// Command wallet-migrate moves customer_points and customer_tokens balances into the
// EnakPoint & EnakCoin wallet (docs/prd-point-coin.md §10). Safe to run more than once:
// each run credits only what earlier runs have not.
//
//	ENV_MODE=staging go run ./cmd/wallet-migrate -dry-run
//	ENV_MODE=staging go run ./cmd/wallet-migrate
//
// It exits non-zero when the legacy totals and the migrated totals disagree.
package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"os"

	"apskel-pos-be/config"
	"apskel-pos-be/internal/db"
	"apskel-pos-be/internal/processor"
	"apskel-pos-be/internal/repository"
)

func main() {
	dryRun := flag.Bool("dry-run", false, "report what would be credited without writing anything")
	batchSize := flag.Int("batch", 500, "customers read per batch")
	flag.Parse()

	cfg := config.LoadConfig()
	pg, err := db.NewPostgres(cfg.Database)
	if err != nil {
		log.Fatal(err)
	}

	migrator := processor.NewWalletMigrationProcessor(
		repository.NewWalletMigrationRepository(pg),
		processor.NewWalletProcessor(repository.NewWalletRepository(pg)),
		repository.NewTxManager(pg),
	)
	report, err := migrator.Run(context.Background(), *dryRun, *batchSize)
	if err != nil {
		log.Fatalf("wallet migration failed: %v", err)
	}

	verb := "credited"
	if report.DryRun {
		verb = "would credit"
	}
	t := report.Totals
	fmt.Printf("customers scanned: %d\n", report.CustomersScanned)
	fmt.Printf("EnakPoint: %s %d in %d rows\n", verb, report.PointsCredited, report.PointCredits)
	fmt.Printf("EnakCoin:  %s %d in %d rows\n", verb, report.CoinsCredited, report.CoinCredits)
	fmt.Printf("\n%-10s %15s %15s %15s\n", "", "legacy", "migrated", "wallet balance")
	fmt.Printf("%-10s %15d %15d %15d\n", "EnakPoint", t.LegacyPoints, t.MigratedPoints, t.WalletPoints)
	fmt.Printf("%-10s %15d %15d %15d\n", "EnakCoin", t.LegacyCoins, t.MigratedCoins, t.WalletCoins)

	if len(report.Discrepancies) > 0 {
		fmt.Printf("\n%d balances shrank in the legacy tables after they were migrated.\n", len(report.Discrepancies))
		fmt.Println("They were left as they are in the wallet; correct them with an adjustment if needed:")
		for _, d := range report.Discrepancies {
			fmt.Printf("  customer %s %s: legacy %d, migrated %d\n", d.CustomerID, d.Currency, d.Legacy, d.Migrated)
		}
	}

	if report.DryRun {
		return
	}
	if !report.Balanced() {
		fmt.Println("\nNOT BALANCED: legacy and migrated totals differ")
		os.Exit(1)
	}
	fmt.Println("\nbalanced: legacy totals = migrated totals")
}