package gudusoft.gsqlparser.stmt.mssql;

import gudusoft.gsqlparser.*;
import gudusoft.gsqlparser.nodes.TConstant;
import gudusoft.gsqlparser.nodes.TObjectName;
import gudusoft.gsqlparser.nodes.TParseTreeVisitor;
import gudusoft.gsqlparser.nodes.TTable;
import gudusoft.gsqlparser.nodes.mssql.TMssqlUpdateTextSqlNode;

/**
 * SQL Server UPDATETEXT statement:
 * <pre>
 * UPDATETEXT { table.dest_column dest_text_ptr }
 *   { NULL | insert_offset } { NULL | delete_length } [ WITH LOG ]
 *   [ inserted_data | { table.src_column src_text_ptr } ]
 * </pre>
 * The destination (and, in the column-copy form, source) {@code table.column}
 * reference is registered as a statement table so name resolution links the
 * column to its table ({@link TObjectName#getSourceTable()}).
 */
public class TMssqlUpdateText extends TCustomSqlStatement {
     public TMssqlUpdateText (EDbVendor dbvendor){
        super(dbvendor);
        sqlstatementtype = ESqlStatementType.sstmssqlupdatetext ;
        }

    void buildsql() {
    }

    void clear() {
    }

    String getasprettytext() {
        return "";
    }

    void iterate(TVisitorAbs pvisitor) {
    }

    private TObjectName destColumnName = null;

    /**
     * Is the name of the table and text, ntext, or image column to be updated.
     * @return
     */
    public TObjectName getDestColumnName() {
        return destColumnName;
    }

    /**
     * Is a text pointer value (returned by the TEXTPTR function) that points to the text, ntext, or image data to be updated.
     * @return
     */
    public TObjectName getDestTextPtr() {
        return destTextPtr;
    }

    private TObjectName destTextPtr = null;
    private TObjectName insertedVariable = null;
    private TConstant insertedLiteral = null;
    private TObjectName sourceColumnName = null;
    private TObjectName sourceTextPtr = null;
    private TTable copySourceTable = null;

    /** The inserted_data operand when given as a variable, null otherwise. */
    public TObjectName getInsertedVariable() {
        return insertedVariable;
    }

    /** The inserted_data operand when given as a literal, null otherwise. */
    public TConstant getInsertedLiteral() {
        return insertedLiteral;
    }

    /** The source {@code table.column} of the column-copy form, null otherwise. */
    public TObjectName getSourceColumnName() {
        return sourceColumnName;
    }

    /** The source text pointer of the column-copy form, null otherwise. */
    public TObjectName getSourceTextPtr() {
        return sourceTextPtr;
    }

    /** The table read by the column-copy form, derived from the source column prefix. Null otherwise. */
    public TTable getCopySourceTable() {
        return copySourceTable;
    }

    /**
     * Register the table part of a fused {@code table.column} reference as a
     * statement table and link the column to it, so both the legacy
     * link-column phase and TSQLResolver2 consumers observe a resolved column.
     * Returns null when the reference has no table prefix (nothing provable).
     */
    static TTable bindLobColumnTable(TCustomSqlStatement stmt, TObjectName columnRef, ETableEffectType effectType) {
        if (columnRef == null) {
            return null;
        }
        columnRef.setDbObjectType(EDbObjectType.column);
        if (columnRef.getObjectToken() == null) {
            return null;
        }
        TObjectName tableName;
        if (columnRef.getDatabaseToken() != null && columnRef.getSchemaToken() != null) {
            tableName = TObjectName.createObjectName(stmt.dbvendor, EDbObjectType.table,
                    columnRef.getDatabaseToken(), columnRef.getSchemaToken(), columnRef.getObjectToken());
        } else if (columnRef.getSchemaToken() != null) {
            tableName = TObjectName.createObjectName(stmt.dbvendor, EDbObjectType.table,
                    columnRef.getSchemaToken(), columnRef.getObjectToken());
        } else {
            tableName = TObjectName.createObjectName(stmt.dbvendor, EDbObjectType.table,
                    columnRef.getObjectToken());
        }
        TTable table = new TTable(tableName);
        table.setPropertyFromObjectName(tableName, effectType);
        table.getLinkedColumns().addObjectName(columnRef);
        columnRef.setSourceTable(table);
        stmt.addToTables(table);
        return table;
    }

    public int doParseStatement(TCustomSqlStatement psql) {
        if (rootNode == null) return -1;
        if (!(rootNode instanceof TMssqlUpdateTextSqlNode)) {
            // shared-dialect grammars (access/odbc) may still produce a stub or
            // dummy node for this statement type -- degrade gracefully
            return super.doParseStatement(psql);
        }
        TMssqlUpdateTextSqlNode updateTextSqlNode = (TMssqlUpdateTextSqlNode)rootNode;
        super.doParseStatement(psql);
        this.destColumnName =  updateTextSqlNode.getDestColumnName();
        this.destTextPtr = updateTextSqlNode.getDestTextPtr();
        this.insertedVariable = updateTextSqlNode.getInsertedVariable();
        this.insertedLiteral = updateTextSqlNode.getInsertedLiteral();
        this.sourceColumnName = updateTextSqlNode.getSourceColumnName();
        this.sourceTextPtr = updateTextSqlNode.getSourceTextPtr();
        TTable table = bindLobColumnTable(this, this.destColumnName, ETableEffectType.tetUpdate);
        if (table != null) {
            setTargetTable(table);
        }
        if (this.sourceColumnName != null) {
            this.copySourceTable = bindLobColumnTable(this, this.sourceColumnName, ETableEffectType.tetSelect);
        }
        return 0;
    }

    public void accept(TParseTreeVisitor v){
        v.preVisit(this);
        v.postVisit(this);
    }

    public void acceptChildren(TParseTreeVisitor v){
        v.preVisit(this);
        v.postVisit(this);
    }

    public void setDestColumnName(TObjectName destColumnName) {
        this.destColumnName = destColumnName;
    }

    public void setDestTextPtr(TObjectName destTextPtr) {
        this.destTextPtr = destTextPtr;
    }
}