package it.inaf.oats.vospace.persistence;

import java.sql.Array;
import net.ivoa.xml.vospace.v2.Node;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import javax.sql.DataSource;
import net.ivoa.xml.vospace.v2.ContainerNode;
import net.ivoa.xml.vospace.v2.DataNode;
import net.ivoa.xml.vospace.v2.Property;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

/**
 *
 * @author bertocco
 */
@Repository
public class NodeDAO {

    @Value("${vospace-authority}")
    private String authority;

    private final JdbcTemplate jdbcTemplate;

    @Autowired
    public NodeDAO(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

    public Node createNode(Node myNode) {

        StringBuilder sb = new StringBuilder();
        sb.append("INSERT INTO ");
        sb.append("NodeProperty");
        sb.append(" (nodeID,propertyURI,propertyValue) SELECT ?, ?, ?");
        sb.append(" WHERE NOT EXISTS (SELECT * FROM NodeProperty");
        sb.append(" WHERE nodeID=? and propertyURI=?)");
        String sqlQuery = sb.toString();

        return myNode;
    }

    public Optional<Node> listNode(String path) {

        String sql = "SELECT os.vos_path, n.node_id, type, async_trans, busy_state, owner_id, group_read, group_write, is_public, content_length, created_on, last_modified from node n\n"
                + "JOIN node_vos_path os ON n.node_id = os.node_id\n"
                + "WHERE n.path ~ (" + getFirstLevelChildrenSelector(path) + ")::lquery\n"
                + "OR os.vos_path = ? ORDER BY vos_path";

        List<Node> parentAndChildren = jdbcTemplate.query(conn -> {
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setString(1, path);
            ps.setString(2, path);
            return ps;
        }, (row, index) -> {
            return getNodeFromResultSet(row);
        });

        if (parentAndChildren.isEmpty()) {
            return Optional.empty();
        }

        // Query returns parent as first node
        Node node = parentAndChildren.get(0);

        // Fill children
        if (node instanceof ContainerNode && parentAndChildren.size() > 1) {
            ContainerNode parent = (ContainerNode) node;
            for (int i = 1; i < parentAndChildren.size(); i++) {
                parent.getNodes().add(parentAndChildren.get(i));
            }
        }

        return Optional.of(node);
    }

    private String getFirstLevelChildrenSelector(String path) {
        String select = "(SELECT path FROM node WHERE node_id = (SELECT node_id FROM node_vos_path WHERE vos_path = ?))::varchar || '";

        if (!"/".equals(path)) {
            select += ".";
        }
        select += "*{1}'";
        return select;
    }

    private Node getNodeFromResultSet(ResultSet rs) throws SQLException {

        Node node = getTypedNode(rs.getString("type"));

        if (node instanceof DataNode) {
            ((DataNode) node).setBusy(rs.getBoolean("busy_state"));
        }

        node.setUri(getUri(rs.getString("vos_path")));

        List<Property> properties = new ArrayList<>();

        addProperty(getPropertyURI("length"), rs.getString("content_length"),
                properties);

        addProperty(getPropertyURI("btime"), rs.getString("created_on"),
                properties);

        addProperty(getPropertyURI("mtime"), rs.getString("last_modified"),
                properties);

        addProperty(getPropertyURI("groupread"), getGroupsString(rs, "group_read"),
                properties);

        addProperty(getPropertyURI("groupwrite"), getGroupsString(rs, "group_write"),
                properties);

        addProperty(getPropertyURI("publicread"), rs.getString("is_public"),
                properties);

        addProperty("urn:async_trans", rs.getString("async_trans"),
                properties);

        node.setProperties(properties);
        return node;
    }

    private String getPropertyURI(String propertyName) {
        return "ivo://ivoa.net/vospace/core#".concat(propertyName);
    }

    private String getGroupsString(ResultSet rs, String column) throws SQLException {
        Array array = rs.getArray(column);
        if (array == null) {
            return null;
        }
        return String.join(" ", (String[]) array.getArray());
    }

    // If value is null does nothing
    private void addProperty(String uri, String value, List<Property> list) {
        if (value != null) {
            Property prop = new Property();
            prop.setUri(uri);
            prop.setValue(value);
            list.add(prop);
        }
    }

    private Node getTypedNode(String type) {
        Node node;
        switch (type) {
            case "container":
                node = new ContainerNode();
                break;
            case "data":
                node = new DataNode();
                break;
            default:
                throw new UnsupportedOperationException("Node type " + type + " not supported yet");
        }
        return node;
    }

    private String getUri(String path) {
        return "vos://" + authority + path;
    }
}