adrianolaselva / csvql

import (

	"adrianolaselva.github.io/csvql/pkg/storage"

	"database/sql"

	"fmt"

	"strings"

)

const (

	sqlCreateTableTemplate = "CREATE TABLE rows (%s\n);"

	sqlInsertTemplate      = "INSERT INTO %s (%s) VALUES (%s);"

	defaultTableName       = "rows"

	dataSourceNameDefault  = ":memory:"

)

type sqLiteStorage struct {

	db        *sql.DB

	tableName string

	columns   []string

}

func NewSqLiteStorage(datasource string) (storage.Storage, error) {

	if datasource == "" {

		datasource = dataSourceNameDefault

	}

	db, err := sql.Open("sqlite3", datasource)

	if err != nil {

		return nil, err

	}

	return &sqLiteStorage{db: db, tableName: defaultTableName}, nil

}

func (s *sqLiteStorage) SetColumns(columns []string) storage.Storage {

	s.columns = columns

	return s

}

// BuildStructure build table creation statement

func (s *sqLiteStorage) BuildStructure() error {

	var tableAttrsRaw strings.Builder

	for i, v := range s.columns {

		tableAttrsRaw.WriteString(fmt.Sprintf("\n\t%s text", v))

		if len(s.columns)-1 > i {

			tableAttrsRaw.WriteString(",")

		}

	}

	query := fmt.Sprintf(sqlCreateTableTemplate, tableAttrsRaw.String())

	if _, err := s.db.Exec(query); err != nil {

		return fmt.Errorf("failed to create structure: %s (sql: %s)", err, query)

	}

	return nil

}

// InsertRow build insert create statement

func (s *sqLiteStorage) InsertRow(values []any) error {

	columnsRaw := strings.Join(s.columns, ", ")

	paramsRaw := strings.Repeat("?, ", len(s.columns))

	query := fmt.Sprintf(sqlInsertTemplate, s.tableName, columnsRaw, paramsRaw[:len(paramsRaw)-2])

	if _, err := s.db.Exec(query, values...); err != nil {

		return fmt.Errorf("failed to execute insert: %s (sql: %s)", err, query)

	}

	return nil

}

// Query execute statements

func (s *sqLiteStorage) Query(cmd string) (*sql.Rows, error) {

	return s.db.Query(cmd)

}

// Close execute in defer

func (s *sqLiteStorage) Close() error {

	return s.db.Close()

}