package server

import (
	"fmt"
	"os"

	log "git.wntrmute.dev/kyle/goutils/log"
	"git.wntrmute.dev/kyle/kdhcp/iptools"
	"gopkg.in/yaml.v2"
)

type LeaseState struct {
	Pools  map[string]*iptools.Pool      `yaml:"pools"`
	Static map[string]*iptools.LeaseInfo `yaml:"static"`
}

func (srv *Server) SaveLeases() error {
	leaseFile, err := os.Create(srv.Config.LeaseFile)
	if err != nil {
		return fmt.Errorf("server: while saving leases: %w", err)
	}
	defer leaseFile.Close()
	encoder := yaml.NewEncoder(leaseFile)

	state := &LeaseState{
		Pools:  srv.Pools,
		Static: srv.Static,
	}

	if err = encoder.Encode(state); err != nil {
		return fmt.Errorf("server: while saving leases: %w", err)
	}

	if err = encoder.Close(); err != nil {
		return fmt.Errorf("server: while saving leases: %w", err)
	}

	return nil
}

func (srv *Server) LoadLeases() error {
	leaseState := &LeaseState{}
	leaseFile, err := os.Open(srv.Config.LeaseFile)
	if err != nil {
		if os.IsNotExist(err) {
			log.Warningf("server: not loading leases from %s: lease file not found", srv.Config.LeaseFile)
			return nil
		}

		return fmt.Errorf("server: while reading leases: %w", err)
	}
	defer leaseFile.Close()
	decoder := yaml.NewDecoder(leaseFile)

	if err = decoder.Decode(leaseState); err != nil {
		return fmt.Errorf("server: while reading leases: %w", err)
	}

	srv.Pools = leaseState.Pools
	srv.Static = leaseState.Static
	return nil
}