--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pkg/models/sr.go	Mon Nov 19 17:14:42 2018 +0100
@@ -0,0 +1,101 @@
+// This is Free Software under GNU Affero General Public License v >= 3.0
+// without warranty, see README.md and license for details.
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// License-Filename: LICENSES/AGPL-3.0.txt
+//
+// Copyright (C) 2018 by via donau
+//   – Österreichische Wasserstraßen-Gesellschaft mbH
+// Software engineering by Intevation GmbH
+//
+// Author(s):
+//  * Sascha L. Teichmann <sascha.teichmann@intevation.de>
+//  * Bernhard E. Reiter <bernhard.reiter@intevation.de>
+
+package models
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"time"
+)
+
+const (
+	SoundingResultDateFormat = "2006-01-02"
+	WGS84                    = 4326
+)
+
+type (
+	SoundingResultDate struct{ time.Time }
+
+	SoundingResultMeta struct {
+		Date           SoundingResultDate `json:"date"`
+		Bottleneck     string             `json:"bottleneck"`
+		EPSG           uint               `json:"epsg"`
+		DepthReference string             `json:"depth-reference"`
+	}
+)
+
+const (
+	checkDepthReferenceSQL = `
+SELECT true FROM depth_references WHERE depth_reference = $1`
+
+	checkBottleneckSQL = `
+SELECT true FROM waterway.bottlenecks WHERE objnam = $1`
+)
+
+func (srd *SoundingResultDate) UnmarshalJSON(data []byte) error {
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return err
+	}
+	d, err := time.Parse(SoundingResultDateFormat, s)
+	if err == nil {
+		*srd = SoundingResultDate{d}
+	}
+	return err
+}
+
+func (m *SoundingResultMeta) Decode(r io.Reader) error {
+	err := json.NewDecoder(r).Decode(m)
+	if err == nil && m.EPSG == 0 {
+		m.EPSG = WGS84
+	}
+	return err
+}
+
+func (m *SoundingResultMeta) Validate(conn *sql.Conn, ctx context.Context) []error {
+
+	var errs []error
+
+	var b bool
+	err := conn.QueryRowContext(ctx,
+		checkDepthReferenceSQL,
+		m.DepthReference).Scan(&b)
+	switch {
+	case err == sql.ErrNoRows:
+		errs = append(errs, fmt.Errorf("Unknown depth reference '%s'\n", m.DepthReference))
+	case err != nil:
+		errs = append(errs, err)
+	case !b:
+		errs = append(errs, errors.New("Unexpected depth reference"))
+	}
+
+	err = conn.QueryRowContext(context.Background(),
+		checkBottleneckSQL,
+		m.Bottleneck).Scan(&b)
+	switch {
+	case err == sql.ErrNoRows:
+		errs = append(errs, fmt.Errorf("Unknown bottleneck '%s'\n", m.Bottleneck))
+	case err != nil:
+		errs = append(errs, err)
+	case !b:
+		errs = append(errs, errors.New("Unexpected bottleneck"))
+	}
+
+	return errs
+}