import type { Page } from 'playwright';
import type { Logger } from '../utils/logger.js';
import type { MessagesRepository, SuccessfulMessagesRepository, SentMessageRecord } from '../database/repositories.js';
import type { PostsRepository } from '../database/repositories.js';

export interface ResponseCheckResult {
  messageId: number;
  recipient: string;
  gotResponse: boolean;
  responseSnippet?: string;
}

export class ResponseCheckerService {
  constructor(
    private page: Page,
    private messagesRepo: MessagesRepository,
    private successfulMessagesRepo: SuccessfulMessagesRepository,
    private postsRepo: PostsRepository,
    private logger: Logger
  ) { }

  async checkForResponses(): Promise<ResponseCheckResult[]> {
    const results: ResponseCheckResult[] = [];

    // Get messages that haven't been checked recently (at least 1 hour old, recheck every 6 hours)
    const minAgeMs = 60 * 60 * 1000; // 1 hour
    const recheckAfterMs = 6 * 60 * 60 * 1000; // 6 hours
    const uncheckedMessages = this.messagesRepo.getUncheckedMessages(minAgeMs, recheckAfterMs, 5);

    if (uncheckedMessages.length === 0) {
      this.logger.debug('No messages to check for responses');
      return results;
    }

    this.logger.info(`Checking ${uncheckedMessages.length} messages for responses...`);

    // Navigate to inbox
    try {
      await this.page.goto('https://www.reddit.com/message/inbox/', {
        waitUntil: 'domcontentloaded',
        timeout: 30000,
      });

      await this.page.waitForTimeout(2000);

      // Get all message threads/conversations
      const conversations = await this.getInboxConversations();
      this.logger.debug(`Found ${conversations.size} conversations in inbox`);

      for (const message of uncheckedMessages) {
        const result = await this.checkMessageResponse(message, conversations);
        results.push(result);

        if (result.gotResponse) {
          // Mark as got response
          this.messagesRepo.markGotResponse(message.id);

          // Get the original post info
          const post = message.postId ? this.postsRepo.getById(message.postId) : undefined;

          // Store as successful message for learning
          this.successfulMessagesRepo.insert({
            sentMessageId: message.id,
            originalMessage: message.message,
            imageAnalysis: post?.imageAnalysis || null,
            postTitle: post?.title || null,
            responseSnippet: result.responseSnippet || null,
            subreddit: post?.subreddit || null,
          });

          this.logger.info(`Got response from u/${message.recipient}! Stored for learning.`);
        } else {
          // Just mark as checked
          this.messagesRepo.markChecked(message.id);
        }
      }
    } catch (error) {
      this.logger.error('Failed to check inbox for responses:', error);
    }

    return results;
  }

  private async getInboxConversations(): Promise<Map<string, { hasReply: boolean; snippet: string }>> {
    const conversations = new Map<string, { hasReply: boolean; snippet: string }>();

    try {
      // Try to get conversation items from inbox
      const messageItems = await this.page.$$('.message, [data-testid="message"], .thing.message');

      for (const item of messageItems) {
        try {
          // Get the author/recipient of the conversation
          const authorEl = await item.$('.author, [data-testid="message-author"], .sender a');
          const author = authorEl ? await authorEl.textContent() : null;

          if (!author) continue;

          const cleanAuthor = author.replace(/^u\//, '').replace(/^\/u\//, '').trim();

          // Check if this is a reply (not from us)
          const isReply = await item.evaluate((el) => {
            // Check various indicators that this is a received message, not sent
            return !el.classList.contains('sent') && !el.querySelector('.sent');
          });

          // Get message snippet
          const bodyEl = await item.$('.md, .message-body, [data-testid="message-body"]');
          const snippet = bodyEl ? (await bodyEl.textContent())?.slice(0, 200) || '' : '';

          this.logger.debug(`Checking inbox item from: ${cleanAuthor}, isReply: ${isReply}`);

          if (isReply && cleanAuthor) {
            conversations.set(cleanAuthor.toLowerCase(), {
              hasReply: true,
              snippet: snippet.trim(),
            });
            this.logger.info(`Found reply from ${cleanAuthor}`);
          }
        } catch {
          // Skip problematic items
        }
      }
    } catch (error) {
      this.logger.warn('Failed to parse inbox conversations:', error);
    }

    return conversations;
  }

  private async checkMessageResponse(
    message: SentMessageRecord,
    conversations: Map<string, { hasReply: boolean; snippet: string }>
  ): Promise<ResponseCheckResult> {
    const recipientLower = message.recipient.toLowerCase();
    const conversation = conversations.get(recipientLower);

    this.logger.debug(`Checking response for ${message.recipient} (key: ${recipientLower}) - Found: ${!!conversation}`);

    if (conversation?.hasReply) {
      return {
        messageId: message.id,
        recipient: message.recipient,
        gotResponse: true,
        responseSnippet: conversation.snippet,
      };
    }

    return {
      messageId: message.id,
      recipient: message.recipient,
      gotResponse: false,
    };
  }

  getSuccessfulExamples(limit: number = 3, subreddit?: string): string[] {
    const successful = subreddit
      ? this.successfulMessagesRepo.getWeightedExamples(subreddit, limit)
      : this.successfulMessagesRepo.getRecent(limit);

    return successful.map((s) => {
      let example = `Message: "${s.originalMessage}"`;
      if (s.imageAnalysis) {
        example = `Context (Image Analysis): "${s.imageAnalysis.slice(0, 300)}..."\n${example}`;
      }
      if (s.postTitle) {
        example = `Post Title: "${s.postTitle}"\n${example}`;
      }
      if (s.responseSnippet) {
        example += `\nTheir reply: "${s.responseSnippet.slice(0, 150)}"`;
      }
      return example;
    });
  }

  getSuccessCount(): number {
    return this.successfulMessagesRepo.count();
  }
}