"""
See Portable Document Format Reference Manual, 1993. ISBN 0-201-62628-4.

See https://ia802202.us.archive.org/8/items/pdfy-0vt8s-egqFwDl7L2/PDF%20Reference%201.0.pdf

PDF Reference, third edition, Version 1.4, 2001. ISBN 0-201-75839-3.

PDF Reference, sixth edition, Version 1.7, 2006.
"""

from enum import IntFlag, auto
from typing import Dict, Tuple


class Core:
    """Keywords that don't quite belong anywhere else."""

    OUTLINES = "/Outlines"
    THREADS = "/Threads"
    PAGE = "/Page"
    PAGES = "/Pages"
    CATALOG = "/Catalog"


class TrailerKeys:
    ROOT = "/Root"
    ENCRYPT = "/Encrypt"
    ID = "/ID"
    INFO = "/Info"
    SIZE = "/Size"


class CatalogAttributes:
    NAMES = "/Names"
    DESTS = "/Dests"


class EncryptionDictAttributes:
    """
    Additional encryption dictionary entries for the standard security handler.

    TABLE 3.19, Page 122
    """

    R = "/R"  # number, required; revision of the standard security handler
    O = "/O"  # 32-byte string, required  # noqa
    U = "/U"  # 32-byte string, required
    P = "/P"  # integer flag, required; permitted operations
    ENCRYPT_METADATA = "/EncryptMetadata"  # boolean flag, optional


class UserAccessPermissions(IntFlag):
    """TABLE 3.20 User access permissions."""

    R1 = 1
    R2 = 2
    PRINT = 4
    MODIFY = 8
    EXTRACT = 16
    ADD_OR_MODIFY = 32
    R7 = 64
    R8 = 128
    FILL_FORM_FIELDS = 256
    EXTRACT_TEXT_AND_GRAPHICS = 512
    ASSEMBLE_DOC = 1024
    PRINT_TO_REPRESENTATION = 2048
    R13 = 2**12
    R14 = 2**13
    R15 = 2**14
    R16 = 2**15
    R17 = 2**16
    R18 = 2**17
    R19 = 2**18
    R20 = 2**19
    R21 = 2**20
    R22 = 2**21
    R23 = 2**22
    R24 = 2**23
    R25 = 2**24
    R26 = 2**25
    R27 = 2**26
    R28 = 2**27
    R29 = 2**28
    R30 = 2**29
    R31 = 2**30
    R32 = 2**31

    @classmethod
    def _is_reserved(cls, name: str) -> bool:
        """Check if the given name corresponds to a reserved flag entry."""
        return name.startswith("R") and name[1:].isdigit()

    @classmethod
    def _is_active(cls, name: str) -> bool:
        """Check if the given reserved name defaults to 1 = active."""
        return name not in {"R1", "R2"}

    def to_dict(self) -> Dict[str, bool]:
        """Convert the given flag value to a corresponding verbose name mapping."""
        result: Dict[str, bool] = {}
        for name, flag in UserAccessPermissions.__members__.items():
            if UserAccessPermissions._is_reserved(name):
                continue
            result[name.lower()] = (self & flag) == flag
        return result

    @classmethod
    def from_dict(cls, value: Dict[str, bool]) -> "UserAccessPermissions":
        """Convert the verbose name mapping to the corresponding flag value."""
        value_copy = value.copy()
        result = cls(0)
        for name, flag in cls.__members__.items():
            if cls._is_reserved(name):
                # Reserved names have a required value. Use it.
                if cls._is_active(name):
                    result |= flag
                continue
            is_active = value_copy.pop(name.lower(), False)
            if is_active:
                result |= flag
        if value_copy:
            raise ValueError(f"Unknown dictionary keys: {value_copy!r}")
        return result

    @classmethod
    def all(cls) -> "UserAccessPermissions":
        return cls((2**32 - 1) - cls.R1 - cls.R2)


class Ressources:
    """TABLE 3.30 Entries in a resource dictionary."""

    EXT_G_STATE = "/ExtGState"  # dictionary, optional
    COLOR_SPACE = "/ColorSpace"  # dictionary, optional
    PATTERN = "/Pattern"  # dictionary, optional
    SHADING = "/Shading"  # dictionary, optional
    XOBJECT = "/XObject"  # dictionary, optional
    FONT = "/Font"  # dictionary, optional
    PROC_SET = "/ProcSet"  # array, optional
    PROPERTIES = "/Properties"  # dictionary, optional


class PagesAttributes:
    """Page Attributes, Table 6.2, Page 52."""

    TYPE = "/Type"  # name, required; must be /Pages
    KIDS = "/Kids"  # array, required; List of indirect references
    COUNT = "/Count"  # integer, required; the number of all nodes und this node
    PARENT = "/Parent"  # dictionary, required; indirect reference to pages object


class PageAttributes:
    """TABLE 3.27 Entries in a page object."""

    TYPE = "/Type"  # name, required; must be /Page
    PARENT = "/Parent"  # dictionary, required; a pages object
    LAST_MODIFIED = (
        "/LastModified"  # date, optional; date and time of last modification
    )
    RESOURCES = "/Resources"  # dictionary, required if there are any
    MEDIABOX = "/MediaBox"  # rectangle, required; rectangle specifying page size
    CROPBOX = "/CropBox"  # rectangle, optional; rectangle
    BLEEDBOX = "/BleedBox"  # rectangle, optional; rectangle
    TRIMBOX = "/TrimBox"  # rectangle, optional; rectangle
    ARTBOX = "/ArtBox"  # rectangle, optional; rectangle
    BOX_COLOR_INFO = "/BoxColorInfo"  # dictionary, optional
    CONTENTS = "/Contents"  # stream or array, optional
    ROTATE = "/Rotate"  # integer, optional; page rotation in degrees
    GROUP = "/Group"  # dictionary, optional; page group
    THUMB = "/Thumb"  # stream, optional; indirect reference to image of the page
    B = "/B"  # array, optional
    DUR = "/Dur"  # number, optional
    TRANS = "/Trans"  # dictionary, optional
    ANNOTS = "/Annots"  # array, optional; an array of annotations
    AA = "/AA"  # dictionary, optional
    METADATA = "/Metadata"  # stream, optional
    PIECE_INFO = "/PieceInfo"  # dictionary, optional
    STRUCT_PARENTS = "/StructParents"  # integer, optional
    ID = "/ID"  # byte string, optional
    PZ = "/PZ"  # number, optional
    TABS = "/Tabs"  # name, optional
    TEMPLATE_INSTANTIATED = "/TemplateInstantiated"  # name, optional
    PRES_STEPS = "/PresSteps"  # dictionary, optional
    USER_UNIT = "/UserUnit"  # number, optional
    VP = "/VP"  # dictionary, optional


class FileSpecificationDictionaryEntries:
    """TABLE 3.41 Entries in a file specification dictionary."""

    Type = "/Type"
    FS = "/FS"  # The name of the file system to be used to interpret this file specification
    F = "/F"  # A file specification string of the form described in Section 3.10.1
    UF = "/UF"  # A unicode string of the file as described in Section 3.10.1
    DOS = "/DOS"
    Mac = "/Mac"
    Unix = "/Unix"
    ID = "/ID"
    V = "/V"
    EF = "/EF"  # dictionary, containing a subset of the keys F , UF , DOS , Mac , and Unix
    RF = "/RF"  # dictionary, containing arrays of /EmbeddedFile
    DESC = "/Desc"  # description of the file
    Cl = "/Cl"


class StreamAttributes:
    """Table 4.2."""

    LENGTH = "/Length"  # integer, required
    FILTER = "/Filter"  # name or array of names, optional
    DECODE_PARMS = "/DecodeParms"  # variable, optional -- 'decodeParams is wrong


class FilterTypes:
    """
    Table 4.3 of the 1.4 Manual.

    Page 354 of the 1.7 Manual
    """

    ASCII_HEX_DECODE = "/ASCIIHexDecode"  # abbreviation: AHx
    ASCII_85_DECODE = "/ASCII85Decode"  # abbreviation: A85
    LZW_DECODE = "/LZWDecode"  # abbreviation: LZW
    FLATE_DECODE = "/FlateDecode"  # abbreviation: Fl, PDF 1.2
    RUN_LENGTH_DECODE = "/RunLengthDecode"  # abbreviation: RL
    CCITT_FAX_DECODE = "/CCITTFaxDecode"  # abbreviation: CCF
    DCT_DECODE = "/DCTDecode"  # abbreviation: DCT
    JPX_DECODE = "/JPXDecode"


class FilterTypeAbbreviations:
    """Table 4.44 of the 1.7 Manual (page 353ff)."""

    AHx = "/AHx"
    A85 = "/A85"
    LZW = "/LZW"
    FL = "/Fl"  # FlateDecode
    RL = "/RL"
    CCF = "/CCF"
    DCT = "/DCT"


class LzwFilterParameters:
    """Table 4.4."""

    PREDICTOR = "/Predictor"  # integer
    COLUMNS = "/Columns"  # integer
    COLORS = "/Colors"  # integer
    BITS_PER_COMPONENT = "/BitsPerComponent"  # integer
    EARLY_CHANGE = "/EarlyChange"  # integer


class CcittFaxDecodeParameters:
    """Table 4.5."""

    K = "/K"  # integer
    END_OF_LINE = "/EndOfLine"  # boolean
    ENCODED_BYTE_ALIGN = "/EncodedByteAlign"  # boolean
    COLUMNS = "/Columns"  # integer
    ROWS = "/Rows"  # integer
    END_OF_BLOCK = "/EndOfBlock"  # boolean
    BLACK_IS_1 = "/BlackIs1"  # boolean
    DAMAGED_ROWS_BEFORE_ERROR = "/DamagedRowsBeforeError"  # integer


class ImageAttributes:
    """Table 4.39 Pdf Reference 1.7 page 340+"""

    TYPE = "/Type"  # name, required; must be /XObject
    SUBTYPE = "/Subtype"  # name, required; must be /Image
    NAME = "/Name"  # name, required
    WIDTH = "/Width"  # integer, required
    HEIGHT = "/Height"  # integer, required
    BITS_PER_COMPONENT = "/BitsPerComponent"  # integer, required
    COLOR_SPACE = "/ColorSpace"  # name, required
    DECODE = "/Decode"  # array, optional
    INTENT = "/Intent"  # string, optional
    INTERPOLATE = "/Interpolate"  # boolean, optional
    IMAGE_MASK = "/ImageMask"  # boolean, optional
    MASK = "/Mask"  # 1-bit image mask stream
    S_MASK = "/SMask"  # dictionary or name, optional


class ColorSpaces:
    DEVICE_RGB = "/DeviceRGB"
    DEVICE_CMYK = "/DeviceCMYK"
    DEVICE_GRAY = "/DeviceGray"


class TypArguments:
    """Table 8.2 of the PDF 1.7 reference."""

    LEFT = "/Left"
    RIGHT = "/Right"
    BOTTOM = "/Bottom"
    TOP = "/Top"


class TypFitArguments:
    """Table 8.2 of the PDF 1.7 reference."""

    FIT = "/Fit"
    FIT_V = "/FitV"
    FIT_BV = "/FitBV"
    FIT_B = "/FitB"
    FIT_H = "/FitH"
    FIT_BH = "/FitBH"
    FIT_R = "/FitR"
    XYZ = "/XYZ"


class GoToActionArguments:
    S = "/S"  # name, required: type of action
    D = "/D"  # name / byte string /array, required: Destination to jump to


class AnnotationDictionaryAttributes:
    """TABLE 8.15 Entries common to all annotation dictionaries."""

    Type = "/Type"
    Subtype = "/Subtype"
    Rect = "/Rect"
    Contents = "/Contents"
    P = "/P"
    NM = "/NM"
    M = "/M"
    F = "/F"
    AP = "/AP"
    AS = "/AS"
    DA = "/DA"
    Border = "/Border"
    C = "/C"
    StructParent = "/StructParent"
    OC = "/OC"


class InteractiveFormDictEntries:
    Fields = "/Fields"
    NeedAppearances = "/NeedAppearances"
    SigFlags = "/SigFlags"
    CO = "/CO"
    DR = "/DR"
    DA = "/DA"
    Q = "/Q"
    XFA = "/XFA"


class FieldDictionaryAttributes:
    """TABLE 8.69 Entries common to all field dictionaries (PDF 1.7 reference)."""

    FT = "/FT"  # name, required for terminal fields
    Parent = "/Parent"  # dictionary, required for children
    Kids = "/Kids"  # array, sometimes required
    T = "/T"  # text string, optional
    TU = "/TU"  # text string, optional
    TM = "/TM"  # text string, optional
    Ff = "/Ff"  # integer, optional
    V = "/V"  # text string or array, optional
    DV = "/DV"  # text string, optional
    AA = "/AA"  # dictionary, optional
    Opt = "/Opt"

    class FfBits:
        ReadOnly = 1 << 0
        Required = 1 << 1
        NoExport = 1 << 2
        Multiline = 1 << 12  # Tx Table 8.77
        Password = 1 << 13  # Tx

        NoToggleToOff = 1 << 14  # Btn table 8.75
        Radio = 1 << 15  # Btn
        Pushbutton = 1 << 16  # Btn

        Combo = 1 << 17  # Ch table 8.79
        Edit = 1 << 18  # Ch
        Sort = 1 << 19  # Ch

        FileSelect = 1 << 20  # Tx

        MultiSelect = 1 << 21  # Ch

        DoNotSpellCheck = 1 << 22  # Tx / Ch
        DoNotScroll = 1 << 23  # Tx
        Comb = 1 << 24  # Tx

        RadiosInUnison = 1 << 25  # Btn

        RichText = 1 << 25  # Tx

        CommitOnSelChange = 1 << 26  # Ch

    @classmethod
    def attributes(cls) -> Tuple[str, ...]:
        """
        Get a tuple of all the attributes present in a Field Dictionary.

        This method returns a tuple of all the attribute constants defined in
        the FieldDictionaryAttributes class. These attributes correspond to the
        entries that are common to all field dictionaries as specified in the
        PDF 1.7 reference.

        Returns:
            A tuple containing all the attribute constants.
        """
        return (
            cls.TM,
            cls.T,
            cls.FT,
            cls.Parent,
            cls.TU,
            cls.Ff,
            cls.V,
            cls.DV,
            cls.Kids,
            cls.AA,
        )

    @classmethod
    def attributes_dict(cls) -> Dict[str, str]:
        """
        Get a dictionary of attribute keys and their human-readable names.

        This method returns a dictionary where the keys are the attribute
        constants defined in the FieldDictionaryAttributes class and the values
        are their corresponding human-readable names. These attributes
        correspond to the entries that are common to all field dictionaries as
        specified in the PDF 1.7 reference.

        Returns:
            A dictionary containing attribute keys and their names.
        """
        return {
            cls.FT: "Field Type",
            cls.Parent: "Parent",
            cls.T: "Field Name",
            cls.TU: "Alternate Field Name",
            cls.TM: "Mapping Name",
            cls.Ff: "Field Flags",
            cls.V: "Value",
            cls.DV: "Default Value",
        }


class CheckboxRadioButtonAttributes:
    """TABLE 8.76 Field flags common to all field types."""

    Opt = "/Opt"  # Options, Optional

    @classmethod
    def attributes(cls) -> Tuple[str, ...]:
        """
        Get a tuple of all the attributes present in a Field Dictionary.

        This method returns a tuple of all the attribute constants defined in
        the CheckboxRadioButtonAttributes class. These attributes correspond to
        the entries that are common to all field dictionaries as specified in
        the PDF 1.7 reference.

        Returns:
            A tuple containing all the attribute constants.
        """
        return (cls.Opt,)

    @classmethod
    def attributes_dict(cls) -> Dict[str, str]:
        """
        Get a dictionary of attribute keys and their human-readable names.

        This method returns a dictionary where the keys are the attribute
        constants defined in the CheckboxRadioButtonAttributes class and the
        values are their corresponding human-readable names. These attributes
        correspond to the entries that are common to all field dictionaries as
        specified in the PDF 1.7 reference.

        Returns:
            A dictionary containing attribute keys and their names.
        """
        return {
            cls.Opt: "Options",
        }


class FieldFlag(IntFlag):
    """TABLE 8.70 Field flags common to all field types."""

    READ_ONLY = 1
    REQUIRED = 2
    NO_EXPORT = 4


class DocumentInformationAttributes:
    """TABLE 10.2 Entries in the document information dictionary."""

    TITLE = "/Title"  # text string, optional
    AUTHOR = "/Author"  # text string, optional
    SUBJECT = "/Subject"  # text string, optional
    KEYWORDS = "/Keywords"  # text string, optional
    CREATOR = "/Creator"  # text string, optional
    PRODUCER = "/Producer"  # text string, optional
    CREATION_DATE = "/CreationDate"  # date, optional
    MOD_DATE = "/ModDate"  # date, optional
    TRAPPED = "/Trapped"  # name, optional


class PageLayouts:
    """Page 84, PDF 1.4 reference."""

    SINGLE_PAGE = "/SinglePage"
    ONE_COLUMN = "/OneColumn"
    TWO_COLUMN_LEFT = "/TwoColumnLeft"
    TWO_COLUMN_RIGHT = "/TwoColumnRight"


class GraphicsStateParameters:
    """Table 58 – Entries in a Graphics State Parameter Dictionary"""

    TYPE = "/Type"  # name, optional
    LW = "/LW"  # number, optional
    LC = "/LC"  # integer, optional
    LJ = "/LJ"  # integer, optional
    ML = "/ML"  # number, optional
    D = "/D"  # array, optional
    RI = "/RI"  # name, optional
    OP = "/OP"
    op = "/op"
    OPM = "/OPM"
    FONT = "/Font"  # array, optional
    BG = "/BG"
    BG2 = "/BG2"
    UCR = "/UCR"
    UCR2 = "/UCR2"
    TR = "/TR"
    TR2 = "/TR2"
    HT = "/HT"
    FL = "/FL"
    SM = "/SM"
    SA = "/SA"
    BM = "/BM"
    S_MASK = "/SMask"  # dictionary or name, optional
    CA = "/CA"
    ca = "/ca"
    AIS = "/AIS"
    TK = "/TK"


class CatalogDictionary:
    """Table 3.25 in the 1.7 reference."""

    TYPE = "/Type"  # name, required; must be /Catalog
    VERSION = "/Version"  # name
    PAGES = "/Pages"  # dictionary, required
    PAGE_LABELS = "/PageLabels"  # number tree, optional
    NAMES = "/Names"  # dictionary, optional
    DESTS = "/Dests"  # dictionary, optional
    VIEWER_PREFERENCES = "/ViewerPreferences"  # dictionary, optional
    PAGE_LAYOUT = "/PageLayout"  # name, optional
    PAGE_MODE = "/PageMode"  # name, optional
    OUTLINES = "/Outlines"  # dictionary, optional
    THREADS = "/Threads"  # array, optional
    OPEN_ACTION = "/OpenAction"  # array or dictionary or name, optional
    AA = "/AA"  # dictionary, optional
    URI = "/URI"  # dictionary, optional
    ACRO_FORM = "/AcroForm"  # dictionary, optional
    METADATA = "/Metadata"  # stream, optional
    STRUCT_TREE_ROOT = "/StructTreeRoot"  # dictionary, optional
    MARK_INFO = "/MarkInfo"  # dictionary, optional
    LANG = "/Lang"  # text string, optional
    SPIDER_INFO = "/SpiderInfo"  # dictionary, optional
    OUTPUT_INTENTS = "/OutputIntents"  # array, optional
    PIECE_INFO = "/PieceInfo"  # dictionary, optional
    OC_PROPERTIES = "/OCProperties"  # dictionary, optional
    PERMS = "/Perms"  # dictionary, optional
    LEGAL = "/Legal"  # dictionary, optional
    REQUIREMENTS = "/Requirements"  # array, optional
    COLLECTION = "/Collection"  # dictionary, optional
    NEEDS_RENDERING = "/NeedsRendering"  # boolean, optional


class OutlineFontFlag(IntFlag):
    """A class used as an enumerable flag for formatting an outline font."""

    italic = 1
    bold = 2


class PageLabelStyle:
    """Table 8.10 in the 1.7 reference."""

    DECIMAL = "/D"  # Decimal arabics
    LOWERCASE_ROMAN = "/r"  # Lowercase roman numbers
    UPPERCASE_ROMAN = "/R"  # Uppercase roman numbers
    LOWERCASE_LETTER = "/a"  # Lowercase letters
    UPPERCASE_LETTER = "/A"  # Uppercase letters


class AnnotationFlag(IntFlag):
    """See 12.5.3 "Annotation Flags"."""

    INVISIBLE = 1
    HIDDEN = 2
    PRINT = 4
    NO_ZOOM = 8
    NO_ROTATE = 16
    NO_VIEW = 32
    READ_ONLY = 64
    LOCKED = 128
    TOGGLE_NO_VIEW = 256
    LOCKED_CONTENTS = 512


PDF_KEYS = (
    AnnotationDictionaryAttributes,
    CatalogAttributes,
    CatalogDictionary,
    CcittFaxDecodeParameters,
    CheckboxRadioButtonAttributes,
    ColorSpaces,
    Core,
    DocumentInformationAttributes,
    EncryptionDictAttributes,
    FieldDictionaryAttributes,
    FilterTypeAbbreviations,
    FilterTypes,
    GoToActionArguments,
    GraphicsStateParameters,
    ImageAttributes,
    FileSpecificationDictionaryEntries,
    LzwFilterParameters,
    PageAttributes,
    PageLayouts,
    PagesAttributes,
    Ressources,
    StreamAttributes,
    TrailerKeys,
    TypArguments,
    TypFitArguments,
)


class ImageType(IntFlag):
    NONE = 0
    XOBJECT_IMAGES = auto()
    INLINE_IMAGES = auto()
    DRAWING_IMAGES = auto()
    ALL = XOBJECT_IMAGES | INLINE_IMAGES | DRAWING_IMAGES
    IMAGES = ALL  # for consistency with ObjectDeletionFlag
