      return String(compliance.value);
    case 'maxNumber':
      return `<= ${compliance.value}`;
    case 'nonEmpty':
      return 'non-empty';
  }
}