// helpers.go
package expr

import (
	"fmt"
	"strings"
)

func EvalString(ctx exprContext, source string) (result any, err error) {
	var tree *ast

	r := strings.NewReader(source)
	scanner := NewScanner(r, DefaultTranslations())
	parser := NewParser(ctx)

	if tree, err = parser.parse(scanner); err == nil {
		result, err = tree.Eval(ctx)
	}
	return
}

type EvalArg struct {
	name  string
	value any
}

func EvalStringA(source string, args ...EvalArg) (result any, err error) {
	return EvalStringV(source, args)
}

func EvalStringV(source string, args []EvalArg) (result any, err error) {
	ctx := NewSimpleFuncStore()
	for _, arg := range args {
		if isFunc(arg.value) {
			if f, ok := arg.value.(FuncTemplate); ok {
				ctx.RegisterFunc(arg.name, f, 0, -1)
			} else {
				err = fmt.Errorf("invalid function specification: %q", arg.name)
			}
		} else if integer, ok := anyInteger(arg.value); ok {
			ctx.SetValue(arg.name, integer)
		} else if float, ok := anyFloat(arg.value); ok {
			ctx.SetValue(arg.name, float)
		} else if _, ok := arg.value.(string); ok {
			ctx.SetValue(arg.name, arg.value)
		} else if _, ok := arg.value.(bool); ok {
			ctx.SetValue(arg.name, arg.value)
		} else {
			err = fmt.Errorf("unsupported type %T specified for item %q", arg.value, arg.name)
		}
	}

	if err == nil {
		result, err = EvalString(ctx, source)
	}
	return
}