package postgres

import (
	"context"
	"fmt"
	"net/url"
	"strings"

	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/config"
	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/datasource"
	"github.com/jackc/pgx/v5/pgxpool"
)

type Factory struct{}

func (Factory) Driver() string {
	return "postgres"
}

func (Factory) Open(ctx context.Context, cfg config.DatabaseConfig) (datasource.DataSource, error) {
	dsn, err := buildDSN(cfg.Params.URI, cfg.Params.Username, cfg.Params.Password)
	if err != nil {
		return nil, fmt.Errorf("open postgres datasource %q: %w", cfg.Name, err)
	}

	pool, err := pgxpool.New(ctx, dsn)
	if err != nil {
		return nil, fmt.Errorf("open postgres datasource %q: %w", cfg.Name, err)
	}

	if err := pool.Ping(ctx); err != nil {
		pool.Close()
		return nil, fmt.Errorf("open postgres datasource %q: ping: %w", cfg.Name, err)
	}

	return &DataSource{pool: pool}, nil
}

type DataSource struct {
	pool *pgxpool.Pool
}

func (d *DataSource) Pool() *pgxpool.Pool {
	if d == nil {
		return nil
	}
	return d.pool
}

func (d *DataSource) Close() {
	if d == nil || d.pool == nil {
		return
	}
	d.pool.Close()
}

func buildDSN(uri, username, password string) (string, error) {
	u, err := url.Parse(strings.TrimSpace(uri))
	if err != nil {
		return "", fmt.Errorf("invalid params.uri: %w", err)
	}
	if strings.TrimSpace(u.Scheme) == "" {
		return "", fmt.Errorf("invalid params.uri: missing scheme")
	}
	if strings.TrimSpace(u.Host) == "" {
		return "", fmt.Errorf("invalid params.uri: missing host")
	}

	u.User = url.UserPassword(strings.TrimSpace(username), strings.TrimSpace(password))
	return u.String(), nil
}