import { NftExecutor } from './nft.executor.js';
import { buildTableSetup, buildFilterChains, buildTableCleanup } from './nft.rulebuilder.table.js';
import { NatManager } from './nft.manager.nat.js';
import { FirewallManager } from './nft.manager.firewall.js';
import { RateLimitManager } from './nft.manager.ratelimit.js';
import type { TNftFamily, INftRuleGroup, INftStatus, ISmartNftablesOptions } from './nft.types.js';

/**
 * SmartNftables — high-level facade for managing nftables rules.
 *
 * Provides sub-managers for NAT, firewall, and rate limiting.
 * All rules are tracked in logical groups and can be removed individually or cleaned up entirely.
 */
export class SmartNftables {
  public readonly nat: NatManager;
  public readonly firewall: FirewallManager;
  public readonly rateLimit: RateLimitManager;

  public readonly tableName: string;
  public readonly family: TNftFamily;
  public readonly executor: NftExecutor;

  private initialized = false;
  private hasFilterChains = false;
  private warnedNonRoot = false;
  private ruleGroups: Map<string, INftRuleGroup> = new Map();

  constructor(options?: ISmartNftablesOptions) {
    this.tableName = options?.tableName ?? 'smartnftables';
    this.family = options?.family ?? 'ip';
    this.executor = new NftExecutor({ dryRun: options?.dryRun });

    this.nat = new NatManager(this);
    this.firewall = new FirewallManager(this);
    this.rateLimit = new RateLimitManager(this);
  }

  /**
   * Initialize the nftables table and NAT chains. Idempotent.
   */
  public async initialize(): Promise<void> {
    if (this.initialized) return;

    if (!this.executor.isRoot()) {
      if (!this.warnedNonRoot) {
        console.warn('smartnftables: not running as root. Rules are tracked but not applied to kernel.');
        this.warnedNonRoot = true;
      }
      this.initialized = true;
      return;
    }

    const commands = buildTableSetup(this.tableName, this.family);
    await this.executor.execBatch(commands);
    this.initialized = true;
  }

  /**
   * Ensure filter chains (input/forward/output) are created.
   * Called automatically when firewall or rate-limit rules are added.
   */
  public async ensureFilterChains(): Promise<void> {
    if (this.hasFilterChains) return;
    await this.ensureInitialized();

    if (this.executor.isRoot()) {
      const commands = buildFilterChains(this.tableName, this.family);
      await this.executor.execBatch(commands);
    }

    this.hasFilterChains = true;
  }

  /**
   * Ensure the table is initialized before applying rules.
   */
  public async ensureInitialized(): Promise<void> {
    if (!this.initialized) {
      await this.initialize();
    }
  }

  /**
   * Apply a group of nft commands and track them under the given ID.
   */
  public async applyRuleGroup(groupId: string, commands: string[]): Promise<void> {
    // Always track the group locally
    this.ruleGroups.set(groupId, {
      id: groupId,
      commands,
      createdAt: Date.now(),
    });

    if (!this.executor.isRoot()) {
      if (!this.warnedNonRoot) {
        console.warn('smartnftables: not running as root. Rules are tracked but not applied to kernel.');
        this.warnedNonRoot = true;
      }
      return;
    }

    await this.ensureInitialized();
    await this.executor.execBatch(commands);
  }

  /**
   * Remove a tracked rule group. Removes from tracking.
   * Note: full kernel cleanup requires cleanup() — individual rule removal
   * would require handle-based tracking.
   */
  public async removeRuleGroup(groupId: string): Promise<void> {
    this.ruleGroups.delete(groupId);
  }

  /**
   * Get a tracked rule group by ID.
   */
  public getRuleGroup(groupId: string): INftRuleGroup | undefined {
    return this.ruleGroups.get(groupId);
  }

  /**
   * Delete the entire nftables table and clear all tracking.
   */
  public async cleanup(): Promise<void> {
    if (this.executor.isRoot() && this.initialized) {
      const commands = buildTableCleanup(this.tableName, this.family);
      await this.executor.execBatch(commands, { continueOnError: true });
    }

    this.ruleGroups.clear();
    this.initialized = false;
    this.hasFilterChains = false;
  }

  /**
   * Get status report of the managed nftables state.
   */
  public status(): INftStatus {
    const groups: Record<string, { ruleCount: number; createdAt: number }> = {};
    for (const [id, group] of this.ruleGroups) {
      groups[id] = {
        ruleCount: group.commands.length,
        createdAt: group.createdAt,
      };
    }

    return {
      initialized: this.initialized,
      tableName: this.tableName,
      family: this.family,
      isRoot: this.executor.isRoot(),
      activeGroups: this.ruleGroups.size,
      groups,
    };
  }
}