type CELMatcher struct {
	CompilationResults []CompilationResult

	// These track if any expressions use fieldSelector and labelSelector,
	// so construction of data passed to the CEL expression can be optimized if those fields are unused.
	UsesLabelSelector bool
	UsesFieldSelector bool

	// These are optional fields which can be populated if metrics reporting is desired
	Metrics        MatcherMetrics
	AuthorizerType string
	AuthorizerName string
}

type CompilationResult struct {
	Program            cel.Program
	ExpressionAccessor ExpressionAccessor

	// These track if a given expression uses fieldSelector and labelSelector,
	// so construction of data passed to the CEL expression can be optimized if those fields are unused.
	UsesFieldSelector bool
	UsesLabelSelector bool
}

type Compiler interface {
	CompileCELExpression(expressionAccessor ExpressionAccessor) (CompilationResult, error)
}

type EvaluationResult struct {
	EvalResult         ref.Val
	ExpressionAccessor ExpressionAccessor
}

type ExpressionAccessor interface {
	GetExpression() string
	ReturnTypes() []*celgo.Type
}

type MatcherMetrics interface {
	// RecordAuthorizationMatchConditionEvaluation records the total time taken to evaluate matchConditions for an Authorize() call to the given authorizer
	RecordAuthorizationMatchConditionEvaluation(ctx context.Context, authorizerType, authorizerName string, elapsed time.Duration)
	// RecordAuthorizationMatchConditionEvaluationFailure increments if any evaluation error was encountered evaluating matchConditions for an Authorize() call to the given authorizer
	RecordAuthorizationMatchConditionEvaluationFailure(ctx context.Context, authorizerType, authorizerName string)
	// RecordAuthorizationMatchConditionExclusion records increments when at least one matchCondition evaluates to false and excludes an Authorize() call to the given authorizer
	RecordAuthorizationMatchConditionExclusion(ctx context.Context, authorizerType, authorizerName string)
}

type NoopMatcherMetrics struct{}

type SubjectAccessReviewMatchCondition struct {
	Expression string
}