package peerfinder

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net"
	"net/netip"
	"strconv"
	"strings"
	"time"

	"github.com/tj/go-semver"

	"github.com/oklog/ulid/v2"
	"github.com/sour-is/ev/pkg/es/event"
)

type Request struct {
	event.AggregateRoot

	RequestID string    `json:"req_id"`
	RequestIP string    `json:"req_ip"`
	Hidden    bool      `json:"hide,omitempty"`
	Created   time.Time `json:"req_created"`

	Responses []Response `json:"responses"`
}

var _ event.Aggregate = (*Request)(nil)

func (a *Request) ApplyEvent(lis ...event.Event) {
	for _, e := range lis {
		switch e := e.(type) {
		case *RequestSubmitted:
			a.RequestID = e.eventMeta.EventID.String()
			a.RequestIP = e.RequestIP
			a.Hidden = e.Hidden
			a.Created = ulid.Time(e.EventMeta().EventID.Time())
		case *ResultSubmitted:
			a.Responses = append(a.Responses, Response{
				PeerID:        e.PeerID,
				ScriptVersion: e.PeerVersion,
				Latency:       e.Latency,
				Jitter:        e.Jitter,
				MinRTT:        e.MinRTT,
				MaxRTT:        e.MaxRTT,
				Sent:          e.Sent,
				Received:      e.Received,
				Unreachable:   e.Unreachable,
				Created:       ulid.Time(e.EventMeta().EventID.Time()),
			})
		}
	}
}

type Time time.Time

func (t *Time) UnmarshalJSON(b []byte) error {
	time, err := time.Parse(`"2006-01-02 15:04:05"`, string(b))
	*t = Time(time)
	return err
}
func (t *Time) MarshalJSON() ([]byte, error) {
	if t == nil {
		return nil, nil
	}
	i := *t
	return time.Time(i).MarshalJSON()
}

type ipFamily string

const (
	ipFamilyV4   ipFamily = "IPv4"
	ipFamilyV6   ipFamily = "IPv6"
	ipFamilyBoth ipFamily = "both"
	ipFamilyNone ipFamily = "none"
)

func (t *ipFamily) UnmarshalJSON(b []byte) error {
	i, err := strconv.Atoi(strings.Trim(string(b), `"`))
	switch i {
	case 1:
		*t = ipFamilyV4
	case 2:
		*t = ipFamilyV6
	case 3:
		*t = ipFamilyBoth
	default:
		*t = ipFamilyNone
	}
	return err
}

type peerType []string

func (t *peerType) UnmarshalJSON(b []byte) error {
	*t = strings.Split(strings.Trim(string(b), `"`), ",")
	return nil
}

type Peer struct {
	ID      string   `json:"peer_id,omitempty"`
	Owner   string   `json:"peer_owner"`
	Nick    string   `json:"peer_nick"`
	Name    string   `json:"peer_name"`
	Country string   `json:"peer_country"`
	Note    string   `json:"peer_note"`
	Family  ipFamily `json:"peer_family"`
	Type    peerType `json:"peer_type"`
	Created Time     `json:"peer_created"`
}

func (p *Peer) CanSupport(ip string) bool {
	addr := net.ParseIP(ip)
	if addr == nil {
		return false
	}
	if !addr.IsGlobalUnicast() {
		return false
	}

	switch p.Family {
	case ipFamilyV4:
		return addr.To4() != nil
	case ipFamilyV6:
		return addr.To16() != nil
	case ipFamilyNone:
		return false
	}

	return true
}

type Response struct {
	Peer          *Peer  `json:"peer"`
	PeerID        string `json:"-"`
	ScriptVersion string `json:"peer_scriptver"`

	Latency     float64 `json:"res_latency"`
	Jitter      float64 `json:"res_jitter,omitempty"`
	MaxRTT      float64 `json:"res_maxrtt,omitempty"`
	MinRTT      float64 `json:"res_minrtt,omitempty"`
	Sent        int     `json:"res_sent,omitempty"`
	Received    int     `json:"res_recv,omitempty"`
	Unreachable bool    `json:"unreachable,omitempty"`

	Created time.Time `json:"res_created"`
}

type RequestSubmitted struct {
	eventMeta event.Meta

	RequestIP string `json:"req_ip"`
	Hidden    bool   `json:"hide,omitempty"`
}

func (r *RequestSubmitted) StreamID() string {
	return r.EventMeta().GetEventID()
}
func (r *RequestSubmitted) RequestID() string {
	return r.EventMeta().GetEventID()
}
func (r *RequestSubmitted) Created() time.Time {
	return r.EventMeta().Created()
}
func (r *RequestSubmitted) CreatedString() string {
	return r.Created().Format("2006-01-02 15:04:05")
}
func (r *RequestSubmitted) Family() int {
	if r == nil {
		return 0
	}

	ip, err := netip.ParseAddr(r.RequestIP)
	switch {
	case err != nil:
		return 0
	case ip.Is4():
		return 1
	default:
		return 2
	}
}

var _ event.Event = (*RequestSubmitted)(nil)

func (e *RequestSubmitted) EventMeta() event.Meta {
	if e == nil {
		return event.Meta{}
	}
	return e.eventMeta
}
func (e *RequestSubmitted) SetEventMeta(m event.Meta) {
	if e != nil {
		e.eventMeta = m
	}
}
func (e *RequestSubmitted) MarshalBinary() (text []byte, err error) {
	return json.Marshal(e)
}
func (e *RequestSubmitted) UnmarshalBinary(b []byte) error {
	return json.Unmarshal(b, e)
}
func (e *RequestSubmitted) MarshalEnviron() ([]byte, error) {
	if e == nil {
		return nil, nil
	}

	var b bytes.Buffer
	b.WriteString("REQ_ID=")
	b.WriteString(e.RequestID())
	b.WriteRune('\n')

	b.WriteString("REQ_IP=")
	b.WriteString(e.RequestIP)
	b.WriteRune('\n')

	b.WriteString("REQ_FAMILY=")
	if family := e.Family(); family > 0 {
		b.WriteString(strconv.Itoa(family))
	}
	b.WriteRune('\n')

	b.WriteString("REQ_CREATED=")
	b.WriteString(e.CreatedString())
	b.WriteRune('\n')

	return b.Bytes(), nil
}

type ResultSubmitted struct {
	eventMeta event.Meta

	RequestID   string  `json:"req_id"`
	PeerID      string  `json:"peer_id"`
	PeerVersion string  `json:"peer_version"`
	Latency     float64 `json:"latency,omitempty"`
	Jitter      float64 `json:"jitter,omitempty"`
	MaxRTT      float64 `json:"maxrtt,omitempty"`
	MinRTT      float64 `json:"minrtt,omitempty"`
	Sent        int     `json:"res_sent,omitempty"`
	Received    int     `json:"res_recv,omitempty"`
	Unreachable bool    `json:"unreachable,omitempty"`
}

func (r *ResultSubmitted) Created() time.Time {
	return r.eventMeta.Created()
}

var _ event.Event = (*ResultSubmitted)(nil)

func (e *ResultSubmitted) EventMeta() event.Meta {
	if e == nil {
		return event.Meta{}
	}
	return e.eventMeta
}
func (e *ResultSubmitted) SetEventMeta(m event.Meta) {
	if e != nil {
		e.eventMeta = m
	}
}
func (e *ResultSubmitted) MarshalBinary() (text []byte, err error) {
	return json.Marshal(e)
}
func (e *ResultSubmitted) UnmarshalBinary(b []byte) error {
	return json.Unmarshal(b, e)
}
func (e *ResultSubmitted) String() string {
	return fmt.Sprintf("id: %s\npeer: %s\nversion: %s\nlatency: %0.4f", e.RequestID, e.PeerID, e.PeerVersion, e.Latency)
}

type Info struct {
	ScriptVersion string `json:"script_version"`

	event.AggregateRoot
}

var _ event.Aggregate = (*Info)(nil)

func (a *Info) ApplyEvent(lis ...event.Event) {
	for _, e := range lis {
		switch e := e.(type) {
		case *VersionChanged:
			a.ScriptVersion = e.ScriptVersion
		}
	}
}
func (a *Info) MarshalEnviron() ([]byte, error) {
	var b bytes.Buffer

	b.WriteString("SCRIPT_VERSION=")
	b.WriteString(a.ScriptVersion)
	b.WriteRune('\n')

	return b.Bytes(), nil
}
func (a *Info) OnUpsert() error {
	if a.StreamVersion() == 0 {
		event.Raise(a, &VersionChanged{ScriptVersion: initVersion})
	}
	current, _ := semver.Parse(initVersion)
	previous, _ := semver.Parse(a.ScriptVersion)

	if current.Compare(previous) > 0 {
		event.Raise(a, &VersionChanged{ScriptVersion: initVersion})
	}

	return nil
}

type VersionChanged struct {
	ScriptVersion string `json:"script_version"`

	eventMeta event.Meta
}

var _ event.Event = (*VersionChanged)(nil)

func (e *VersionChanged) EventMeta() event.Meta {
	if e == nil {
		return event.Meta{}
	}
	return e.eventMeta
}
func (e *VersionChanged) SetEventMeta(m event.Meta) {
	if e != nil {
		e.eventMeta = m
	}
}
func (e *VersionChanged) MarshalBinary() (text []byte, err error) {
	return json.Marshal(e)
}
func (e *VersionChanged) UnmarshalBinary(b []byte) error {
	return json.Unmarshal(b, e)
}