package engine

import (
	"io"
	"strconv"
	"testing"
	"testing/fstest"
)

type benchmarkCatalogConfig struct {
	Catalog map[string]string `yaml:"catalog"`
}

type benchmarkNodeConfig struct {
	Node string `yaml:"node"`
}

func BenchmarkUnderlayBroadCatalog(b *testing.B) {
	for _, width := range []int{128, 256, 512} {
		b.Run(strconv.Itoa(width), func(b *testing.B) {
			inputs := make([]Input, 2)
			for half := range inputs {
				catalog := make(map[string]any, width/2)
				for index := range width / 2 {
					catalog["item-"+strconv.Itoa(half*width/2+index)] = "value"
				}
				inputs[half] = Input{Source: Mapping("catalog-"+strconv.Itoa(half), map[string]any{"catalog": catalog})}
			}
			options := LayeredOptions[benchmarkCatalogConfig]{Underlays: []Underlay{{Inputs: inputs}}}
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if _, err := LoadLayered(Input{Source: NoSource()}, testSecretBinding(), options); err != nil {
					b.Fatal(err)
				}
			}
		})
	}
}

func BenchmarkUnderlayManySmallTiers(b *testing.B) {
	for _, count := range []int{32, 64, 128} {
		b.Run(strconv.Itoa(count), func(b *testing.B) {
			groups := make([]Underlay, count)
			for index := range groups {
				groups[index].Inputs = []Input{{Source: Mapping("item", map[string]any{
					"catalog": map[string]any{"item-" + strconv.Itoa(index): "value"},
				})}}
			}
			options := LayeredOptions[benchmarkCatalogConfig]{Underlays: groups}
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if _, err := LoadLayered(Input{Source: NoSource()}, testSecretBinding(), options); err != nil {
					b.Fatal(err)
				}
			}
		})
	}
}

func BenchmarkUnderlaySubtreeReplacement(b *testing.B) {
	for _, count := range []int{32, 64, 128} {
		b.Run(strconv.Itoa(count), func(b *testing.B) {
			groups := make([]Underlay, count)
			for index := range groups {
				var node any = "temporary"
				if index%2 == 0 {
					node = map[string]any{"left": "one", "right": "two", "nested": map[string]any{"enabled": false}}
				}
				groups[index].Inputs = []Input{{Source: Mapping("replacement", map[string]any{"node": node})}}
			}
			options := LayeredOptions[benchmarkNodeConfig]{Underlays: groups}
			main := Input{Source: Mapping("main", map[string]any{"node": "final"})}
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if _, err := LoadLayered(main, testSecretBinding(), options); err != nil {
					b.Fatal(err)
				}
			}
		})
	}
}

func BenchmarkUnderlayNativeImports(b *testing.B) {
	for _, count := range []int{16, 32, 64} {
		b.Run(strconv.Itoa(count), func(b *testing.B) {
			files := fstest.MapFS{
				"main.yml": &fstest.MapFile{Data: []byte("configkit: {imports: [{glob: 'defaults/*.yml'}]}\n")},
			}
			for index := range count {
				name := "item-" + strconv.Itoa(index)
				files["defaults/"+name+".yml"] = &fstest.MapFile{Data: []byte("catalog: {" + name + ": value}\n")}
			}
			filesystem := NewFilesystem("bundle", files)
			main := Input{Source: filesystem.File("main.yml"), Imports: true}
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if _, err := LoadLayered[benchmarkCatalogConfig](main, testSecretBinding()); err != nil {
					b.Fatal(err)
				}
			}
		})
	}
}

func BenchmarkUnderlayRetainedHistory(b *testing.B) {
	for _, count := range []int{16, 32, 64} {
		b.Run(strconv.Itoa(count), func(b *testing.B) {
			groups := make([]Underlay, count)
			for index := range groups {
				groups[index].Inputs = []Input{{Source: Mapping("value", map[string]any{
					"catalog": map[string]any{"shared": strconv.Itoa(index)},
				})}}
			}
			options := LayeredOptions[benchmarkCatalogConfig]{Underlays: groups}
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				result, err := LoadLayered(Input{Source: NoSource()}, testSecretBinding(), options)
				if err != nil {
					b.Fatal(err)
				}
				if _, ok := result.Inspection.Explain(Keys("catalog", "shared")); !ok {
					b.Fatal("retained path was not explained")
				}
			}
		})
	}
}

func BenchmarkUnderlayRenderedHistory(b *testing.B) {
	for _, count := range []int{32, 64, 128} {
		b.Run(strconv.Itoa(count), func(b *testing.B) {
			groups := make([]Underlay, count)
			for index := range groups {
				groups[index].Inputs = []Input{{Source: Mapping("value", map[string]any{
					"catalog": map[string]any{"shared": strconv.Itoa(index)},
				})}}
			}
			result, err := LoadLayered(Input{Source: NoSource()}, testSecretBinding(), LayeredOptions[benchmarkCatalogConfig]{Underlays: groups})
			if err != nil {
				b.Fatal(err)
			}
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if err := result.Inspection.WriteExplanation(io.Discard, Keys("catalog", "shared")); err != nil {
					b.Fatal(err)
				}
			}
		})
	}
}