/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jena.sparql.util;

import java.io.Reader ;
import java.io.StringReader ;

import org.apache.jena.atlas.io.IndentedLineBuffer ;
import org.apache.jena.atlas.io.IndentedWriter ;
import org.apache.jena.graph.Node ;
import org.apache.jena.query.ARQ ;
import org.apache.jena.query.Query ;
import org.apache.jena.query.QueryFactory ;
import org.apache.jena.query.QueryParseException ;
import org.apache.jena.shared.PrefixMapping ;
import org.apache.jena.sparql.ARQConstants ;
import org.apache.jena.sparql.engine.ExecutionContext ;
import org.apache.jena.sparql.engine.binding.Binding ;
import org.apache.jena.sparql.engine.binding.BindingRoot ;
import org.apache.jena.sparql.expr.* ;
import org.apache.jena.sparql.function.FunctionEnv ;
import org.apache.jena.sparql.lang.arq.* ;
import org.apache.jena.sparql.serializer.FmtExprSPARQL ;
import org.apache.jena.sparql.serializer.SerializationContext ;
import org.apache.jena.sparql.sse.SSE ;
import org.apache.jena.sparql.sse.SSE_ParseException ;
import org.apache.jena.sparql.sse.builders.SSE_ExprBuildException ;
import org.apache.jena.sys.JenaSystem ;


/** Misc support for Expr */

public class ExprUtils
{
    static { JenaSystem.init(); }

    /** Go from a node to an expression.
     * @deprecated Use {@link ExprLib#nodeToExpr(Node)} instead*/
    @Deprecated
    public static Expr nodeToExpr(Node n) {
        return ExprLib.nodeToExpr(n);
    }

    public static Expr parse(String s) {
        return parse(s, ARQConstants.getGlobalPrefixMap());
    }

    public static Expr parse(String s, PrefixMapping pmap) {
        Query query = QueryFactory.make();
        query.setPrefixMapping(pmap);
        return parse(query, s, true);
    }

    public static Expr parse(Query query, String s, boolean checkAllUsed) {
        try {
            Reader in = new StringReader(s);
            ARQParser parser = new ARQParser(in);
            parser.setQuery(query);
            Expr expr = parser.Expression();

            if ( checkAllUsed ) {
                Token t = parser.getNextToken();
                if ( t.kind != ARQParserTokenManager.EOF )
                    throw new QueryParseException("Extra tokens beginning \"" + t.image + "\" starting line " + t.beginLine + ", column "
                                                  + t.beginColumn, t.beginLine, t.beginColumn);
            }
            return expr;
        } catch (ParseException ex) {
            throw new QueryParseException(ex.getMessage(), ex.currentToken.beginLine, ex.currentToken.beginLine);
        } catch (TokenMgrError tErr) {
            throw new QueryParseException(tErr.getMessage(), -1, -1);
        } catch (Error err) {
            // The token stream can throw java.lang.Error's
            String tmp = err.getMessage();
            if ( tmp == null )
                throw new QueryParseException(err, -1, -1);
            throw new QueryParseException(tmp, -1, -1);
        }
    }

    public static NodeValue parseNodeValue(String s) {
        Node n = NodeFactoryExtra.parseNode(s);
        NodeValue nv = NodeValue.makeNode(n);
        return nv;
    }

    public static void fmtSPARQL(IndentedWriter iOut, Expr expr, SerializationContext sCxt) {
        FmtExprSPARQL v = new FmtExprSPARQL(iOut, sCxt);
        v.format(expr);
    }

    public static void fmtSPARQL(IndentedWriter iOut, Expr expr) {
        fmtSPARQL(iOut, expr, FmtUtils.sCxt());
    }

    public static String fmtSPARQL(Expr expr) {
        IndentedLineBuffer buff = new IndentedLineBuffer();
        fmtSPARQL(buff, expr);
        return buff.toString();
    }

    // ExprLists

    public static void fmtSPARQL(IndentedWriter iOut, ExprList exprs, SerializationContext pmap) {
        FmtExprSPARQL fmt = new FmtExprSPARQL(iOut, pmap);
        String sep = "";
        for ( Expr expr : exprs ) {
            iOut.print(sep);
            sep = " , ";
            fmt.format(expr);
        }
    }

    public static void fmtSPARQL(IndentedWriter iOut, ExprList exprs) {
        fmtSPARQL(iOut, exprs, FmtUtils.sCxt());
    }

    public static String fmtSPARQL(ExprList exprs) {
        IndentedLineBuffer buff = new IndentedLineBuffer();
        fmtSPARQL(buff, exprs);
        return buff.toString();
    }

    public static String fmtSPARQL(ExprList exprs, SerializationContext sCxt) {
        IndentedLineBuffer buff = new IndentedLineBuffer();
        fmtSPARQL(buff, exprs, sCxt);
        return buff.toString();
    }

    public static String strComparison(int cmp) {
        switch (cmp) {
            case Expr.CMP_GREATER :
                return "GT";
            case Expr.CMP_EQUAL :
                return "EQ";
            case Expr.CMP_LESS :
                return "LT";
            case Expr.CMP_INDETERMINATE :
                return "indeterminate";
            default :
                return "??";
        }
    }

    // --- Debugging : evaluate and print

    public static void expr(String exprStr) {
        expr(exprStr, null);
    }

    public static void expr(String exprStr, Binding binding) {
        try {
            Expr expr = ExprUtils.parse(exprStr, ARQConstants.getGlobalPrefixMap());
            evalPrint(expr, binding);
        } catch (QueryParseException ex) {
            System.err.println("Parse error: " + ex.getMessage());
            return;
        }
    }

    public static void exprPrefix(String exprStr) {
        exprPrefix(exprStr, null);
    }

    public static void evalPrint(Expr expr, Binding binding) {
        try {
            NodeValue r = eval(expr, binding);
            // System.out.println(r.asQuotedString()) ;
            Node n = r.asNode();
            String s = FmtUtils.stringForNode(n);
            System.out.println(s);
        } catch (ExprEvalException ex) {
            System.out.println("Exception: " + ex.getMessage());
            return;
        } catch (SSE_ExprBuildException ex) {
            System.err.println("Build exception: " + ex.getMessage());
            return;
        }
    }

    public static NodeValue eval(Expr expr) {
        return eval(expr, BindingRoot.create());
    }

    public static NodeValue eval(Expr expr, Binding binding) {
        Context context = ARQ.getContext().copy();
        context.set(ARQConstants.sysCurrentTime, NodeFactoryExtra.nowAsDateTime());
        FunctionEnv env = new ExecutionContext(context, null, null, null);
        NodeValue r = expr.eval(binding, env);
        return r;
    }

    public static void exprPrefix(String string, Binding binding) {
        try {
            Expr expr = SSE.parseExpr(string);
            evalPrint(expr, binding);
        } catch (SSE_ParseException ex) {
            System.err.println("Parse error: " + ex.getMessage());
            return;
        }
    }
}
