package opts

import (
	"encoding/csv"
	"fmt"
	"strconv"
	"strings"

	"github.com/docker/docker/api/types/swarm"
)

const (
	portOptTargetPort    = "target"
	portOptPublishedPort = "published"
	portOptProtocol      = "protocol"
	portOptMode          = "mode"
)

// PortOpt represents a port config in swarm mode.
type PortOpt struct {
	ports []swarm.PortConfig
}

// Set a new port value
func (p *PortOpt) Set(value string) error {
	csvReader := csv.NewReader(strings.NewReader(value))
	fields, err := csvReader.Read()
	if err != nil {
		return err
	}

	pConfig := swarm.PortConfig{}
	for _, field := range fields {
		parts := strings.SplitN(field, "=", 2)
		if len(parts) != 2 {
			return fmt.Errorf("invalid field %s", field)
		}

		key := strings.ToLower(parts[0])
		value := strings.ToLower(parts[1])

		switch key {
		case portOptProtocol:
			if value != string(swarm.PortConfigProtocolTCP) && value != string(swarm.PortConfigProtocolUDP) {
				return fmt.Errorf("invalid protocol value %s", value)
			}

			pConfig.Protocol = swarm.PortConfigProtocol(value)
		case portOptMode:
			if value != string(swarm.PortConfigPublishModeIngress) && value != string(swarm.PortConfigPublishModeHost) {
				return fmt.Errorf("invalid publish mode value %s", value)
			}

			pConfig.PublishMode = swarm.PortConfigPublishMode(value)
		case portOptTargetPort:
			tPort, err := strconv.ParseUint(value, 10, 16)
			if err != nil {
				return err
			}

			pConfig.TargetPort = uint32(tPort)
		case portOptPublishedPort:
			pPort, err := strconv.ParseUint(value, 10, 16)
			if err != nil {
				return err
			}

			pConfig.PublishedPort = uint32(pPort)
		default:
			return fmt.Errorf("invalid field key %s", key)
		}
	}

	if pConfig.TargetPort == 0 {
		return fmt.Errorf("missing mandatory field %q", portOptTargetPort)
	}

	p.ports = append(p.ports, pConfig)
	return nil
}

// Type returns the type of this option
func (p *PortOpt) Type() string {
	return "port"
}

// String returns a string repr of this option
func (p *PortOpt) String() string {
	ports := []string{}
	for _, port := range p.ports {
		repr := fmt.Sprintf("%v:%v/%s/%s", port.PublishedPort, port.TargetPort, port.Protocol, port.PublishMode)
		ports = append(ports, repr)
	}
	return strings.Join(ports, ", ")
}

// Value returns the ports
func (p *PortOpt) Value() []swarm.PortConfig {
	return p.ports
}