package flydns

import (
	"fmt"
	"net"
	"net/netip"
	"strings"
)

func combineString(inp []string) string {
	return strings.Join(inp, "")
}

func GetAppAddresses(appName string) ([]netip.Addr, error) {
	addrs, err := net.LookupAddr(fmt.Sprintf("%s.internal", appName))
	if err != nil {
		return nil, err
	}

	var result []netip.Addr

	for _, addr := range addrs {
		ip, err := netip.ParseAddr(addr)
		if err != nil {
			return nil, err
		}

		result = append(result, ip)
	}

	return result, nil
}

func GetIndividualInstanceAddress(instanceID string, appName string) (netip.Addr, error) {
	var ip netip.Addr
	addr, err := net.LookupAddr(fmt.Sprintf("%s.vm.%s.internal", instanceID, appName))
	if err != nil {
		return ip, err
	}

	ip, err = netip.ParseAddr(addr[0])
	if err != nil {
		return ip, err
	}

	return ip, nil
}

func GetAppInstancesInRegion(appName string, region string) ([]netip.Addr, error) {
	instances, err := net.LookupHost(fmt.Sprintf("%s.%s.internal", appName, region))
	if err != nil {
		return nil, err
	}

	var result []netip.Addr

	for _, instance := range instances {
		ip, err := netip.ParseAddr(instance)
		if err != nil {
			return nil, err
		}

		result = append(result, ip)
	}

	return result, nil
}

func GetClosestInstances(appName string, count int) ([]netip.Addr, error) {
	instances, err := net.LookupHost(fmt.Sprintf("top%d.nearest.of.%s.internal", count, appName))
	if err != nil {
		return nil, err
	}

	var result []netip.Addr

	for _, instance := range instances {
		ip, err := netip.ParseAddr(instance)
		if err != nil {
			return nil, err
		}

		result = append(result, ip)
	}

	return result, nil
}

func GetApps() ([]string, error) {
	appString, err := net.LookupTXT("_apps.internal")
	if err != nil {
		return nil, err
	}

	var result []string
	for _, resp := range strings.Split(appString[0], ",") {
		result = append(result, strings.Split(resp, ",")...)
	}

	return result, nil
}

type Machine struct {
	ID     string
	Region string
}

func parseMachine(input string) (Machine, error) {
	var result Machine
	split := strings.Split(input, " ")
	if len(split) != 2 {
		return result, fmt.Errorf("invalid input")
	}

	result.ID = split[0]
	result.Region = split[1]

	return result, nil
}

func GetMachines(appName string) ([]Machine, error) {
	machines, err := net.LookupTXT(fmt.Sprintf("vms.%s.internal", appName))
	if err != nil {
		return nil, err
	}

	var result []Machine
	for _, machine := range strings.Split(combineString(machines), ",") {
		m, err := parseMachine(machine)
		if err != nil {
			return nil, err
		}

		result = append(result, m)
	}

	return result, nil

}

func GetRegions(appName string) ([]string, error) {
	regions, err := net.LookupTXT(fmt.Sprintf("regions.%s.internal", appName))
	if err != nil {
		return nil, err
	}

	return strings.Split(combineString(regions), ","), nil
}