package cluster

import (
	"io/fs"

	"darvaza.org/resolver"
	"darvaza.org/slog"
	"github.com/gofrs/uuid/v5"
)

var (
	_ MachineIterator = (*Zone)(nil)
	_ MachineIterator = (*Zones)(nil)
	_ ZoneIterator    = (*Zones)(nil)
)

// A ZoneIterator is a set of Zones we can iterate on
type ZoneIterator interface {
	ForEachZone(func(*Zone) bool)
}

// Zone represents one zone in a cluster
type Zone struct {
	zones  *Zones
	logger `json:"-" yaml:"-"`

	ID   int
	Name string

	Machines
}

func (z *Zone) String() string {
	return z.Name
}

// SetGateway configures a machine to be the zone's ring0 gateway
func (z *Zone) SetGateway(gatewayID int, enabled bool) error {
	var err error
	var found bool

	z.ForEachMachine(func(p *Machine) bool {
		if p.ID == gatewayID {
			found = true
			err = p.SetGateway(enabled)

			return true
		}
		return false
	})

	switch {
	case err != nil:
		return err
	case !found:
		return fs.ErrNotExist
	default:
		return nil
	}
}

// GatewayIDs returns the list of IDs of machines that act as ring0 gateways
func (z *Zone) GatewayIDs() ([]int, int) {
	var out []int
	z.ForEachMachine(func(p *Machine) bool {
		if p.IsGateway() {
			out = append(out, p.ID)
		}
		return false
	})

	return out, len(out)
}

// revive:disable:line-length-limit

// Zones represents all zones in a cluster
type Zones struct {
	dir      fs.FS
	log      slog.Logger
	resolver resolver.Resolver
	domain   string

	CephFSID uuid.UUID `json:"ceph_fsid,omitempty" yaml:"ceph_fsid,omitempty"`
	Zones    []*Zone
}

// revive:enable:line-length-limit

// ForEachMachine calls a function for each Machine in the cluster
// until instructed to terminate the loop
func (m *Zones) ForEachMachine(fn func(*Machine) bool) {
	m.ForEachZone(func(z *Zone) bool {
		var term bool

		z.ForEachMachine(func(p *Machine) bool {
			term = fn(p)
			return term
		})

		return term
	})
}

// ForEachZone calls a function for each Zone in the cluster
// until instructed to terminate the loop
func (m *Zones) ForEachZone(fn func(*Zone) bool) {
	for _, p := range m.Zones {
		if fn(p) {
			// terminate
			return
		}
	}
}

// GetMachineByName looks for a machine with the specified
// name on any zone
func (m *Zones) GetMachineByName(name string) (*Machine, bool) {
	var out *Machine

	if name != "" {
		m.ForEachMachine(func(p *Machine) bool {
			if p.Name == name {
				out = p
			}

			return out != nil
		})
	}

	return out, out != nil
}