package main

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"slices"
	"strings"

	_ "modernc.org/sqlite"
)

func main() {
	db, err := sql.Open("sqlite", os.Args[1])
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	tables, err := Tables(db)
	if err != nil {
		log.Fatal(err)
	}
	if len(os.Args) > 2 {
		tables = slices.DeleteFunc(tables, func(s string) bool { return !slices.Contains(os.Args[2:], s) })
	}

	for i, table := range tables {
		if err := func() error {
			rows, err := db.Query(fmt.Sprintf(`SELECT * FROM %q`, table))
			if err != nil {
				return err
			}
			defer rows.Close()

			columns, err := rows.Columns()
			if err != nil {
				return err
			}

			if i > 0 {
				fmt.Println("")
			}
			fmt.Println("---", table)
			fmt.Println(strings.Join(func() []string {
				quoted := []string{}
				for _, col := range columns {
					quoted = append(quoted, fmt.Sprintf("%q", col))
				}
				return quoted
			}(), ","))

			row := make([]any, len(columns))
			for rows.Next() {
				for i := range row {
					var a any
					row[i] = &a
				}
				if err := rows.Scan(row...); err != nil {
					return err
				}
				jsons := []string{}
				for i := range row {
					row[i] = *(row[i].(*any))
					if b, ok := row[i].([]byte); ok {
						row[i] = string(b)
					}
					b, _ := json.Marshal(row[i])
					jsons = append(jsons, string(b))
				}
				fmt.Println(strings.Join(jsons, ","))
			}

			return rows.Err()
		}(); err != nil {
			log.Fatalf("%s: %v", table, err)
		}
	}
}

func Tables(db *sql.DB) ([]string, error) {
	return Select[string](db, `SELECT name FROM sqlite_schema WHERE type = 'table' AND name NOT LIKE 'sqlite_%'`)
}

func Select[T any](db *sql.DB, q string, args ...any) ([]T, error) {
	rows, err := db.Query(q, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	results := []T{}
	for rows.Next() {
		var some T
		if err := rows.Scan(&some); err != nil {
			return nil, err
		}
		results = append(results, some)
	}

	return results, rows.Err()
}