schematics/src/symbols/stored_directory.rs

use std::borrow::{Borrow, Cow};
use std::error::Error;
use std::fmt;
use std::fs;
use std::io;
use std::path::Path;
use std::str::FromStr;

use command_runner::CommandRunner;
use resources::Resource;
use storage::Storage;
use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};

#[derive(Debug, PartialEq)]
pub enum StorageDirection {
  Load,
  Save,
}

pub struct StoredDirectory<'a, S, C: 'a + CommandRunner>
where
  S: Storage,
{
  path: Cow<'a, str>,
  storage: S,
  dir: StorageDirection,
  command_runner: &'a C,
}

impl<'a, S, C: CommandRunner> StoredDirectory<'a, S, C>
where
  S: Storage,
{
  pub fn new(path: Cow<'a, str>, storage: S, dir: StorageDirection, command_runner: &'a C) -> Self {
    StoredDirectory {
      path,
      storage,
      dir,
      command_runner,
    }
  }
}

impl<'a, S, C: CommandRunner> fmt::Display for StoredDirectory<'a, S, C>
where
  S: Storage,
{
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
    write!(f, "Stored directory {} ({:?})", self.path, self.dir)
  }
}

impl<'a, S, C: CommandRunner> Symbol for StoredDirectory<'a, S, C>
where
  S: Storage,
{
  fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
    let metadata = fs::metadata(self.path.as_ref());
    // Check if dir exists
    if let Err(e) = metadata {
      return if e.kind() == io::ErrorKind::NotFound {
        Ok(self.dir == StorageDirection::Save)
      } else {
        Err(Box::new(e))
      };
    }
    if !metadata.unwrap().is_dir() {
      return Err(Box::new(io::Error::new(
        io::ErrorKind::AlreadyExists,
        "Could not create a directory, non-directory file exists",
      )));
    }

    let dump_date = self.storage.recent_date()?;
    let output = self.command_runner.get_output(
      "sh",
      &[
        "-c",
        &format!(
          "find {} -printf '%T@\\n' | sort -r | head -n1 | grep '^[0-9]\\+' -o",
          self.path
        ),
      ],
    )?;
    let modified_date = u64::from_str(String::from_utf8(output)?.trim_end())?;
    if if self.dir == StorageDirection::Save {
      modified_date > dump_date
    } else {
      dump_date > modified_date
    } {
      let output = self.command_runner.run_with_args(
        "diff",
        &["-rq", &self.storage.read_filename()?, self.path.borrow()],
      )?;
      match output.status.code() {
        Some(0) => Ok(true),
        Some(1) => Ok(false),
        _ => Err(String::from_utf8(output.stderr)?.into()),
      }
    } else {
      Ok(true)
    }
  }

  fn execute(&self) -> Result<(), Box<dyn Error>> {
    if self.dir == StorageDirection::Load {
      self
        .command_runner
        .run_successfully("rm", &["-rf", self.path.borrow()])?;
      self.command_runner.run_successfully(
        "cp",
        &["-a", &self.storage.read_filename()?, self.path.borrow()],
      )
    } else {
      self.command_runner.run_successfully(
        "cp",
        &["-a", self.path.borrow(), &self.storage.write_filename()],
      )
    }
  }

  fn get_prerequisites(&self) -> Vec<Resource> {
    if self.dir == StorageDirection::Save {
      return vec![];
    }
    if let Some(parent) = Path::new(self.path.as_ref()).parent() {
      vec![Resource::new("dir", parent.to_string_lossy())]
    } else {
      vec![]
    }
  }

  fn provides(&self) -> Option<Vec<Resource>> {
    if self.dir == StorageDirection::Load {
      Some(vec![Resource::new("dir", self.path.to_string())])
    } else {
      None
    }
  }

  fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
    Box::new(SymbolAction::new(runner, self))
  }

  fn into_action<'b>(self: Box<Self>, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b>
  where
    Self: 'b,
  {
    Box::new(OwnedSymbolAction::new(runner, *self))
  }
}

#[cfg(test)]
mod test {}