package engine

import (
	"strconv"
	"testing"

	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
)

func BenchmarkComposeWideMappings(b *testing.B) {
	for _, width := range []int{128, 256, 512} {
		b.Run(strconv.Itoa(width), func(b *testing.B) {
			left := benchmarkCatalog("source-1", 0, width)
			right := benchmarkCatalog("source-2", width, width)
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if _, diagnostics := composeDocuments(left, right); len(diagnostics) != 0 {
					b.Fatal(diagnostics)
				}
			}
		})
	}
}

func BenchmarkOverlayRecursiveMappings(b *testing.B) {
	for _, width := range []int{128, 256, 512} {
		b.Run(strconv.Itoa(width), func(b *testing.B) {
			base, diagnostics := composeDocuments(benchmarkCatalog("source-1", 0, width))
			if len(diagnostics) != 0 {
				b.Fatal(diagnostics)
			}
			overlay := benchmarkCatalog("source-2", width/2, width)
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if _, diagnostics := overlayDocuments(base, overlay); len(diagnostics) != 0 {
					b.Fatal(diagnostics)
				}
			}
		})
	}
}

func BenchmarkOverlayManyApplications(b *testing.B) {
	for _, count := range []int{32, 64, 128} {
		inputs := make([]*document.Node, count)
		for index := range inputs {
			inputs[index] = benchmarkCatalog("source-2", index, 1)
		}
		benchmarkOverlayApplications(b, count, inputs)
	}
}

func BenchmarkOverlayRepeatedReplacement(b *testing.B) {
	for _, count := range []int{32, 64, 128} {
		inputs := make([]*document.Node, count)
		for index := range inputs {
			location := document.Location{SourceID: "source-2"}
			value := &document.Node{Kind: document.String, Text: "replacement", Location: location}
			if index%2 == 0 {
				value = &document.Node{Kind: document.Mapping, Location: location, Mapping: []document.Entry{{
					Key: "enabled", Value: &document.Node{Kind: document.Boolean, Text: "false", Location: location},
				}}}
			}
			inputs[index] = &document.Node{Kind: document.Mapping, Location: location, Mapping: []document.Entry{{
				Key: "catalog", Value: &document.Node{Kind: document.Mapping, Location: location, Mapping: []document.Entry{{
					Key: "item-0", Value: value,
				}}},
			}}}
		}
		benchmarkOverlayApplications(b, count, inputs)
	}
}

func benchmarkOverlayApplications(b *testing.B, count int, inputs []*document.Node) {
	base, diagnostics := composeDocuments(benchmarkCatalog("source-1", 0, 1))
	if len(diagnostics) != 0 {
		b.Fatal(diagnostics)
	}
	for _, mode := range []string{"owned", "copy-preserving"} {
		b.Run(mode+"/"+strconv.Itoa(count), func(b *testing.B) {
			b.ReportAllocs()
			b.ResetTimer()
			for range b.N {
				if mode == "owned" {
					assembly := newAssemblyAccumulator(cloneComposedDocument(base))
					for _, input := range inputs {
						if diagnostics := assembly.applyOverlay(input, nil, nil, LayerOverlay); len(diagnostics) != 0 {
							b.Fatal(diagnostics)
						}
					}
					continue
				}
				current := base
				for _, input := range inputs {
					current, diagnostics = overlayDocuments(current, input)
					if len(diagnostics) != 0 {
						b.Fatal(diagnostics)
					}
				}
			}
		})
	}
}

func benchmarkCatalog(source string, first, width int) *document.Node {
	location := document.Location{SourceID: source}
	entries := make([]document.Entry, width)
	for index := range entries {
		entries[index] = document.Entry{
			Key:   "item-" + strconv.Itoa(first+index),
			Value: &document.Node{Kind: document.Mapping, Location: location, Mapping: []document.Entry{{Key: "enabled", Value: &document.Node{Kind: document.Boolean, Text: "true", Location: location}}}},
		}
	}
	return &document.Node{Kind: document.Mapping, Location: location, Mapping: []document.Entry{{
		Key: "catalog", Value: &document.Node{Kind: document.Mapping, Location: location, Mapping: entries},
	}}}
}