package main

import (
	"database/sql"
	"fmt"
	"github.com/boramalper/magnetico/pkg/persistence"
	"github.com/cheggaaa/pb/v3"
	_ "github.com/mattn/go-sqlite3"
	"go.uber.org/zap"
	"gopkg.in/alecthomas/kingpin.v2"
	"net/url"
)

var (
	goDatabaseUrl = kingpin.Flag("go-database", "magneticod Go version database URL.").Short('g').String()
	pyDatabaseUrl = kingpin.Flag("py-database", "Python version database URL.").Short('p').Required().String()
)

func main() {
	logger, _ := zap.NewDevelopment()
	defer logger.Sync()
	zap.ReplaceGlobals(logger)

	kingpin.Parse()

	goDatabase, err := persistence.MakeDatabase(*goDatabaseUrl, logger)
	if err != nil {
		logger.Panic("Could not open Go database.", zap.String("url", *goDatabaseUrl), zap.Error(err))
	}
	defer goDatabase.Close()

	oldSqliteUrl, err := url.Parse(*pyDatabaseUrl)
	if err != nil {
		logger.Panic("Can't parse Python database URL.", zap.String("url", *pyDatabaseUrl), zap.Error(err))
	}

	pyDatabase, err := openSqliteDb(*oldSqliteUrl)
	if err != nil {
		logger.Panic("Couldn't open Python database.", zap.String("url", *pyDatabaseUrl), zap.Error(err))
	}
	defer pyDatabase.Close()

	err = process(*pyDatabase, goDatabase)
	if err != nil {
		logger.Error("Error while processing data", zap.Error(err))
	}
}

func process(pyDb sql.DB, goDb persistence.Database) error {
	torrentsTotal, err := getNumberOfTorrents(pyDb)
	if err != nil {
		zap.L().Panic("Couldn't count torrents", zap.Error(err))
	}

	bar := pb.StartNew(int(torrentsTotal))

	// TODO

	return nil
}

func getNumberOfTorrents(db sql.DB) (uint, error) {
	rows, err := db.Query("SELECT COUNT(id) FROM torrents;")
	if err != nil {
		return 0, err
	}
	defer rows.Close()

	if rows.Next() != true {
		return 0, fmt.Errorf("No rows returned from `SELECT COUNT(id)`")
	}

	var n *uint
	if err = rows.Scan(&n); err != nil {
		return 0, err
	}

	// If the database is empty (i.e. 0 entries in 'torrents') then the query will return nil.
	if n == nil {
		return 0, nil
	} else {
		return *n, nil
	}
}

func openSqliteDb(url_ url.URL) (*sql.DB, error) {
	url_.Scheme = ""
	return sql.Open("sqlite3", url_.String())
}