# Generic Gateway Architecture Demo

# This script demonstrates the new generic gateway architecture that we've implemented.
# Instead of having separate MPGS tables, we now use the existing pos_transaction tables
# with generic gateway fields and JSON metadata for gateway-specific data.

import DaProductApp.Repo
import Ecto.Query

alias DaProductApp.Acquirer.GenericProcessor
alias DaProductApp.Acquirer.Schemas.{PosTempTransaction, PosTransaction}
alias DaProductApp.Transactions

# Demo configuration
mpgs_config = %{
  mpgs_config: %{
    merchant_id: "TEST_MERCHANT",
    api_base_url: "https://ap-gateway.mastercard.com",
    api_version: "63"
  },
  network_name: "MPGS_TEST"
}

# Sample transaction message
sample_transaction = %{
  field_41: "12345678",  # Terminal ID
  mti: "0200",           # Purchase request
  field_3: "000000",     # Processing code (purchase)
  field_4: "1000",       # Amount (10.00)
  currency_code: "840",  # USD
  masked_pan: "411111****1111",
  amount: Decimal.new("10.00")
}

IO.puts """
=== Generic Gateway Architecture Demo ===

🎯 Key Benefits:
✅ Works for ANY gateway (MPGS, VISA, AMEX, etc.)
✅ Clean existing schema - no gateway-specific fields
✅ Flexible JSON metadata for gateway-specific data
✅ Easy reporting across all gateways
✅ Future-proof architecture

🏗️ Database Changes Added:
- gateway_type: "MPGS", "VISA", "AMEX", etc.
- gateway_reference_id: Gateway's transaction ID
- gateway_status: "PENDING", "SUCCESS", "FAILED"
- processing_state: "CREATED", "PROCESSING", "COMPLETED"
- settlement_date: Settlement date
- settlement_status: "PENDING", "SETTLED"
- metadata: JSON field with gateway-specific data

📊 Current Tables:
- pos_temp_transaction: Processing/pending transactions with gateway fields
- pos_transaction: Final transactions with gateway fields
- payment_methods: Reusable across all gateways (kept from Phase 4)

🔄 Usage Pattern:
1. GenericProcessor.process_transaction("MPGS", config, transaction_data)
2. Gateway-specific processor handles the transaction
3. Response stored with standardized metadata structure
4. GenericProcessor.finalize_transaction() moves to permanent storage

📈 Reporting Examples:
- Cross-gateway volume reports
- Settlement reconciliation
- Failed transaction analysis
- Gateway performance comparison

🚀 Next Steps:
1. Test MPGS integration with new architecture
2. Add VISA processor using same pattern
3. Implement settlement reporting
4. Add gateway-specific queries using JSON functions

💡 Example Metadata Structure (MPGS):
{
  "gateway": {
    "type": "MPGS",
    "version": "63",
    "session": {"id": "SESSION_123", ...},
    "response": {"authorization_code": "123456", ...},
    "settlement": {"batch_id": "BATCH_20250103", ...}
  }
}

This architecture is clean, flexible, and scales to any number of gateways! 🎉
"""

# Example of how to use the new architecture
IO.puts "\n=== Example Usage ==="

try do
  # This would process a transaction through MPGS using the generic architecture
  IO.puts "1. Process transaction: GenericProcessor.process_transaction(\"MPGS\", config, transaction)"
  IO.puts "2. Store with metadata: All gateway-specific data in JSON metadata field"
  IO.puts "3. Query examples: Transactions.list_transactions_by_gateway(\"MPGS\")"
  IO.puts "4. Settlement: Transactions.settlement_reconciliation(Date.utc_today())"

  IO.puts "\n✅ Generic Gateway Architecture is ready for testing!"
rescue
  e -> IO.puts "Note: #{Exception.message(e)}"
end