turash/bugulma/backend/internal/geospatial/postgis_integration.go

package geospatial

import (
	"fmt"
)

// PostGISIntegrationImpl implements PostGISIntegration interface
type PostGISIntegrationImpl struct {
	config *Config
}

// NewPostGISIntegration creates a new PostGIS integration helper
func NewPostGISIntegration(config *Config) PostGISIntegration {
	return &PostGISIntegrationImpl{
		config: config,
	}
}

// PointToPostGIS generates a PostGIS geometry string for a point
func (pgi *PostGISIntegrationImpl) PointToPostGIS(point Point) string {
	return fmt.Sprintf("ST_GeogFromText('POINT(%f %f)')", point.Longitude, point.Latitude)
}

// BoundingBoxToPostGIS generates a PostGIS geometry string for a bounding box
func (pgi *PostGISIntegrationImpl) BoundingBoxToPostGIS(bbox BoundingBox) string {
	// Create a POLYGON from bounding box
	return fmt.Sprintf(
		"ST_GeogFromText('POLYGON((%f %f, %f %f, %f %f, %f %f, %f %f))')",
		bbox.SouthWest.Longitude, bbox.SouthWest.Latitude, // Bottom-left
		bbox.NorthEast.Longitude, bbox.SouthWest.Latitude, // Bottom-right
		bbox.NorthEast.Longitude, bbox.NorthEast.Latitude, // Top-right
		bbox.SouthWest.Longitude, bbox.NorthEast.Latitude, // Top-left
		bbox.SouthWest.Longitude, bbox.SouthWest.Latitude, // Close polygon
	)
}

// WithinRadiusQuery generates a PostGIS query for finding points within a radius
func (pgi *PostGISIntegrationImpl) WithinRadiusQuery(center Point, radiusKm float64) (string, []interface{}) {
	radiusMeters := radiusKm * 1000
	query := `
		ST_DWithin(
			location_geometry::geography,
			ST_SetSRID(ST_MakePoint(?, ?), 4326)::geography,
			?
		)
	`
	args := []interface{}{center.Longitude, center.Latitude, radiusMeters}
	return query, args
}

// DistanceQuery generates a PostGIS query for calculating distance
func (pgi *PostGISIntegrationImpl) DistanceQuery(p1, p2 Point) string {
	return fmt.Sprintf(
		"ST_Distance(%s::geography, %s::geography) / 1000",
		pgi.PointToPostGIS(p1),
		pgi.PointToPostGIS(p2),
	)
}

// BearingQuery generates a PostGIS query for calculating bearing
func (pgi *PostGISIntegrationImpl) BearingQuery(from, to Point) string {
	return fmt.Sprintf(
		"ST_Azimuth(%s, %s)",
		pgi.PointToPostGIS(from),
		pgi.PointToPostGIS(to),
	)
}