/*
 *  Copyright (c) 2026 Kaiy Ragur
 *
 *  This Source Code Form is subject to the terms of the Mozilla Public
 *  License, v. 2.0. If a copy of the MPL was not distributed with this
 *  file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
package local

import (
	"bytes"
	"io"
	"log"
	"os"

	"github.com/neilalexander/yggmail/internal/storage"
	"github.com/neilalexander/yggmail/internal/storage/types"
)

type LocalStorage struct {
	storage.Storage
	db        storage.MailStore
	blobs     storage.BlobStore
	threshold int64
	log       log.Logger
}

func NewLocalStorage(store storage.MailStore, blobs storage.BlobStore, threshold int64) storage.Storage {
	if threshold <= 0 {
		threshold = 65536 // Default 64KB
	}
	return &LocalStorage{
		Storage:   store,
		db:        store,
		blobs:     blobs,
		threshold: threshold,
		log:       *log.New(os.Stdout, "DB :: ", 0555),
	}
}

type body struct {
	io.ReadCloser
	io.Seeker
}

func (l *LocalStorage) MailSelect(pk string, mailbox string, id int) (int, *types.Mail, error) {
	seq, mail, err := l.db.MailSelect(pk, mailbox, id)
	if err != nil {
		return 0, nil, err
	}

	if mail.MailFile != "" {
		l.log.Println("Message Blob large take from ", mail.MailFile)
		rc, err := l.blobs.ReadMail(mail.MailFile)
		if err != nil {
			return 0, nil, err
		}
		mail.Body = rc
	} else {
		l.log.Println("Message Blob less take from DB")
		br := bytes.NewReader(mail.RawData)
		mail.Body = body{io.NopCloser(br), br}
	}
	return seq, mail, nil
}

func (l *LocalStorage) MailCreate(pk string, mailbox string, r io.Reader, size int) (int, error) {
	if int64(size) > l.threshold {
		location, written, err := l.blobs.StoreMail(pk, mailbox, r)
		if err != nil {
			return 0, err
		}
		l.log.Println("Message Blob large save in ", location)
		return l.db.MailCreateRaw(pk, mailbox, nil, location, written)
	}
	l.log.Println("Message Blob less save in DB")
	return l.db.MailCreateRaw(pk, mailbox, r, "", int64(size))
}

func (l *LocalStorage) MailMove(pk string, mailbox string, id int, destination string) (int, error) {
	_, mail, err := l.MailSelect(pk, mailbox, id)
	if err != nil {
		return 0, err
	}

	id, err = l.db.MailMove(pk, mailbox, id, destination)
	if err != nil {
		return 0, err
	}

	if mail.MailFile != "" {
		_, err := l.blobs.MoveMail(mail.MailFile, destination)
		if err != nil {
			return 0, err
		}
	}
	return id, nil
}

func (s *LocalStorage) MailDelete(pk string, mailbox string, id int) error {
	log.Println("Delete: ", pk, mailbox, id)
	_, mail, err := s.Storage.MailSelect(pk, mailbox, id)
	if err == nil && mail.MailFile != "" {
		_ = s.blobs.DeleteMail(mail.MailFile)
	}
	return s.Storage.MailDelete(pk, mailbox, id)
}