import { defineEventHandler, readBody, createError } from 'h3'
import { getSubdomainFromRequest, isCentralSubdomain } from '~/server/utils/tenant'
import { setSessionCookie, setTenantIdCookie } from '~/server/utils/session'

export default defineEventHandler(async (event) => {
  const config = useRuntimeConfig()
  const body = await readBody(event)
  
  // Extract subdomain from the request
  const subdomain = getSubdomainFromRequest(event)
  
  if (!subdomain) {
    throw createError({
      statusCode: 400,
      statusMessage: 'Unable to determine tenant from subdomain',
    })
  }

  // Determine the backend URL based on whether this is central admin or tenant
  const isCentral = isCentralSubdomain(subdomain)
  const backendUrl = config.backendUrl || 'http://localhost:3000'
  const loginEndpoint = isCentral ? '/api/auth/central/login' : '/api/auth/login'

  try {
    // Forward login request to NestJS backend with subdomain header
    const response = await fetch(`${backendUrl}${loginEndpoint}`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-tenant-subdomain': subdomain,
      },
      body: JSON.stringify(body),
    })

    const data = await response.json()

    if (!response.ok) {
      throw createError({
        statusCode: response.status,
        statusMessage: data.message || 'Login failed',
        data: data,
      })
    }

    // Extract token and tenant info from response
    const { access_token, user, tenantId } = data

    if (!access_token) {
      throw createError({
        statusCode: 500,
        statusMessage: 'No access token received from backend',
      })
    }

    // Set HTTP-only cookie with the JWT token
    setSessionCookie(event, access_token)
    
    // Set tenant ID cookie (readable by client for context)
    if (tenantId) {
      setTenantIdCookie(event, tenantId)
    }

    // Return user info (but NOT the token - it's in HTTP-only cookie)
    return {
      success: true,
      user,
      tenantId,
    }
  } catch (error: any) {
    // Re-throw H3 errors
    if (error.statusCode) {
      throw error
    }
    
    console.error('Login proxy error:', error)
    throw createError({
      statusCode: 500,
      statusMessage: 'Failed to connect to authentication service',
    })
  }
})