use std::collections::HashSet;
use std::fs::{DirBuilder, File};
use std::io::{self, Write};
use std::path::Path;
use std::process::Command;

use tempdir::TempDir;

use duplicate_destroyer;
use duplicate_destroyer::DuplicateObject;

fn write_file(path: &Path, contents: &str) -> io::Result<()> {
    let mut file = File::create(path).expect("Could not create a file.");
    writeln!(file, "{}", contents)?;
    Ok(())
}

#[test]
/// Create a directory structure with the schema
/// tempdir
/// ├── A
/// │   ├── a.txt
/// │   └── b
/// │       ├── alpha.txt
/// │       └── beta.txt
/// └── B
///     ├── a.txt
///     └── b
///         ├── alpha.txt
///         └── beta.txt
/// where alpha.txt, beta.txt and a.txt are duplicated.
///
/// Check that we got a duplicate object with two duplicate directories tempdir/A and tempdir/B.
fn duplicate_dirs_test() -> io::Result<()> {
    // Create a temporary directory
    let tmp_dir = TempDir::new("add_directories_success_test").expect("Failed creating temp dir.");
    let tmp_dir_str = tmp_dir.path().to_owned().into_os_string();
    let tmp_dir_path = tmp_dir.path();

    // Create files and folders
    for topdir in ["A", "B"] {
        DirBuilder::new().create(tmp_dir_path.join(topdir))?;

        let a_file_path = tmp_dir_path.join(topdir).join("a.txt");
        write_file(&a_file_path, "test_text_a")?;

        let b_folder_path = tmp_dir_path.join(topdir).join("b");
        DirBuilder::new().create(&b_folder_path)?;

        write_file(&b_folder_path.join("alpha.txt"), "test_text_alpha")?;
        write_file(&b_folder_path.join("beta.txt"), "test_text_beta")?;
    }

    // Create args for DuDe
    let mut options: duplicate_destroyer::Config = Default::default();
    options.set_minimum_size(0);
    let paths = vec![tmp_dir_str.clone()];

    // Run DuDe
    let duplicates = duplicate_destroyer::get_duplicates(paths, &options);

    // Check results
    let expected_duplicate = DuplicateObject::new(
        8235,
        HashSet::from([
            tmp_dir_path.join("A").into_os_string(),
            tmp_dir_path.join("B").into_os_string(),
        ]),
    );

    assert_eq!(Ok(vec![expected_duplicate]), duplicates);

    // Prevent removing of tmp_dir until all tests are done
    tmp_dir.close()?;

    Ok(())
}

#[test]
/// Create a directory structure with the schema
/// tempdir
/// ├── A
/// │   ├── a.txt
/// │   └── diff.txt
/// └── B
///     ├── a.txt
///     └── diff.txt
/// where a.txt is duplicated and diff.txt is not.
///
/// Check that we got a duplicate object with the files tempdir/A/a.txt and tempdir/B/a.txt .
fn duplicate_files_test() -> io::Result<()>{
    // Create a temporary directory
    let tmp_dir = TempDir::new("add_directories_success_test").expect("Failed creating temp dir.");
    let tmp_dir_str = tmp_dir.path().to_owned().into_os_string();
    let tmp_dir_path = tmp_dir.path();

    // Create files and folders
    for topdir in ["A", "B"] {
        DirBuilder::new().create(tmp_dir_path.join(topdir))?;

        let a_file_path = tmp_dir_path.join(topdir).join("a.txt");
        write_file(&a_file_path, "test_text_a")?;

        let differing_file_path = tmp_dir_path.join(topdir).join("diff.txt");
        write_file(&differing_file_path, &["test_text_", topdir].join(""))?;
    }

    // Create args for DuDe
    let mut options: duplicate_destroyer::Config = Default::default();
    options.set_minimum_size(0);
    let paths = vec![tmp_dir_str.clone()];

    // Run DuDe
    let duplicates = duplicate_destroyer::get_duplicates(paths, &options);

    // Check results
    let expected_duplicate = DuplicateObject::new(
        12,
        HashSet::from([
            tmp_dir_path.join("A/a.txt").into_os_string(),
            tmp_dir_path.join("B/a.txt").into_os_string(),
        ]),
    );

    assert_eq!(Ok(vec![expected_duplicate]), duplicates);

    // Prevent removing of tmp_dir until all tests are done
    tmp_dir.close()?;
    Ok(())
}

#[test]
/// Create a directory structure with the schema
/// tempdir
/// ├── A
/// │   ├── a.txt
/// │   └── b
/// │       ├── alpha.txt
/// │       └── beta.txt
/// ├── B
/// │   ├── a.txt
/// │   └── b
/// │       ├── alpha.txt
/// │       └── beta.txt
/// └── C
///     ├── a.txt
///     ├── diff.txt
///     └── b
///         ├── alpha.txt
///         └── beta.txt
/// where a.txt and b dir are duplicated.
///
/// Check that we got a duplicate object with the files tempdir/A/ and tempdir/B/ and a duplicate
/// object with tempdir/A/b, tempdir/B/b and tempdir/C/b is not yielded.
///
/// We check for both cases - when C dir is added first and last. This ensures that the C/b dir is
/// not included in the duplicates irrespective of whether it is found first or last.
fn contained_duplicate_test() -> io::Result<()> {
    // Create a temporary directory
    let tmp_dir = TempDir::new("add_directories_success_test").expect("Failed creating temp dir.");
    let tmp_dir_path = tmp_dir.path();

    // Create files and folders
    for topdir in ["A", "B", "C"] {
        DirBuilder::new().create(tmp_dir_path.join(topdir))?;

        let a_file_path = tmp_dir_path.join(topdir).join("a.txt");
        write_file(&a_file_path, "test_text_a")?;

        let b_folder_path = tmp_dir_path.join(topdir).join("b");
        DirBuilder::new().create(&b_folder_path)?;

        write_file(&b_folder_path.join("alpha.txt"), "test_text_alpha")?;
        write_file(&b_folder_path.join("beta.txt"), "test_text_beta")?;
    }

    let diff_file_path = tmp_dir_path.join("C").join("diff.txt");
    write_file(&diff_file_path, "test_text_diff")?;

    // Create args for DuDe
    let mut options: duplicate_destroyer::Config = Default::default();
    options.set_minimum_size(0);
    let mut paths = vec![
        tmp_dir_path.join("A").to_owned().into_os_string(),
        tmp_dir_path.join("B").to_owned().into_os_string(),
        tmp_dir_path.join("C").to_owned().into_os_string(),
    ];

    let expected_duplicate = DuplicateObject::new(
        8235,
        HashSet::from([
            tmp_dir_path.join("A").into_os_string(),
            tmp_dir_path.join("B").into_os_string(),
        ]),
    );

    // Run DuDe with the paths to A, B, C
    let duplicates = duplicate_destroyer::get_duplicates(paths.clone(), &options);
    assert_eq!(Ok(vec![expected_duplicate.clone()]), duplicates);

    paths.reverse();
    let reversed_duplicates = duplicate_destroyer::get_duplicates(paths, &options);
    assert_eq!(Ok(vec![expected_duplicate]), reversed_duplicates);

    // Prevent removing of tmp_dir until all tests are done
    tmp_dir.close()?;
    Ok(())
}