package ownership

import (
	"context"
	"errors"
	"time"
)

var (
	ErrInvalidOwnership     = errors.New("invalid proxy ownership request")
	ErrOwnershipUnavailable = errors.New("proxy is unavailable for ownership")
	ErrAlreadyOwned         = errors.New("proxy is already owned")
	ErrStaleAssignment      = errors.New("proxy ownership assignment is stale")
	ErrNotDraining          = errors.New("proxy ownership is not draining")
	ErrDrainNotReady        = errors.New("proxy still has active or reserved runtime")
)

type Assignment struct {
	ProxyID   string
	WorkerID  string
	Epoch     uint64
	Version   uint64
	ExpiresAt time.Time
	Draining  bool
}

// Repository is the shared authority for ownership changes. Implementations
// that also support extraction must serialize both operations transactionally.
type Repository interface {
	Assign(context.Context, time.Time, string, string, time.Duration) (Assignment, error)
	Renew(context.Context, time.Time, string, string, uint64, time.Duration) (Assignment, error)
	BeginDrain(context.Context, string, string, uint64) (Assignment, error)
	AcknowledgeDrain(context.Context, string, string, uint64, int64, int64) error
	Get(context.Context, string) (Assignment, bool, error)
	Expire(context.Context, time.Time, int) ([]Assignment, error)
}