package models

import (
	"bytes"
	"crypto/sha256"
	"encoding/gob"
	"fmt"
	"time"

	"git.capotej.com/capotej/communique/config"
	"github.com/dgraph-io/badger/v3"
	"github.com/segmentio/ksuid"
)

type OutboxItem struct {
	Handler   config.Handler
	Content   []byte
	Id        []byte
	Sha256    string
	CreatedAt time.Time
}

// used for lookup purposes (count, collect, find)
func NewOutboxItem(h config.Handler) *OutboxItem {
	aso := &OutboxItem{Handler: h}
	return aso
}

func CreateOutboxItem(h config.Handler, content []byte) *OutboxItem {
	t := time.Now()
	hash := sha256.New()
	hash.Write(content)
	binHash := hash.Sum(nil)
	k, _ := ksuid.NewRandomWithTime(t)
	aso := &OutboxItem{
		Handler:   h,
		CreatedAt: t,
		Content:   content,
		Sha256:    fmt.Sprintf("%x", binHash),
		Id:        []byte(k.String()), // NOTE: we want the bytes of the string representation of a hash, NOT a binary hash
	}
	return aso
}

func (a *OutboxItem) Name() string {
	return "OutboxItem"
}

func (a *OutboxItem) Key() string {
	return fmt.Sprintf("%s:%s", a.Keybase(), a.Id)
}

func (a *OutboxItem) DedupKey() string {
	return fmt.Sprintf("dd:%s:sha256:%s", a.Keybase(), a.Sha256)
}

func (a *OutboxItem) Keybase() string {
	keyBase := fmt.Sprintf("outboxes:%s", a.Handler.Name)
	return keyBase
}

func (a *OutboxItem) SaveDedup(txn *badger.Txn) error {
	if len(a.Content) == 0 {
		return fmt.Errorf("content not set")
	}
	if len(a.Sha256) == 0 {
		return fmt.Errorf("sha256 not set")
	}
	e := badger.NewEntry([]byte(a.DedupKey()), nil).WithTTL(a.Handler.DedupWindow)
	return txn.SetEntry(e)
}

func (a *OutboxItem) Save(txn *badger.Txn) error {
	if len(a.Content) == 0 {
		return fmt.Errorf("content not set")
	}
	if len(a.Id) == 0 {
		return fmt.Errorf("id not set")
	}
	if len(a.Sha256) == 0 {
		return fmt.Errorf("sha256 not set")
	}

	var network bytes.Buffer
	enc := gob.NewEncoder(&network)
	err := enc.Encode(a)
	if err != nil {
		return fmt.Errorf("could not encode outbox item: %w", err)
	}
	e := badger.NewEntry([]byte(a.Key()), network.Bytes())
	return txn.SetEntry(e)
}