// License: GPL. For details, see LICENSE file.
options {
  STATIC = false;
}

PARSER_BEGIN(MapCSSParser)
package org.openstreetmap.josm.gui.mappaint.mapcss.parser;

import java.awt.Color;
import java.util.ArrayList;
import java.util.List;

import org.openstreetmap.josm.gui.mappaint.mapcss.Condition;
import org.openstreetmap.josm.gui.mappaint.mapcss.Expression;
import org.openstreetmap.josm.gui.mappaint.mapcss.Instruction;
import org.openstreetmap.josm.gui.mappaint.mapcss.MapCSSRule;
import org.openstreetmap.josm.gui.mappaint.mapcss.MapCSSStyleSource;
import org.openstreetmap.josm.gui.mappaint.mapcss.Selector;
import org.openstreetmap.josm.gui.mappaint.mapcss.Expression.FunctionExpression;
import org.openstreetmap.josm.gui.mappaint.mapcss.Expression.LiteralExpression;
import org.openstreetmap.josm.tools.Pair;

public class MapCSSParser {
    MapCSSStyleSource sheet;
}
PARSER_END(MapCSSParser)

/*************
 * Token definitions
 */

<DEFAULT>
TOKEN:
{
    < IDENT: ["a"-"z","A"-"Z","_"] ( ["a"-"z","A"-"Z","_","-","0"-"9"] )* >
|   < UINT: ["1"-"9"] ( ["0"-"9"] )* >
|   < UFLOAT: ( ["0"-"9"] )+ ( "." ( ["0"-"9"] )+ )? >
|   < STRING: "\"" ( [" ","!","#"-"[","]"-"~","\u0080"-"\uFFFF"] | "\\\"" | "\\\\" )*  "\"" >
|   < #REGEX_CHAR_WITHOUT_STAR: [" "-")","+"-".","0"-"[","]"-"~","\u0080"-"\uFFFF"] | "\\/" | "\\\\" >
|   < REGEX: "/" <REGEX_CHAR_WITHOUT_STAR> ( <REGEX_CHAR_WITHOUT_STAR> | "*" )*  "/" >
|   < #H: ["0"-"9","a"-"f","A"-"F"] >
|   < HEXCOLOR: "#" ( <H><H><H><H><H><H> | <H><H><H> ) >
|   < S: ( " " | "\t" | "\n" | "\r" | "\f" )+ >
|   < STAR: "*" >
|   < SLASH: "/" >
|   < LBRACE: "{" >
|   < RBRACE: "}" >
|   < LSQUARE: "[" >
|   < RSQUARE: "]" >
|   < LPAR: "(" >
|   < RPAR: ")" >
|   < GREATER_EQUAL: ">=" >
|   < LESS_EQUAL: "<=" >
|   < GREATER: ">" >
|   < LESS: "<" >
|   < EQUAL: "=" >
|   < EXCLAMATION: "!" >
|   < TILDE: "~" >
|   < COLON: ":" >
|   < DCOLON: "::" >
|   < SEMICOLON: ";" >
|   < COMMA: "," >
|   < PIPE: "|" >
|   < PIPE_Z: "|z" >
|   < PLUS: "+" >
|   < MINUS: "-" >
|   < AMPERSAND: "&" >
|   < QUESTION: "?" >
|   < DOLLAR: "$" >
|   < CARET: "^" >
|   < COMMENT_START: "/*" > : COMMENT
|   < UNEXPECTED_CHAR : ~[] > // avoid TokenMgrErrors because they are hard to recover from
}

<COMMENT>
TOKEN:
{
    < COMMENT_END: "*/" > : DEFAULT
}

<COMMENT>
SKIP:
{
    < ~[] >
}

/*************
 * Parser definitions
 *
 *                       rule
 *  _______________________|______________________________
 * |                                                      |
 *        selector                      declaration
 *  _________|___________________   _________|____________
 * |                             | |                      |
 *
 * way|z11-12[highway=residential] { color: red; width: 3 }
 *
 *    |_____||___________________|   |_________|
 *       |            |                   |
 *     zoom       condition          instruction
 *
 * more general:
 *
 * way|z13-[a=b][c=d]::subpart, way|z-3[u=v]:closed::subpart2 { p1 : val; p2 : val; }
 *
 * 'val' can be a literal, or an expression like "prop(width, default) + 0.8".
 *
 */

int uint() :
{
    Token i;
}
{
    i=<UINT> { return Integer.parseInt(i.image); }
}

float ufloat() :
{
    Token f;
}
{
    ( f=<UFLOAT> | f=<UINT> )
    { return Float.parseFloat(f.image); }
}

float float_() :
{
    float f;
}
{
    <MINUS> f=ufloat() { return -f; } | f=ufloat() { return f; }
}

String string() :
{
    Token t;
}
{
    t=<STRING>
    { return t.image.substring(1, t.image.length() - 1).replace("\\\"", "\"").replace("\\\\", "\\"); }
}

String string_or_ident() :
{
    Token t;
    String s;
}
{
    t=<IDENT> { return t.image; } | s=string() { return s; }
}

String regex() :
{
    Token t;
}
{
    t=<REGEX>
    { return t.image.substring(1, t.image.length() - 1); }
}

/**
 * white-space
 */
void s() :
{
}
{
    ( <S> )?
}

/**
 * mix of white-space and comments
 */
void w() :
{
}
{
    ( <S> | <COMMENT_START> <COMMENT_END> )*
}

/**
 * comma delimited list of floats (at least 2, all >= 0)
 */
List<Float> float_array() :
{
    float f;
    List<Float> fs = new ArrayList<Float>();
}
{
    f=ufloat() { fs.add(f); }
    (
        <COMMA> s()
        f=ufloat() { fs.add(f); }
    )+
    {
        return fs;
    }
}

/**
 * root
 */
void sheet(MapCSSStyleSource sheet):
{
    MapCSSRule r;
    Token com = null;
}
{
    { this.sheet = sheet; }
    w()
    (
        try {
            r=rule() { if (r != null) { sheet.rules.add(r); } } w()
        } catch (ParseException ex) {
            error_skipto(RBRACE);
            w();
        }
    )*
    <EOF>
}

MapCSSRule rule():
{
    List<Selector> selectors = new ArrayList<Selector>();
    Selector sel;
    List<Instruction> decl;
}
{
    sel=selector() { selectors.add(sel); } w()
    (
        <COMMA> w()
        sel=selector() { selectors.add(sel); } w()
    )*
    decl=declaration()
    { return new MapCSSRule(selectors, decl); }
}

Selector selector() :
{
    Token base;
    Condition c;
    Pair<Integer, Integer> r = null;
    List<Condition> conditions = new ArrayList<Condition>();
    String sub = null;
}
{
    ( base=<IDENT> | base=<STAR> )
    ( r=zoom() )?
    ( ( c=condition() | c=pseudoclass() ) { conditions.add(c); } )*
    ( sub=subpart() )?
    { return new Selector(base.image, r, conditions, sub); }
}

Pair<Integer, Integer> zoom() :
{
    Integer min = 0;
    Integer max = Integer.MAX_VALUE;
}
{
    <PIPE_Z>
    (
            <MINUS> max=uint()
        |
            min=uint() ( <MINUS> ( max=uint() )? )?
    )
    { return new Pair<Integer, Integer>(min, max); }
}

Condition condition() :
{
    Condition c;
    Expression e;
}
{
    <LSQUARE>
    (
        LOOKAHEAD(3)
            c=simple_key_condition() <RSQUARE> { return c; }
        |
        LOOKAHEAD(5)
            c=simple_key_value_condition() <RSQUARE> { return c; }
        |
            e=expression() <RSQUARE> { return new Condition.ExpressionCondition(e); }
    )
}

Condition simple_key_condition() :
{
    boolean not = false;
    boolean yes = false;
    String key;
}
{
    ( <EXCLAMATION> { not = true; } )?
    key=string_or_ident()
    ( <QUESTION> { yes = true; } )?
    { return new Condition.KeyCondition(key, not, yes); }
}

Condition simple_key_value_condition() :
{
    String key;
    String val;
    float f;
    Condition.Op op;
}
{
    key=string_or_ident()
    (
            (
                    <EXCLAMATION> <EQUAL> { op=Condition.Op.NEQ; } val=string_or_ident()
                |
                    <EQUAL> { op=Condition.Op.EQ; }
                    (
                            <TILDE> { op=Condition.Op.REGEX; }
                            val=regex()
                        |
                            val=string_or_ident()
                    )
                |
                    <TILDE> <EQUAL> { op=Condition.Op.ONE_OF; } val=string_or_ident()
                |
                    <CARET> <EQUAL> { op=Condition.Op.BEGINS_WITH; } val=string_or_ident()
                |
                    <DOLLAR> <EQUAL> { op=Condition.Op.ENDS_WITH; } val=string_or_ident()
                |
                    <STAR> <EQUAL> { op=Condition.Op.CONTAINS; } val=string_or_ident()
            )
            { return new Condition.KeyValueCondition(key, val, op); }
        |
            (
                    <GREATER_EQUAL> { op=Condition.Op.GREATER_OR_EQUAL; }
                |
                    <GREATER> { op=Condition.Op.GREATER; }
                |
                    <LESS_EQUAL> { op=Condition.Op.LESS_OR_EQUAL; }
                |
                    <LESS> { op=Condition.Op.LESS; }
            )
            f=float_()
            { return new Condition.KeyValueCondition(key, Float.toString(f), op); }
    )
}

Condition pseudoclass() :
{
    Token t;
    boolean not = false;
}
{
    ( <EXCLAMATION> { not = true; } )? 
    <COLON>
    t=<IDENT>
    { return new Condition.PseudoClassCondition(t.image, not); }
}

String subpart() :
{
    Token t;
}
{
    <DCOLON>
    ( t=<IDENT> | t=<STAR> )
    { return t.image; }
}

List<Instruction> declaration() :
{
    List<Instruction> ins = new ArrayList<Instruction>();
    Instruction i;
    Token key;
    Object val;
}
{
    <LBRACE> w()
    (
        key=<IDENT> w() <COLON> w()
        (
            LOOKAHEAD( float_array() w() ( <SEMICOLON> | <RBRACE> ) )
                val=float_array()
                { ins.add(new Instruction.AssignmentInstruction(key.image, val)); }
                w()
                ( <RBRACE> { return ins; } | <SEMICOLON> w() )
            |
            LOOKAHEAD( expression() ( <SEMICOLON> | <RBRACE> ) )
                val=expression()
                { ins.add(new Instruction.AssignmentInstruction(key.image, val)); }
                ( <RBRACE> { return ins; } | <SEMICOLON> w() )
            |
                val=readRaw() w() { ins.add(new Instruction.AssignmentInstruction(key.image, val)); }
        )
    )*
    <RBRACE>
    { return ins; }
}

Expression expression():
{
    List<Expression> args = new ArrayList<Expression>();
    Expression e;
    String op = null;
}
{
    (
        <EXCLAMATION> { op = "not"; } w() e=primary() { args.add(e); } w()
    |
        <MINUS> { op = "minus"; } w() e=primary() { args.add(e); } w()
    |

        (
            e=primary() { args.add(e); } w()
            (
                    ( <PLUS> { op = "plus"; } w() e=primary() { args.add(e); } w() )+
                |
                    ( <STAR> { op = "times"; } w() e=primary() { args.add(e); } w() )+
                |
                    ( <MINUS> { op = "minus"; } w() e=primary() { args.add(e); } w() )+
                |
                    ( <SLASH> { op = "divided_by"; } w() e=primary() { args.add(e); } w() )+
                |
                    <GREATER_EQUAL> { op = "greater_equal"; } w() e=primary() { args.add(e); } w()
                |
                    <LESS_EQUAL> { op = "less_equal"; } w() e=primary() { args.add(e); } w()
                |
                    <GREATER> { op = "greater"; } w() e=primary() { args.add(e); } w()
                |
                    <EQUAL> ( <EQUAL> )? { op = "equal"; } w() e=primary() { args.add(e); } w()
                |
                    <LESS> { op = "less"; } w() e=primary() { args.add(e); } w()
                |
                    <AMPERSAND> <AMPERSAND> { op = "and"; } w() e=primary() { args.add(e); } w()
                |
                    <PIPE> <PIPE> { op = "or"; } w() e=primary() { args.add(e); } w()
                |
                    <QUESTION> { op = "cond"; } w() e=primary() { args.add(e); } w() <COLON> w() e=primary() { args.add(e); } w()
            )?
        )
    )
    {
        if (op == null)
            return args.get(0);
        return new FunctionExpression(op, args);
    }
}

Expression primary() :
{
    Expression nested;
    FunctionExpression fn;
    Object lit;
}
{
    LOOKAHEAD(2) // both function and identifier start with an identifier
        fn=function() { return fn; }
    |
        lit=literal() { return new LiteralExpression(lit); }
    |
        <LPAR> w() nested=expression() <RPAR> { return nested; }
}

FunctionExpression function() :
{
    Token tmp;
    Expression arg;
    String name;
    List<Expression> args = new ArrayList<Expression>();
}
{
    tmp=<IDENT> { name = tmp.image; } w()
    <LPAR> w()
    (
        arg=expression() { args.add(arg); }
        ( <COMMA> w() arg=expression() { args.add(arg); } )*
    )?
    <RPAR>
    { return new FunctionExpression(name, args); }
}

Object literal() :
{
    Object val;
    Token t;
    float f;
}
{
        val=string_or_ident() { return val; }
    |
        <PLUS> f=ufloat() { return new Instruction.RelativeFloat(f); }
    |
        f=ufloat() { return f; }
    |
        t=<HEXCOLOR>
            {
                String clr = t.image.substring(1);
                if (clr.length() == 3) {
                    clr = new String(new char[] {clr.charAt(0),clr.charAt(0),clr.charAt(1),clr.charAt(1),clr.charAt(2),clr.charAt(2)});
                }
                if (clr.length() != 6)
                    throw new AssertionError();
                return new Color(Integer.parseInt(clr, 16));
            }
}

JAVACODE
void error_skipto(int kind) {
    if (token.kind == EOF)
        throw new ParseException("Reached end of file while parsing");
    ParseException e = generateParseException();
    System.err.println("Skipping to the next rule, because of an error:");
    System.err.println(e);
    if (sheet != null) {
        sheet.logError(new ParseException(e.getMessage()));
    }
    Token t;
    do {
        t = getNextToken();
    } while (t.kind != kind && t.kind != EOF);
    if (t.kind == EOF)
        throw new ParseException("Reached end of file while parsing");
}

JAVACODE
/**
 * read everything to the next semicolon
 */
String readRaw() {
    Token t;
    StringBuilder s = new StringBuilder();
    while (true) {
        t = getNextToken();
        if ((t.kind == S || t.kind == STRING || t.kind == UNEXPECTED_CHAR) &&
                t.image.contains("\n")) {
            ParseException e = new ParseException(String.format("Warning: end of line while reading an unquoted string at line %s column %s.", t.beginLine, t.beginColumn));
            System.err.println(e);
            if (sheet != null) {
                sheet.logError(e);
            }
        }
        if (t.kind == SEMICOLON || t.kind == EOF)
            break;
        s.append(t.image);
    }
    if (t.kind == EOF)
        throw new ParseException("Reached end of file while parsing");
    return s.toString();
}