// Copyright 2014 The Chromium Authors. All rights reserved.
// Copyright (C) 2016 Apple Inc. All rights reserved.
//
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// modification, are permitted provided that the following conditions are
// met:
//
//    * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above
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// in the documentation and/or other materials provided with the
// distribution.
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// contributors may be used to endorse or promote products derived from
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//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#pragma once

#include "CSSParserSelector.h"
#include "CSSParserTokenRange.h"
#include <memory>

namespace WebCore {

struct CSSParserContext;
class CSSSelectorList;
class StyleSheetContents;

// FIXME: We should consider building CSSSelectors directly instead of using
// the intermediate CSSParserSelector.
class CSSSelectorParser {
public:
    static CSSSelectorList parseSelector(CSSParserTokenRange, const CSSParserContext&, StyleSheetContents*);

    static bool consumeANPlusB(CSSParserTokenRange&, std::pair<int, int>&);

private:
    CSSSelectorParser(const CSSParserContext&, StyleSheetContents*);

    // These will all consume trailing comments if successful

    CSSSelectorList consumeComplexSelectorList(CSSParserTokenRange&);
    CSSSelectorList consumeCompoundSelectorList(CSSParserTokenRange&);

    std::unique_ptr<CSSParserSelector> consumeComplexSelector(CSSParserTokenRange&);
    std::unique_ptr<CSSParserSelector> consumeCompoundSelector(CSSParserTokenRange&);
    // This doesn't include element names, since they're handled specially
    std::unique_ptr<CSSParserSelector> consumeSimpleSelector(CSSParserTokenRange&);

    bool consumeName(CSSParserTokenRange&, AtomString& name, AtomString& namespacePrefix);

    // These will return nullptr when the selector is invalid
    std::unique_ptr<CSSParserSelector> consumeId(CSSParserTokenRange&);
    std::unique_ptr<CSSParserSelector> consumeClass(CSSParserTokenRange&);
    std::unique_ptr<CSSParserSelector> consumePseudo(CSSParserTokenRange&);
    std::unique_ptr<CSSParserSelector> consumeAttribute(CSSParserTokenRange&);

    CSSSelector::RelationType consumeCombinator(CSSParserTokenRange&);
    CSSSelector::Match consumeAttributeMatch(CSSParserTokenRange&);
    CSSSelector::AttributeMatchType consumeAttributeFlags(CSSParserTokenRange&);

    const AtomString& defaultNamespace() const;
    const AtomString& determineNamespace(const AtomString& prefix);
    void prependTypeSelectorIfNeeded(const AtomString& namespacePrefix, const AtomString& elementName, CSSParserSelector*);
    static std::unique_ptr<CSSParserSelector> addSimpleSelectorToCompound(std::unique_ptr<CSSParserSelector> compoundSelector, std::unique_ptr<CSSParserSelector> simpleSelector);
    static std::unique_ptr<CSSParserSelector> splitCompoundAtImplicitShadowCrossingCombinator(std::unique_ptr<CSSParserSelector> compoundSelector, const CSSParserContext&);

    const CSSParserContext& m_context;
    RefPtr<StyleSheetContents> m_styleSheet; // FIXME: Should be const

    bool m_failedParsing = false;
    bool m_disallowPseudoElements = false;

    class DisallowPseudoElementsScope {
        WTF_MAKE_NONCOPYABLE(DisallowPseudoElementsScope);
    public:
        DisallowPseudoElementsScope(CSSSelectorParser* parser)
            : m_parser(parser), m_wasDisallowed(m_parser->m_disallowPseudoElements)
        {
            m_parser->m_disallowPseudoElements = true;
        }

        ~DisallowPseudoElementsScope()
        {
            m_parser->m_disallowPseudoElements = m_wasDisallowed;
        }

    private:
        CSSSelectorParser* m_parser;
        bool m_wasDisallowed;
    };
};

} // namespace WebCore