# YSP Configuration Consolidation Summary

## Overview
Successfully consolidated YSP configuration from multiple scattered locations into a unified, well-organized structure that aligns with other network configurations.

## Changes Made

### 1. Configuration Removal/Consolidation
- ❌ **Removed** YSP configuration from `config/config.exs` (lines 38-57)
- ❌ **Consolidated** YSP processor configuration from `config/incoming_listeners.exs`
- ✅ **Enhanced** YSP configuration in `config/upstream_networks.exs`

### 2. Enhanced Upstream Networks Configuration
Updated `config/upstream_networks.exs` with comprehensive YSP configuration:

```elixir
ysp_ssl: %{
  # Connection, routing, framing, header, SSL configs...
  ysp_config: %{
    acquiring_institution_code: "999999",
    network_identifier: "782",
    default_terminal_id: "YSP00001",
    default_merchant_id: "MERCURYPAY001",
    supported_mtis: ["0100", "0200", "0220", "0400", "0800"],
    supported_fields: [2, 3, 4, 11, 12, 13, 14, 22, 23, 24, 25, 35, 37, 38, 39, 41, 42, 49, 52, 55, 62, 63],
    echo_response_code: "301",
    pin_ipek_response_code: "161",
    default_master_key: "0123456789ABCDEF0123456789ABCDEF",
    processing_timeout: 30_000,
    max_retries: 3,
    retry_delay: 5_000,
    required_fields: %{
      "0100" => [2, 3, 4, 11],  # Authorization request
      "0200" => [2, 3, 4, 11],  # Purchase request
      "0220" => [2, 3, 4, 11],  # Completion request
      "0400" => [3, 4, 11],     # Reversal - no PAN required
      "0800" => [11]            # Network management - no PAN required
    },
    processing_codes: %{
      "000001" => "000000",
      "preauth" => "330000", 
      "tmk" => "991380",
      "pin_ipek" => "990280"
    }
  }
}
```

### 3. Created Centralized Configuration Module
**New file:** `lib/da_product_app/acquirer/ysp/config.ex`

Provides unified access to YSP configuration with helper functions:
- `get_ysp_config/0` - Get complete configuration
- `get_required_fields/1` - Get MTI-specific required fields
- `get_processing_code/1` - Get processing code transformations
- `get_nii/0`, `get_acquiring_institution_code/0`, etc. - Specific config getters

### 4. Updated Message Processors
**Updated files:**
- `lib/da_product_app/acquirer/ysp/message_processor.ex`
- `lib/da_product_app/acquirer/ysp/ysp_processor.ex`

Both now use the centralized `DaProductApp.Acquirer.YSP.Config` module instead of direct `Application.get_env/2` calls.

### 5. Fixed BadMapError Issue
**Root Cause:** Code was trying to use `Map.get/2` on keyword lists returned by `Application.get_env/2`.

**Solution:** Updated configuration access to use proper map structures from the consolidated configuration.

### 6. Fixed MTI 0400/0800 Field Validation
**Issue:** Field 2 (PAN) was incorrectly required for MTI 0400 (reversal) and 0800 (network management).

**Solution:** 
- Added MTI-specific required fields configuration
- MTI 0400: Requires fields [3, 4, 11] (no PAN)  
- MTI 0800: Requires field [11] only (no PAN)
- Other MTIs: Still require [2, 3, 4, 11] including PAN

## Benefits

### 1. Consistency
- YSP configuration now follows the same pattern as other networks (Visa, MasterCard, etc.)
- All network configurations are in `upstream_networks.exs`

### 2. Maintainability  
- Single source of truth for YSP configuration
- Centralized config module with helper functions
- Easy to update configuration in one place

### 3. Flexibility
- Supports both `ysp_ssl` and `ysp_plain` network variants
- Fallback to default configuration if network config missing
- MTI-specific field validation rules

### 4. Error Resolution
- Fixed `BadMapError` that was causing YSP message processing failures
- Proper field validation for reversal and network management messages

## Configuration Location Summary

| Configuration Type | Previous Location | New Location |
|-------------------|------------------|--------------|
| YSP Network Settings | `config/config.exs` | `config/upstream_networks.exs` (ysp_ssl/ysp_plain) |
| YSP Processor Settings | `config/incoming_listeners.exs` | `config/upstream_networks.exs` (ysp_config section) |
| Field Validation Rules | Hardcoded in processors | `config/upstream_networks.exs` (required_fields) |
| Processing Code Maps | `config/incoming_listeners.exs` | `config/upstream_networks.exs` (processing_codes) |

## Next Steps

1. **Test the consolidated configuration** in your environment
2. **Update any other modules** that might be using the old configuration paths
3. **Consider moving other network-specific configurations** to follow the same pattern
4. **Update documentation** to reflect the new configuration structure

The YSP configuration is now properly aligned with your other network configurations and should resolve the `BadMapError` and field validation issues you were experiencing.