--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/backend/src/main/java/org/dive4elements/river/model/River.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,345 @@
+package org.dive4elements.river.model;
+
+import org.dive4elements.river.backend.SessionHolder;
+
+import java.io.Serializable;
+import java.math.BigDecimal;
+import java.math.MathContext;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
+import javax.persistence.OrderBy;
+import javax.persistence.SequenceGenerator;
+import javax.persistence.Table;
+
+import org.hibernate.Query;
+import org.hibernate.Session;
+
+
+@Entity
+@Table(name = "rivers")
+public class River
+implements   Serializable
+{
+    public static final MathContext PRECISION = new MathContext(6);
+
+    public static final double EPSILON = 1e-5;
+
+    public static final Comparator<Double> KM_CMP = new Comparator<Double>() {
+        @Override
+        public int compare(Double a, Double b) {
+            double diff = a - b;
+            if (diff < -EPSILON) return -1;
+            if (diff >  EPSILON) return +1;
+            return 0;
+        }
+    };
+
+    private Integer id;
+
+    private Long    officialNumber;
+
+    private String  name;
+
+    private boolean kmUp;
+
+    private List<Gauge> gauges;
+
+    private List<MeasurementStation> measurementstations;
+
+    private Unit wstUnit;
+
+    @Id
+    @SequenceGenerator(
+        name           = "SEQUENCE_RIVERS_ID_SEQ",
+        sequenceName   = "RIVERS_ID_SEQ",
+        allocationSize = 1)
+    @GeneratedValue(
+        strategy  = GenerationType.SEQUENCE,
+        generator = "SEQUENCE_RIVERS_ID_SEQ")
+    @Column(name = "id")
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    @Column(name = "official_number")
+    public Long getOfficialNumber() {
+        return officialNumber;
+    }
+
+    public void setOfficialNumber(Long officialNumber) {
+        this.officialNumber = officialNumber;
+    }
+
+    @Column(name = "name")
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Column(name = "km_up")
+    public boolean getKmUp() {
+        return kmUp;
+    }
+
+    public void setKmUp(boolean kmUp) {
+        this.kmUp = kmUp;
+    }
+
+    public River() {
+    }
+
+    public River(String name, Unit wstUnit) {
+        this.name    = name;
+        this.wstUnit = wstUnit;
+    }
+
+    @OneToMany
+    @JoinColumn(name="river_id")
+    public List<Gauge> getGauges() {
+        return gauges;
+    }
+
+    public void setGauges(List<Gauge> gauges) {
+        this.gauges = gauges;
+    }
+
+
+    @OneToMany
+    @OrderBy("station")
+    @JoinColumn(name="river_id")
+    public List<MeasurementStation> getMeasurementStations() {
+        return measurementstations;
+    }
+
+    public void setMeasurementStations(List<MeasurementStation> mstations) {
+        this.measurementstations = mstations;
+    }
+
+    @OneToOne
+    @JoinColumn(name = "wst_unit_id" )
+    public Unit getWstUnit() {
+        return wstUnit;
+    }
+
+    public void setWstUnit(Unit wstUnit) {
+        this.wstUnit = wstUnit;
+    }
+
+
+
+    @Override
+    public String toString() {
+        return name != null ? name : "";
+    }
+
+
+    /**
+     * This method returns the gauges that intersect with <i>a</i> and
+     * <i>b</i>,
+     *
+     * @param a A start point.
+     * @param b An end point.
+     *
+     * @return the intersecting gauges.
+     */
+    public List<Gauge> determineGauges(double a, double b) {
+        Session session = SessionHolder.HOLDER.get();
+
+        if (a > b) { double t = a; a = b; b = t; }
+
+        Query query = session.createQuery(
+            "from Gauge where river=:river " +
+            "and not (range.a > :b or range.b < :a) order by a");
+        query.setParameter("river", this);
+        query.setParameter("a", new BigDecimal(a, PRECISION));
+        query.setParameter("b", new BigDecimal(b, PRECISION));
+
+        return query.list();
+    }
+
+    public Gauge maxOverlap(double a, double b) {
+        List<Gauge> gauges = determineGauges(a, b);
+        if (gauges == null) {
+            return null;
+        }
+
+        if (a > b) { double t = a; a = b; b = t; }
+
+        double max = -Double.MAX_VALUE;
+
+        Gauge result = null;
+
+        for (Gauge gauge: gauges) {
+            Range  r = gauge.getRange();
+            double c = r.getA().doubleValue();
+            double d = r.getB().doubleValue();
+
+            double start = c >= a ? c : a;
+            double stop  = d <= b ? d : b;
+
+            double length = stop - start;
+
+            if (length > max) {
+                max = length;
+                result = gauge;
+            }
+        }
+
+        return result;
+    }
+
+    public Gauge determineGaugeByName(String name) {
+        Session session = SessionHolder.HOLDER.get();
+        Query query = session.createQuery(
+            "from Gauge where river=:river and name=:name");
+        query.setParameter("river", this);
+        query.setParameter("name", name);
+        List<Gauge> gauges = query.list();
+        return gauges.isEmpty() ? null : gauges.get(0);
+    }
+
+    public Gauge determineGaugeByPosition(double p) {
+        Session session = SessionHolder.HOLDER.get();
+        Query query = session.createQuery(
+            "from Gauge g where river=:river "  +
+            "and :p between g.range.a and g.range.b");
+        query.setParameter("river", this);
+        query.setParameter("p", new BigDecimal(p, PRECISION));
+        List<Gauge> gauges = query.list();
+        return gauges.isEmpty() ? null : gauges.get(0);
+    }
+
+    public Gauge determineGaugeByStation(double a, double b) {
+
+        if (a > b) { double t = a; a = b; b = t; }
+
+        Session session = SessionHolder.HOLDER.get();
+
+        Query query = session.createQuery(
+            "from Gauge where river.id=:river " +
+            "and station between :a and :b");
+        query.setParameter("river", getId());
+        query.setParameter("a", new BigDecimal(a));
+        query.setParameter("b", new BigDecimal(b));
+
+        List<Gauge> gauges = query.list();
+        return gauges.isEmpty() ? null : gauges.get(0);
+    }
+
+    public double[] determineMinMaxQ() {
+        Session session = SessionHolder.HOLDER.get();
+
+        Query query = session.createQuery(
+            "select min(wqr.q) as min, max(wqr.q) as max " +
+            "from Wst as w " +
+            "join w.columns as wc " +
+            "join wc.columnQRanges as wcqr " +
+            "join wcqr.wstQRange as wqr " +
+            "where w.kind = 0 and river_id = :river");
+
+        query.setParameter("river", getId());
+
+        double minmax[] = new double[] { Double.MAX_VALUE, Double.MIN_VALUE };
+
+        List<Object> results = query.list();
+
+        if (!results.isEmpty()) {
+            Object[] arr = (Object[]) results.get(0);
+            BigDecimal minq = (BigDecimal)arr[0];
+            BigDecimal maxq = (BigDecimal)arr[1];
+            minmax[0] = minq.doubleValue();
+            minmax[1] = maxq.doubleValue();
+        }
+
+        return minmax;
+    }
+
+
+    /**
+     * This method returns the first gauge that is intersected by <i>a</i> and
+     * <i>b</i>,
+     *
+     * @param a A start point.
+     * @param b An end point.
+     *
+     * @return the first intersecting gauge.
+     */
+    public Gauge determineGauge(double a, double b) {
+        List<Gauge> gauges = determineGauges(a, b);
+
+        int idx = a < b ? 0 : gauges.size() - 1;
+
+        return gauges.isEmpty() ? null : gauges.get(idx);
+    }
+
+    /**
+     * Returns the min and max distance of this river. The first position in the
+     * resulting array contains the min distance, the second position the max
+     * distance.
+     *
+     * @return the min and max distance of this river.
+     */
+    public double[] determineMinMaxDistance() {
+        List<Gauge> gauges = getGauges();
+
+        if (gauges == null || gauges.isEmpty()) {
+            return null;
+        }
+
+        double minmax[] = new double[] { Double.MAX_VALUE, Double.MIN_VALUE };
+
+        for (Gauge g: gauges) {
+            Range r = g.getRange();
+
+            if (r == null) {
+                continue;
+            }
+
+            double a  = r.getA().doubleValue();
+            minmax[0] = minmax[0] < a ? minmax[0] : a;
+
+            BigDecimal bigB = r.getB();
+            if (bigB != null) {
+                double b  = bigB.doubleValue();
+                minmax[1] = minmax[1] > b ? minmax[1] : b;
+            }
+        }
+
+        return minmax;
+    }
+
+    public Map<Double, Double> queryGaugeDatumsKMs() {
+        List<Gauge> gauges = getGauges();
+        Map result = new TreeMap<Double, Double>(KM_CMP);
+
+        for (Gauge gauge: gauges) {
+            BigDecimal km    = gauge.getStation();
+            BigDecimal datum = gauge.getDatum();
+            if (km != null && datum != null) {
+                result.put(km.doubleValue(), datum.doubleValue());
+            }
+        }
+
+        return result;
+    }
+
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :