// Ported from filius-ipad (GPLv2/GPLv3):
//   State/TopologyNetworkRuntimeEngine.swift (TopologyNetworkRuntimeTopologySnapshot)
// What the runtime starts from: the topology and every configuration, frozen
// at the moment the simulation starts. Later protocol slices add their
// configuration maps here (NAT, remote link, wireless).

import { compareIds, type Id } from '../ids.js';
import type { NodeKind } from '../model/node.js';
import { canonicalMacAddress } from '../model/node.js';
import type {
  DeviceConfiguration,
  DhcpClientConfiguration,
  DhcpServerConfiguration,
  DnsServerConfiguration,
  EchoServerConfiguration,
  FirewallConfiguration,
  GatewayPortForwardingRow,
  InterfaceConfiguration,
  InterfaceKey,
  ManualRoute,
  SimpleClientConfiguration,
  SwitchConfiguration,
  WebServerConfiguration,
  EmailServerAccount,
  EmailClientConfiguration,
} from './config.js';
import type { VirtualFileSystem } from '../model/virtualFileSystem.js';
import type { PageLanguage } from './apps/routerPages.js';

/** An installed web server: its configuration, and whether it is switched on (Java: WebServer.aktiv). */
export interface WebServerSnapshot extends WebServerConfiguration {
  readonly isActive: boolean;
}

/**
 * An installed e-mail server (EmailServer): its domain, its accounts with
 * their mailboxes, and whether it is switched on. Java's server keeps its
 * accounts in /mailserver/konten.txt; the model's are what Java loads from it.
 */
export interface EmailServerSnapshot {
  readonly domain: string;
  readonly accounts: readonly EmailServerAccount[];
  readonly isActive: boolean;
}

/** An installed echo server: its port, and whether it is switched on (Java: ServerBaustein.aktiv). */
export interface EchoServerSnapshot extends EchoServerConfiguration {
  readonly isActive: boolean;
}

export interface PortSnapshot {
  readonly id: Id;
  readonly label: string;
  /** Canonical, or undefined for a port whose MAC address is derived from its id. */
  readonly macAddress?: string;
}

export function portSnapshot(id: Id, label: string, macAddress?: string): PortSnapshot {
  const canonical = canonicalMacAddress(macAddress);
  return canonical === undefined ? { id, label } : { id, label, macAddress: canonical };
}

export interface NodeSnapshot {
  readonly id: Id;
  readonly kind: NodeKind;
  readonly ports: readonly PortSnapshot[];
}

export interface LinkSnapshot {
  readonly id: Id;
  readonly sourceNodeId: Id;
  readonly sourcePortId: Id;
  readonly targetNodeId: Id;
  readonly targetPortId: Id;
}

export interface TopologySnapshot {
  /** Sorted by id (Swift `uuidString` order). */
  readonly nodes: readonly NodeSnapshot[];
  /** Sorted by id (Swift `uuidString` order). */
  readonly links: readonly LinkSnapshot[];
  readonly deviceConfigurations: ReadonlyMap<Id, DeviceConfiguration>;
  readonly interfaceConfigurations: ReadonlyMap<InterfaceKey, InterfaceConfiguration>;
  readonly manualRoutesByNodeId: ReadonlyMap<Id, readonly ManualRoute[]>;
  readonly ripEnabledByNodeId: ReadonlyMap<Id, boolean>;
  readonly dhcpClientConfigurationsByNodeId: ReadonlyMap<Id, DhcpClientConfiguration>;
  readonly dhcpServerConfigurationsByNodeId: ReadonlyMap<Id, DhcpServerConfiguration>;
  /** The DNS servers switched on (Java: aktiv), by node. */
  readonly dnsServerConfigurationsByNodeId: ReadonlyMap<Id, DnsServerConfiguration>;
  readonly firewallConfigurationsByNodeId: ReadonlyMap<Id, FirewallConfiguration>;
  /** A home router's port forwarding (Java GatewayFirmware.staticNAT), by node. */
  readonly portForwardingRowsByNodeId: ReadonlyMap<Id, readonly GatewayPortForwardingRow[]>;
  readonly switchConfigurationsByNodeId: ReadonlyMap<Id, SwitchConfiguration>;
  /** Nodes whose IP forwarding differs from their kind's (forwardsIPv4ByDefault): a host that forwards. */
  readonly ipForwardingByNodeId: ReadonlyMap<Id, boolean>;
  /** The installed echo servers (ServerBaustein), by node. */
  readonly echoServersByNodeId: ReadonlyMap<Id, EchoServerSnapshot>;
  /** The installed generic clients (ClientBaustein) with the server they last talked to, by node. */
  readonly simpleClientsByNodeId: ReadonlyMap<Id, SimpleClientConfiguration>;
  /** The installed web servers (WebServer), by node. */
  readonly webServersByNodeId: ReadonlyMap<Id, WebServerSnapshot>;
  /** The nodes with the web browser installed (WebBrowser). */
  readonly webBrowserNodeIds: ReadonlySet<Id>;
  /** The installed e-mail servers, by node; a run's deliveries change their mailboxes here. */
  readonly emailServersByNodeId: ReadonlyMap<Id, EmailServerSnapshot>;
  /** The nodes with the command line installed (Terminal); it works on the node's files. */
  readonly terminalNodeIds: ReadonlySet<Id>;
  /** The installed e-mail programs, by node; a run's sent and fetched mails change their folders here. */
  readonly emailClientsByNodeId: ReadonlyMap<Id, EmailClientConfiguration>;
  /** Each node's files, which its programs read (a web server its pages). */
  readonly fileSystemsByNodeId: ReadonlyMap<Id, VirtualFileSystem>;
  /** The language of the pages the devices write themselves (a router's), as Java's in the locale it runs in. */
  readonly language: PageLanguage;
}

export interface TopologySnapshotInput {
  nodes: readonly NodeSnapshot[];
  links: readonly LinkSnapshot[];
  deviceConfigurations?: ReadonlyMap<Id, DeviceConfiguration>;
  interfaceConfigurations?: ReadonlyMap<InterfaceKey, InterfaceConfiguration>;
  manualRoutesByNodeId?: ReadonlyMap<Id, readonly ManualRoute[]>;
  ripEnabledByNodeId?: ReadonlyMap<Id, boolean>;
  dhcpClientConfigurationsByNodeId?: ReadonlyMap<Id, DhcpClientConfiguration>;
  dhcpServerConfigurationsByNodeId?: ReadonlyMap<Id, DhcpServerConfiguration>;
  dnsServerConfigurationsByNodeId?: ReadonlyMap<Id, DnsServerConfiguration>;
  firewallConfigurationsByNodeId?: ReadonlyMap<Id, FirewallConfiguration>;
  portForwardingRowsByNodeId?: ReadonlyMap<Id, readonly GatewayPortForwardingRow[]>;
  switchConfigurationsByNodeId?: ReadonlyMap<Id, SwitchConfiguration>;
  ipForwardingByNodeId?: ReadonlyMap<Id, boolean>;
  echoServersByNodeId?: ReadonlyMap<Id, EchoServerSnapshot>;
  simpleClientsByNodeId?: ReadonlyMap<Id, SimpleClientConfiguration>;
  webServersByNodeId?: ReadonlyMap<Id, WebServerSnapshot>;
  webBrowserNodeIds?: ReadonlySet<Id>;
  emailServersByNodeId?: ReadonlyMap<Id, EmailServerSnapshot>;
  emailClientsByNodeId?: ReadonlyMap<Id, EmailClientConfiguration>;
  terminalNodeIds?: ReadonlySet<Id>;
  fileSystemsByNodeId?: ReadonlyMap<Id, VirtualFileSystem>;
  language?: PageLanguage;
}

export function topologySnapshot(input: TopologySnapshotInput): TopologySnapshot {
  return {
    nodes: [...input.nodes].sort((lhs, rhs) => compareIds(lhs.id, rhs.id)),
    links: [...input.links].sort((lhs, rhs) => compareIds(lhs.id, rhs.id)),
    deviceConfigurations: input.deviceConfigurations ?? new Map(),
    interfaceConfigurations: input.interfaceConfigurations ?? new Map(),
    manualRoutesByNodeId: input.manualRoutesByNodeId ?? new Map(),
    ripEnabledByNodeId: input.ripEnabledByNodeId ?? new Map(),
    dhcpClientConfigurationsByNodeId: input.dhcpClientConfigurationsByNodeId ?? new Map(),
    dhcpServerConfigurationsByNodeId: input.dhcpServerConfigurationsByNodeId ?? new Map(),
    dnsServerConfigurationsByNodeId: input.dnsServerConfigurationsByNodeId ?? new Map(),
    firewallConfigurationsByNodeId: input.firewallConfigurationsByNodeId ?? new Map(),
    portForwardingRowsByNodeId: input.portForwardingRowsByNodeId ?? new Map(),
    switchConfigurationsByNodeId: input.switchConfigurationsByNodeId ?? new Map(),
    ipForwardingByNodeId: input.ipForwardingByNodeId ?? new Map(),
    echoServersByNodeId: input.echoServersByNodeId ?? new Map(),
    simpleClientsByNodeId: input.simpleClientsByNodeId ?? new Map(),
    webServersByNodeId: input.webServersByNodeId ?? new Map(),
    webBrowserNodeIds: input.webBrowserNodeIds ?? new Set(),
    emailServersByNodeId: input.emailServersByNodeId ?? new Map(),
    emailClientsByNodeId: input.emailClientsByNodeId ?? new Map(),
    terminalNodeIds: input.terminalNodeIds ?? new Set(),
    fileSystemsByNodeId: input.fileSystemsByNodeId ?? new Map(),
    language: input.language ?? 'de',
  };
}

/** The same snapshot with some fields replaced (Swift rebuilds it field by field). */
export function withSnapshot(
  snapshot: TopologySnapshot,
  changes: Partial<TopologySnapshotInput>,
): TopologySnapshot {
  return topologySnapshot({ ...snapshot, ...changes });
}

export const EMPTY_TOPOLOGY_SNAPSHOT: TopologySnapshot = topologySnapshot({ nodes: [], links: [] });