package mysql

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"

	"hyapp/pkg/appcode"
	"hyapp/pkg/xerr"
)

type transactionRow struct {
	TransactionID string
	MetadataJSON  string
}

func (r *Repository) lookupTransaction(ctx context.Context, tx *sql.Tx, commandID string, requestHash string, bizType string) (transactionRow, bool, error) {
	return r.lookupTransactionWithConflictCode(ctx, tx, commandID, requestHash, bizType, xerr.LedgerConflict)
}

func (r *Repository) lookupTransactionWithConflictCode(ctx context.Context, tx *sql.Tx, commandID string, requestHash string, bizType string, conflictCode xerr.Code) (transactionRow, bool, error) {
	row := tx.QueryRowContext(ctx,
		`SELECT transaction_id, request_hash, biz_type, COALESCE(CAST(metadata_json AS CHAR), '{}')
		 FROM wallet_transactions
		 WHERE app_code = ? AND command_id = ?
		 FOR UPDATE`,
		appcode.FromContext(ctx),
		commandID,
	)

	var txRow transactionRow
	var storedHash string
	var storedBizType string
	if err := row.Scan(&txRow.TransactionID, &storedHash, &storedBizType, &txRow.MetadataJSON); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return transactionRow{}, false, nil
		}
		return transactionRow{}, false, err
	}
	if storedHash != requestHash || storedBizType != bizType {

		return transactionRow{}, true, xerr.New(conflictCode, "wallet command idempotency conflict")
	}
	return txRow, true, nil
}

func (r *Repository) insertTransaction(ctx context.Context, tx *sql.Tx, transactionID string, commandID string, bizType string, requestHash string, externalRef string, metadata any, nowMs int64) error {
	metadataJSON, err := json.Marshal(metadata)
	if err != nil {
		return err
	}
	_, err = tx.ExecContext(ctx,
		`INSERT INTO wallet_transactions (
		   app_code, transaction_id, command_id, biz_type, status, request_hash, external_ref, metadata_json, created_at_ms, updated_at_ms
		 ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
		appcode.FromContext(ctx),
		transactionID,
		commandID,
		bizType,
		transactionStatusSucceeded,
		requestHash,
		externalRef,
		string(metadataJSON),
		nowMs,
		nowMs,
	)
	return err
}