package jsondocument

import (
	"encoding/json"
	"strings"
	"testing"
)

func TestDecodeUseNumberEnforcesOneUnambiguousDocument(t *testing.T) {
	valid := map[string]any{}
	if err := DecodeUseNumber([]byte(`{"value":9007199254740993,"nested":{"name":"first"}}`), &valid); err != nil {
		t.Fatalf("valid document: %v", err)
	}
	if number, ok := valid["value"].(json.Number); !ok || number.String() != "9007199254740993" {
		t.Fatalf("number = %#v, want preserved json.Number", valid["value"])
	}

	for name, document := range map[string]string{
		"trailing value":       `{"value":1}{"value":2}`,
		"duplicate root key":   `{"value":1,"value":2}`,
		"duplicate nested key": `{"nested":{"value":1,"value":2}}`,
	} {
		t.Run(name, func(t *testing.T) {
			var target any
			if err := DecodeUseNumber([]byte(document), &target); err == nil {
				t.Fatalf("DecodeUseNumber accepted %s", document)
			}
		})
	}

	invalidUTF8 := append([]byte(`{"value":"`), 0xff)
	invalidUTF8 = append(invalidUTF8, []byte(`"}`)...)
	var target any
	if err := DecodeUseNumber(invalidUTF8, &target); err == nil || !strings.Contains(err.Error(), "UTF-8") {
		t.Fatalf("invalid UTF-8 error = %v", err)
	}
}