package address

import (
	"errors"
	"fmt"
	"strings"

	"github.com/nspcc-dev/neofs-api-go/v2/refs"
	cid "github.com/nspcc-dev/neofs-sdk-go/container/id"
	oid "github.com/nspcc-dev/neofs-sdk-go/object/id"
)

// Address represents v2-compatible object address.
type Address refs.Address

var errInvalidAddressString = errors.New("incorrect format of the string object address")

const (
	addressParts     = 2
	addressSeparator = "/"
)

// NewAddressFromV2 converts v2 Address message to Address.
//
// Nil refs.Address converts to nil.
func NewAddressFromV2(aV2 *refs.Address) *Address {
	return (*Address)(aV2)
}

// NewAddress creates and initializes blank Address.
//
// Works similar as NewAddressFromV2(new(Address)).
//
// Defaults:
// 	- cid: nil;
//	- oid: nil.
func NewAddress() *Address {
	return NewAddressFromV2(new(refs.Address))
}

// ToV2 converts Address to v2 Address message.
//
// Nil Address converts to nil.
func (a *Address) ToV2() *refs.Address {
	return (*refs.Address)(a)
}

// ContainerID returns container identifier.
func (a *Address) ContainerID() (v cid.ID, isSet bool) {
	v2 := (*refs.Address)(a)

	cidV2 := v2.GetContainerID()
	if cidV2 != nil {
		_ = v.ReadFromV2(*cidV2)
		isSet = true
	}

	return
}

// SetContainerID sets container identifier.
func (a *Address) SetContainerID(id cid.ID) {
	var cidV2 refs.ContainerID
	id.WriteToV2(&cidV2)

	(*refs.Address)(a).SetContainerID(&cidV2)
}

// ObjectID returns object identifier.
func (a *Address) ObjectID() (v oid.ID, isSet bool) {
	v2 := (*refs.Address)(a)

	oidV2 := v2.GetObjectID()
	if oidV2 != nil {
		_ = v.ReadFromV2(*oidV2)
		isSet = true
	}

	return
}

// SetObjectID sets object identifier.
func (a *Address) SetObjectID(id oid.ID) {
	var oidV2 refs.ObjectID
	id.WriteToV2(&oidV2)

	(*refs.Address)(a).SetObjectID(&oidV2)
}

// Parse converts base58 string representation into Address.
func (a *Address) Parse(s string) error {
	var (
		err   error
		oid   oid.ID
		id    cid.ID
		parts = strings.Split(s, addressSeparator)
	)

	if len(parts) != addressParts {
		return errInvalidAddressString
	} else if err = id.DecodeString(parts[0]); err != nil {
		return err
	} else if err = oid.DecodeString(parts[1]); err != nil {
		return err
	}

	a.SetObjectID(oid)
	a.SetContainerID(id)

	return nil
}

// String returns string representation of Object.Address.
func (a *Address) String() string {
	var cidStr, oidStr string

	if cID, set := a.ContainerID(); set {
		cidStr = cID.String()
	}

	if oID, set := a.ObjectID(); set {
		oidStr = oID.String()
	}

	return strings.Join([]string{cidStr, oidStr}, addressSeparator)
}

// Marshal marshals Address into a protobuf binary form.
func (a *Address) Marshal() ([]byte, error) {
	return (*refs.Address)(a).StableMarshal(nil)
}

var errCIDNotSet = errors.New("container ID is not set")
var errOIDNotSet = errors.New("object ID is not set")

// Unmarshal unmarshals protobuf binary representation of Address.
func (a *Address) Unmarshal(data []byte) error {
	err := (*refs.Address)(a).Unmarshal(data)
	if err != nil {
		return err
	}

	v2 := a.ToV2()

	return checkFormat(v2)
}

// MarshalJSON encodes Address to protobuf JSON format.
func (a *Address) MarshalJSON() ([]byte, error) {
	return (*refs.Address)(a).MarshalJSON()
}

// UnmarshalJSON decodes Address from protobuf JSON format.
func (a *Address) UnmarshalJSON(data []byte) error {
	v2 := (*refs.Address)(a)

	err := v2.UnmarshalJSON(data)
	if err != nil {
		return err
	}

	return checkFormat(v2)
}

func checkFormat(v2 *refs.Address) error {
	var (
		cID cid.ID
		oID oid.ID
	)

	cidV2 := v2.GetContainerID()
	if cidV2 == nil {
		return errCIDNotSet
	}

	err := cID.ReadFromV2(*cidV2)
	if err != nil {
		return fmt.Errorf("could not convert V2 container ID: %w", err)
	}

	oidV2 := v2.GetObjectID()
	if oidV2 == nil {
		return errOIDNotSet
	}

	err = oID.ReadFromV2(*oidV2)
	if err != nil {
		return fmt.Errorf("could not convert V2 object ID: %w", err)
	}

	return nil
}