/*
 * Copyright (C) 2003-2019 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#pragma once

#include <wtf/Forward.h>
#include <wtf/RetainPtr.h>
#include <wtf/text/WTFString.h>

#if USE(CF)
typedef const struct __CFURL* CFURLRef;
#endif

#if USE(FOUNDATION)
OBJC_CLASS NSURL;
#endif

namespace WTF {

class TextStream;

class URLTextEncoding {
public:
    virtual Vector<uint8_t> encodeForURLParsing(StringView) const = 0;
protected:
    virtual ~URLTextEncoding() { }
};

class URL {
    WTF_MAKE_FAST_ALLOCATED;
public:
    // Generates a URL which contains a null string.
    URL() { invalidate(); }

    explicit URL(HashTableDeletedValueType);
    bool isHashTableDeletedValue() const { return m_string.isHashTableDeletedValue(); }

    // Resolves the relative URL with the given base URL. If provided, the
    // URLTextEncoding is used to encode non-ASCII characers. The base URL can be
    // null or empty, in which case the relative URL will be interpreted as absolute.
    WTF_EXPORT_PRIVATE URL(const URL& base, const String& relative, const URLTextEncoding* = nullptr);

    WTF_EXPORT_PRIVATE static URL fakeURLWithRelativePart(StringView);
    WTF_EXPORT_PRIVATE static URL fileURLWithFileSystemPath(StringView);

    WTF_EXPORT_PRIVATE String strippedForUseAsReferrer() const;

    // Makes a deep copy. Helpful only if you need to use a URL on another
    // thread. Since the underlying StringImpl objects are immutable, there's
    // no other reason to ever prefer isolatedCopy() over plain old assignment.
    WTF_EXPORT_PRIVATE URL isolatedCopy() const;

    bool isNull() const;
    bool isEmpty() const;
    bool isValid() const;

    // Returns true if you can set the host and port for the URL.
    // Non-hierarchical URLs don't have a host and port.
    bool canSetHostOrPort() const { return isHierarchical(); }

    bool canSetPathname() const { return isHierarchical(); }
    WTF_EXPORT_PRIVATE bool isHierarchical() const;

    const String& string() const { return m_string; }
    WTF_EXPORT_PRIVATE String stringCenterEllipsizedToLength(unsigned length = 1024) const;

    // Unlike user() and password(), encodedUser() and encodedPassword() don't decode escape sequences.
    // This is necessary for accurate round-tripping, because encoding doesn't encode '%' characters.

    WTF_EXPORT_PRIVATE StringView protocol() const;
    WTF_EXPORT_PRIVATE StringView encodedUser() const;
    WTF_EXPORT_PRIVATE StringView encodedPassword() const;
    WTF_EXPORT_PRIVATE StringView host() const;
    WTF_EXPORT_PRIVATE Optional<uint16_t> port() const;
    WTF_EXPORT_PRIVATE StringView path() const;
    WTF_EXPORT_PRIVATE StringView lastPathComponent() const;
    WTF_EXPORT_PRIVATE StringView query() const;
    WTF_EXPORT_PRIVATE StringView fragmentIdentifier() const;

    WTF_EXPORT_PRIVATE StringView queryWithLeadingQuestionMark() const;
    WTF_EXPORT_PRIVATE StringView fragmentIdentifierWithLeadingNumberSign() const;
    WTF_EXPORT_PRIVATE StringView stringWithoutQueryOrFragmentIdentifier() const;
    StringView stringWithoutFragmentIdentifier() const;

    WTF_EXPORT_PRIVATE String protocolHostAndPort() const;
    WTF_EXPORT_PRIVATE String hostAndPort() const;
    WTF_EXPORT_PRIVATE String user() const;
    WTF_EXPORT_PRIVATE String password() const;
    WTF_EXPORT_PRIVATE String fileSystemPath() const;

    WTF_EXPORT_PRIVATE URL truncatedForUseAsBase() const;

    bool hasQuery() const;
    bool hasFragmentIdentifier() const;
    bool hasPath() const;

    bool hasCredentials() const;

    // Returns true if the current URL's protocol is the same as the null-
    // terminated ASCII argument. The argument must be lower-case.
    WTF_EXPORT_PRIVATE bool protocolIs(const char*) const;
    WTF_EXPORT_PRIVATE bool protocolIs(StringView) const;
    bool protocolIsBlob() const { return protocolIs("blob"); }
    bool protocolIsData() const { return protocolIs("data"); }
    WTF_EXPORT_PRIVATE bool protocolIsAbout() const;
    WTF_EXPORT_PRIVATE bool protocolIsJavaScript() const;
    bool protocolIsInHTTPFamily() const;
    WTF_EXPORT_PRIVATE bool isLocalFile() const;
    bool cannotBeABaseURL() const { return m_cannotBeABaseURL; }

    WTF_EXPORT_PRIVATE bool isAboutBlank() const;
    WTF_EXPORT_PRIVATE bool isAboutSrcDoc() const;

    WTF_EXPORT_PRIVATE bool isMatchingDomain(StringView) const;

    WTF_EXPORT_PRIVATE bool setProtocol(StringView);
    WTF_EXPORT_PRIVATE void setHost(StringView);

    WTF_EXPORT_PRIVATE void setPort(Optional<uint16_t>);

    // Input is like "foo.com" or "foo.com:8000".
    WTF_EXPORT_PRIVATE void setHostAndPort(StringView);

    WTF_EXPORT_PRIVATE void setUser(StringView);
    WTF_EXPORT_PRIVATE void setPassword(StringView);
    WTF_EXPORT_PRIVATE void removeCredentials();

    // If you pass an empty path for HTTP or HTTPS URLs, the resulting path will be "/".
    WTF_EXPORT_PRIVATE void setPath(StringView);

    // The query may begin with a question mark, or, if not, one will be added
    // for you. Setting the query to the empty string will leave a "?" in the
    // URL (with nothing after it). To clear the query, pass a null string.
    WTF_EXPORT_PRIVATE void setQuery(StringView);

    WTF_EXPORT_PRIVATE void setFragmentIdentifier(StringView);
    WTF_EXPORT_PRIVATE void removeFragmentIdentifier();

    WTF_EXPORT_PRIVATE void removeQueryAndFragmentIdentifier();

    WTF_EXPORT_PRIVATE static bool hostIsIPAddress(StringView);

    unsigned pathStart() const;
    unsigned pathEnd() const;
    unsigned pathAfterLastSlash() const;

#if USE(CF)
    WTF_EXPORT_PRIVATE URL(CFURLRef);
    WTF_EXPORT_PRIVATE RetainPtr<CFURLRef> createCFURL() const;
#endif

#if USE(FOUNDATION)
    WTF_EXPORT_PRIVATE URL(NSURL *);
    WTF_EXPORT_PRIVATE operator NSURL *() const;
#endif

#ifndef NDEBUG
    void print() const;
#endif

    template<typename Encoder> void encode(Encoder&) const;
    template<typename Decoder> static WARN_UNUSED_RETURN bool decode(Decoder&, URL&);
    template<typename Decoder> static Optional<URL> decode(Decoder&);

private:
    friend class URLParser;

    WTF_EXPORT_PRIVATE void invalidate();
    unsigned hostStart() const;
    unsigned credentialsEnd() const;
    void remove(unsigned start, unsigned length);
    void parse(const String&);

    friend WTF_EXPORT_PRIVATE bool protocolHostAndPortAreEqual(const URL&, const URL&);

    String m_string;

    unsigned m_isValid : 1;
    unsigned m_protocolIsInHTTPFamily : 1;
    unsigned m_cannotBeABaseURL : 1;

    // This is out of order to align the bits better. The port is after the host.
    unsigned m_portLength : 3;
    static constexpr unsigned maxPortLength = (1 << 3) - 1;

    static constexpr unsigned maxSchemeLength = (1 << 26) - 1;
    unsigned m_schemeEnd : 26;
    unsigned m_userStart;
    unsigned m_userEnd;
    unsigned m_passwordEnd;
    unsigned m_hostEnd;
    unsigned m_pathAfterLastSlash;
    unsigned m_pathEnd;
    unsigned m_queryEnd;
};

static_assert(sizeof(URL) == sizeof(String) + 8 * sizeof(unsigned), "URL should stay small");

bool operator==(const URL&, const URL&);
bool operator==(const URL&, const String&);
bool operator==(const String&, const URL&);
bool operator!=(const URL&, const URL&);
bool operator!=(const URL&, const String&);
bool operator!=(const String&, const URL&);

WTF_EXPORT_PRIVATE bool equalIgnoringFragmentIdentifier(const URL&, const URL&);
WTF_EXPORT_PRIVATE bool protocolHostAndPortAreEqual(const URL&, const URL&);

WTF_EXPORT_PRIVATE const URL& aboutBlankURL();
WTF_EXPORT_PRIVATE const URL& aboutSrcDocURL();

// Functions to do URL operations on strings.
// These are operations that aren't faster on a parsed URL.
// These are also different from the WTF::URL functions in that they don't require the string to be a valid and parsable URL.
// This is especially important because valid javascript URLs are not necessarily considered valid by WTF::URL.

WTF_EXPORT_PRIVATE bool protocolIs(StringView url, const char* protocol);
WTF_EXPORT_PRIVATE bool protocolIsJavaScript(StringView url);
WTF_EXPORT_PRIVATE bool protocolIsInHTTPFamily(StringView url);

WTF_EXPORT_PRIVATE Optional<uint16_t> defaultPortForProtocol(StringView protocol);
WTF_EXPORT_PRIVATE bool isDefaultPortForProtocol(uint16_t port, StringView protocol);
WTF_EXPORT_PRIVATE bool portAllowed(const URL&); // Blacklist ports that should never be used for Web resources.

WTF_EXPORT_PRIVATE void registerDefaultPortForProtocolForTesting(uint16_t port, const String& protocol);
WTF_EXPORT_PRIVATE void clearDefaultPortForProtocolMapForTesting();

WTF_EXPORT_PRIVATE String mimeTypeFromDataURL(StringView dataURL);

// FIXME: This needs a new, more specific name. The general thing named here can't be implemented correctly, since different parts of a URL need different escaping.
WTF_EXPORT_PRIVATE String encodeWithURLEscapeSequences(const String&);

#ifdef __OBJC__

WTF_EXPORT_PRIVATE RetainPtr<id> makeNSArrayElement(const URL&);
WTF_EXPORT_PRIVATE Optional<URL> makeVectorElement(const URL*, id);

#endif

WTF_EXPORT_PRIVATE TextStream& operator<<(TextStream&, const URL&);

template<> struct DefaultHash<URL>;
template<> struct HashTraits<URL>;

// Function template and inline function definitions.

template<typename Encoder> void URL::encode(Encoder& encoder) const
{
    encoder << m_string;
}

template<typename Decoder> bool URL::decode(Decoder& decoder, URL& url)
{
    auto optionalURL = decode(decoder);
    if (!optionalURL)
        return false;
    url = WTFMove(*optionalURL);
    return true;
}

template<typename Decoder> Optional<URL> URL::decode(Decoder& decoder)
{
    Optional<String> string;
    decoder >> string;
    if (!string)
        return WTF::nullopt;
    return URL(URL(), WTFMove(*string));
}

inline bool operator==(const URL& a, const URL& b)
{
    return a.string() == b.string();
}

inline bool operator==(const URL& a, const String& b)
{
    return a.string() == b;
}

inline bool operator==(const String& a, const URL& b)
{
    return a == b.string();
}

inline bool operator!=(const URL& a, const URL& b)
{
    return a.string() != b.string();
}

inline bool operator!=(const URL& a, const String& b)
{
    return a.string() != b;
}

inline bool operator!=(const String& a, const URL& b)
{
    return a != b.string();
}

inline URL::URL(HashTableDeletedValueType)
    : m_string(HashTableDeletedValue)
{
}

inline bool URL::isNull() const
{
    return m_string.isNull();
}

inline bool URL::isEmpty() const
{
    return m_string.isEmpty();
}

inline bool URL::isValid() const
{
    return m_isValid;
}

inline bool URL::hasPath() const
{
    return m_pathEnd > pathStart();
}

inline bool URL::hasCredentials() const
{
    return m_passwordEnd > m_userStart;
}

inline bool URL::hasQuery() const
{
    return m_queryEnd > m_pathEnd;
}

inline bool URL::hasFragmentIdentifier() const
{
    return m_isValid && m_string.length() > m_queryEnd;
}

inline bool URL::protocolIsInHTTPFamily() const
{
    return m_protocolIsInHTTPFamily;
}

inline unsigned URL::pathStart() const
{
    return m_hostEnd + m_portLength;
}

inline unsigned URL::pathEnd() const
{
    return m_pathEnd;
}

inline unsigned URL::pathAfterLastSlash() const
{
    return m_pathAfterLastSlash;
}

} // namespace WTF

using WTF::aboutBlankURL;
using WTF::aboutSrcDocURL;