From 55e6217b71ff3e3733cc863145fccbcc8b1af6a1 Mon Sep 17 00:00:00 2001
From: Brooke Bryan <brooke@bajb.net>
Date: Wed, 15 Apr 2020 21:40:11 +0100
Subject: [PATCH] Support for pool select mode

---
 docs/connectors/pool.md |  2 ++
 v1/connector/pool.go    | 11 +++++++++++
 2 files changed, 13 insertions(+)

diff --git a/docs/connectors/pool.md b/docs/connectors/pool.md
index 43672d6..849fdc7 100644
--- a/docs/connectors/pool.md
+++ b/docs/connectors/pool.md
@@ -14,6 +14,7 @@ As with all configs, the standard wrapper is used.
   "specVersion": "v1",                        // Must be set to the correct version
   "selector": {},                             // May be used to apply this to a subset of charges
   "spec": {
+    "selectMode": "default",                  // Can be set to: "default" or "priorityMerge"
     "restriction": "unrestricted",            // Can be set to: "unrestricted", "noRepeat" or "lowestUsage"
     "connectors": [                           // Connectors contains the list of connectors in the pool
       {
@@ -29,6 +30,7 @@ As with all configs, the standard wrapper is used.
 ## Spec Definition
 FieldName | Required | Definition 
 ---:|---|:---
+selectMode | false | "default" or "priorityMerge"
 restriction | false | "unrestricted" (Default) , "noRepeat" or "lowestUsage"
 [connectors](#connector-definition) | false | Non-empty list of the connectors in the pool
 
diff --git a/v1/connector/pool.go b/v1/connector/pool.go
index ed61506..125a5f7 100644
--- a/v1/connector/pool.go
+++ b/v1/connector/pool.go
@@ -23,8 +23,19 @@ const (
 	RestrictionLowestUsage Restriction = "lowestUsage"
 )
 
+type SelectMode string
+
+const (
+	// SelectModeDefault groups all connectors in the pool, and orders by priority
+	SelectModeDefault SelectMode = "default"
+
+	// SelectModePriorityMerge selects a single connector from each priority (after weighting shuffle)
+	SelectModePriorityMerge SelectMode = "priorityMerge"
+)
+
 // Pool is used to select a group of connectors and the order that they should be used in
 type Pool struct {
+	SelectMode  SelectMode  `json:"selectMode" yaml:"selectMode" validate:"oneof=default priorityMerge"`
 	Restriction Restriction `json:"restriction" yaml:"restriction" validate:"oneof=unrestricted noRepeat lowestUsage"`
 	Connectors  []PoolItem  `json:"connectors" yaml:"connectors" validate:"gt=0,dive"`
 }