package db

import (
	"context"
	"database/sql"
	"fmt"
	"log/slog"
	"regexp"
	"strings"
	"vctp/db/queries"

	_ "github.com/jackc/pgx/v5/stdlib"
	"github.com/jmoiron/sqlx"
)

type PostgresDB struct {
	logger  *slog.Logger
	db      *sqlx.DB
	queries *queries.Queries
}

var _ Database = (*PostgresDB)(nil)

func (d *PostgresDB) DB() *sqlx.DB {
	return d.db
}

func (d *PostgresDB) Queries() Querier {
	return d.queries
}

func (d *PostgresDB) Logger() *slog.Logger {
	return d.logger
}

func (d *PostgresDB) Close() error {
	return d.db.Close()
}

func newPostgresDB(logger *slog.Logger, dsn string) (*PostgresDB, error) {
	if strings.TrimSpace(dsn) == "" {
		return nil, fmt.Errorf("postgres DSN is required")
	}
	db, err := sqlx.Open("pgx", dsn)
	if err != nil {
		return nil, err
	}
	db.SetMaxOpenConns(10)

	rebindDB := rebindDBTX{db: db}
	return &PostgresDB{logger: logger, db: db, queries: queries.New(rebindDB)}, nil
}

type rebindDBTX struct {
	db *sqlx.DB
}

func (r rebindDBTX) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
	return r.db.ExecContext(ctx, rebindQuery(query), args...)
}

func (r rebindDBTX) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
	return r.db.PrepareContext(ctx, rebindQuery(query))
}

func (r rebindDBTX) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
	return r.db.QueryContext(ctx, rebindQuery(query), args...)
}

func (r rebindDBTX) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
	return r.db.QueryRowContext(ctx, rebindQuery(query), args...)
}

var numberedPlaceholderRe = regexp.MustCompile(`\?\d+`)

func rebindQuery(query string) string {
	unindexed := numberedPlaceholderRe.ReplaceAllString(query, "?")
	return sqlx.Rebind(sqlx.DOLLAR, unindexed)
}