package common

import (
	"fmt"
	"math/rand"
	"testing"
)

// testItem implements Identifiable for benchmarking
type testItem struct {
	id    int32
	name  string
	value int32
	flag  bool
}

func (t *testItem) GetID() int32 { return t.id }

// BenchmarkMasterListOperations benchmarks the generic MasterList
func BenchmarkMasterListOperations(b *testing.B) {
	// Create master list with test data
	ml := NewMasterList[int32, *testItem]()
	const numItems = 10000
	
	// Pre-populate
	b.StopTimer()
	for i := 0; i < numItems; i++ {
		item := &testItem{
			id:    int32(i + 1),
			name:  fmt.Sprintf("Item %d", i+1),
			value: int32(rand.Intn(100)),
			flag:  rand.Intn(2) == 1,
		}
		ml.Add(item)
	}
	b.StartTimer()

	b.Run("Get", func(b *testing.B) {
		b.RunParallel(func(pb *testing.PB) {
			for pb.Next() {
				id := int32(rand.Intn(numItems) + 1)
				_ = ml.Get(id)
			}
		})
	})

	b.Run("Filter_10Percent", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = ml.Filter(func(item *testItem) bool {
				return item.value < 10 // ~10% match
			})
		}
	})

	b.Run("Filter_50Percent", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = ml.Filter(func(item *testItem) bool {
				return item.value < 50 // ~50% match
			})
		}
	})

	b.Run("Filter_90Percent", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = ml.Filter(func(item *testItem) bool {
				return item.value < 90 // ~90% match
			})
		}
	})

	b.Run("Count_10Percent", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = ml.Count(func(item *testItem) bool {
				return item.value < 10
			})
		}
	})

	b.Run("Count_50Percent", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = ml.Count(func(item *testItem) bool {
				return item.value < 50
			})
		}
	})

	b.Run("Find", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			targetValue := int32(rand.Intn(100))
			_, _ = ml.Find(func(item *testItem) bool {
				return item.value == targetValue
			})
		}
	})

	b.Run("ForEach", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			ml.ForEach(func(id int32, item *testItem) {
				_ = item.value + 1 // Minimal work
			})
		}
	})

	b.Run("WithReadLock", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			ml.WithReadLock(func(items map[int32]*testItem) {
				count := 0
				for _, item := range items {
					if item.value < 50 {
						count++
					}
				}
				_ = count
			})
		}
	})

	b.Run("FilterWithCapacity_Accurate", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = ml.FilterWithCapacity(func(item *testItem) bool {
				return item.value < 50
			}, 5000) // Accurate estimate: 50% of 10k = 5k
		}
	})

	b.Run("FilterInto_Reuse", func(b *testing.B) {
		var reusableSlice []*testItem
		for i := 0; i < b.N; i++ {
			reusableSlice = ml.FilterInto(func(item *testItem) bool {
				return item.value < 50
			}, reusableSlice)
		}
	})

	b.Run("CountAndFilter_Combined", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_, _ = ml.CountAndFilter(func(item *testItem) bool {
				return item.value < 50
			})
		}
	})
}

// BenchmarkMemoryAllocations tests allocation patterns
func BenchmarkMemoryAllocations(b *testing.B) {
	ml := NewMasterList[int32, *testItem]()
	const numItems = 1000
	
	// Pre-populate
	for i := 0; i < numItems; i++ {
		item := &testItem{
			id:    int32(i + 1),
			name:  fmt.Sprintf("Item %d", i+1),
			value: int32(rand.Intn(100)),
			flag:  rand.Intn(2) == 1,
		}
		ml.Add(item)
	}

	b.Run("Filter_Allocations", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			_ = ml.Filter(func(item *testItem) bool {
				return item.value < 50
			})
		}
	})

	b.Run("GetAll_Allocations", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			_ = ml.GetAll()
		}
	})

	b.Run("GetAllSlice_Allocations", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			_ = ml.GetAllSlice()
		}
	})

	b.Run("FilterWithCapacity_Allocations", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			_ = ml.FilterWithCapacity(func(item *testItem) bool {
				return item.value < 50
			}, 500) // Accurate capacity estimate
		}
	})

	b.Run("FilterInto_Allocations", func(b *testing.B) {
		b.ReportAllocs()
		reusableSlice := make([]*testItem, 0, 600) // Pre-sized
		for i := 0; i < b.N; i++ {
			reusableSlice = ml.FilterInto(func(item *testItem) bool {
				return item.value < 50
			}, reusableSlice)
		}
	})

	b.Run("CountAndFilter_Allocations", func(b *testing.B) {
		b.ReportAllocs()
		for i := 0; i < b.N; i++ {
			_, _ = ml.CountAndFilter(func(item *testItem) bool {
				return item.value < 50
			})
		}
	})
}