package main

import (
	"fmt"
	"os"

	"gemini-grc/gemini"
	_ "github.com/jackc/pgx/v5/stdlib" // PGX driver for PostgreSQL
	"github.com/jmoiron/sqlx"
)

// MANUALLY SET TO TRUE WHEN MIGRATION HAS BEEN APPLIED
func checkIfDone() bool { return true }

func MustSelect(tx *sqlx.Tx, dest interface{}, query string, args ...interface{}) {
	if err := tx.Select(dest, query, args...); err != nil {
		panic(err)
	}
}

// Populates the `host` field
func main() {
	if checkIfDone() {
		fmt.Println("Migration already applied")
		return
	}

	db := connectToDB()
	defer db.Close()

	batchSize := 1000
	for {
		// Start the transaction
		tx := db.MustBegin()
		query := `SELECT * FROM snapshots WHERE url NOT LIKE '%1965%' LIMIT $1`
		var snapshots []gemini.Snapshot
		MustSelect(tx, &snapshots, query, batchSize)
		if len(snapshots) == 0 {
			fmt.Println("No snapshots remaining, done")
			break
		}
		for i, s := range snapshots {
			_, err := gemini.ParseURL(s.URL.String(), "")
			if err != nil {
				panic(fmt.Sprintf("Error parsing URL. ID %d URL %s\n", s.ID, s.URL))
			}
			fmt.Printf("Saving %d %d %s\n", i+1, s.ID, s.URL)
			err = gemini.UpsertSnapshot(0, tx, &s)
			if err != nil {
				panic(fmt.Sprintf("Error saving %s: %s", s.URL, err))
			}
			tx.MustExec(`DELETE FROM snapshots WHERE id=$1`, s.ID)
		}
		err := tx.Commit()
		if err != nil {
			fmt.Println(err)
			err := tx.Rollback()
			if err != nil {
				panic(err)
			}
		}
	}
}

func connectToDB() *sqlx.DB {
	connStr := fmt.Sprintf("postgres://%s:%s@%s:%s/%s",
		os.Getenv("PG_USER"),
		os.Getenv("PG_PASSWORD"),
		os.Getenv("PG_HOST"),
		os.Getenv("PG_PORT"),
		os.Getenv("PG_DATABASE"),
	)

	// Create a connection pool
	db, err := sqlx.Open("pgx", connStr)
	if err != nil {
		panic(fmt.Sprintf("Unable to connect to database with URL %s: %v\n", connStr, err))
	}
	db.SetMaxOpenConns(20)
	err = db.Ping()
	if err != nil {
		panic(fmt.Sprintf("Unable to ping database: %v\n", err))
	}

	fmt.Println("Connected to database")
	return db
}