execution

var (
	// DefaultFuncCollection is the default collection of functions that can be executed.
	DefaultFuncCollection = NewFuncCollection(
		FuncLen,
		FuncAdd,
		FuncToString,
		FuncToInt,
		FuncToFloat,
		FuncMerge,
		FuncReverse,
		FuncTypeOf,
		FuncMax,
		FuncMin,
		FuncIgnore,
		FuncBase64Encode,
		FuncBase64Decode,
		FuncParse,
		FuncReadFile,
		FuncHas,
		FuncGet,
		FuncContains,
		FuncSum,
		FuncJoin,
		FuncReplace,
		FuncKeys,
		FuncSplit,
		FuncToLower,
		FuncToUpper,
		FuncTrim,
		FuncTrimPrefix,
		FuncTrimSuffix,
		FuncStartsWith,
		FuncEndsWith,
		FuncIndexOf,
		FuncAbs,
		FuncFloor,
		FuncCeil,
		FuncRound,
		FuncAvg,
		FuncFlatten,
		FuncUnique,
		FuncFirst,
		FuncLast,
		FuncValues,
		FuncEntries,
		FuncFromEntries,
		FuncToBool,
		FuncStringify,
	)
)

var FuncAbs = NewFunc(
	"abs",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if input.IsInt() {
			v, err := input.IntValue()
			if err != nil {
				return nil, fmt.Errorf("abs could not read int value: %w", err)
			}
			if v < 0 {
				v = -v
			}
			return model.NewIntValue(v), nil
		}

		v, err := input.FloatValue()
		if err != nil {
			return nil, fmt.Errorf("abs expects a numeric value: %w", err)
		}
		return model.NewFloatValue(math.Abs(v)), nil
	},
	ValidateArgsMax(1),
)

var FuncAdd = NewFunc(
	"add",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var foundInts, foundFloats int
		var intRes int64
		var floatRes float64
		for _, arg := range args {
			if arg.IsFloat() {
				foundFloats++
				v, err := arg.FloatValue()
				if err != nil {
					return nil, fmt.Errorf("error getting float value: %w", err)
				}
				floatRes += v
				continue
			}
			if arg.IsInt() {
				foundInts++
				v, err := arg.IntValue()
				if err != nil {
					return nil, fmt.Errorf("error getting int value: %w", err)
				}
				intRes += v
				continue
			}
			return nil, fmt.Errorf("expected int or float, got %s", arg.Type())
		}
		if foundFloats > 0 {
			return model.NewFloatValue(floatRes + float64(intRes)), nil
		}
		return model.NewIntValue(intRes), nil
	},
	ValidateArgsMin(1),
)

var FuncAvg = NewFunc(
	"avg",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var sum float64

		for _, arg := range args {
			if arg.IsInt() {
				intVal, err := arg.IntValue()
				if err != nil {
					return nil, err
				}
				sum += float64(intVal)
				continue
			}
			if arg.IsFloat() {
				floatVal, err := arg.FloatValue()
				if err != nil {
					return nil, err
				}
				sum += floatVal
				continue
			}
			return nil, fmt.Errorf("cannot average non-numeric value of type %s", arg.Type().String())
		}

		return model.NewFloatValue(sum / float64(len(args))), nil
	},
	ValidateArgsMin(1),
)

var FuncBase64Decode = NewFunc(
	"base64d",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		arg := args[0]
		strVal, err := arg.StringValue()
		if err != nil {
			return nil, err
		}
		out, err := base64.StdEncoding.DecodeString(strVal)
		if err != nil {
			return nil, err
		}
		return model.NewStringValue(string(out)), nil
	},
	ValidateArgsExactly(1),
)

var FuncBase64Encode = NewFunc(
	"base64e",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		arg := args[0]
		strVal, err := arg.StringValue()
		if err != nil {
			return nil, err
		}
		out := base64.StdEncoding.EncodeToString([]byte(strVal))
		return model.NewStringValue(out), nil
	},
	ValidateArgsExactly(1),
)

var FuncCeil = NewFunc(
	"ceil",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if input.IsInt() {
			v, err := input.IntValue()
			if err != nil {
				return nil, fmt.Errorf("ceil could not read int value: %w", err)
			}
			return model.NewIntValue(v), nil
		}

		v, err := input.FloatValue()
		if err != nil {
			return nil, fmt.Errorf("ceil expects a numeric value: %w", err)
		}
		return model.NewIntValue(int64(math.Ceil(v))), nil
	},
	ValidateArgsMax(1),
)

var FuncContains = NewFunc(
	"contains",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var contains bool

		target := args[0]

		length, err := data.SliceLen()
		if err != nil {
			return nil, fmt.Errorf("error getting slice length: %w", err)
		}

		for i := 0; i < length; i++ {
			v, err := data.GetSliceIndex(i)
			if err != nil {
				return nil, fmt.Errorf("error getting slice index %d: %w", i, err)
			}
			matches, err := v.Equal(target)
			if err != nil {
				continue
			}
			matchesBool, err := matches.BoolValue()
			if err != nil {
				return nil, err
			}
			if matchesBool {
				contains = true
				break
			}
		}

		return model.NewBoolValue(contains), nil
	},
	ValidateArgsExactly(1),
)

var FuncEndsWith = NewFunc(
	"endsWith",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var suffix string
		var err error

		if len(args) == 2 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("endsWith expects a string as the first argument: %w", err)
			}
			suffix, err = args[1].StringValue()
			if err != nil {
				return nil, fmt.Errorf("endsWith expects a string suffix as the second argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("endsWith expects data to be a string: %w", err)
			}
			suffix, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("endsWith expects a string suffix as the first argument: %w", err)
			}
		}

		return model.NewBoolValue(strings.HasSuffix(input, suffix)), nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncEntries = NewFunc(
	"entries",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		if !data.IsMap() {
			return nil, fmt.Errorf("entries can only be used on maps, got %s", data.Type().String())
		}

		res := model.NewSliceValue()
		if err := data.RangeMap(func(key string, value *model.Value) error {
			entry := model.NewMapValue()
			if err := entry.SetMapKey("key", model.NewStringValue(key)); err != nil {
				return err
			}
			if err := entry.SetMapKey("value", value); err != nil {
				return err
			}
			return res.Append(entry)
		}); err != nil {
			return nil, err
		}

		return res, nil
	},
	ValidateArgsExactly(0),
)

var FuncFirst = NewFunc(
	"first",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if !input.IsSlice() {
			return nil, fmt.Errorf("first expects an array, got %s", input.Type().String())
		}

		length, err := input.SliceLen()
		if err != nil {
			return nil, err
		}
		if length == 0 {
			return model.NewNullValue(), nil
		}

		return input.GetSliceIndex(0)
	},
	ValidateArgsMax(1),
)

var FuncFlatten = NewFunc(
	"flatten",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if !input.IsSlice() {
			return nil, fmt.Errorf("flatten expects an array, got %s", input.Type().String())
		}

		res := model.NewSliceValue()
		if err := input.RangeSlice(func(i int, value *model.Value) error {
			if value.IsSlice() {
				return value.RangeSlice(func(j int, inner *model.Value) error {
					return res.Append(inner)
				})
			}
			return res.Append(value)
		}); err != nil {
			return nil, err
		}

		return res, nil
	},
	ValidateArgsMax(1),
)

var FuncFloor = NewFunc(
	"floor",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if input.IsInt() {
			v, err := input.IntValue()
			if err != nil {
				return nil, fmt.Errorf("floor could not read int value: %w", err)
			}
			return model.NewIntValue(v), nil
		}

		v, err := input.FloatValue()
		if err != nil {
			return nil, fmt.Errorf("floor expects a numeric value: %w", err)
		}
		return model.NewIntValue(int64(math.Floor(v))), nil
	},
	ValidateArgsMax(1),
)

var FuncFromEntries = NewFunc(
	"fromEntries",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if !input.IsSlice() {
			return nil, fmt.Errorf("fromEntries expects an array, got %s", input.Type().String())
		}

		res := model.NewMapValue()
		if err := input.RangeSlice(func(i int, entry *model.Value) error {
			if !entry.IsMap() {
				return fmt.Errorf("fromEntries expects each element to be an object, got %s at index %d", entry.Type().String(), i)
			}

			keyVal, err := entry.GetMapKey("key")
			if err != nil {
				return fmt.Errorf("fromEntries expects each element to have a \"key\" field: %w", err)
			}
			key, err := keyVal.StringValue()
			if err != nil {
				return fmt.Errorf("fromEntries expects \"key\" to be a string: %w", err)
			}

			value, err := entry.GetMapKey("value")
			if err != nil {
				return fmt.Errorf("fromEntries expects each element to have a \"value\" field: %w", err)
			}

			return res.SetMapKey(key, value)
		}); err != nil {
			return nil, err
		}

		return res, nil
	},
	ValidateArgsMax(1),
)

var FuncGet = NewFunc(
	"get",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {

		arg := args[0]

		switch arg.Type() {
		case model.TypeInt:
			index, err := arg.IntValue()
			if err != nil {
				return nil, err
			}
			return data.GetSliceIndex(int(index))
		case model.TypeString:
			key, err := arg.StringValue()
			if err != nil {
				return nil, err
			}
			return data.GetMapKey(key)
		default:
			return nil, fmt.Errorf("get expects string or int argument")
		}
	},
	ValidateArgsExactly(1),
)

var FuncHas = NewFunc(
	"has",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {

		arg := args[0]

		switch arg.Type() {
		case model.TypeInt:

			if data.Type() != model.TypeSlice {
				return model.NewBoolValue(false), nil
			}
			index, err := arg.IntValue()
			if err != nil {
				return nil, err
			}
			sliceLen, err := data.SliceLen()
			if err != nil {
				return nil, err
			}
			return model.NewBoolValue(index >= 0 && index < int64(sliceLen)), nil
		case model.TypeString:

			if data.Type() != model.TypeMap {
				return model.NewBoolValue(false), nil
			}
			key, err := arg.StringValue()
			if err != nil {
				return nil, err
			}
			exists, err := data.MapKeyExists(key)
			if err != nil {
				return nil, err
			}
			return model.NewBoolValue(exists), nil
		default:
			return nil, fmt.Errorf("has expects string or int argument")
		}
	},
	ValidateArgsMin(1),
)

var FuncIgnore = NewFunc(
	"ignore",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		data.MarkAsIgnore()
		return data, nil
	},
	ValidateArgsExactly(0),
)

var FuncIndexOf = NewFunc(
	"indexOf",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var substr string
		var err error

		if len(args) == 2 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("indexOf expects a string as the first argument: %w", err)
			}
			substr, err = args[1].StringValue()
			if err != nil {
				return nil, fmt.Errorf("indexOf expects a string substring as the second argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("indexOf expects data to be a string: %w", err)
			}
			substr, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("indexOf expects a string substring as the first argument: %w", err)
			}
		}

		return model.NewIntValue(int64(strings.Index(input, substr))), nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncJoin = NewFunc(
	"join",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		separator, err := args[0].StringValue()
		if err != nil {
			return nil, fmt.Errorf("join expects a string separator as the first argument: %w", err)
		}

		var valuesToJoin []string

		if len(args) == 2 && args[1].IsSlice() {
			if err := args[1].RangeSlice(func(i int, value *model.Value) error {
				strVal, err := value.StringValue()
				if err != nil {
					return fmt.Errorf("could not read string value of index %d: %w", i, err)
				}
				valuesToJoin = append(valuesToJoin, strVal)
				return nil
			}); err != nil {
				return nil, err
			}
		} else if len(args) > 1 {

			for i := 1; i < len(args); i++ {
				strVal, err := args[i].StringValue()
				if err != nil {
					return nil, fmt.Errorf("could not read string value of argument index %d: %w", i, err)
				}
				valuesToJoin = append(valuesToJoin, strVal)
			}
		} else {
			if err := data.RangeSlice(func(i int, value *model.Value) error {
				strVal, err := value.StringValue()
				if err != nil {
					return fmt.Errorf("could not read string value of index %d: %w", i, err)
				}
				valuesToJoin = append(valuesToJoin, strVal)
				return nil
			}); err != nil {
				return nil, err
			}
		}

		joined := strings.Join(valuesToJoin, separator)

		return model.NewStringValue(joined), nil
	},
	ValidateArgsMin(1),
)

var FuncKeys = NewFunc(
	"keys",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		switch data.Type() {
		case model.TypeMap:
			keys, err := data.MapKeys()
			if err != nil {
				return nil, err
			}
			res := model.NewSliceValue()
			for _, key := range keys {
				if err := res.Append(model.NewStringValue(key)); err != nil {
					return nil, err
				}
			}
			return res, nil
		case model.TypeSlice:
			len, err := data.SliceLen()
			if err != nil {
				return nil, err
			}
			res := model.NewSliceValue()
			for i := 0; i < len; i++ {
				if err := res.Append(model.NewIntValue(int64(i))); err != nil {
					return nil, err
				}
			}
			return res, nil
		default:
			return nil, fmt.Errorf("keys can only be used on maps and slices")
		}
	},
	ValidateArgsExactly(0),
)

var FuncLast = NewFunc(
	"last",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if !input.IsSlice() {
			return nil, fmt.Errorf("last expects an array, got %s", input.Type().String())
		}

		length, err := input.SliceLen()
		if err != nil {
			return nil, err
		}
		if length == 0 {
			return model.NewNullValue(), nil
		}

		return input.GetSliceIndex(length - 1)
	},
	ValidateArgsMax(1),
)

var FuncLen = NewFunc(
	"len",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		arg := args[0]

		l, err := arg.Len()
		if err != nil {
			return nil, err
		}

		return model.NewIntValue(int64(l)), nil
	},
	ValidateArgsExactly(1),
)

var FuncMax = NewFunc(
	"max",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		res := model.NewNullValue()
		for _, arg := range args {
			if res.IsNull() {
				res = arg
				continue
			}
			gt, err := arg.GreaterThan(res)
			if err != nil {
				return nil, err
			}
			gtBool, err := gt.BoolValue()
			if err != nil {
				return nil, err
			}
			if gtBool {
				res = arg
			}
		}
		return res, nil
	},
	ValidateArgsMin(1),
)

var FuncMerge = NewFunc(
	"merge",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		if len(args) == 1 {
			return args[0], nil
		}

		expectedType := args[0].Type()

		switch expectedType {
		case model.TypeMap:
			break
		default:
			return nil, fmt.Errorf("merge exects a map, found %s", expectedType)
		}

		for _, a := range args {
			if a.Type() != expectedType {
				return nil, fmt.Errorf("merge expects all arguments to be of the same type. expected %s, got %s", expectedType.String(), a.Type().String())
			}
		}

		base := model.NewMapValue()

		for i := 0; i < len(args); i++ {
			next := args[i]

			nextKVs, err := next.MapKeyValues()
			if err != nil {
				return nil, fmt.Errorf("merge failed to extract key values for arg %d: %w", i, err)
			}

			for _, kv := range nextKVs {
				if err := base.SetMapKey(kv.Key, kv.Value); err != nil {
					return nil, fmt.Errorf("merge failed to set map key %s: %w", kv.Key, err)
				}
			}
		}

		return base, nil
	},
	ValidateArgsMin(1),
)

var FuncMin = NewFunc(
	"min",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		res := model.NewNullValue()
		for _, arg := range args {
			if res.IsNull() {
				res = arg
				continue
			}
			lt, err := arg.LessThan(res)
			if err != nil {
				return nil, err
			}
			ltBool, err := lt.BoolValue()
			if err != nil {
				return nil, err
			}
			if ltBool {
				res = arg
			}
		}
		return res, nil
	},
	ValidateArgsMin(1),
)

var FuncParse = NewFunc(
	"parse",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var format parsing.Format
		var content []byte
		{
			strVal, err := args[0].StringValue()
			if err != nil {
				return nil, err
			}
			format = parsing.Format(strVal)
		}
		{
			strVal, err := args[1].StringValue()
			if err != nil {
				return nil, err
			}
			content = []byte(strVal)
		}

		reader, err := format.NewReader(parsing.DefaultReaderOptions())
		if err != nil {
			return nil, err
		}

		doc, err := reader.Read(content)
		if err != nil {
			return nil, err
		}

		return doc, nil
	},
	ValidateArgsExactly(2),
)

var FuncReadFile = NewFunc(
	"readFile",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		filepath, err := args[0].StringValue()
		if err != nil {
			return nil, fmt.Errorf("readFile: %w", err)
		}

		f, err := os.Open(filepath)
		if err != nil {
			return nil, fmt.Errorf("readFile: %w", err)
		}
		defer func() {
			_ = f.Close()
		}()

		fileBytes, err := io.ReadAll(f)
		if err != nil {
			return nil, fmt.Errorf("readFile: %w", err)
		}

		return model.NewStringValue(string(fileBytes)), nil
	},
	ValidateArgsExactly(1),
)

var FuncReplace = NewFunc(
	"replace",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		inputData := data
		if len(args)%2 != 0 {
			inputData = args[0]
			args = args[1:]
		}

		argStrings := make([]string, len(args))
		for i, arg := range args {
			s, err := arg.StringValue()
			if err != nil {
				return nil, err
			}
			argStrings[i] = s
		}
		replacer := strings.NewReplacer(argStrings...)

		inputString, err := inputData.StringValue()
		if err != nil {
			return nil, err
		}

		outputString := replacer.Replace(inputString)

		return model.NewStringValue(outputString), nil
	},
	ValidateArgsMin(2),
)

var FuncReverse = NewFunc(
	"reverse",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		arg := args[0]

		switch arg.Type() {
		case model.TypeString:
			return arg.StringIndexRange(-1, 0)
		case model.TypeSlice:
			return arg.SliceIndexRange(-1, 0)
		default:
			return nil, fmt.Errorf("reverse expects a slice or string, got %s", arg.Type())
		}
	},
	ValidateArgsExactly(1),
)

var FuncRound = NewFunc(
	"round",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if input.IsInt() {
			v, err := input.IntValue()
			if err != nil {
				return nil, fmt.Errorf("round could not read int value: %w", err)
			}
			return model.NewIntValue(v), nil
		}

		v, err := input.FloatValue()
		if err != nil {
			return nil, fmt.Errorf("round expects a numeric value: %w", err)
		}
		return model.NewIntValue(int64(math.Round(v))), nil
	},
	ValidateArgsMax(1),
)

var FuncSplit = NewFunc(
	"split",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		separator, err := args[0].StringValue()
		if err != nil {
			return nil, fmt.Errorf("split expects a string separator as the first argument: %w", err)
		}

		var input string
		if len(args) == 2 {
			input, err = args[1].StringValue()
			if err != nil {
				return nil, fmt.Errorf("split expects a string as the second argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("split expects data to be a string: %w", err)
			}
		}

		parts := strings.Split(input, separator)

		res := model.NewSliceValue()
		for _, part := range parts {
			if err := res.Append(model.NewStringValue(part)); err != nil {
				return nil, fmt.Errorf("could not append split result: %w", err)
			}
		}

		return res, nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncStartsWith = NewFunc(
	"startsWith",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var prefix string
		var err error

		if len(args) == 2 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("startsWith expects a string as the first argument: %w", err)
			}
			prefix, err = args[1].StringValue()
			if err != nil {
				return nil, fmt.Errorf("startsWith expects a string prefix as the second argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("startsWith expects data to be a string: %w", err)
			}
			prefix, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("startsWith expects a string prefix as the first argument: %w", err)
			}
		}

		return model.NewBoolValue(strings.HasPrefix(input, prefix)), nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncStringify = NewFunc(
	"stringify",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		formatStr, err := args[0].StringValue()
		if err != nil {
			return nil, err
		}
		format := parsing.Format(formatStr)

		input := data
		if len(args) == 2 {
			input = args[1]
		}

		writer, err := format.NewWriter(parsing.DefaultWriterOptions())
		if err != nil {
			return nil, err
		}

		b, err := writer.Write(input)
		if err != nil {
			return nil, err
		}

		b = bytes.TrimSuffix(b, []byte("\n"))

		return model.NewStringValue(string(b)), nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncSum = NewFunc(
	"sum",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		returnType := model.TypeInt

		for _, arg := range args {
			if arg.IsInt() {
				continue
			}
			if arg.IsFloat() {
				returnType = model.TypeFloat
				break
			}
			return nil, fmt.Errorf("cannot sum non-numeric value of type %s", arg.Type().String())
		}

		switch returnType {
		case model.TypeInt:
			var sum int64
			for _, arg := range args {
				if arg.IsInt() {
					intVal, err := arg.IntValue()
					if err != nil {
						return nil, err
					}
					sum += intVal
					continue
				}

				floatVal, err := arg.FloatValue()
				if err != nil {
					return nil, err
				}
				sum += int64(floatVal)
			}
			return model.NewIntValue(sum), nil
		case model.TypeFloat:
			var sum float64
			for _, arg := range args {
				if arg.IsInt() {
					intVal, err := arg.IntValue()
					if err != nil {
						return nil, err
					}
					sum += float64(intVal)
					continue
				}

				floatVal, err := arg.FloatValue()
				if err != nil {
					return nil, err
				}
				sum += floatVal
			}
			return model.NewFloatValue(sum), nil
		default:
			return nil, fmt.Errorf("unsupported return type %s", returnType.String())
		}
	},
	ValidateArgsMin(1),
)

var FuncToBool = NewFunc(
	"toBool",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		switch args[0].Type() {
		case model.TypeBool:
			b, err := args[0].BoolValue()
			if err != nil {
				return nil, err
			}
			return model.NewBoolValue(b), nil
		case model.TypeString:
			s, err := args[0].StringValue()
			if err != nil {
				return nil, err
			}
			switch strings.ToLower(s) {
			case "true", "1", "yes":
				return model.NewBoolValue(true), nil
			case "false", "0", "no", "":
				return model.NewBoolValue(false), nil
			default:
				return nil, fmt.Errorf("cannot convert string %q to bool", s)
			}
		case model.TypeInt:
			i, err := args[0].IntValue()
			if err != nil {
				return nil, err
			}
			return model.NewBoolValue(i != 0), nil
		case model.TypeFloat:
			f, err := args[0].FloatValue()
			if err != nil {
				return nil, err
			}
			return model.NewBoolValue(f != 0), nil
		case model.TypeNull:
			return model.NewBoolValue(false), nil
		default:
			return nil, fmt.Errorf("cannot convert %s to bool", args[0].Type())
		}
	},
	ValidateArgsExactly(1),
)

var FuncToFloat = NewFunc(
	"toFloat",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		switch args[0].Type() {
		case model.TypeString:
			stringValue, err := args[0].StringValue()
			if err != nil {
				return nil, err
			}

			i, err := strconv.ParseFloat(stringValue, 64)
			if err != nil {
				return nil, err
			}

			return model.NewFloatValue(i), nil
		case model.TypeInt:
			i, err := args[0].IntValue()
			if err != nil {
				return nil, err
			}
			return model.NewFloatValue(float64(i)), nil
		case model.TypeFloat:
			return args[0], nil
		case model.TypeBool:
			i, err := args[0].BoolValue()
			if err != nil {
				return nil, err
			}
			if i {
				return model.NewFloatValue(1), nil
			}
			return model.NewFloatValue(0), nil
		default:
			return nil, fmt.Errorf("cannot convert %s to float", args[0].Type())
		}
	},
	ValidateArgsExactly(1),
)

var FuncToInt = NewFunc(
	"toInt",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		switch args[0].Type() {
		case model.TypeString:
			stringValue, err := args[0].StringValue()
			if err != nil {
				return nil, err
			}

			i, err := strconv.ParseInt(stringValue, 0, 64)
			if err != nil {
				return nil, err
			}

			return model.NewIntValue(i), nil
		case model.TypeInt:
			return args[0], nil
		case model.TypeFloat:
			i, err := args[0].FloatValue()
			if err != nil {
				return nil, err
			}
			return model.NewIntValue(int64(i)), nil
		case model.TypeBool:
			i, err := args[0].BoolValue()
			if err != nil {
				return nil, err
			}
			if i {
				return model.NewIntValue(1), nil
			}
			return model.NewIntValue(0), nil
		default:
			return nil, fmt.Errorf("cannot convert %s to int", args[0].Type())
		}
	},
	ValidateArgsExactly(1),
)

var FuncToLower = NewFunc(
	"toLower",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var err error
		if len(args) == 1 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("toLower expects a string argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("toLower expects data to be a string: %w", err)
			}
		}
		return model.NewStringValue(strings.ToLower(input)), nil
	},
	ValidateArgsMax(1),
)

var FuncToString = NewFunc(
	"toString",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		switch args[0].Type() {
		case model.TypeString:
			stringValue, err := args[0].StringValue()
			if err != nil {
				return nil, err
			}
			model.NewStringValue(stringValue)
			return args[0], nil
		case model.TypeInt:
			i, err := args[0].IntValue()
			if err != nil {
				return nil, err
			}
			return model.NewStringValue(fmt.Sprintf("%d", i)), nil
		case model.TypeFloat:
			i, err := args[0].FloatValue()
			if err != nil {
				return nil, err
			}
			return model.NewStringValue(fmt.Sprintf("%g", i)), nil
		case model.TypeBool:
			i, err := args[0].BoolValue()
			if err != nil {
				return nil, err
			}
			return model.NewStringValue(fmt.Sprintf("%v", i)), nil
		default:
			return nil, fmt.Errorf("cannot convert %s to string", args[0].Type())
		}
	},
	ValidateArgsExactly(1),
)

var FuncToUpper = NewFunc(
	"toUpper",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var err error
		if len(args) == 1 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("toUpper expects a string argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("toUpper expects data to be a string: %w", err)
			}
		}
		return model.NewStringValue(strings.ToUpper(input)), nil
	},
	ValidateArgsMax(1),
)

var FuncTrim = NewFunc(
	"trim",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var err error
		if len(args) == 1 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trim expects a string argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("trim expects data to be a string: %w", err)
			}
		}
		return model.NewStringValue(strings.TrimSpace(input)), nil
	},
	ValidateArgsMax(1),
)

var FuncTrimPrefix = NewFunc(
	"trimPrefix",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var prefix string
		var err error

		if len(args) == 2 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimPrefix expects a string as the first argument: %w", err)
			}
			prefix, err = args[1].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimPrefix expects a string prefix as the second argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimPrefix expects data to be a string: %w", err)
			}
			prefix, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimPrefix expects a string prefix as the first argument: %w", err)
			}
		}

		return model.NewStringValue(strings.TrimPrefix(input, prefix)), nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncTrimSuffix = NewFunc(
	"trimSuffix",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input string
		var suffix string
		var err error

		if len(args) == 2 {
			input, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimSuffix expects a string as the first argument: %w", err)
			}
			suffix, err = args[1].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimSuffix expects a string suffix as the second argument: %w", err)
			}
		} else {
			input, err = data.StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimSuffix expects data to be a string: %w", err)
			}
			suffix, err = args[0].StringValue()
			if err != nil {
				return nil, fmt.Errorf("trimSuffix expects a string suffix as the first argument: %w", err)
			}
		}

		return model.NewStringValue(strings.TrimSuffix(input, suffix)), nil
	},
	ValidateArgsMinMax(1, 2),
)

var FuncTypeOf = NewFunc(
	"typeOf",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		return model.NewStringValue(args[0].Type().String()), nil
	},
	ValidateArgsExactly(1),
)

var FuncUnique = NewFunc(
	"unique",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		var input *model.Value
		if len(args) == 1 {
			input = args[0]
		} else {
			input = data
		}

		if !input.IsSlice() {
			return nil, fmt.Errorf("unique expects an array, got %s", input.Type().String())
		}

		res := model.NewSliceValue()
		if err := input.RangeSlice(func(i int, value *model.Value) error {
			duplicate := false
			_ = res.RangeSlice(func(j int, existing *model.Value) error {
				equal, err := value.EqualTypeValue(existing)
				if err != nil {
					return nil
				}
				if equal {
					duplicate = true
				}
				return nil
			})
			if !duplicate {
				return res.Append(value)
			}
			return nil
		}); err != nil {
			return nil, err
		}

		return res, nil
	},
	ValidateArgsMax(1),
)

var FuncValues = NewFunc(
	"values",
	func(ctx context.Context, data *model.Value, args model.Values) (*model.Value, error) {
		if !data.IsMap() {
			return nil, fmt.Errorf("values can only be used on maps, got %s", data.Type().String())
		}

		res := model.NewSliceValue()
		if err := data.RangeMap(func(key string, value *model.Value) error {
			return res.Append(value)
		}); err != nil {
			return nil, err
		}

		return res, nil
	},
	ValidateArgsExactly(0),
)