feat(internal): Using OSRM for calculating distance from backend

Signed-off-by: Ashish Kumar <ashishkr23438@gmail.com>

internal/database/location.go

@@ -0,0 +1,62 @@
+/*GRP-GNU-AGPL******************************************************************
+
+File: location.go
+
+Copyright (C) 2021  Team Georepublic <info@georepublic.de>
+
+Developer(s):
+Copyright (C) 2021  Ashish Kumar <ashishkr23438@gmail.com>
+
+-----
+
+This file is part of pg_scheduleserv.
+
+pg_scheduleserv is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pg_scheduleserv is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with pg_scheduleserv.  If not, see <https://www.gnu.org/licenses/>.
+
+******************************************************************GRP-GNU-AGPL*/
+
+package database
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v4"
+)
+
+func (q *Queries) DBGetProjectLocations(ctx context.Context, project_id int64) ([]int64, error) {
+	sql := `
+	SELECT unnest(ARRAY[location_id]) AS location_id FROM jobs WHERE project_id = $1 UNION
+	SELECT unnest(ARRAY[p_location_id, d_location_id]) FROM shipments WHERE project_id = $1 UNION
+	SELECT unnest(ARRAY[start_id, end_id]) FROM vehicles WHERE project_id = $1`
+
+	rows, err := q.db.Query(ctx, sql, project_id)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	return scanProjectLocationRows(rows)
+}
+
+func scanProjectLocationRows(rows pgx.Rows) ([]int64, error) {
+	var locations []int64
+	for rows.Next() {
+		var location_id int64
+		err := rows.Scan(&location_id)
+		if err != nil {
+			return nil, err
+		}
+		locations = append(locations, location_id)
+	}
+	return locations, nil
+}

internal/database/querier.go

@@ -79,6 +79,9 @@ type Querier interface {
 	DBGetVehicle(ctx context.Context, id int64) (Vehicle, error)
 	DBUpdateVehicle(ctx context.Context, arg UpdateVehicleParams, vehicle_id int64) (Vehicle, error)
 	DBDeleteVehicle(ctx context.Context, id int64) (Vehicle, error)
+
+	// Locations
+	DBGetProjectLocations(ctx context.Context, project_id int64) ([]int64, error)
 }
 
 var _ Querier = (*Queries)(nil)

internal/database/schedule.go

@@ -38,8 +38,24 @@ import (
 )
 
 func (q *Queries) DBCreateSchedule(ctx context.Context, projectID int64) error {
-	query := fmt.Sprintf("SELECT create_schedule(%d)", projectID)
-	_, err := q.db.Exec(ctx, query)
+	// get project locations by calling DBGetProjectLocations
+	locationIds, err := q.DBGetProjectLocations(ctx, projectID)
+	if err != nil {
+		return err
+	}
+
+	startIds, endIds, durations, err := util.GetMatrix(locationIds)
+	if err != nil {
+		return err
+	}
+
+	// if either of startIds, endIds, durations is empty, return error
+	if len(startIds) == 0 || len(endIds) == 0 || len(durations) == 0 {
+		return fmt.Errorf("No locations present in the project")
+	}
+
+	query := "SELECT create_schedule_with_matrix($1, $2, $3, $4)"
+	_, err = q.db.Exec(ctx, query, projectID, startIds, endIds, durations)
 	return err
 }
 

internal/util/osrm_api.go

@@ -0,0 +1,119 @@
+/*GRP-GNU-AGPL******************************************************************
+
+File: osrm_api.go
+
+Copyright (C) 2021  Team Georepublic <info@georepublic.de>
+
+Developer(s):
+Copyright (C) 2021  Ashish Kumar <ashishkr23438@gmail.com>
+
+-----
+
+This file is part of pg_scheduleserv.
+
+pg_scheduleserv is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pg_scheduleserv is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with pg_scheduleserv.  If not, see <https://www.gnu.org/licenses/>.
+
+******************************************************************GRP-GNU-AGPL*/
+
+package util
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+)
+
+// make get request to an url with content-type, and return the response body as json
+func Get(url string, contentType string, target interface{}) error {
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", contentType)
+
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		return fmt.Errorf("HTTP error: %s", res.Status)
+	}
+
+	return json.NewDecoder(res.Body).Decode(target)
+}
+
+func GetMatrix(locationIds []int64) (startIds []int64, endIds []int64, durations []int64, err error) {
+	// iterate through locationIds, convert all the ids to latitude and longitude, and append [longitude, latitude] in an array
+	coordinates := make([][]float64, 0)
+	for _, id := range locationIds {
+		latitude, longitude := GetCoordinates(id)
+		coordinates = append(coordinates, []float64{longitude, latitude})
+	}
+
+	// call the osrm api function to get the matrix
+	matrix, err := GetMatrixFromOSRM(coordinates)
+
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	// iterate through the 2D matrix and append the start and end ids and durations. start id is locationIds[i], end id is locationIds[j], duration is matrix[i][j]
+	for i := 0; i < len(locationIds); i++ {
+		for j := 0; j < len(locationIds); j++ {
+			startIds = append(startIds, locationIds[i])
+			endIds = append(endIds, locationIds[j])
+			durations = append(durations, matrix[i][j])
+		}
+	}
+
+	return startIds, endIds, durations, nil
+}
+
+func GetMatrixFromOSRM(coordinates [][]float64) ([][]int64, error) {
+	// convert the coordinates to a string
+	coordinatesString := make([]string, 0)
+	for _, coordinate := range coordinates {
+		coordinatesString = append(coordinatesString, fmt.Sprintf("%.4f,%.4f", coordinate[0], coordinate[1]))
+	}
+
+	baseUrl := "http://router.project-osrm.org"
+
+	// call the osrm api function to get the matrix
+	url := fmt.Sprintf("%s/table/v1/driving/%s", baseUrl, strings.Join(coordinatesString, ";"))
+
+	// decode the response body as json, pass json in Get() function
+	response := make(map[string]interface{})
+	err := Get(url, "application/json", &response)
+	if err != nil {
+		return nil, err
+	}
+
+	// get the matrix from the response
+	matrix := response["durations"].([]interface{})
+
+	// convert the matrix to int64
+	matrixInt64 := make([][]int64, 0)
+	for _, row := range matrix {
+		rowInt64 := make([]int64, 0)
+		for _, value := range row.([]interface{}) {
+			rowInt64 = append(rowInt64, int64(value.(float64)))
+		}
+		matrixInt64 = append(matrixInt64, rowInt64)
+	}
+
+	return matrixInt64, nil
+}