//! Error types.

use std::io::Error as IoError;
use std::path::PathBuf;

use plist::Error as PlistError;
use quick_xml::events::attributes::AttrError;
use quick_xml::{DeError, Error as XmlError};
use thiserror::Error;

pub use crate::shared_types::ColorError;
use crate::write::CustomSerializationError;
use crate::Name;

/// An error that occurs while attempting to read a designspace file from disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum DesignSpaceLoadError {
    /// An [`std::io::Error`].
    #[error("failed to read designspace file: {0}")]
    Io(#[from] IoError),

    /// A parse error.
    #[error("failed to deserialize designspace: {0}")]
    DeError(#[from] DeError),
}

/// An error that occurs while attempting to write a designspace file to disk.
#[derive(Debug, Error)]
pub enum DesignSpaceSaveError {
    /// An [`std::io::Error`].
    #[error("failed to open/write designspace file: {0}")]
    Io(#[from] IoError),

    /// A serialization error.
    #[error("failed to serialize designspace: {0}")]
    SeError(#[from] DeError),
}

/// An error representing a failure to (re)name something.
#[derive(Debug, Error)]
pub enum NamingError {
    /// An error returned when an item is duplicated.
    #[error("item '{0}' already exists")]
    Duplicate(String),
    /// An error returned when an expected item is missing.
    #[error("item '{0}' does not exist")]
    Missing(String),
    /// A name is empty, or contains [control characters].
    ///
    /// [control characters]: https://unifiedfontobject.org/versions/ufo3/conventions/#controls
    #[error("'{0}' is not a valid name")]
    Invalid(String),
    /// An error returned when the name "public.default" is used for a non-default layer.
    #[error("only the default layer may be named 'public.default'")]
    ReservedName,
}

/// An error that occurs while attempting to read a .glif file from disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum GlifLoadError {
    /// An [`std::io::Error`].
    #[error("failed to read file")]
    Io(#[from] IoError),
    /// A [`quick_xml::Error`].
    #[error("failed to read or parse XML structure")]
    Xml(#[from] XmlError),
    /// An error in an XML attribute
    #[error("error parsing XML attribute")]
    XmlAttr(#[from] AttrError),
    /// The .glif file was malformed.
    #[error("failed to parse glyph data: {0}")]
    Parse(ErrorKind),
    /// The glyph lib's `public.objectLibs` value was something other than a dictionary.
    #[error("the glyph lib's 'public.objectLibs' value must be a dictionary")]
    PublicObjectLibsMustBeDictionary,
    /// The entry with the given identifier within the glyph lib's `public.objectLibs` dictionary was not a dictionary.
    #[error("the glyph lib's 'public.objectLibs' entry for the object with identifier '{0}' must be a dictionary")]
    ObjectLibMustBeDictionary(String),
}

/// An error that occurs while attempting to read a UFO package from disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum FontLoadError {
    /// The UFO cannot be accessed.
    #[error("cannot access UFO package")]
    AccessUfoDir(#[source] IoError),
    /// Failed to load a file from the data store.
    #[error("failed to load data store")]
    DataStore(#[source] StoreEntryError),
    /// Failed to load the features.fea file.
    #[error("failed to read features.fea file")]
    FeatureFile(#[source] IoError),
    /// Failed to load the fontinfo.plist file.
    #[error("failed to load font info data")]
    FontInfo(#[source] FontInfoLoadError),
    /// The upgrade process failed to move font info data from the old lib.plist schema to the new fontinfo.plist schema.
    #[error("failed to upgrade old lib.plist to current fontinfo.plist data: {0}")]
    FontInfoV1Upconversion(FontInfoErrorKind),
    /// The upgrade process failed to convert kerning groups from old to the new UFO v3 format.
    #[error("failed to upconvert groups to the latest supported format")]
    GroupsUpconversionFailure(#[source] GroupsValidationError),
    /// Failed to load a file from the image store.
    #[error("failed to load images store")]
    ImagesStore(#[source] StoreEntryError),
    /// The (kerning) groups in kerning.plist fail validation.
    #[error("failed to load (kerning) groups")]
    InvalidGroups(#[source] GroupsValidationError),
    /// Failed to load a specific layer.
    #[error("failed to load layer '{name}' from '{path}'")]
    Layer {
        /// The layer name.
        name: String,
        /// The path to the layer.
        path: PathBuf,
        /// The underlying error.
        source: Box<LayerLoadError>,
    },
    /// The lib.plist file was something other than a dictionary.
    #[error("the lib.plist file must contain a dictionary (<dict>...</dict>)")]
    LibFileMustBeDictionary,
    /// The UFO does not have a default layer.
    #[error("missing the default layer ('glyphs' subdirectory)")]
    MissingDefaultLayer,
    /// The UFO does not have a default layer.
    #[error("cannot find the layercontents.plist file")]
    MissingLayerContentsFile,
    /// The UFO does not have a metainfo.plist layer.
    #[error("cannot find the metainfo.plist file")]
    MissingMetaInfoFile,
    /// Failed to parse a .plist file.
    #[error("failed to parse {name} file")]
    ParsePlist {
        /// The name of the file.
        name: &'static str,
        /// The underlying error.
        source: PlistError,
    },
    /// Norad can currently only open UFO (directory) packages.
    #[error("only UFO (directory) packages are supported")]
    UfoNotADir,
}

/// An error that occurs while attempting to read a UFO layer from disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum LayerLoadError {
    /// Loading a glyph from a path failed.
    #[error("failed to load glyph '{name}' from '{path}'")]
    Glyph {
        /// The glyph name.
        name: String,
        /// The path to the glif file.
        path: PathBuf,
        /// The underlying error.
        source: GlifLoadError,
    },
    /// Could not find the layer's contents.plist.
    #[error("cannot find the contents.plist file")]
    MissingContentsFile,
    /// Failed to parse a .plist file.
    #[error("failed to parse {name} file")]
    ParsePlist {
        /// The name of the file.
        name: &'static str,
        /// The underlying error.
        source: PlistError,
    },
}

/// An error that occurs while attempting to read a UFO fontinfo.plist file from disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum FontInfoLoadError {
    /// The upgrade process failed to convert an older fontinfo.plist to newer data structures.
    #[error("failed to upgrade fontinfo.plist contents to latest UFO version data: {0}")]
    FontInfoUpconversion(FontInfoErrorKind),
    /// The UFO lib.plist's `public.objectLibs` entry for the given guideline is not a dictionary.
    #[error("the lib.plist file's 'public.objectLibs' entry for the global guideline with identifier '{0}' in the fontinfo.plist file must be a dictionary")]
    GlobalGuidelineLibMustBeDictionary(String),
    /// The fontinfo.plist file contains invalid data.
    #[error("fontinfo.plist contains invalid data: {0}")]
    InvalidData(FontInfoErrorKind),
    /// Could not parse the UFO's fontinfo.plist.
    #[error("failed to parse fontinfo.plist file")]
    ParsePlist(#[source] PlistError),
    /// The font lib's `public.objectLibs` value was something other than a dictionary.
    #[error("the lib.plist file's 'public.objectLibs' value must be a dictionary")]
    PublicObjectLibsMustBeDictionary,
}

/// An error pointing to invalid data in the font's info.
#[derive(Debug)]
#[non_exhaustive]
pub enum FontInfoErrorKind {
    /// openTypeOS2Selection contained bits 0, 5 or 6.
    DisallowedSelectionBits,
    /// Guideline identifiers were not unique within the fontinfo.plist file.
    DuplicateGuidelineIdentifiers,
    /// Found an empty WOFF element or record. If you have them, you have to fill them all in.
    EmptyWoffAttribute(&'static str),
    /// The openTypeHeadCreated had the wrong format.
    InvalidOpenTypeHeadCreatedDate,
    /// The openTypeOS2FamilyClass had out of range values.
    InvalidOs2FamilyClass,
    /// The openTypeOS2Panose field did not have exactly ten elements.
    InvalidOs2Panose,
    /// A Postscript data list had more elements than the specification allows.
    InvalidPostscriptListLength {
        /// The name of the property.
        name: &'static str,
        /// The maximum allowed number of elements.
        max_len: u8,
        /// The found number of elements.
        len: usize,
    },
    /// A Postscript data list must contain pairs.
    PostscriptListMustBePairs(&'static str),
    /// Unrecognized UFO v1 fontStyle field.
    UnknownFontStyle(i32),
    /// Unrecognized UFO v1 msCharSet field.
    UnknownMsCharSet(i32),
    /// Unrecognized styleMapStyleName.
    UnknownStyleMapStyleName,
    /// Unrecognized openTypeOS2WidthClass.
    UnknownWidthClass(String),
    /// Unrecognized WOFF writing direction.
    UnknownWoffDirection,
    /// The openTypeGaspRangeRecords field was unsorted.
    UnsortedGaspEntries,
}

impl std::fmt::Display for FontInfoErrorKind {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        use FontInfoErrorKind::*;
        match self {
            DisallowedSelectionBits => {
                write!(f, "openTypeOS2Selection must not contain bits 0, 5 or 6")
            }
            DuplicateGuidelineIdentifiers => {
                write!(f, "guideline identifiers must be unique within the fontinfo.plist file")
            }
            EmptyWoffAttribute(s) => {
                write!(f, "a '{}' element must not be empty", s)
            }
            InvalidOpenTypeHeadCreatedDate => {
                write!(f, "openTypeHeadCreated must be of format 'YYYY/MM/DD HH:MM:SS'")
            }
            InvalidOs2FamilyClass => {
                write!(f, "openTypeOS2FamilyClass must be two numbers in the range 0-14 and 0-15, respectively")
            }
            InvalidOs2Panose => {
                write!(f, "openTypeOS2Panose must have exactly ten elements")
            }
            InvalidPostscriptListLength { name, max_len, len } => {
                write!(
                    f,
                    "the Postscript field '{}' must contain at most {} items but found {}",
                    name, max_len, len
                )
            }
            PostscriptListMustBePairs(name) => {
                write!(f, "the Postscript field '{}' must contain pairs", name)
            }
            UnknownFontStyle(s) => {
                write!(f, "unrecognized fontStyle '{}'", s)
            }
            UnknownMsCharSet(c) => {
                write!(f, "unrecognized msCharSet '{}'", c)
            }
            UnknownStyleMapStyleName => {
                write!(f, "unknown value for styleMapStyleName")
            }
            UnknownWidthClass(w) => {
                write!(f, "unrecognized OS/2 width class '{}'", w)
            }
            UnknownWoffDirection => {
                write!(f, "unknown value for the WOFF direction attribute")
            }
            UnsortedGaspEntries => {
                write!(f, "openTypeGaspRangeRecords must be sorted by their rangeMaxPPEM values")
            }
        }
    }
}

/// An error representing a failure with a particular [`crate::datastore::Store`] entry.
#[derive(Debug, Error)]
#[error("store entry '{path}' is invalid")]
pub struct StoreEntryError {
    path: PathBuf,
    source: StoreError,
}

impl StoreEntryError {
    /// Returns a new [`StoreEntryError`].
    pub(crate) fn new(path: PathBuf, source: StoreError) -> Self {
        Self { path, source }
    }
}

/// An error representing a failure to insert content into a [`crate::datastore::Store`].
#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum StoreError {
    /// Tried to insert a path whose ancestor is in the store already, implying nesting a file under a file.
    #[error("the parent of the file is a file itself")]
    DirUnderFile,
    /// The path was empty.
    #[error("an empty path cannot be used as a key in the store")]
    EmptyPath,
    /// The path was neither plain file nor directory, but e.g. a symlink.
    #[error("only plain files and directories are allowed, no symlinks")]
    NotPlainFileOrDir,
    /// The path was absolute; only relative paths are allowed.
    #[error("the path must be relative")]
    PathIsAbsolute,
    /// The path was not a plain file, but e.g. a directory or symlink.
    #[error("only plain files are allowed, no symlinks")]
    NotPlainFile,
    /// The path contained a subdirectory; `images` is a flat directory.
    #[error("subdirectories are not allowed in the image store")]
    Subdir,
    /// The image did not have a valid PNG header.
    #[error("an image must be a valid PNG")]
    InvalidImage,
    /// Encountered an IO error while trying to load data
    #[error("encountered an IO error while trying to load content")]
    Io(#[from] std::sync::Arc<std::io::Error>),
}

/// An error representing a failure to validate UFO groups.
#[derive(Debug, Error)]
pub enum GroupsValidationError {
    /// An error returned when there is an invalid groups name.
    #[error("a kerning group name must have at least one character after the common 'public.kernN.' prefix.")]
    InvalidName,
    /// An error returned when there are overlapping kerning groups.
    #[error("the glyph '{glyph_name}' appears in more than one kerning group. Last found in '{group_name}'")]
    OverlappingKerningGroups {
        /// The glyph name.
        glyph_name: Name,
        /// The group name.
        group_name: Name,
    },
}

/// An error returned when there is an inappropriate negative sign on a value.
#[derive(Debug, Error)]
#[error("expected a positive value")]
pub struct ExpectedPositiveValue;

/// An error returned when there is a problem with kurbo contour conversion.
#[cfg(feature = "kurbo")]
#[derive(Debug, Error)]
#[error("failed to convert contour: '{0}'")]
pub struct ConvertContourError(ErrorKind);

#[cfg(feature = "kurbo")]
impl ConvertContourError {
    pub(crate) fn new(kind: ErrorKind) -> Self {
        ConvertContourError(kind)
    }
}

/// An error that occurs while attempting to write a UFO package to disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum FontWriteError {
    /// Cannot clean up previous UFO package before writing out new one.
    #[error("failed to remove target directory before overwriting")]
    Cleanup(#[source] IoError),
    /// Failed to create the images directory.
    #[error("failed to create store directory '{path}'")]
    CreateStoreDir {
        /// The path to the entry.
        path: PathBuf,
        /// The underlying error.
        source: IoError,
    },
    /// Failed to create the UFO package directory.
    #[error("failed to create target font directory")]
    CreateUfoDir(#[source] IoError),
    /// Failed to write out a customly-serialized file.
    #[error("failed to write {name} file")]
    CustomFile {
        /// The name of the file.
        name: &'static str,
        /// The underlying error.
        source: CustomSerializationError,
    },
    /// Failed to write data entry.
    #[error("failed to write data file")]
    Data {
        /// The path to the entry.
        path: PathBuf,
        /// The underlying error.
        source: IoError,
    },
    /// Norad does not currently support downgrading to older UFO formats.
    #[error("downgrading below UFO v3 is not currently supported")]
    Downgrade,
    /// Failed to write out the feature.fea file.
    #[error("failed to write feature.fea file")]
    FeatureFile(#[source] IoError),
    /// Failed to write out an image file.
    #[error("failed to write image file")]
    Image {
        /// The path to the entry.
        path: PathBuf,
        /// The underlying error.
        source: IoError,
    },
    /// The font info contains invalid data.
    #[error("font info contains invalid data: {0}")]
    InvalidFontInfo(FontInfoErrorKind),
    /// The groups contains invalid data.
    #[error("failed to write (kerning) groups")]
    InvalidGroups(#[source] GroupsValidationError),
    /// The data or images store contains invalid data.
    #[error("store entry '{path}' is invalid")]
    InvalidStoreEntry {
        /// The path to the entry.
        path: PathBuf,
        /// The underlying error.
        source: StoreError,
    },
    /// Failed to write out a layer.
    #[error("failed to write layer '{name}' to '{path}'")]
    Layer {
        /// The name of the layer.
        name: String,
        /// The path to the layer.
        path: PathBuf,
        /// The underlying error.
        source: Box<LayerWriteError>,
    },
    /// There exists a `public.objectLibs` lib key when it should be set only by norad.
    #[error("the `public.objectLibs` lib key is managed by norad and must not be set manually")]
    PreexistingPublicObjectLibsKey,
}

/// An error that occurs while attempting to read a UFO layer from disk.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum LayerWriteError {
    /// Failed to write out the contents.plist file
    #[error("failed to write contents.plist file")]
    Contents(#[source] CustomSerializationError),
    /// Failed to create the layer's directory.
    #[error("cannot create layer directory")]
    CreateDir(#[source] IoError),
    /// Failed to write out a glyph.
    #[error("failed to write glyph '{name}' to '{path}'")]
    Glyph {
        /// The name of the glyph.
        name: String,
        /// The path to the glyph.
        path: PathBuf,
        /// The underlying error.
        source: GlifWriteError,
    },
    /// Failed to write out the layerinfo.plist file
    #[error("failed to write layerinfo.plist file")]
    LayerInfo(#[source] CustomSerializationError),
}

/// An error when attempting to write a .glif file.
#[derive(Debug, Error)]
#[non_exhaustive]
pub enum GlifWriteError {
    /// Failed to serialize a glyph to an internal buffer.
    #[error("failed to serialize glyph to an internal buffer")]
    Buffer(#[source] IoError),
    /// When writing out the 'lib' section, we use the plist crate to generate
    /// the plist xml, and then strip the preface and closing `</plist>` tag.
    ///
    /// If for some reason the implementation of that crate changes, we could
    /// be affected, although this is very unlikely.
    #[error("internal error while writing lib data, please open an issue")]
    InternalLibWriteError,
    /// Failed to write a .glif file to disk.
    #[error("failed to write .glif file")]
    Io(#[source] IoError),
    /// Plist serialization error. Wraps a [PlistError].
    #[error("error serializing glyph lib data internally")]
    Plist(#[source] PlistError),
    /// There exists a `public.objectLibs` glyph lib key when it should be set only by norad.
    #[error("the `public.objectLibs` lib key is managed by norad and must not be set manually")]
    PreexistingPublicObjectLibsKey,
    /// XML serialization error. Wraps a [XmlError].
    #[error("error serializing glyph to XML")]
    Xml(#[source] XmlError),
}

/// The reason for a glif parse failure.
#[derive(Debug, Clone, Copy)]
pub enum ErrorKind {
    /// The glif version is not supported by this library.
    UnsupportedGlifVersion,
    /// An unknown point type.
    UnknownPointType,
    /// The first XML element of a glif file is invalid.
    WrongFirstElement,
    /// Missing a close tag.
    MissingCloseTag,
    /// Has an invalid hexadecimal value.
    BadHexValue,
    /// Has an invalid numeric value.
    BadNumber,
    /// Has an invalid color value.
    BadColor,
    /// Has an invalid anchor definition.
    BadAnchor,
    /// Has an invalid point definition.
    BadPoint,
    /// Has an invalid guideline definition.
    BadGuideline,
    /// Has an invalid component definition.
    BadComponent,
    /// Has an invalid image definition.
    BadImage,
    /// Has an invalid identifier.
    BadIdentifier,
    /// Name is not a valid [`Name`].
    InvalidName,
    /// Has an invalid lib.
    BadLib,
    /// Has an unexected duplicate value.
    UnexpectedDuplicate,
    /// Has an unexpected move definition.
    UnexpectedMove,
    /// Has an unexpected smooth definition.
    UnexpectedSmooth,
    /// Has an unexpected element definition.
    UnexpectedElement,
    /// Has an unexpected attribute definition.
    UnexpectedAttribute,
    /// Has an unexpected end of file definition.
    UnexpectedEof,
    /// Has an unexpected point following an off curve point definition.
    UnexpectedPointAfterOffCurve,
    /// Has too many off curve points in sequence.
    TooManyOffCurves,
    /// The contour pen path was not started
    PenPathNotStarted,
    /// Has trailing off curve points defined.
    TrailingOffCurves,
    /// Has duplicate identifiers.
    DuplicateIdentifier,
    /// Has unexepected drawing data.
    UnexpectedDrawing,
    /// Has incomplete drawing data.
    UnfinishedDrawing,
    /// Has an unexpected point field.
    UnexpectedPointField,
    /// Has an unexpected component field.
    UnexpectedComponentField,
    /// Has an unexpected anchor field.
    UnexpectedAnchorField,
    /// Has an unexpected guideline field.
    UnexpectedGuidelineField,
    /// Has an unexpected image field.
    UnexpectedImageField,
    /// An element that can occur just once occured a second time.
    DuplicateElement(&'static str),
    /// An element that can occur just once occured a second time.
    UnexpectedV1Element(&'static str),
    /// An element that can occur just once occured a second time.
    UnexpectedV1Attribute(&'static str),
    /// A component had an empty `base` attribute.
    ComponentEmptyBase,
    /// A component was missing a `base` attribute.
    ComponentMissingBase,
    /// The glyph 'lib' element must contain a dictionary.
    LibMustBeDictionary,
    /// An angle was out of bounds.
    BadAngle,
}

impl std::fmt::Display for ErrorKind {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        use ErrorKind::*;
        match self {
            UnsupportedGlifVersion => write!(f, "unsupported glif version"),
            UnknownPointType => write!(f, "unknown point type"),
            WrongFirstElement => write!(f, "wrong first XML element in glif file"),
            MissingCloseTag => write!(f, "missing close tag"),
            BadHexValue => write!(f, "bad hex value"),
            BadNumber => write!(f, "bad number"),
            BadColor => write!(f, "bad color"),
            BadAnchor => write!(f, "bad anchor"),
            BadPoint => write!(f, "bad point"),
            BadGuideline => write!(f, "bad guideline"),
            BadComponent => write!(f, "bad component"),
            BadImage => write!(f, "bad image"),
            BadIdentifier => write!(f, "an identifier must be at most 100 characters long and contain only ASCII characters in the range 0x20 to 0x7E"),
            InvalidName => write!(f, "name is empty or contains control characters"),
            BadLib => write!(f, "bad lib"),
            UnexpectedDuplicate => write!(f, "unexpected duplicate"),
            UnexpectedMove => {
                write!(f, "unexpected move point, can only occur at start of contour")
            }
            UnexpectedSmooth => write!(f, "unexpected smooth attribute on an off-curve point"),
            UnexpectedElement => write!(f, "unexpected element"),
            UnexpectedAttribute => write!(f, "unexpected attribute"),
            UnexpectedEof => write!(f, "unexpected EOF"),
            UnexpectedPointAfterOffCurve => {
                write!(f, "an off-curve point must be followed by a curve or qcurve")
            }
            TooManyOffCurves => write!(f, "at most two off-curve points can precede a curve"),
            PenPathNotStarted => {
                write!(f, "must call begin_path() before calling add_point() or end_path()")
            }
            TrailingOffCurves => write!(f, "open contours must not have trailing off-curves"),
            DuplicateIdentifier => write!(f, "duplicate identifier"),
            UnexpectedDrawing => write!(f, "unexpected drawing without an outline"),
            UnfinishedDrawing => write!(f, "unfinished drawing, you must call end_path"),
            UnexpectedPointField => write!(f, "unexpected point field"),
            UnexpectedComponentField => write!(f, "unexpected component field"),
            UnexpectedAnchorField => write!(f, "unexpected anchor field"),
            UnexpectedGuidelineField => write!(f, "unexpected guideline field"),
            UnexpectedImageField => write!(f, "unexpected image field"),
            DuplicateElement(s) => write!(f, "there must be only one '{}' element", s),
            UnexpectedV1Element(s) => write!(f, "unexpected element in a format 1 glif: {}", s),
            UnexpectedV1Attribute(s) => write!(f, "unexpected attribute in a format 1 glif: {}", s),
            ComponentEmptyBase => write!(f, "a 'component' element has an empty 'base' attribute"),
            ComponentMissingBase => {
                write!(f, "a 'component' element is missing a 'base' attribute")
            }
            LibMustBeDictionary => write!(f, "the glyph lib must be a dictionary"),
            BadAngle => write!(f, "an angle must be between 0 and 360°"),
        }
    }
}

#[doc(hidden)]
impl From<ErrorKind> for GlifLoadError {
    fn from(src: ErrorKind) -> Self {
        Self::Parse(src)
    }
}

#[doc(hidden)]
impl From<IoError> for StoreError {
    fn from(src: IoError) -> StoreError {
        StoreError::Io(std::sync::Arc::new(src))
    }
}