/**
 * Service for polling NIP-34 repo announcements and auto-provisioning repos
 */

import { NostrClient } from './nostr-client.js';
import { KIND } from '../../types/nostr.js';
import type { NostrEvent } from '../../types/nostr.js';
import { RepoManager } from '../git/repo-manager.js';
import { OwnershipTransferService } from './ownership-transfer-service.js';
import { getCachedUserLevel } from '../security/user-level-cache.js';
import logger from '../logger.js';
import { extractCloneUrls } from '../../utils/nostr-utils.js';

export class RepoPollingService {
  private nostrClient: NostrClient;
  private repoManager: RepoManager;
  private pollingInterval: number;
  private intervalId: NodeJS.Timeout | null = null;
  private domain: string;
  private relays: string[];
  private initialPollPromise: Promise<void> | null = null;
  private isInitialPollComplete: boolean = false;

  constructor(
    relays: string[],
    repoRoot: string,
    domain: string,
    pollingInterval: number = 60000 // 1 minute
  ) {
    this.relays = relays;
    this.nostrClient = new NostrClient(relays);
    this.repoManager = new RepoManager(repoRoot, domain);
    this.pollingInterval = pollingInterval;
    this.domain = domain;
  }

  /**
   * Start polling for repo announcements
   * Returns a promise that resolves when the initial poll completes
   */
  start(): Promise<void> {
    if (this.intervalId) {
      this.stop();
    }

    // Poll immediately and wait for it to complete
    this.initialPollPromise = this.poll();

    // Then poll at intervals
    this.intervalId = setInterval(() => {
      this.poll();
    }, this.pollingInterval);

    return this.initialPollPromise;
  }

  /**
   * Wait for initial poll to complete (useful for server startup)
   */
  async waitForInitialPoll(): Promise<void> {
    if (this.initialPollPromise) {
      await this.initialPollPromise;
    }
  }

  /**
   * Check if initial poll has completed
   */
  isReady(): boolean {
    return this.isInitialPollComplete;
  }

  /**
   * Stop polling and cleanup resources
   */
  stop(): void {
    if (this.intervalId) {
      clearInterval(this.intervalId);
      this.intervalId = null;
    }
    // Close Nostr client connections
    if (this.nostrClient) {
      this.nostrClient.close();
    }
  }

  /**
   * Trigger a manual poll (useful after user verification)
   */
  async triggerPoll(): Promise<void> {
    logger.info('Manual poll triggered');
    return this.poll();
  }

  /**
   * Poll for new repo announcements and provision repos
   */
  private async poll(): Promise<void> {
    try {
      logger.debug('Starting repo poll...');
      const events = await this.nostrClient.fetchEvents([
        {
          kinds: [KIND.REPO_ANNOUNCEMENT],
          limit: 100
        }
      ]);

      // Filter for repos that list our domain
      const relevantEvents = events.filter(event => {
        // Skip local-only forks (synthetic announcements not published to Nostr)
        const isLocalOnly = event.tags.some(t => t[0] === 'local-only' && t[1] === 'true');
        if (isLocalOnly) {
          return false;
        }
        
        const cloneUrls = this.extractCloneUrls(event);
        const listsDomain = cloneUrls.some(url => url.includes(this.domain));
        if (listsDomain) {
          logger.debug({ 
            eventId: event.id, 
            pubkey: event.pubkey.slice(0, 16) + '...',
            cloneUrls: cloneUrls.slice(0, 3) // Log first 3 URLs
          }, 'Found repo announcement that lists this domain');
        }
        return listsDomain;
      });

      logger.info({ 
        totalEvents: events.length, 
        relevantEvents: relevantEvents.length,
        domain: this.domain
      }, 'Filtered repo announcements');

      // Provision each repo
      for (const event of relevantEvents) {
        try {
          // Extract repo ID from d-tag
          const dTag = event.tags.find(t => t[0] === 'd')?.[1];
          if (!dTag) {
            logger.warn({ eventId: event.id }, 'Repo announcement missing d-tag');
            continue;
          }

          // Check if this is an existing repo or new repo
          const cloneUrls = this.extractCloneUrls(event);
          const domainUrl = cloneUrls.find(url => url.includes(this.domain));
          if (!domainUrl) continue;

          const repoPath = this.repoManager.parseRepoUrl(domainUrl);
          if (!repoPath) continue;

          const repoExists = this.repoManager.repoExists(repoPath.fullPath);
          const isExistingRepo = repoExists;

          // Fetch self-transfer event for this repo
          const ownershipService = new OwnershipTransferService(this.relays);
          const repoTag = `${KIND.REPO_ANNOUNCEMENT}:${event.pubkey}:${dTag}`;
          
          const selfTransferEvents = await this.nostrClient.fetchEvents([
            {
              kinds: [KIND.OWNERSHIP_TRANSFER],
              '#a': [repoTag],
              authors: [event.pubkey],
              limit: 10
            }
          ]);

          // Find self-transfer event (from owner to themselves)
          let selfTransferEvent: NostrEvent | undefined;
          for (const transferEvent of selfTransferEvents) {
            const pTag = transferEvent.tags.find(t => t[0] === 'p');
            if (pTag && pTag[1] === event.pubkey) {
              // Decode npub if needed
              let toPubkey = pTag[1];
              try {
                const { nip19 } = await import('nostr-tools');
                const decoded = nip19.decode(toPubkey);
                if (decoded.type === 'npub') {
                  toPubkey = decoded.data as string;
                }
              } catch {
                // Assume it's already hex
              }
              
              if (transferEvent.pubkey === event.pubkey && toPubkey === event.pubkey) {
                selfTransferEvent = transferEvent;
                break;
              }
            }
          }

          // For existing repos without self-transfer, create one retroactively
          if (isExistingRepo && !selfTransferEvent) {
            // Security: Truncate pubkey in logs
            const truncatedPubkey = event.pubkey.length > 16 ? `${event.pubkey.slice(0, 8)}...${event.pubkey.slice(-4)}` : event.pubkey;
            logger.info({ repoId: dTag, pubkey: truncatedPubkey }, 'Existing repo has no self-transfer event. Creating template for owner to sign and publish.');
            
            try {
              // Create a self-transfer event template for the existing repo
              // The owner will need to sign and publish this to relays
              const initialOwnershipEvent = ownershipService.createInitialOwnershipEvent(event.pubkey, dTag);
              
              // Create an unsigned event template that can be included in the repo
              // This serves as a reference and the owner can use it to create the actual event
              const selfTransferTemplate = {
                ...initialOwnershipEvent,
                id: '', // Will be computed when signed
                sig: '', // Needs owner signature
                _note: 'This is a template. The owner must sign and publish this event to relays for it to be valid.'
              } as NostrEvent & { _note?: string };
              
              // Use the template (even though it's unsigned, it will be included in the repo)
              selfTransferEvent = selfTransferTemplate;
              
              logger.warn({ repoId: dTag, pubkey: event.pubkey }, 'Self-transfer event template created. Owner should sign and publish it to relays.');
            } catch (err) {
              logger.error({ error: err, repoId: dTag }, 'Failed to create self-transfer event template');
            }
          }

          // Check if user has unlimited access before provisioning new repos
          // This prevents spam and abuse
          if (!isExistingRepo) {
            const userLevel = getCachedUserLevel(event.pubkey);
            const { hasUnlimitedAccess } = await import('../../utils/user-access.js');
            const hasAccess = hasUnlimitedAccess(userLevel?.level);
            
            logger.debug({ 
              eventId: event.id, 
              pubkey: event.pubkey.slice(0, 16) + '...',
              cachedLevel: userLevel?.level || 'none',
              hasAccess,
              isExistingRepo
            }, 'Checking user access for repo provisioning');
            
            if (!hasAccess) {
              logger.warn({ 
                eventId: event.id, 
                pubkey: event.pubkey.slice(0, 16) + '...',
                level: userLevel?.level || 'none',
                cacheExists: !!userLevel
              }, 'Skipping repo provisioning: user does not have unlimited access');
              continue;
            }
          }

          // Provision the repo with self-transfer event if available
          await this.repoManager.provisionRepo(event, selfTransferEvent, isExistingRepo);
          logger.info({ eventId: event.id, isExistingRepo }, 'Provisioned repo from announcement');
        } catch (error) {
          logger.error({ error, eventId: event.id }, 'Failed to provision repo from announcement');
        }
      }
      
      // Mark initial poll as complete
      if (!this.isInitialPollComplete) {
        this.isInitialPollComplete = true;
        logger.info('Initial repo poll completed');
      }
    } catch (error) {
      logger.error({ error }, 'Error polling for repo announcements');
      
      // Still mark as complete even on error (to prevent blocking)
      if (!this.isInitialPollComplete) {
        this.isInitialPollComplete = true;
        logger.warn('Initial repo poll completed with errors');
      }
    }
  }

  /**
   * Extract clone URLs from a NIP-34 repo announcement
   * Uses shared utility (without normalization)
   */
  private extractCloneUrls(event: NostrEvent): string[] {
    return extractCloneUrls(event, false);
  }
}