package main

import (
	"database/sql"
	"fmt"
	"log"
	"strconv"
	"strings"

	_ "github.com/mattn/go-sqlite3"
)

var (
	db *sql.DB
)

func init() {
	var err error
	db, err = sql.Open("sqlite3", "sn-rss2tg.sqlite3")
	if err != nil {
		log.Fatal(err)
	}
	migrate(db)
}

func migrate(db *sql.DB) {
	_, err := db.Exec(`
		CREATE TABLE IF NOT EXISTS items (
			id INTEGER PRIMARY KEY,
			title TEXT NOT NULL,
			link TEXT NOT NULL,
			pub_date TIMESTAMP WITH TIME ZONE NOT NULL
		)
	`)
	if err != nil {
		err = fmt.Errorf("error during migration: %w", err)
		log.Fatal(err)
	}
}

func extractIdFromItem(item Item) int {
	parts := strings.Split(item.Guid, "/")
	id, err := strconv.Atoi(parts[len(parts)-1])
	if err != nil {
		err = fmt.Errorf("error during item id extraction: %w", err)
		log.Fatal(err)
	}
	return id
}

func ItemExists(item Item) bool {
	id := extractIdFromItem(item)
	var count int
	err := db.QueryRow(`SELECT COUNT(1) FROM items WHERE id = ?`, id).Scan(&count)
	if err != nil {
		err = fmt.Errorf("error during item check: %w", err)
		log.Fatal(err)
	}
	return count > 0
}

func SaveItem(item Item) {
	id := extractIdFromItem(item)
	_, err := db.Exec(`INSERT INTO items(id, title, link, pub_date) VALUES (?, ?, ?, ?)`, id, item.Title, item.Link, item.PubDate.Time)
	if err != nil {
		err = fmt.Errorf("error during item insert: %w", err)
		log.Fatal(err)
	}
}