use std::fmt::{Debug, Display};

use flexi_logger::FlexiLoggerError;
use thiserror::Error;

#[derive(Error, Debug)]
pub enum ErrorKind {
    #[error("[EpubError]: {0}")]
    EpubError(String),
    #[error("[HTTPError]: {0}")]
    HTTPError(String),
    #[error("[IOError]: {0}")]
    IOError(String),
    #[error("[UTF8Error]: {0}")]
    UTF8Error(String),
    #[error("[ReadabilityError]: {0}")]
    ReadabilityError(String),
}

#[derive(Error, Debug)]
#[error("{kind}")]
/// Used to represent errors from downloading images. Errors from here are used solely for debugging
/// as they are considered recoverable.
pub struct ImgError {
    kind: ErrorKind,
    url: Option<String>,
}

impl ImgError {
    pub fn with_kind(kind: ErrorKind) -> Self {
        ImgError { url: None, kind }
    }

    pub fn set_url(&mut self, url: &str) {
        self.url = Some(url.to_string());
    }

    pub fn url(&self) -> &Option<String> {
        &self.url
    }
}

impl From<ErrorKind> for ImgError {
    fn from(kind: ErrorKind) -> Self {
        ImgError::with_kind(kind)
    }
}

impl From<surf::Error> for ImgError {
    fn from(err: surf::Error) -> Self {
        ImgError::with_kind(ErrorKind::HTTPError(err.to_string()))
    }
}

impl From<url::ParseError> for ImgError {
    fn from(err: url::ParseError) -> Self {
        ImgError::with_kind(ErrorKind::HTTPError(err.to_string()))
    }
}

impl From<std::io::Error> for ImgError {
    fn from(err: std::io::Error) -> Self {
        ImgError::with_kind(ErrorKind::IOError(err.to_string()))
    }
}

#[derive(Error, Debug)]
#[error("{kind}")]
pub struct PaperoniError {
    article_source: Option<String>,
    kind: ErrorKind,
}

impl PaperoniError {
    pub fn with_kind(kind: ErrorKind) -> Self {
        PaperoniError {
            article_source: None,
            kind,
        }
    }

    pub fn kind(&self) -> &ErrorKind {
        &self.kind
    }

    pub fn article_source(&self) -> &Option<String> {
        &self.article_source
    }

    pub fn set_article_source(&mut self, article_source: &str) {
        self.article_source = Some(article_source.to_owned());
    }
}

impl From<ErrorKind> for PaperoniError {
    fn from(kind: ErrorKind) -> Self {
        PaperoniError::with_kind(kind)
    }
}

impl From<epub_builder::Error> for PaperoniError {
    fn from(err: epub_builder::Error) -> Self {
        PaperoniError::with_kind(ErrorKind::EpubError(err.description().to_owned()))
    }
}

impl From<surf::Error> for PaperoniError {
    fn from(err: surf::Error) -> Self {
        PaperoniError::with_kind(ErrorKind::HTTPError(err.to_string()))
    }
}

impl From<url::ParseError> for PaperoniError {
    fn from(err: url::ParseError) -> Self {
        PaperoniError::with_kind(ErrorKind::HTTPError(err.to_string()))
    }
}

impl From<std::io::Error> for PaperoniError {
    fn from(err: std::io::Error) -> Self {
        PaperoniError::with_kind(ErrorKind::IOError(err.to_string()))
    }
}

impl From<std::str::Utf8Error> for PaperoniError {
    fn from(err: std::str::Utf8Error) -> Self {
        PaperoniError::with_kind(ErrorKind::UTF8Error(err.to_string()))
    }
}

#[derive(Debug, Error)]
pub enum LogError {
    #[error(transparent)]
    FlexiError(#[from] FlexiLoggerError),
    #[error("Unable to get user directories for logging purposes")]
    UserDirectoriesError,
    #[error("Can't create log directory: {0}")]
    CreateLogDirectoryError(#[from] std::io::Error),
}

// dumb hack to allow for comparing errors in testing.
// derive macros cannot be used because underlying errors like io::Error do not derive PartialEq
impl PartialEq for LogError {
    fn eq(&self, other: &Self) -> bool {
        format!("{:?}", self) == format!("{:?}", other)
    }
}

#[derive(Debug, Error)]
pub enum CliError<BuilderError: Debug + Display> {
    #[error("Failed to open file with urls: {0}")]
    UrlFileError(#[from] std::io::Error),
    #[error("Failed to parse max connection value: {0}")]
    InvalidMaxConnectionCount(#[from] std::num::ParseIntError),
    #[error("No urls were provided")]
    NoUrls,
    #[error("Failed to build cli application: {0}")]
    AppBuildError(BuilderError),
    #[error("Invalid output path name for merged epubs: {0}")]
    InvalidOutputPath(String),
    #[error("Wrong output directory")]
    WrongOutputDirectory,
    #[error("Output directory does not exist")]
    OutputDirectoryNotExists,
    #[error("Unable to start logger!\n{0}")]
    LogError(#[from] LogError),
    #[error("The --inline-toc flag can only be used when exporting to epub")]
    WrongExportInliningToC,
    #[error("The --inline-images flag can only be used when exporting to html")]
    WrongExportInliningImages,
}

// dumb hack to allow for comparing errors in testing.
// derive macros cannot be used because underlying errors like io::Error do not derive PartialEq
impl<T: Debug + Display> PartialEq for CliError<T> {
    fn eq(&self, other: &Self) -> bool {
        format!("{:?}", self) == format!("{:?}", other)
    }
}