//! Contains utilities for the CLI.
use serde::{de::DeserializeOwned, Serialize};
use std::{
    fs::{File, OpenOptions},
    io::Write,
    os::unix::prelude::OpenOptionsExt,
    path::Path,
};

use crate::error::{CliError, CliTypedResult};

/// Opens a file in read-only mode.
pub fn open_file(path: &Path) -> CliTypedResult<File> {
    File::open(path)
        .map_err(|e| CliError::UnableToReadFile(format!("{}", path.display()), e.to_string()))
}

/// Read a file into a Vec.
pub fn read_from_file(path: &Path) -> CliTypedResult<Vec<u8>> {
    std::fs::read(path)
        .map_err(|e| CliError::UnableToReadFile(format!("{}", path.display()), e.to_string()))
}

/// Write a `&[u8]` to a file
pub fn write_to_file(path: &Path, name: &str, bytes: &[u8]) -> CliTypedResult<()> {
    write_to_file_with_opts(path, name, bytes, &mut OpenOptions::new())
}

/// Write a User only read / write file
pub fn write_to_user_only_file(path: &Path, name: &str, bytes: &[u8]) -> CliTypedResult<()> {
    let mut opts = OpenOptions::new();
    #[cfg(unix)]
    opts.mode(0o600);
    write_to_file_with_opts(path, name, bytes, &mut opts)
}

/// Write a `&[u8]` to a file with the given options
pub fn write_to_file_with_opts(
    path: &Path,
    name: &str,
    bytes: &[u8],
    opts: &mut OpenOptions,
) -> CliTypedResult<()> {
    let mut file = opts
        .write(true)
        .create(true)
        .truncate(true)
        .open(path)
        .map_err(|e| CliError::IO(name.to_string(), e))?;
    file.write_all(bytes)
        .map_err(|e| CliError::IO(name.to_string(), e))
}

pub fn to_yaml<T: Serialize + ?Sized>(input: &T) -> CliTypedResult<String> {
    Ok(serde_yaml::to_string(input)?)
}

pub fn from_yaml<T: DeserializeOwned>(input: &str) -> CliTypedResult<T> {
    Ok(serde_yaml::from_str(input)?)
}