#!/usr/bin/env elixir

# =============================================================================
# Simple connectivity and packet test
# =============================================================================
# This script verifies basic connectivity to the jPOS server and tests
# a single SALE transaction to ensure the framework is working correctly.
#
# Usage:
#   elixir test_connectivity.exs [--host HOST] [--port PORT]
#
# Example:
#   elixir test_connectivity.exs
#   elixir test_connectivity.exs --host 192.168.1.100 --port 9103
# =============================================================================

Mix.install([])

Code.require_file("lib/iso8583/packet_builder.ex", __DIR__)
Code.require_file("lib/iso8583/parser.ex", __DIR__)

defmodule ConnectivityTest do
  def main(args) do
    config = parse_args(args, %{host: "localhost", port: 14001})
    
    IO.puts("\n" <> String.duplicate("=", 60))
    IO.puts("jPOS Server Connectivity Test")
    IO.puts(String.duplicate("=", 60))
    IO.puts("Server: #{config.host}:#{config.port}")
    IO.puts(String.duplicate("=", 60))
    
    # Test 1: Basic connectivity
    IO.puts("\n[1/3] Testing basic connectivity...")
    if !test_connectivity(config) do
      IO.puts("❌ FAILED: Cannot connect to server")
      IO.puts("\nPlease verify:")
      IO.puts("  1. jPOS server is running")
      IO.puts("  2. Server is listening on #{config.host}:#{config.port}")
      IO.puts("  3. No firewall blocking the connection")
      System.halt(1)
    end
    IO.puts("✓ Connection successful")
    
    # Test 2: Send simple packet
    IO.puts("\n[2/3] Building test packet...")
    test_case = %{
      test_id: "TEST-001",
      scenario: "connectivity_test",
      description: "Basic connectivity test - $10 Visa purchase",
      tid: "41448413",
      mid: "285414480000000",
      stan: "000001",
      amount: "000000001000",
      pan: "4111111111111111",
      processing_code: "000000",
      mti: "0200",
      nii: "782",
      expected_mti_response: "0210",
      expected_response_code: "00"
    }
    
    packet = ISO8583.PacketBuilder.build(test_case)
    IO.puts("✓ Packet built (#{byte_size(packet)} bytes)")
    IO.puts("  Hex: #{String.slice(Base.encode16(packet), 0, 40)}...")
    
    # Test 3: Send and receive
    IO.puts("\n[3/3] Sending packet and waiting for response...")
    case send_and_receive(packet, config) do
      {:ok, response} ->
        IO.puts("✓ Response received (#{byte_size(response)} bytes)")
        IO.puts("  Hex: #{String.slice(Base.encode16(response), 0, 40)}...")
        
        case ISO8583.Parser.parse(response) do
          {:ok, parsed} ->
            IO.puts("\n" <> String.duplicate("=", 60))
            IO.puts("Response Parsed Successfully!")
            IO.puts(String.duplicate("=", 60))
            IO.puts("MTI:           #{parsed.mti}")
            IO.puts("Response Code: #{ISO8583.Parser.get_response_code(parsed) || "N/A"}")
            IO.puts("Approval Code: #{ISO8583.Parser.get_approval_code(parsed) || "N/A"}")
            IO.puts("STAN:          #{ISO8583.Parser.get_stan(parsed) || "N/A"}")
            IO.puts("Fields:        #{inspect(parsed.present_fields)}")
            
            IO.puts("\n✅ SUCCESS: Framework is working correctly!")
            IO.puts("\nYou can now run the full test suite:")
            IO.puts("  elixir run_tests.exs --type sale")
            
          {:error, reason} ->
            IO.puts("\n⚠️  WARNING: Response received but parsing failed")
            IO.puts("Error: #{inspect(reason)}")
            IO.puts("\nThis might indicate:")
            IO.puts("  1. Server using different ISO8583 format")
            IO.puts("  2. Response packet structure mismatch")
            IO.puts("\nRaw response hex:")
            IO.puts(Base.encode16(response))
        end
        
      {:error, reason} ->
        IO.puts("❌ FAILED: #{inspect(reason)}")
        System.halt(1)
    end
    
    IO.puts("\n" <> String.duplicate("=", 60))
  end
  
  defp test_connectivity(config) do
    host = String.to_charlist(config.host)
    
    case :gen_tcp.connect(host, config.port, [:binary, active: false], 3000) do
      {:ok, socket} ->
        :gen_tcp.close(socket)
        true
      {:error, _} ->
        false
    end
  end
  
  defp send_and_receive(packet, config) do
    host = String.to_charlist(config.host)
    
    case :gen_tcp.connect(host, config.port, [:binary, active: false], 5000) do
      {:ok, socket} ->
        case :gen_tcp.send(socket, packet) do
          :ok ->
            result = :gen_tcp.recv(socket, 0, 10_000)
            :gen_tcp.close(socket)
            result
          error ->
            :gen_tcp.close(socket)
            error
        end
      error ->
        error
    end
  end
  
  defp parse_args([], config), do: config
  defp parse_args(["--host", host | rest], config) do
    parse_args(rest, Map.put(config, :host, host))
  end
  defp parse_args(["--port", port | rest], config) do
    parse_args(rest, Map.put(config, :port, String.to_integer(port)))
  end
  defp parse_args([_ | rest], config), do: parse_args(rest, config)
end

ConnectivityTest.main(System.argv())