package rules

import (
	"github.com/vektah/gqlparser/v2/ast"
	//nolint:staticcheck // Validator rules each use dot imports for convenience.
	. "github.com/vektah/gqlparser/v2/validator/core"
)

var UniqueDirectivesPerLocationRule = Rule{
	Name: "UniqueDirectivesPerLocation",
	RuleFunc: func(observers *Events, addError AddErrFunc) {
		observers.OnDirectiveList(func(walker *Walker, directives []*ast.Directive) {
			seen := map[string]bool{}

			for _, dir := range directives {
				if dir.Name != "repeatable" && seen[dir.Name] {
					addError(
						Message(
							`The directive "@%s" can only be used once at this location.`,
							dir.Name,
						),
						At(dir.Position),
					)
				}
				seen[dir.Name] = true
			}
		})
	},
}
