package db

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"ssender/internal/models"

	"github.com/boltdb/bolt"
)

func InitDb(rss models.Rss2, dbpath string) error {
	db, err := openDB(dbpath)
	if err != nil {
		return err
	}
	log.Println("Initialize DB")
	defer db.Close()

	err = db.Update(func(tx *bolt.Tx) error {
		b, err := tx.CreateBucketIfNotExists([]byte("rss"))
		if err != nil {
			return err
		}
		for _, v := range rss.ItemList {
			encoded, err := json.Marshal(v)
			if err != nil {
				return err
			}
			err = b.Put([]byte(v.Link), encoded)
			if err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		return err
	}
	return nil
}

func FindItems(rss models.Rss2, dbpath string) (*models.SendItems, error) {
	var sendItems models.SendItems
	
	// Check if DB file exists
	if _, err := os.Stat(dbpath); os.IsNotExist(err) {
		return nil, fmt.Errorf("database file does not exist: %s", dbpath)
	}
	
	// Open database
	db, err := openDB(dbpath)
	if err != nil {
		return nil, err
	}
	defer db.Close()

	log.Println("Finding new items in DB")
	
	err = db.View(func(tx *bolt.Tx) error {
		b := tx.Bucket([]byte("rss"))
		if b == nil {
			return fmt.Errorf("bucket 'rss' not found in database")
		}
		for _, v := range rss.ItemList {
			if b.Get([]byte(v.Link)) != nil {
				sendItems.ItemList = append(sendItems.ItemList, v)
			}
		}
		return nil
	})
	if err != nil {
		return nil, err
	}
	
	log.Printf("Found %d new items", len(sendItems.ItemList))
	
	return &sendItems, nil
}

func UpdateDb(dbpath string, senditems *models.SendItems) error {
	db, err := openDB(dbpath)
	if err != nil {
		return err
	}
	log.Println("Update DB")
	defer db.Close()

	err = db.Update(func(tx *bolt.Tx) error {
		b := tx.Bucket([]byte("rss"))
		for _, v := range senditems.ItemList {
			encoded, err := json.Marshal(v)
			if err != nil {
				return err
			}
			err = b.Put([]byte(v.Link), encoded)
			if err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		return err
	}
	return nil
}

func openDB(dbpath string) (*bolt.DB, error) {
	return bolt.Open(dbpath, 0600, nil)
}