use crate::ui::utf8_to_local;

use crate::ui::UiError;

use crate::NoRepoInCwdError;

use format_bytes::format_bytes;

use hg::config::{ConfigError, ConfigParseError};

use hg::errors::HgError;

use hg::repo::RepoError;

use hg::revlog::revlog::RevlogError;

use hg::utils::files::get_bytes_from_path;

use std::convert::From;

/// The kind of command error

#[derive(Debug)]

pub enum CommandError {

    /// Exit with an error message and "standard" failure exit code.

    Abort { message: Vec<u8> },

    /// Encountered something (such as a CLI argument, repository layout, …)

    /// not supported by this version of `rhg`. Depending on configuration

    /// `rhg` may attempt to silently fall back to Python-based `hg`, which

    /// may or may not support this feature.

    UnsupportedFeature { message: Vec<u8> },

}

impl CommandError {

    pub fn abort(message: impl AsRef<str>) -> Self {

        CommandError::Abort {

            // TODO: bytes-based (instead of Unicode-based) formatting

            // of error messages to handle non-UTF-8 filenames etc:

            // https://www.mercurial-scm.org/wiki/EncodingStrategy#Mixing_output

            message: utf8_to_local(message.as_ref()).into(),

        }

    }

    pub fn unsupported(message: impl AsRef<str>) -> Self {

        CommandError::UnsupportedFeature {

            message: utf8_to_local(message.as_ref()).into(),

        }

    }

}

/// For now we don’t differenciate between invalid CLI args and valid for `hg`

/// but not supported yet by `rhg`.

impl From<clap::Error> for CommandError {

    fn from(error: clap::Error) -> Self {

        CommandError::unsupported(error.to_string())

    }

}

impl From<HgError> for CommandError {

    fn from(error: HgError) -> Self {

        match error {

            HgError::UnsupportedFeature(message) => {

                CommandError::unsupported(message)

            }

            _ => CommandError::abort(error.to_string()),

        }

    }

}

impl From<UiError> for CommandError {

    fn from(_error: UiError) -> Self {

        // If we already failed writing to stdout or stderr,

        // writing an error message to stderr about it would be likely to fail

        // too.

        CommandError::abort("")

    }

}

impl From<RepoError> for CommandError {

    fn from(error: RepoError) -> Self {

        match error {

            RepoError::NotFound { at } => CommandError::Abort {

                message: format_bytes!(

                    get_bytes_from_path(at)

                ),

            },

            RepoError::ConfigParseError(error) => error.into(),

            RepoError::Other(error) => error.into(),

        }

    }

}

impl<'a> From<&'a NoRepoInCwdError> for CommandError {

    fn from(error: &'a NoRepoInCwdError) -> Self {

        let NoRepoInCwdError { cwd } = error;

        CommandError::Abort {

            message: format_bytes!(

                b"abort: no repository found in '{}' (.hg not found)!",

                get_bytes_from_path(cwd)

            ),

        }

    }

}

impl From<ConfigError> for CommandError {

    fn from(error: ConfigError) -> Self {

        match error {

            ConfigError::Parse(error) => error.into(),

            ConfigError::Other(error) => error.into(),

        }

    }

}

impl From<ConfigParseError> for CommandError {

    fn from(error: ConfigParseError) -> Self {

        let ConfigParseError {

            origin,

            line,

            message,

        } = error;

        let line_message = if let Some(line_number) = line {

            format_bytes!(b":{}", line_number.to_string().into_bytes())

        } else {

            Vec::new()

        };

        CommandError::Abort {

            message: format_bytes!(

                b"config error at {}{}: {}",

                origin,

                line_message,

                message

            ),

        }

    }

}

impl From<(RevlogError, &str)> for CommandError {

    fn from((err, rev): (RevlogError, &str)) -> CommandError {

        match err {

            RevlogError::InvalidRevision => CommandError::abort(format!(

                "abort: invalid revision identifier: {}",

                rev

            )),

            RevlogError::AmbiguousPrefix => CommandError::abort(format!(

                "abort: ambiguous revision identifier: {}",

                rev

            )),

            RevlogError::Other(error) => error.into(),

        }

    }

}