/**
 * securityStore.ts - Security Status and Audit Log Management
 *
 * Manages ZCLAW security layers, security status, and audit logs.
 * Uses local security checks (security-index.ts + Tauri commands) instead of REST API.
 */
import { create } from 'zustand';
import { invoke } from '@tauri-apps/api/core';
import type { GatewayClient } from '../lib/gateway-client';

// === Types ===

export interface SecurityLayer {
  name: string;
  enabled: boolean;
  description?: string;
}

export interface SecurityStatus {
  layers: SecurityLayer[];
  enabledCount: number;
  totalCount: number;
  securityLevel: 'critical' | 'high' | 'medium' | 'low';
}

export interface AuditLogEntry {
  id: string;
  timestamp: string;
  action: string;
  actor?: string;
  result?: 'success' | 'failure';
  details?: Record<string, unknown>;
  // Merkle hash chain fields
  hash?: string;
  previousHash?: string;
}

// === Helpers ===

function calculateSecurityLevel(enabledCount: number, totalCount: number): 'critical' | 'high' | 'medium' | 'low' {
  if (totalCount === 0) return 'low';
  const ratio = enabledCount / totalCount;
  if (ratio >= 0.875) return 'critical'; // 14-16 layers
  if (ratio >= 0.625) return 'high';     // 10-13 layers
  if (ratio >= 0.375) return 'medium';   // 6-9 layers
  return 'low';                          // 0-5 layers
}

/**
 * Check if OS Keyring (secure store) is available via Tauri command.
 * Returns false if not in Tauri environment or if keyring is unavailable.
 */
async function checkKeyringAvailable(): Promise<boolean> {
  try {
    return await invoke<boolean>('secure_store_is_available');
  } catch {
    // Not in Tauri environment or command failed
    return false;
  }
}

/**
 * Check if the ZCLAW Kernel is initialized via Tauri command.
 */
async function checkKernelInitialized(): Promise<boolean> {
  try {
    const status = await invoke<{ initialized: boolean }>('kernel_status');
    return status.initialized;
  } catch {
    return false;
  }
}

/**
 * Build the 16-layer security model from local security checks.
 */
async function buildLocalSecurityLayers(): Promise<SecurityLayer[]> {
  // Gather local security status
  let auditEnabled = false;
  let keychainAvailable = false;
  let chatStorageInitialized = false;

  try {
    const { getSecurityStatus } = await import('../lib/security-index');
    const status = await getSecurityStatus();
    auditEnabled = status.auditEnabled;
    keychainAvailable = status.keychainAvailable;
    chatStorageInitialized = status.chatStorageInitialized;
  } catch {
    // Security module not available - use defaults
  }

  // Check OS Keyring availability directly via Tauri
  const keyringAvailable = await checkKeyringAvailable();
  const kernelInitialized = await checkKernelInitialized();

  // Use keychainAvailable from security-index as primary, keyringAvailable as fallback
  const hasSecureStorage = keychainAvailable || keyringAvailable;

  // Map local security capabilities to the 16-layer security model
  const layers: SecurityLayer[] = [
    {
      name: 'input.validation',
      enabled: true,
      description: 'security-utils.ts provides input validation and sanitization',
    },
    {
      name: 'output.filter',
      enabled: true,
      description: 'security-utils.ts provides output sanitization and content filtering',
    },
    {
      name: 'rate.limit',
      enabled: true,
      description: 'security-utils.ts provides rate limiting',
    },
    {
      name: 'auth.identity',
      enabled: hasSecureStorage,
      description: hasSecureStorage
        ? 'OS Keyring available for secure identity storage'
        : 'OS Keyring not available',
    },
    {
      name: 'incident.response',
      enabled: auditEnabled,
      description: auditEnabled
        ? 'Automated incident detection and alerting via audit events'
        : 'Requires audit logging for incident response',
    },
    {
      name: 'session.management',
      enabled: true,
      description: 'Session management is always active',
    },
    {
      name: 'auth.rbac',
      enabled: hasSecureStorage,
      description: hasSecureStorage
        ? 'Device authentication and role-based access available'
        : 'Requires OS Keyring for device authentication',
    },
    {
      name: 'encryption',
      enabled: chatStorageInitialized,
      description: chatStorageInitialized
        ? 'Encrypted chat storage is initialized (AES-256-GCM)'
        : 'Encrypted storage not yet initialized',
    },
    {
      name: 'audit.logging',
      enabled: auditEnabled,
      description: auditEnabled
        ? 'Security audit logging is active'
        : 'Audit logging is disabled',
    },
    {
      name: 'integrity',
      enabled: auditEnabled,
      description: auditEnabled
        ? 'Integrity verification enabled via audit log'
        : 'Requires audit logging for integrity verification',
    },
    {
      name: 'sandbox',
      enabled: true,
      description: 'Tauri sandbox provides process isolation',
    },
    {
      name: 'network.security',
      enabled: true,
      description: 'WSS enforced, CSP headers active',
    },
    {
      name: 'resource.limits',
      enabled: true,
      description: 'Path validation and timeout limits active',
    },
    {
      name: 'capability.gates',
      enabled: kernelInitialized,
      description: kernelInitialized
        ? 'Kernel capability gates active'
        : 'Kernel not yet initialized',
    },
    {
      name: 'prompt.defense',
      enabled: true,
      description: 'Input sanitization includes prompt injection defense',
    },
    {
      name: 'anomaly.detection',
      enabled: auditEnabled,
      description: auditEnabled
        ? 'Anomaly detection via security audit events'
        : 'Requires audit logging for anomaly detection',
    },
  ];

  return layers;
}

// === Client Interface ===

interface SecurityClient {
  getSecurityStatus(): Promise<{ layers?: SecurityLayer[] } | null>;
  getAuditLogs(opts?: { limit?: number; offset?: number }): Promise<{ logs?: AuditLogEntry[] } | null>;
}

// === Store Interface ===

export interface SecurityStateSlice {
  securityStatus: SecurityStatus | null;
  securityStatusLoading: boolean;
  securityStatusError: string | null;
  auditLogs: AuditLogEntry[];
  auditLogsLoading: boolean;
}

export interface SecurityActionsSlice {
  loadSecurityStatus: () => Promise<void>;
  loadAuditLogs: (opts?: { limit?: number; offset?: number }) => Promise<void>;
}

export type SecurityStore = SecurityStateSlice & SecurityActionsSlice & { client: SecurityClient | null };

// === Store Implementation ===

export const useSecurityStore = create<SecurityStore>((set, get) => ({
  // Initial state
  securityStatus: null,
  securityStatusLoading: false,
  securityStatusError: null,
  auditLogs: [],
  auditLogsLoading: false,
  client: null,

  loadSecurityStatus: async () => {
    set({ securityStatusLoading: true, securityStatusError: null });
    try {
      const layers = await buildLocalSecurityLayers();
      const enabledCount = layers.filter(l => l.enabled).length;
      const totalCount = layers.length;
      const securityLevel = calculateSecurityLevel(enabledCount, totalCount);
      set({
        securityStatus: { layers, enabledCount, totalCount, securityLevel },
        securityStatusLoading: false,
        securityStatusError: null,
      });
    } catch (err: unknown) {
      const message = err instanceof Error ? err.message : String(err);
      set({
        securityStatusLoading: false,
        securityStatusError: message || 'Failed to detect security status',
      });
    }
  },

  loadAuditLogs: async (opts?: { limit?: number; offset?: number }) => {
    const client = get().client;
    if (!client) return;

    set({ auditLogsLoading: true });
    try {
      const result = await client.getAuditLogs(opts);
      set({ auditLogs: (result?.logs || []) as AuditLogEntry[], auditLogsLoading: false });
    } catch {
      set({ auditLogsLoading: false });
      /* ignore if audit API not available */
    }
  },
}));

// === Client Injection ===

function createSecurityClientFromGateway(client: GatewayClient): SecurityClient {
  return {
    getSecurityStatus: () => client.getSecurityStatus() as Promise<{ layers?: SecurityLayer[] } | null>,
    getAuditLogs: (opts) => client.getAuditLogs(opts) as Promise<{ logs?: AuditLogEntry[] } | null>,
  };
}

export function setSecurityStoreClient(client: unknown): void {
  const securityClient = createSecurityClientFromGateway(client as GatewayClient);
  useSecurityStore.setState({ client: securityClient });
}