/**
 * POST /api/messages/:instanceId/new-chat
 * Create or get a chat by phone number to start a new conversation
 */
import { query } from '../../../utils/database'
import { baileysManager } from '../../../services/baileys/manager'
import { randomUUID } from 'crypto'

interface NewChatBody {
  phoneNumber: string
}

export default defineEventHandler(async (event) => {
  const username = getHeader(event, 'x-authentik-username')
  if (!username) {
    throw createError({ statusCode: 401, message: 'Unauthorized' })
  }

  const instanceId = getRouterParam(event, 'instanceId')
  if (!instanceId) {
    throw createError({ statusCode: 400, message: 'Missing instanceId' })
  }

  // Verify instance exists and is connected
  const socket = baileysManager.getSocket(instanceId)
  if (!socket) {
    throw createError({ statusCode: 400, message: 'Instance not connected' })
  }

  const body = await readBody<NewChatBody>(event)

  if (!body.phoneNumber?.trim()) {
    throw createError({ statusCode: 400, message: 'Phone number is required' })
  }

  // Clean phone number: remove spaces, dashes, parentheses, and + prefix
  const cleanNumber = body.phoneNumber.replace(/[\s\-\(\)\+]/g, '')

  // Validate it's a numeric string
  if (!/^\d+$/.test(cleanNumber)) {
    throw createError({ statusCode: 400, message: 'Invalid phone number format' })
  }

  // Build WhatsApp JID (individual chat)
  const jid = `${cleanNumber}@s.whatsapp.net`

  try {
    // Check if chat already exists
    const existingChat = await query(
      `SELECT id, jid, name, is_group, unread_count, last_message_at, last_message_type,
              (SELECT COALESCE(content, caption) FROM messages m
               WHERE m.chat_id = chats.id ORDER BY timestamp DESC LIMIT 1) as last_message
       FROM chats
       WHERE instance_id = $1 AND jid = $2`,
      [instanceId, jid]
    )

    if (existingChat.rows.length > 0) {
      // Chat exists, return it
      const chat = existingChat.rows[0]
      return {
        success: true,
        chat: {
          id: chat.id,
          jid: chat.jid,
          name: chat.name || cleanNumber,
          isGroup: chat.is_group,
          unreadCount: chat.unread_count || 0,
          lastMessage: chat.last_message,
          lastMessageAt: chat.last_message_at,
          lastMessageType: chat.last_message_type
        },
        isNew: false
      }
    }

    // Chat doesn't exist, create it
    const chatId = randomUUID()

    // Try to get contact name from WhatsApp (optional, may fail)
    let contactName = cleanNumber
    try {
      // Check if number exists on WhatsApp using onWhatsApp
      const [exists] = await socket.onWhatsApp(jid)
      if (!exists?.exists) {
        throw createError({
          statusCode: 400,
          message: 'Este número no está registrado en WhatsApp'
        })
      }

      // Try to get the push name or contact name
      if (exists.notify) {
        contactName = exists.notify
      }
    } catch (e: any) {
      // If it's our validation error, rethrow
      if (e.statusCode === 400) {
        throw e
      }
      // Otherwise just use the number as name
      console.log('[NewChat] Could not verify WhatsApp status:', e.message)
    }

    // Insert new chat
    await query(
      `INSERT INTO chats (id, instance_id, jid, name, is_group, unread_count, created_at, updated_at)
       VALUES ($1, $2, $3, $4, false, 0, NOW(), NOW())`,
      [chatId, instanceId, jid, contactName]
    )

    return {
      success: true,
      chat: {
        id: chatId,
        jid: jid,
        name: contactName,
        isGroup: false,
        unreadCount: 0,
        lastMessage: null,
        lastMessageAt: null,
        lastMessageType: null
      },
      isNew: true
    }
  } catch (e: any) {
    // Rethrow HTTP errors
    if (e.statusCode) {
      throw e
    }

    console.error('[NewChat] Error creating chat:', e)
    throw createError({
      statusCode: 500,
      message: `Error creating chat: ${e.message}`
    })
  }
})