use bakare::backup;
use bakare::restore;
use bakare::restore::WhatToRestore::SpecificPath;

use dir_diff::is_different;
use std::fs::File;
use std::io::Error;
use std::io::Read;
use std::io::Write;
use std::path::Path;
use tempfile::tempdir;
use tempfile::TempDir;

#[test]
fn restore_backed_up_files() -> Result<(), Error> {
    let source = Source::new()?;
    let repository = tempdir()?;

    source.write_text_to_file("first", "some contents")?;
    source.write_text_to_file("second", "some contents")?;
    source.write_text_to_file("third", "some other contents")?;

    assert_same_after_restore(source.path(), repository.path())
}

#[test]
fn restore_older_version_of_file() -> Result<(), Error> {
    let source = Source::new()?;
    let repository = tempdir()?;
    let backup_engine = backup::Engine::new(source.path(), repository.path());
    let path = "some path";
    let new_contents = "totally new contents";
    let restore_target = tempdir()?;
    let restore_engine = restore::Engine::new(repository.path(), &restore_target.path());
    let old_contents = "some old contents";

    source.write_text_to_file(path, old_contents)?;
    backup_engine.backup()?;
    let old_version = backup_engine.file_version(path.as_ref());

    source.write_text_to_file(path, new_contents)?;
    backup_engine.backup()?;

    restore_engine.restore_as_of_version(SpecificPath(path.into()), old_version)?;

    assert_target_file_contents(restore_target.path(), path, old_contents)?;
    Ok(())
}

// TODO: restore latest version by default
// TODO: deduplicate data

fn assert_target_file_contents(target: &Path, filename: &str, expected_contents: &str) -> Result<(), Error> {
    let restored_path = target.join(filename);
    let mut actual_contents = String::new();
    File::open(restored_path)?.read_to_string(&mut actual_contents)?;
    assert_eq!(expected_contents, actual_contents);
    Ok(())
}

fn assert_same_after_restore(source_path: &Path, repository_path: &Path) -> Result<(), Error> {
    let backup_engine = backup::Engine::new(source_path, repository_path);
    backup_engine.backup()?;

    let restore_target = tempdir()?;
    let restore_engine = restore::Engine::new(repository_path, &restore_target.path());
    restore_engine.restore_all()?;

    let are_source_and_target_different = is_different(source_path, &restore_target.path()).unwrap();
    assert!(!are_source_and_target_different);
    Ok(())
}

struct Source {
    directory: TempDir,
}

impl Source {
    fn new() -> Result<Self, Error> {
        Ok(Self { directory: tempdir()? })
    }

    fn write_text_to_file(&self, filename: &str, text: &str) -> Result<(), Error> {
        Ok(File::create(self.directory.path().join(filename))?.write_all(text.as_bytes())?)
    }

    fn path(&self) -> &Path {
        self.directory.path()
    }
}