/*
 * 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 static org.apache.jena.atlas.lib.Lib.uppercase;

import java.util.regex.Pattern ;

import org.apache.jena.atlas.io.IndentedWriter ;
import org.apache.jena.atlas.logging.Log ;
import org.apache.jena.graph.Node ;
import org.apache.jena.graph.Node_Literal ;
import org.apache.jena.graph.Triple ;
import org.apache.jena.irix.IRIException;
import org.apache.jena.irix.IRIx;
import org.apache.jena.rdf.model.Model ;
import org.apache.jena.rdf.model.RDFNode ;
import org.apache.jena.rdf.model.Resource ;
import org.apache.jena.riot.out.NodeFmtLib;
import org.apache.jena.shared.PrefixMapping ;
import org.apache.jena.sparql.ARQConstants ;
import org.apache.jena.sparql.ARQInternalErrorException ;
import org.apache.jena.sparql.core.BasicPattern ;
import org.apache.jena.sparql.core.Prologue ;
import org.apache.jena.sparql.core.Quad ;
import org.apache.jena.sparql.serializer.SerializationContext ;
import org.apache.jena.vocabulary.XSD ;

/** Presentation forms of various kinds of objects.
 *  Beware that bNodes are abbreviated to _:b0 etc.
 *  @see NodeFmtLib
 */

public class FmtUtils {
    // See also riot.NodeFmtLib

    // Consider withdrawing non-serialization context forms of this.
    // Or a temporary SerialzationContext does not abbreviate bNodes.
    static final String indentPrefix = "  ";
    public static boolean multiLineExpr = false;
    public static boolean printOpName = true;

    static NodeToLabelMap bNodeMap = new NodeToLabelMapBNode("b", false);

    public static SerializationContext sCxt() {
        return sCxt(ARQConstants.getGlobalPrefixMap());
    }

    public static SerializationContext sCxt(PrefixMapping pmap) {
        return new SerializationContext(pmap);
    }

    // Formatting various items
    public static String stringForTriple(Triple triple) {
        StringBuilder result = new StringBuilder();
        stringForNode(result, triple.getSubject());
        result.append(" ");
        stringForNode(result, triple.getPredicate());
        result.append(" ");
        stringForNode(result, triple.getObject());
        return result.toString();
    }

    public static String stringForTriple(Triple triple, PrefixMapping prefixMap) {
        return stringForTriple(triple, sCxt(prefixMap));
    }

    public static String stringForTriple(Triple triple, SerializationContext sCxt) {
        StringBuilder result = new StringBuilder();
        stringForTriple(result, triple, sCxt);
        return result.toString();
    }

    public static void stringForTriple(StringBuilder result, Triple triple, SerializationContext sCxt) {
        stringForNode(result, triple.getSubject(), sCxt);
        result.append(" ");
        stringForNode(result, triple.getPredicate(), sCxt);
        result.append(" ");
        stringForNode(result, triple.getObject(), sCxt);
    }

    public static String stringForQuad(Quad quad, PrefixMapping prefixMap) {
        return stringForQuad(quad, sCxt(prefixMap));
    }

    public static String stringForQuad(Quad quad) {
        StringBuilder sb = new StringBuilder();

        if ( quad.getGraph() != null ) {
            sb.append(stringForNode(quad.getGraph()));
            sb.append(" ");
        }

        stringForNode(sb, quad.getSubject());
        sb.append(" ");
        stringForNode(sb, quad.getPredicate());
        sb.append(" ");
        stringForNode(sb, quad.getObject());
        return sb.toString();
    }

    public static String stringForQuad(Quad quad, SerializationContext sCxt) {
        StringBuilder sb = new StringBuilder();
        stringForQuad(sb, quad, sCxt);
        return sb.toString();
    }

    public static void stringForQuad(StringBuilder sb, Quad quad, SerializationContext sCxt) {
        if ( quad.getGraph() != null ) {
            sb.append(stringForNode(quad.getGraph(), sCxt));
            sb.append(" ");
        }

        stringForNode(sb, quad.getSubject(), sCxt);
        sb.append(" ");
        stringForNode(sb, quad.getPredicate(), sCxt);
        sb.append(" ");
        stringForNode(sb, quad.getObject(), sCxt);
    }

    public static void formatPattern(IndentedWriter out, BasicPattern pattern, SerializationContext sCxt) {
        StringBuilder buffer = new StringBuilder();
        boolean first = true;
        for ( Triple triple : pattern ) {
            if ( !first )
                buffer.append("\n");
            stringForTriple(buffer, triple, sCxt);
            buffer.append(" .");
            out.print(buffer.toString());
            buffer.setLength(0);
            first = false;
        }
    }

    public static String stringForObject(Object obj) {
        if ( obj == null )
            return "<<null>>";

        if ( obj instanceof RDFNode )
            return stringForRDFNode((RDFNode)obj);
        if ( obj instanceof Node )
            return stringForNode((Node)obj);
        return obj.toString();
    }

    public static String stringForRDFNode(RDFNode obj) {
        Model m = null;
        if ( obj instanceof Resource )
            m = obj.getModel();
        return stringForRDFNode(obj, newSerializationContext(m));
    }

    public static String stringForRDFNode(RDFNode obj, SerializationContext context) {
        return stringForNode(obj.asNode(), context);
    }

    public static String stringForLiteral(Node_Literal literal, SerializationContext context) {
        StringBuilder result = new StringBuilder();
        stringForLiteral(result, literal, context);
        return result.toString();
    }

    public static void stringForLiteral(StringBuilder result, Node_Literal literal, SerializationContext context) {
        String datatype = literal.getLiteralDatatypeURI();
        String lang = literal.getLiteralLanguage();
        String s = literal.getLiteralLexicalForm();

        // For some literals we can use plain literal form unless the Serialization
        // Context explicitly says not to. For backwards compatibility if using a
        // null context then we use plain literal forms where possible as this was
        // the existing behaviour prior to this addition to the API
        if ( datatype != null && (context == null || context.getUsePlainLiterals()) ) {
            // Special form we know how to handle?
            // Assume valid text
            if ( datatype.equals(XSD.integer.getURI()) ) {
                try {
                    String s1 = s;
                    // BigInteger does not allow leading +
                    // so chop it off before the format test
                    // BigDecimal does allow a leading +
                    if ( s.startsWith("+") )
                        s1 = s.substring(1);
                    new java.math.BigInteger(s1);
                    result.append(s);
                    return;
                } catch (NumberFormatException nfe) {}
                // No luck. Continue.
                // Continuing is always safe.
            }

            if ( datatype.equals(XSD.decimal.getURI()) ) {
                if ( s.indexOf('.') > 0 ) {
                    try {
                        // BigDecimal does allow a leading +
                        new java.math.BigDecimal(s);
                        result.append(s);
                        return;
                    } catch (NumberFormatException nfe) {}
                    // No luck. Continue.
                }
            }

            if ( datatype.equals(XSD.xdouble.getURI()) ) {
                // Assumes SPARQL has decimals and doubles.
                // Must have 'e' or 'E' to be a double short form.

                if ( s.indexOf('e') >= 0 || s.indexOf('E') >= 0 ) {
                    try {
                        Double.parseDouble(s);
                        result.append(s);
                        return;  // returm the original lexical form.
                    } catch (NumberFormatException nfe) {}
                    // No luck. Continue.
                }
            }

            if ( datatype.equals(XSD.xboolean.getURI()) ) {
                // Pragmatics: if the data wrote "1"^^xsd:boolean, keep that form.
                // The lexical form must be lower case.
                // if ( s.equals("true") || s.equals("1") ) return s ;
                // if ( s.equals("false") || s.equals("0") ) return s ;
                if ( s.equals("true") || s.equals("false") ) {
                    result.append(s);
                    return;
                }

            }
            // Not a recognized form.
        }

        result.append("\"");
        stringEsc(result, s, true);
        result.append("\"");

        if ( NodeUtils.isSimpleString(literal) ) {
            // No op.
            return;
        }

        if ( NodeUtils.isLangString(literal) ) {
            result.append("@");
            result.append(lang);
            return;
        }

        if ( datatype != null ) {
            result.append("^^");
            stringForURI(result, datatype, context);
        }
    }

    public static String stringForString(String str) {
        StringBuilder sbuff = new StringBuilder();
        sbuff.append("\"");
        stringEsc(sbuff, str, true);
        sbuff.append("\"");
        return sbuff.toString();
    }

    public static String stringForResource(Resource r) {
        return stringForResource(r, newSerializationContext(r.getModel()));
    }

    public static String stringForResource(Resource r, SerializationContext context) {
        return stringForNode(r.asNode(), context);
    }

    public static String stringForNode(Node n) {
        StringBuilder sb = new StringBuilder();
        stringForNode(sb, n, ARQConstants.getGlobalPrefixMap());
        return sb.toString();
    }

    public static void stringForNode(StringBuilder result, Node n) {
        stringForNode(result, n, ARQConstants.getGlobalPrefixMap());
    }

    public static String stringForNode(Node n, PrefixMapping prefixMap) {
        StringBuilder sb = new StringBuilder();
        stringForNode(sb, n, newSerializationContext(prefixMap));
        return sb.toString();
    }

    public static void stringForNode(StringBuilder result, Node n, PrefixMapping prefixMap) {
        stringForNode(result, n, newSerializationContext(prefixMap));
    }

    public static String stringForNode(Node n, Prologue prologue) {
        StringBuilder sb = new StringBuilder();
        stringForNode(sb, n, newSerializationContext(prologue));
        return sb.toString();
    }

    public static String stringForNode(Node n, SerializationContext context) {
        StringBuilder sb = new StringBuilder();
        stringForNode(sb, n, context);
        return sb.toString();
    }

    public static void stringForNode(StringBuilder result, Node n, SerializationContext context) {
        if ( n == null ) {
            result.append("<<null>>");
            return;
        }

        // mappable?
        if ( context != null && context.getBNodeMap() != null ) {
            String str = context.getBNodeMap().asString(n);
            if ( str != null ) {
                result.append(str);
                return;
            }
        }

        if ( n.isBlank() ) {
            result.append("_:").append(n.getBlankNodeLabel());
        } else if ( n.isLiteral() ) {
            stringForLiteral(result, (Node_Literal)n, context);
        } else if ( n.isURI() ) {
            String uri = n.getURI();
            stringForURI(result, uri, context);
        } else if ( n.isVariable() ) {
            result.append("?").append(n.getName());
        } else if ( n.equals(Node.ANY) ) {
            result.append("ANY");
        } else if ( n.isNodeTriple() ) {
            Triple t = n.getTriple();
            result.append("<< ");
            stringForNode(result, t.getSubject(), context);
            result.append(" ");
            stringForNode(result, t.getPredicate(), context);
            result.append(" ");
            stringForNode(result, t.getObject(), context);
            result.append(" >>");
        } else if ( n.isNodeGraph() ) {
            Log.warn(FmtUtils.class, "Can not turn a graph term node into a string");
            result.append(" { graph }");
        } else {
            Log.warn(FmtUtils.class, "Failed to turn a node into a string: " + n);
            result.append(n.toString());
        }
    }

    public static String stringForURI(String uri) {
        StringBuilder sb = new StringBuilder();
        stringForURI(sb, uri);
        return sb.toString();
    }

    public static void stringForURI(StringBuilder target, String uri) {
        target.append("<");
        stringEsc(target, uri);
        target.append(">");
    }

    public static String stringForURI(String uri, Prologue prologue) {
        return stringForURI(uri, prologue.getBaseURI(), prologue.getPrefixMapping());
    }

    public static String stringForURI(String uri, String baseIRI) {
        return stringForURI(uri, baseIRI, null);
    }

    public static String stringForURI(String uri, SerializationContext context) {
        if ( context == null )
            return stringForURI(uri, null, null);
        return stringForURI(uri, context.getBaseIRI(), context.getPrefixMapping());
    }

    public static void stringForURI(StringBuilder result, String uri, SerializationContext context) {
        if ( context == null )
            stringForURI(result, uri, null, null);
        else
            stringForURI(result, uri, context.getBaseIRI(), context.getPrefixMapping());
    }

    public static String stringForURI(String uri, PrefixMapping mapping)
    { return stringForURI(uri, null, mapping) ; }

    public static String stringForURI(String uri, String base, PrefixMapping mapping) {
        StringBuilder result = new StringBuilder();
        stringForURI(result, uri, base, mapping);
        return result.toString();
    }

    public static void stringForURI(StringBuilder result, String uri, String base, PrefixMapping mapping) {
        if ( mapping != null ) {
            String pname = prefixFor(uri, mapping);
            if ( pname != null ) {
                result.append(pname);
                return;
            }

        }
        if ( base != null ) {
            String x = abbrevByBase(uri, base);
            if ( x != null ) {
                result.append("<");
                result.append(x);
                result.append(">");
                return;
            }
        }
        stringForURI(result, uri);
    }

    public static String abbrevByBase(String uriStr, String base) {
        try {
            IRIx baseIRI = IRIx.create(base);
            if ( baseIRI == null )
                return null;
            IRIx relInput = IRIx.create(uriStr);
            IRIx relativized = baseIRI.relativize(relInput);
            return (relativized==null) ? null : relativized.toString();
        } catch (IRIException ex) {
            return null;
        }
    }

    static private Pattern schemePattern = Pattern.compile("[A-Za-z]+:") ;
    static private boolean hasScheme(String uriStr) {
        return schemePattern.matcher(uriStr).matches() ;
    }

    private static String prefixFor(String uri, PrefixMapping mapping) {
        if ( mapping == null )
            return null;

        String pname = mapping.shortForm(uri);
        if ( pname != uri && checkValidPrefixName(pname) )
            return pname;
        pname = mapping.qnameFor(uri);
        if ( pname != null && checkValidPrefixName(pname) )
            return pname;
        return null;
    }

    private static boolean checkValidPrefixName(String prefixedName) {
        // Split it to get the parts.
        int i = prefixedName.indexOf(':');
        if ( i < 0 )
            throw new ARQInternalErrorException("Broken short form -- " + prefixedName);
        String p = prefixedName.substring(0, i);
        String x = prefixedName.substring(i + 1);
        // Check legality
        if ( checkValidPrefix(p) && checkValidLocalname(x) )
            return true;
        return false;
    }

    private static boolean checkValidPrefix(String prefixStr) {
        if ( prefixStr.startsWith("_") )
            // Should .equals??
            return false;
        return checkValidLocalname(prefixStr);
    }

    private static boolean checkValidLocalname(String localname) {
        if ( localname.length() == 0 )
            return true;

        for ( int idx = 0 ; idx < localname.length() ; idx++ ) {
            char ch = localname.charAt(idx);
            if ( !validPNameChar(ch) )
                return false;
        }

        // Test start and end - at least one character in the name.

        if ( localname.endsWith(".") )
            return false;
        if ( localname.startsWith(".") )
            return false;

        return true;
    }

    private static boolean validPNameChar(char ch) {
        if ( Character.isLetterOrDigit(ch) ) return true ;
        if ( ch == '.' )    return true ;
        if ( ch == ':' )    return true ;
        if ( ch == '-' )    return true ;
        if ( ch == '_' )    return true ;
        return false ;
    }

    static boolean applyUnicodeEscapes = false ;

    // Take unescape code from ParserBase.

    // take a string and make it safe for writing.
    public static String stringEsc(String s)
    { return stringEsc( s, true ) ; }

    public static String stringEsc(String s, boolean singleLineString) {
        StringBuilder sb = new StringBuilder();
        stringEsc(sb, s, singleLineString);
        return sb.toString();
    }

    public static void stringEsc(StringBuilder sbuff, String s)
    { stringEsc( sbuff,  s, true ) ; }

    public static void stringEsc(StringBuilder sbuff, String s, boolean singleLineString) {
        int len = s.length();
        for ( int i = 0 ; i < len ; i++ ) {
            char c = s.charAt(i);

            // Escape escapes and quotes
            if ( c == '\\' || c == '"' ) {
                sbuff.append('\\');
                sbuff.append(c);
                continue;
            }

//            // Characters to literally output.
//            // This would generate 7-bit safe files
//            if ( c >= 32 && c < 127 ) {
//                sbuff.append(c);
//                continue;
//            }

            // Whitespace
            if ( singleLineString && (c == '\n' || c == '\r' || c == '\f' || c == '\t') ) {
                if ( c == '\n' )
                    sbuff.append("\\n");
                if ( c == '\t' )
                    sbuff.append("\\t");
                if ( c == '\r' )
                    sbuff.append("\\r");
                if ( c == '\f' )
                    sbuff.append("\\f");
                continue;
            }

            // Output as is (subject to UTF-8 encoding on output that is)

            if ( !applyUnicodeEscapes )
                sbuff.append(c);
            else {
                // Unicode escapes
                // c < 32, c >= 127, not whitespace or other specials
                if ( c >= 32 && c < 127 ) {
                    sbuff.append(c);
                } else {
                    String hexstr = uppercase(Integer.toHexString(c));
                    int pad = 4 - hexstr.length();
                    sbuff.append("\\u");
                    for ( ; pad > 0 ; pad-- )
                        sbuff.append("0");
                    sbuff.append(hexstr);
                }
            }
        }
    }

    public static void resetBNodeLabels() {
        bNodeMap = new NodeToLabelMapBNode("b", false);
    }

    private static SerializationContext newSerializationContext(PrefixMapping prefixMapping) {
        return new SerializationContext(prefixMapping, bNodeMap);
    }

    private static SerializationContext newSerializationContext(Prologue prologue) {
        return new SerializationContext(prologue, bNodeMap);
    }

}
