Add shell_interface and environment and prepare main application for those changes

src/environment.rs

@@ -0,0 +1,44 @@
+use std::env;
+use std::env::VarError;
+use std::ffi::{OsStr, OsString};
+use std::path::PathBuf;
+
+pub trait Environment {
+  fn args_os(&self) -> Vec<OsString>;
+  fn var<K>(&self, key: K) -> Result<String, VarError>
+  where
+    K: AsRef<OsStr>;
+  fn set_var<K, V>(&self, key: K, value: V)
+  where
+    K: AsRef<OsStr>,
+    V: AsRef<OsStr>;
+  fn get_home_directory(&self) -> Option<PathBuf>;
+}
+
+#[derive(Debug, Default)]
+pub struct Prod;
+
+impl Environment for Prod {
+  fn args_os(&self) -> Vec<OsString> {
+    env::args_os().collect()
+  }
+
+  fn var<K>(&self, key: K) -> Result<String, VarError>
+  where
+    K: AsRef<OsStr>,
+  {
+    env::var(key)
+  }
+
+  fn set_var<K, V>(&self, key: K, value: V)
+    where
+      K: AsRef<OsStr>,
+      V: AsRef<OsStr>
+  {
+    env::set_var(key, value);
+  }
+
+  fn get_home_directory(&self) -> Option<PathBuf> {
+    homedir::my_home().ok().flatten()
+  }
+}

src/server.rs

@@ -1,4 +1,4 @@
-use crate::get_home_directory;
+use crate::environment::{Environment, Prod};
 use std::cell::LazyCell;
 use std::error::Error;
 use std::fmt::{Display, Formatter};
@@ -72,9 +72,13 @@ impl FromStr for ServerReference {
   type Err = ServerReferenceParseError;
 
   fn from_str(s: &str) -> Result<Self, Self::Err> {
-    Server::from_str(s, RelativeLocalPathAnker::CurrentDirectory)
-      .map(Self::Resolved)
-      .or_else(|_| Ok(Self::Identifier(s.to_string())))
+    Server::from_str(s, RelativeLocalPathAnker::CurrentDirectory, || {
+      Prod::default()
+        .get_home_directory()
+        .ok_or("missing home directory".to_string())
+    })
+    .map(Self::Resolved)
+    .or_else(|_| Ok(Self::Identifier(s.to_string())))
   }
 }
 
@@ -126,10 +130,14 @@ impl Server {
     }
   }
 
-  pub fn from_str(
+  pub fn from_str<F>(
     s: &str,
     relative_local_path_anker: RelativeLocalPathAnker,
-  ) -> Result<Self, ServerParseError> {
+    get_home_directory: F,
+  ) -> Result<Self, ServerParseError>
+  where
+    F: Fn() -> Result<PathBuf, String>,
+  {
     s.split_once(':')
       .ok_or(ServerParseError::MissingServerDirectory)
       .and_then(|(identifier, server_directory)| {

src/shell_interface.rs

@@ -0,0 +1,313 @@
+use crate::log;
+use crate::logger::{LogLevel, Logger};
+use std::error::Error;
+use std::ffi::OsString;
+use std::fmt::{Debug, Display, Formatter};
+use std::io;
+use std::iter::once;
+use std::path::PathBuf;
+use std::process::Command;
+
+#[derive(Debug)]
+pub struct EnvCommand<'a, E> {
+  command: ShellCommand,
+  environment: &'a E,
+}
+
+#[derive(Debug, Clone)]
+pub enum ShellCommand {
+  Ssh {
+    address: String,
+    server_command: ServerCommand,
+  },
+  Scp {
+    source: ScpParam,
+    destination: ScpParam,
+  },
+  SshAgent,
+  ShhAdd,
+  Editor(Vec<OsString>),
+  Execute {
+    working_directory: PathBuf,
+    command: OsString,
+  },
+}
+
+impl ShellCommand {
+  pub fn at<E>(self, environment: &E) -> EnvCommand<E> {
+    EnvCommand {
+      command: self,
+      environment,
+    }
+  }
+}
+
+#[derive(Debug, Clone)]
+pub enum ServerCommand {
+  Realpath {
+    path: PathBuf,
+  },
+  Ls {
+    dir: PathBuf,
+  },
+  Rm {
+    file: PathBuf,
+  },
+  Mv {
+    source: PathBuf,
+    destination: PathBuf,
+  },
+  Execute {
+    working_directory: PathBuf,
+    command: OsString,
+  },
+}
+
+#[derive(Debug, Clone)]
+pub struct ScpParam {
+  pub server: Option<String>,
+  pub path: PathBuf,
+}
+
+impl Display for ShellCommand {
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    write!(
+      f,
+      "{}",
+      command_to_string(&build_command_from_shell_command(self))
+    )
+  }
+}
+
+fn command_to_string(command: &Command) -> String {
+  once(command.get_program().to_string_lossy().to_string())
+    .chain(command.get_args().map(|arg| {
+      let arg_str = arg.to_string_lossy();
+      if arg_str.contains(' ') {
+        format!("\"{arg_str}\"")
+      } else {
+        arg_str.to_string()
+      }
+    }))
+    .collect::<Vec<_>>()
+    .join(" ")
+}
+
+fn build_command_from_shell_command(shell_command: &ShellCommand) -> Command {
+  todo!()
+}
+
+pub trait ShellInterface {
+  fn run(self) -> CommandResult<ExitStatus, StartError>;
+  fn output(self) -> CommandResult<CommandOutput, StartError>;
+  fn run_logged(self, logger: &Logger) -> CommandResult<LoggedRunOutput, StartError>
+  where
+    Self: Sized,
+  {
+    match logger.level {
+      LogLevel::Debug | LogLevel::Info => {
+        let res = self.run();
+        CommandResult {
+          result: res.result.map(LoggedRunOutput::from),
+          command: res.command,
+        }
+      }
+      LogLevel::Error => {
+        let res = self.output();
+        CommandResult {
+          result: res.result.map(LoggedRunOutput::from),
+          command: res.command,
+        }
+      }
+    }
+  }
+}
+
+pub trait MaybeCast<T> {
+  fn maybe_cast(&self) -> Option<&T>;
+}
+
+impl<T> MaybeCast<T> for T {
+  fn maybe_cast(&self) -> Option<&T> {
+    Some(self)
+  }
+}
+
+#[derive(Debug)]
+pub enum LoggedRunOutput {
+  ExitStatus(ExitStatus),
+  CommandOutput(CommandOutput),
+}
+
+impl From<ExitStatus> for LoggedRunOutput {
+  fn from(value: ExitStatus) -> Self {
+    Self::ExitStatus(value)
+  }
+}
+
+impl From<CommandOutput> for LoggedRunOutput {
+  fn from(value: CommandOutput) -> Self {
+    Self::CommandOutput(value)
+  }
+}
+
+impl AsRef<ExitStatus> for LoggedRunOutput {
+  fn as_ref(&self) -> &ExitStatus {
+    match self {
+      LoggedRunOutput::ExitStatus(status) => status,
+      LoggedRunOutput::CommandOutput(output) => output.as_ref(),
+    }
+  }
+}
+
+impl MaybeCast<CommandOutput> for LoggedRunOutput {
+  fn maybe_cast(&self) -> Option<&CommandOutput> {
+    match self {
+      LoggedRunOutput::ExitStatus(_) => None,
+      LoggedRunOutput::CommandOutput(output) => Some(output),
+    }
+  }
+}
+
+#[derive(Debug)]
+pub struct CommandResult<T, E> {
+  pub command: ShellCommand,
+  pub result: Result<T, E>,
+}
+
+impl<T, E> CommandResult<T, E> {
+  pub fn into_result(self) -> Result<T, CommandError<E>> {
+    self.result.map_err(|error| CommandError {
+      command: self.command,
+      error,
+    })
+  }
+}
+
+impl<T> CommandResult<T, StartError> {
+  pub fn and_expect_success(self) -> CommandResult<T, ExecutionError<T>>
+  where
+    T: AsRef<ExitStatus>,
+  {
+    CommandResult {
+      result: self.result.map_err(ExecutionError::from).and_then(|t| {
+        if t.as_ref().success {
+          Ok(t)
+        } else {
+          Err(ExecutionError::BadExitStatus(t))
+        }
+      }),
+      command: self.command,
+    }
+  }
+}
+
+impl CommandResult<CommandOutput, ExecutionError<CommandOutput>> {
+  pub fn into_result_with_error_logging(
+    self,
+    logger: &Logger,
+  ) -> Result<CommandOutput, CommandError<ExecutionError<CommandOutput>>> {
+    self.result.map_err(|error| {
+      if let ExecutionError::BadExitStatus(output) = &error {
+        log!(logger, error, "{}", output.stdout.to_string_lossy());
+        log!(logger, error, "{}", output.stderr.to_string_lossy());
+      }
+      CommandError {
+        command: self.command,
+        error,
+      }
+    })
+  }
+}
+
+#[derive(Debug, Clone)]
+pub struct CommandOutput {
+  pub stdout: OsString,
+  pub stderr: OsString,
+  pub status: ExitStatus,
+}
+
+impl AsRef<ExitStatus> for CommandOutput {
+  fn as_ref(&self) -> &ExitStatus {
+    &self.status
+  }
+}
+
+#[derive(Debug, Clone)]
+pub struct ExitStatus {
+  pub success: bool,
+  pub string_form: String,
+  pub code: Option<i32>,
+}
+
+impl AsRef<ExitStatus> for ExitStatus {
+  fn as_ref(&self) -> &ExitStatus {
+    self
+  }
+}
+
+impl Display for ExitStatus {
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    Display::fmt(&self.string_form, f)
+  }
+}
+
+#[derive(Debug)]
+pub struct CommandError<E> {
+  pub command: ShellCommand,
+  pub error: E,
+}
+
+impl<E> Display for CommandError<E>
+where
+  E: Display,
+{
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    write!(
+      f,
+      "Error while running command '{}': {}",
+      self.command, self.error
+    )
+  }
+}
+
+impl<E> Error for CommandError<E> where E: Error {}
+
+#[derive(Debug)]
+pub struct StartError(io::Error);
+
+impl Display for StartError {
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    write!(f, "Failed to run command: {}", self.0)
+  }
+}
+
+impl Error for StartError {}
+
+#[derive(Debug)]
+pub enum ExecutionError<T> {
+  StartError(StartError),
+  BadExitStatus(T),
+}
+
+impl<T> From<StartError> for ExecutionError<T> {
+  fn from(value: StartError) -> Self {
+    Self::StartError(value)
+  }
+}
+
+impl<T> Display for ExecutionError<T>
+where
+  T: AsRef<ExitStatus>,
+{
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    match self {
+      ExecutionError::StartError(e) => Display::fmt(e, f),
+      ExecutionError::BadExitStatus(status) => {
+        write!(f, "execution failed with {}", status.as_ref())
+      }
+    }
+  }
+}
+
+impl<T> Error for ExecutionError<T> where T: AsRef<ExitStatus> + Debug {}