package yaml

import (
	"bytes"
	"reflect"
	"testing"

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

func FuzzParseDocument(f *testing.F) {
	for _, seed := range []string{
		"{}\n",
		"service:\n  enabled: true\n  ports: [8080, 8081]\n",
		"values: {empty: '', nothing: null, number: -1.5e2}\n",
		"duplicate: one\nduplicate: two\n",
		"alias: &value one\nother: *value\n",
	} {
		f.Add([]byte(seed))
	}

	limits := Limits{Depth: 64, Nodes: 4096, ParserDepth: 128}
	f.Fuzz(func(t *testing.T, input []byte) {
		if len(input) > 64<<10 {
			return
		}
		parsed, issues := Parse(bytes.NewReader(input), "fuzz-input", limits)
		if len(issues) != 0 {
			return
		}

		var output bytes.Buffer
		if err := Write(&output, parsed); err != nil {
			t.Fatalf("Write() failed for accepted document: %v", err)
		}
		reparsed, issues := Parse(bytes.NewReader(output.Bytes()), "round-trip", limits)
		if len(issues) != 0 {
			t.Fatalf("rendered accepted document was rejected: %#v", issues)
		}
		clearLocations(parsed)
		clearLocations(reparsed)
		if !reflect.DeepEqual(parsed, reparsed) {
			t.Fatalf("document changed across parse/write/parse: before=%#v after=%#v", parsed, reparsed)
		}
	})
}

func clearLocations(node *document.Node) {
	if node == nil {
		return
	}
	node.Location = document.Location{}
	for index := range node.Mapping {
		node.Mapping[index].KeyLocation = document.Location{}
		node.Mapping[index].ValueLocation = document.Location{}
		clearLocations(node.Mapping[index].Value)
	}
	for _, child := range node.Sequence {
		clearLocations(child)
	}
}