fix(cli): log dropped recs from --min-pool-size filter (closes #359)

applyFilters now emits one INFO line per dropped rec:
  INFO: --min-pool-size=2.0 dropped rds/us-east-1/db.t3.micro (avg=0.80 < threshold)
and a summary line after all drops are counted:
  INFO: --min-pool-size dropped N recommendation(s) (X avg instances/hr total)

The pool-size check is lifted out of passesDimensionFilters and evaluated
first in applyFilters so drops can be observed and counted without adding
side effects to the pure shouldIncludePoolSize predicate.

Adds TestShouldIncludePoolSize (5 cases) and TestApplyFilters_PoolSizeLogs
to assert both the per-rec and summary log lines.

Author: cristim

cmd/multi_service_filters.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"fmt"
+	"log"
 	"slices"
 	"strings"
 
@@ -11,14 +13,27 @@ import (
 // currentRegion is the region being processed in the current loop iteration - if non-empty, only recommendations for that region are included
 func applyFilters(recs []common.Recommendation, cfg Config, instanceVersions map[string][]InstanceEngineVersion, versionInfo map[string]MajorEngineVersionInfo, currentRegion string) []common.Recommendation {
 	var filtered []common.Recommendation
+	var poolDrops []string
+	var poolDropInstances float64
 
 	for _, rec := range recs {
+		if cfg.MinPoolSize > 0 && !shouldIncludePoolSize(rec, cfg) {
+			poolDropInstances += rec.AverageInstancesUsedPerHour
+			label := fmt.Sprintf("%s/%s/%s", rec.Service, rec.Region, rec.ResourceType)
+			log.Printf("INFO: --min-pool-size=%.1f dropped %s (avg=%.2f < threshold)", cfg.MinPoolSize, label, rec.AverageInstancesUsedPerHour)
+			poolDrops = append(poolDrops, label)
+			continue
+		}
 		adjusted, include := processRecommendation(rec, cfg, instanceVersions, versionInfo, currentRegion)
 		if include {
 			filtered = append(filtered, adjusted)
 		}
 	}
 
+	if len(poolDrops) > 0 {
+		log.Printf("INFO: --min-pool-size dropped %d recommendation(s) (%.2f avg instances/hr total)", len(poolDrops), poolDropInstances)
+	}
+
 	return filtered
 }
 

cmd/multi_service_filters_test.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"bytes"
+	"log"
 	"testing"
 
 	"github.com/LeanerCloud/CUDly/pkg/common"
@@ -413,3 +415,62 @@ func TestShouldIncludeAccount(t *testing.T) {
 		})
 	}
 }
+
+func TestShouldIncludePoolSize(t *testing.T) {
+	tests := []struct {
+		name     string
+		avg      float64
+		minPool  float64
+		expected bool
+	}{
+		{"filter disabled (0)", 0.5, 0, true},
+		{"avg=0 passes through", 0, 2.0, true},
+		{"avg below threshold", 1.5, 2.0, false},
+		{"avg equal to threshold", 2.0, 2.0, true},
+		{"avg above threshold", 3.0, 2.0, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			rec := common.Recommendation{AverageInstancesUsedPerHour: tt.avg}
+			cfg := Config{MinPoolSize: tt.minPool}
+			assert.Equal(t, tt.expected, shouldIncludePoolSize(rec, cfg))
+		})
+	}
+}
+
+// TestApplyFilters_PoolSizeLogs verifies that applyFilters emits per-rec and
+// summary log lines when --min-pool-size drops recommendations.
+func TestApplyFilters_PoolSizeLogs(t *testing.T) {
+	origCfg := toolCfg
+	defer func() { toolCfg = origCfg }()
+
+	// Capture log output.
+	var buf bytes.Buffer
+	origFlags := log.Flags()
+	origWriter := log.Writer()
+	log.SetOutput(&buf)
+	log.SetFlags(0) // strip timestamps so the assertions are stable
+	defer func() {
+		log.SetOutput(origWriter)
+		log.SetFlags(origFlags)
+	}()
+
+	recs := []common.Recommendation{
+		{Service: "rds", Region: "us-east-1", ResourceType: "db.t3.micro", AverageInstancesUsedPerHour: 0.8, Count: 1},
+		{Service: "rds", Region: "us-east-1", ResourceType: "db.r5.large", AverageInstancesUsedPerHour: 3.5, Count: 2},
+	}
+	cfg := Config{MinPoolSize: 2.0}
+
+	result := applyFilters(recs, cfg, nil, nil, "")
+
+	// Only the rec above threshold passes through.
+	assert.Len(t, result, 1)
+	assert.Equal(t, "db.r5.large", result[0].ResourceType)
+
+	output := buf.String()
+	// Per-rec line present.
+	assert.Contains(t, output, "--min-pool-size=2.0 dropped rds/us-east-1/db.t3.micro (avg=0.80 < threshold)")
+	// Summary line present.
+	assert.Contains(t, output, "--min-pool-size dropped 1 recommendation(s)")
+}