//go:build ignore

package main

import (
	"database/sql"
	"fmt"
	"os"
	"strings"

	_ "github.com/go-sql-driver/mysql"
)

func main() {
	dsn := strings.TrimPrefix(os.Getenv("IM_MYSQL_DSN"), "mysql://")
	query := os.Getenv("IM_SQL_QUERY")
	if dsn == "" || query == "" {
		fatal("IM_MYSQL_DSN and IM_SQL_QUERY are required")
	}
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		fatal(err)
	}
	defer db.Close()
	rows, err := db.Query(query)
	if err != nil {
		fatal(err)
	}
	defer rows.Close()

	cols, err := rows.Columns()
	if err != nil {
		fatal(err)
	}
	fmt.Println(strings.Join(cols, "\t"))
	for rows.Next() {
		values := make([]sql.NullString, len(cols))
		scan := make([]any, len(cols))
		for i := range values {
			scan[i] = &values[i]
		}
		if err := rows.Scan(scan...); err != nil {
			fatal(err)
		}
		out := make([]string, len(cols))
		for i, value := range values {
			if value.Valid {
				out[i] = value.String
			}
		}
		fmt.Println(strings.Join(out, "\t"))
	}
	if err := rows.Err(); err != nil {
		fatal(err)
	}
}

func fatal(v any) {
	fmt.Fprintln(os.Stderr, v)
	os.Exit(1)
}