subparse 0.7.0

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

use self::errors::*;
use crate::errors::Result as SubtitleParserResult;
use crate::timetypes::{TimePoint, TimeSpan};
use crate::{SubtitleEntry, SubtitleFileInterface, SubtitleFormat};
use failure::ResultExt;

use vobsub;

/// `.sub` `VobSub`-parser-specific errors
#[allow(missing_docs)]
pub mod errors {
    use vobsub;

    define_error!(Error, ErrorKind);

    #[derive(Debug, Fail)]
    pub enum ErrorKind {
        // TODO: Vobsub-ErrorKind display
        /// Since `vobsub::Error` does not implement Sync. We cannot use #[cause] for it.
        VobSubError { cause: vobsub::ErrorKind },
    }

    impl fmt::Display for ErrorKind {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            match self {
                ErrorKind::VobSubError { cause } => writeln!(f, "VobSub error: {}", cause),
            }
        }
    }
}

#[derive(Debug, Clone)]
/// Represents a `.sub` (`VobSub`) file.
pub struct VobFile {
    /// Saves the file data.
    data: Vec<u8>,

    /// The (with vobsub) extracted subtitle lines.
    lines: Vec<VobSubSubtitle>,
}

#[derive(Debug, Clone)]
/// Represents a line in a `VobSub` `.sub` file.
struct VobSubSubtitle {
    timespan: TimeSpan,
}

impl VobFile {
    /// Parse contents of a `VobSub` `.sub` file to `VobFile`.
    pub fn parse(b: &[u8]) -> SubtitleParserResult<Self> {
        let lines = vobsub::subtitles(b)
            .map(|sub_res| -> vobsub::Result<VobSubSubtitle> {
                let sub = sub_res?;

                // only extract the timestamps, discard the big image data
                Ok(VobSubSubtitle {
                    timespan: TimeSpan {
                        start: TimePoint::from_msecs((sub.start_time() * 1000.0) as i64),
                        end: TimePoint::from_msecs((sub.end_time() * 1000.0) as i64),
                    },
                })
            })
            .collect::<vobsub::Result<Vec<VobSubSubtitle>>>()
            .map_err(|e| ErrorKind::VobSubError {
                cause: vobsub::ErrorKind::from(e),
            })
            .with_context(|_| crate::errors::ErrorKind::ParsingError)?;

        Ok(VobFile {
            data: b.to_vec(),
            lines: lines,
        })
    }
}

impl SubtitleFileInterface for VobFile {
    fn get_subtitle_entries(&self) -> SubtitleParserResult<Vec<SubtitleEntry>> {
        Ok(self
            .lines
            .iter()
            .map(|vsub| SubtitleEntry {
                timespan: vsub.timespan,
                line: None,
            })
            .collect())
    }

    fn update_subtitle_entries(&mut self, _: &[SubtitleEntry]) -> SubtitleParserResult<()> {
        Err(crate::errors::ErrorKind::UpdatingEntriesNotSupported {
            format: SubtitleFormat::VobSubSub,
        }
        .into())
    }

    fn to_data(&self) -> SubtitleParserResult<Vec<u8>> {
        Ok(self.data.clone())
    }
}