retention

type Period interface {
	fmt.Stringer

	// Duration is the duration of the retention period
	Duration() time.Duration

	// Equal checks whether to retention periods are equal
	Equal(other Period) bool
}

type PeriodsByDuration []Period

type PoliciesByPeriod []Policy

type Policy interface {
	fmt.Stringer

	// Resolution is the resolution at which the datapoints will be stored
	Resolution() Resolution

	// Period is the amount of time to retain the datapoints
	Period() Period

	// Equal checks whether this retention policy is equal to another
	Equal(other Policy) bool
}

type PolicyResolver interface {
	// ResolveTimeline resolves the retention Policy timeline for a given id
	ResolveTimeline(id string, from, until time.Time) ([]PolicyTimeRange, error)
}

type PolicyResolverOptions interface {
	// Logger is the resolver's logger
	Logger(logger xlog.Logger) PolicyResolverOptions
	GetLogger() xlog.Logger

	// Clock is the resolver's clock
	Clock(c clock.Clock) PolicyResolverOptions
	GetClock() clock.Clock
}

type PolicyTimeRange struct {
	xtime.Range
	Policy
}

type Resolution interface {
	fmt.Stringer

	// WindowSize is the size of the bucket represented by the resolution
	WindowSize() time.Duration

	// Precision defines the precision of datapoints stored at this resolution
	Precision() xtime.Unit

	// AlignToStart aligns the given time to the start of the bucket containing that time
	AlignToStart(t time.Time) time.Time

	// WindowContaining returns the time range containing the given time at the resolution
	WindowContaining(t time.Time) xtime.Range

	// Equal compares this resolution to another
	Equal(other Resolution) bool
}

type Rule interface {
	// Policies are the retention policies at the time of the rule, ordered
	// by retention period (from shorted to longest)
	Policies() []Policy
	SetPolicies(p []Policy) Rule

	// CutoverTime is the time that the rule will begin to be applied
	CutoverTime() time.Time
	SetCutoverTime(t time.Time) Rule

	// CutoffTime is the time that the rule no longer applies
	CutoffTime() time.Time
	SetCutoffTime(t time.Time) Rule
}

type RuleProvider interface {
	// FindRules returns the list of retention rules that apply
	// for the given id over the requested time range
	FindRules(id string, start, end time.Time) ([]Rule, error)
}

type RulesByCutoffTime []Rule