package iptools

import (
	"net/netip"
	"time"
)

type Pool struct {
	Name      string                   `yaml:"name"`
	Range     *Range                   `yaml:"range"`
	Expiry    time.Duration            `yaml:"expiry"`
	Available []LeaseInfo              `yaml:"available"`
	Active    map[netip.Addr]LeaseInfo `yaml:"active"`
	Limbo     map[netip.Addr]LeaseInfo `yaml:"limbo"` // leases that are currently being offered
}

func NewPool(name string, exp time.Duration, r *Range) (*Pool, error) {
	p := &Pool{
		Name:      name,
		Expiry:    exp,
		Available: enumerateRange(name, r, true),
	}

	return p, nil
}

func (p *Pool) Sort() {
	p.Available = SortLeases(p.Available)
}

func (p *Pool) IsAddressAvailable() bool {
	return len(p.Available) > 0
}

func (p *Pool) Peek(t time.Time, waitFor time.Duration) netip.Addr {
	lease := p.Available[0]
	p.Available = p.Available[1:]
	lease.ResetExpiry(t, waitFor)

	p.Limbo[lease.Addr] = lease

	return lease.Addr
}

// Update checks expirations on leases, moving any expired leases back
// to the available pool and removing any limbo leases that are expired.
func (p *Pool) Update(t time.Time) {
	for k, v := range p.Active {
		if v.IsExpired(t) {
			delete(p.Active, k)
			v = v.Reset()
			p.Available = append(p.Available, v)
		}
	}

	for k, v := range p.Limbo {
		if v.IsExpired(t) {
			delete(p.Limbo, k)
			v = v.Reset()
			p.Available = append(p.Available, v)
		}
	}

	p.Sort()
}

func (p *Pool) Renew(lease LeaseInfo, t time.Time) {

}