/**
 * List emails functionality
 */
const config = require('../config');
const { callGraphAPI } = require('../utils/graph-api');
const { ensureAuthenticated } = require('../auth');
const { buildODataFilter, buildDateFilter } = require('../utils/odata-helpers');
const { resolveFolderPath } = require('./folder-utils');

/**
 * List emails handler
 * @param {object} args - Tool arguments
 * @returns {object} - MCP response
 */
async function handleListEmails(args) {
  const folder = args.folder || "inbox";
  const count = Math.min(parseInt(args.count, 10) || 10, config.MAX_RESULT_COUNT);
  
  try {
    // Get access token
    const accessToken = await ensureAuthenticated();
    
    // Resolve folder path using the proper folder utilities
    const endpoint = await resolveFolderPath(accessToken, folder);
    
    // Add query parameters
    const queryParams = {
      $top: count,
      $orderby: 'receivedDateTime desc',
      $select: config.EMAIL_SELECT_FIELDS
    };
    
    // Add date filtering if specified
    const dateConditions = buildDateFilter(args.dateFrom, args.dateTo, args.dateRange);
    if (dateConditions.length > 0) {
      queryParams.$filter = buildODataFilter(dateConditions);
    }
    
    // Make API call
    const response = await callGraphAPI(accessToken, 'GET', endpoint, null, queryParams);
    
    if (!response.value || response.value.length === 0) {
      return {
        content: [{ 
          type: "text", 
          text: `No emails found in ${folder}.`
        }]
      };
    }
    
    // Format results
    const emailList = response.value.map((email, index) => {
      const sender = email.from ? email.from.emailAddress : { name: 'Unknown', address: 'unknown' };
      const date = new Date(email.receivedDateTime).toLocaleString();
      const readStatus = email.isRead ? '' : '[UNREAD] ';
      const convLine = email.conversationId ? `ConversationID: ${email.conversationId}\n` : '';

      return `${index + 1}. ${readStatus}${date} - From: ${sender.name} (${sender.address})\nSubject: ${email.subject}\nID: ${email.id}\n${convLine}`;
    }).join("\n");
    
    // Build result message with date filter info
    let resultMessage = `Found ${response.value.length} emails in ${folder}`;
    
    if (args.dateRange) {
      resultMessage += ` (${args.dateRange})`;
    } else if (args.dateFrom || args.dateTo) {
      const dateInfo = [];
      if (args.dateFrom) dateInfo.push(`from: ${args.dateFrom}`);
      if (args.dateTo) dateInfo.push(`to: ${args.dateTo}`);
      resultMessage += ` (${dateInfo.join(', ')})`;
    }
    
    resultMessage += `:\n\n${emailList}`;
    
    return {
      content: [{
        type: "text",
        text: resultMessage
      }]
    };
  } catch (error) {
    if (error.message === 'Authentication required') {
      return {
        content: [{ 
          type: "text", 
          text: "Authentication required. Please use the 'authenticate' tool first."
        }]
      };
    }
    
    return {
      content: [{ 
        type: "text", 
        text: `Error listing emails: ${error.message}`
      }]
    };
  }
}

module.exports = handleListEmails;