#ifndef TAG_PARSER_ID3V2TAG_H
#define TAG_PARSER_ID3V2TAG_H

#include "./id3v2frame.h"

#include "../fieldbasedtag.h"

#include <map>

namespace TagParser {

class Id3v2Tag;

struct TAG_PARSER_EXPORT FrameComparer {
    bool operator()(uint32 lhs, uint32 rhs) const;
};

class TAG_PARSER_EXPORT Id3v2TagMaker {
    friend class Id3v2Tag;

public:
    void make(std::ostream &stream, uint32 padding, Diagnostics &diag);
    const Id3v2Tag &tag() const;
    uint64 requiredSize() const;

private:
    Id3v2TagMaker(Id3v2Tag &tag, Diagnostics &diag);

    Id3v2Tag &m_tag;
    uint32 m_framesSize;
    uint32 m_requiredSize;
    std::vector<Id3v2FrameMaker> m_maker;
};

/*!
 * \brief Returns the associated tag.
 */
inline const Id3v2Tag &Id3v2TagMaker::tag() const
{
    return m_tag;
}

/*!
 * \brief Returns the number of bytes which will be written when making the tag.
 * \remarks Excludes padding!
 */
inline uint64 Id3v2TagMaker::requiredSize() const
{
    return m_requiredSize;
}

/*!
 * \brief Defines traits for the TagField implementation of the Id3v2Tag class.
 */
template <> class TAG_PARSER_EXPORT FieldMapBasedTagTraits<Id3v2Tag> {
public:
    typedef Id3v2Frame FieldType;
    typedef FrameComparer Compare;
};

class TAG_PARSER_EXPORT Id3v2Tag : public FieldMapBasedTag<Id3v2Tag> {
    friend class FieldMapBasedTag<Id3v2Tag>;

public:
    Id3v2Tag();

    static constexpr TagType tagType = TagType::Id3v2Tag;
    static constexpr const char *tagName = "ID3v2 tag";
    static constexpr TagTextEncoding defaultTextEncoding = TagTextEncoding::Utf16LittleEndian;
    TagTextEncoding proposedTextEncoding() const override;
    bool canEncodingBeUsed(TagTextEncoding encoding) const override;
    bool supportsDescription(KnownField field) const override;
    bool supportsMimeType(KnownField field) const override;

    void parse(std::istream &sourceStream, const uint64 maximalSize, Diagnostics &diag);
    Id3v2TagMaker prepareMaking(Diagnostics &diag);
    void make(std::ostream &targetStream, uint32 padding, Diagnostics &diag);

    byte majorVersion() const;
    byte revisionVersion() const;
    void setVersion(byte majorVersion, byte revisionVersion);
    bool isVersionSupported() const;
    byte flags() const;
    bool isUnsynchronisationUsed() const;
    bool hasExtendedHeader() const;
    bool isExperimental() const;
    bool hasFooter() const;
    uint32 extendedHeaderSize() const;
    uint32 paddingSize() const;

protected:
    IdentifierType internallyGetFieldId(KnownField field) const;
    KnownField internallyGetKnownField(const IdentifierType &id) const;
    TagDataType internallyGetProposedDataType(const uint32 &id) const;

private:
    byte m_majorVersion;
    byte m_revisionVersion;
    byte m_flags;
    uint32 m_sizeExcludingHeader;
    uint32 m_extendedHeaderSize;
    uint32 m_paddingSize;
};

/*!
 * \brief Constructs a new tag.
 */
inline Id3v2Tag::Id3v2Tag()
    : m_majorVersion(4)
    , m_revisionVersion(0)
    , m_flags(0)
    , m_sizeExcludingHeader(0)
    , m_extendedHeaderSize(0)
    , m_paddingSize(0)
{
}

inline TagTextEncoding Id3v2Tag::proposedTextEncoding() const
{
    return m_majorVersion > 3 ? TagTextEncoding::Utf8 : TagTextEncoding::Utf16LittleEndian;
}

inline bool Id3v2Tag::canEncodingBeUsed(TagTextEncoding encoding) const
{
    return encoding == TagTextEncoding::Latin1 || (encoding == TagTextEncoding::Utf8 && m_majorVersion > 3)
        || encoding == TagTextEncoding::Utf16BigEndian || encoding == TagTextEncoding::Utf16LittleEndian;
}

inline bool Id3v2Tag::supportsDescription(KnownField field) const
{
    return field == KnownField::Cover;
}

inline bool Id3v2Tag::supportsMimeType(KnownField field) const
{
    return field == KnownField::Cover;
}

/*!
 * \brief Returns the major version if known; otherwise returns 0.
 */
inline byte Id3v2Tag::majorVersion() const
{
    return m_majorVersion;
}

/*!
 * \brief Returns the revision version if known; otherwise returns 0.
 */
inline byte Id3v2Tag::revisionVersion() const
{
    return m_revisionVersion;
}

/*!
 * \brief Returns an indication whether the version is supported by
 *        the Id3v2Tag class.
 *
 * Major versions 2, 3 and 4 are currently supported.
 */
inline bool Id3v2Tag::isVersionSupported() const
{
    return m_majorVersion == 2 || m_majorVersion == 3 || m_majorVersion == 4;
}

/*!
 * \brief Returns the flags read from the ID3v2 header.
 */
inline byte Id3v2Tag::flags() const
{
    return m_flags;
}

/*!
 * \brief Returns an indication whether unsynchronisation is used.
 */
inline bool Id3v2Tag::isUnsynchronisationUsed() const
{
    return m_flags & 0x80;
}

/*!
 * \brief Returns an indication whether an extended header is used.
 */
inline bool Id3v2Tag::hasExtendedHeader() const
{
    return (m_majorVersion >= 3) && (m_flags & 0x40);
}

/*!
 * \brief Returns an indication whether the tag is labeled as experimental.
 */
inline bool Id3v2Tag::isExperimental() const
{
    return (m_majorVersion >= 3) && (m_flags & 0x20);
}

/*!
 * \brief Returns an indication whether a footer is present.
 */
inline bool Id3v2Tag::hasFooter() const
{
    return (m_majorVersion >= 3) && (m_flags & 0x10);
}

/*!
 * \brief Returns the size of the extended header if one is present; otherwise returns 0.
 */
inline uint32 Id3v2Tag::extendedHeaderSize() const
{
    return m_extendedHeaderSize;
}

/*!
 * \brief Returns the size of the padding between the tag and the first MPEG frame
 *        if one is present; otherwise returns 0.
 */
inline uint32 Id3v2Tag::paddingSize() const
{
    return m_paddingSize;
}

} // namespace TagParser

#endif // TAG_PARSER_ID3V2TAG_H