// Copyright 2021-2024 Martin Pool

//! Public API tests for `cp_r`.

use std::fs::{create_dir, metadata, read, write, DirEntry, FileType};
use std::io;
use std::path::{Path, PathBuf};

use tempfile::TempDir;

use cp_r::*;

#[test]
fn basic_copy() {
    let src = tempfile::tempdir().unwrap();
    let dest = tempfile::tempdir().unwrap();
    let file_content = b"hello world\n";
    let file_name = "a file";
    let src_file_path = src.path().join(file_name);
    write(&src_file_path, file_content).unwrap();

    let stats = CopyOptions::default()
        .copy_tree(src.path(), dest.path())
        .unwrap();

    let dest_file_path = &dest.path().join(file_name);
    assert_eq!(read(dest_file_path).unwrap(), file_content);
    assert_eq!(stats.files, 1);
    assert_eq!(stats.file_bytes, file_content.len() as u64);

    let src_mtime = metadata(&src_file_path).unwrap().modified().unwrap();
    let dest_mtime = metadata(dest_file_path).unwrap().modified().unwrap();
    dbg!(src_mtime, dest_mtime);

    // Filesystems might not retain perfect resolution on mtimes, but they should at least be
    // within 1ms everywhere(?); the error might be in either direction.
    let d = dest_mtime
        .duration_since(src_mtime)
        .or_else(|_| src_mtime.duration_since(dest_mtime))
        .unwrap();
    dbg!(d);
    assert!(d.as_micros() < 1000);
}

#[test]
fn subdirs() {
    let src = TempDir::new().unwrap();
    let dest = TempDir::new().unwrap();

    create_dir(src.path().join("a")).unwrap();
    create_dir(src.path().join("a").join("aa")).unwrap();
    create_dir(src.path().join("b")).unwrap();
    create_dir(src.path().join("b/bb")).unwrap();

    let file_content = b"some file content\n";
    write(src.path().join("a/aa/aaafile"), file_content).unwrap();

    // Note here that we can just path a reference to the TempDirs without calling
    // `.path()`, because they `AsRef` to a `Path`.
    let stats = CopyOptions::default().copy_tree(&src, &dest).unwrap();

    assert_eq!(
        read(dest.path().join("a/aa/aaafile")).unwrap(),
        file_content
    );
    assert!(metadata(dest.path().join("b/bb"))
        .unwrap()
        .file_type()
        .is_dir());
    assert_eq!(stats.files, 1);
    assert_eq!(stats.file_bytes, file_content.len() as u64);
    assert_eq!(stats.dirs, 4);
}

#[test]
fn clean_error_on_nonexistent_source() {
    let dest = tempfile::tempdir().unwrap();
    let err = CopyOptions::new().copy_tree("nothing", &dest).unwrap_err();
    println!("err = {:#?}", err);
    assert!(err.path().starts_with("nothing"));
    assert_eq!(err.kind(), ErrorKind::ReadDir);
    assert_eq!(err.io_error().unwrap().kind(), io::ErrorKind::NotFound);
}

#[test]
fn create_destination_by_default() {
    let empty_src = tempfile::tempdir().unwrap();
    let dest_parent = tempfile::tempdir().unwrap();
    let dest = dest_parent.path().join("nonexistent_child");
    let stats = CopyOptions::new()
        .copy_tree(empty_src.path(), &dest)
        .unwrap();
    assert!(dest.is_dir());
    assert_eq!(stats.dirs, 1);
    assert_eq!(stats.files, 0);
}

#[test]
fn create_destination_when_requested() {
    let empty_src = tempfile::tempdir().unwrap();
    let dest_parent = tempfile::tempdir().unwrap();
    let dest = dest_parent.path().join("nonexistent_child");
    let stats = CopyOptions::new()
        .create_destination(true)
        .copy_tree(&empty_src, &dest)
        .unwrap();
    assert!(dest.is_dir());
    assert_eq!(stats.dirs, 1);
    assert_eq!(stats.files, 0);
}

#[test]
fn optionally_destination_must_exist() {
    // TODO: At least add an option to create the destination if it does not exist.
    // But, for now, it must.
    let dest_parent = tempfile::tempdir().unwrap();
    let dest = dest_parent.path().join("nonexistent_child");
    let err = CopyOptions::new()
        .create_destination(false)
        .copy_tree("src", &dest)
        .unwrap_err();
    println!("err = {:#?}", err);
    assert_eq!(err.kind(), ErrorKind::DestinationDoesNotExist);
    assert!(
        err.path().starts_with(&dest),
        "path in the error relates to the destination"
    );
    assert!(err.io_error().is_none(), "no underlying io::Error");
}

#[cfg(unix)]
#[test]
fn clean_error_failing_to_copy_devices() {
    let dest = tempfile::tempdir().unwrap();
    let err = CopyOptions::new()
        .copy_tree("/dev", dest.path())
        .unwrap_err();
    println!("{:#?}", err);
    let kind = err.kind();
    assert!(
        kind == ErrorKind::UnsupportedFileType || kind == ErrorKind::CopyFile,
        "unexpected ErrorKind {:?}",
        kind
    );
    // Depending on OS peculiarities, we might detect this at different points, and therefore
    // return different error kinds, and there may or may not be an ioerror.
    assert!(err.path().strip_prefix("/dev/").is_ok());
    let formatted = format!("{}", err);
    assert!(
        formatted.starts_with("unsupported file type: /dev/")
            || formatted.contains(
                "the source path is neither a regular file nor a symlink to a regular file"
            ),
        "unexpected string format: {:?}",
        formatted
    );
}

#[cfg(unix)]
#[test]
fn copy_dangling_symlink() {
    let src = tempfile::tempdir().unwrap();
    let dest = tempfile::tempdir().unwrap();
    std::os::unix::fs::symlink("dangling target", src.path().join("a_link")).unwrap();
    let stats = CopyOptions::new()
        .copy_tree(src.path(), dest.path())
        .unwrap();
    println!("{:#?}", stats);
    assert_eq!(
        stats,
        CopyStats {
            files: 0,
            dirs: 0,
            symlinks: 1,
            file_bytes: 0,
            filtered_out: 0,
        }
    );
}

#[test]
fn filter_by_path() {
    let src = tempfile::tempdir().unwrap();
    let dest = tempfile::tempdir().unwrap();

    create_dir(src.path().join("a")).unwrap();
    create_dir(src.path().join("b")).unwrap();
    create_dir(src.path().join("b/bb")).unwrap();
    create_dir(src.path().join("a").join("aa")).unwrap();

    let file_content = b"some file content\n";
    write(src.path().join("a/aa/aaafile"), file_content).unwrap();

    fn not_b(path: &Path, _: &DirEntry) -> cp_r::Result<bool> {
        Ok(path != Path::new("b"))
    }
    let stats = CopyOptions::new()
        .filter(not_b)
        .copy_tree(src.path(), dest.path())
        .unwrap();

    assert_eq!(
        read(dest.path().join("a/aa/aaafile")).unwrap(),
        file_content
    );
    assert!(!dest.path().join("b").exists());
    assert_eq!(
        stats,
        CopyStats {
            files: 1,
            file_bytes: file_content.len() as u64,
            dirs: 2,
            symlinks: 0,
            filtered_out: 1,
        }
    );
}

const AAA_CONTENT: &[u8] = b"some file content\n";

fn setup_a_b_src() -> tempfile::TempDir {
    let src = tempfile::tempdir().unwrap();
    create_dir(src.path().join("a")).unwrap();
    create_dir(src.path().join("b")).unwrap();
    create_dir(src.path().join("b/bb")).unwrap();
    create_dir(src.path().join("a").join("aa")).unwrap();

    let file_content = AAA_CONTENT;
    write(src.path().join("a/aa/aaafile"), file_content).unwrap();

    src
}

#[test]
fn filter_by_mut_closure() {
    let src = setup_a_b_src();
    let dest = tempfile::tempdir().unwrap();

    // Filter paths and also collect all the paths we've seen, as an example of a filter
    // that's more than a simple function pointer.
    let mut filter_seen_paths: Vec<String> = Vec::new();
    let stats = CopyOptions::default()
        .filter(|path: &Path, _de| {
            filter_seen_paths.push(path.to_str().unwrap().replace('\\', "/"));
            Ok(path != Path::new("b"))
        })
        .copy_tree(src.path(), dest.path())
        .unwrap();

    assert_eq!(read(dest.path().join("a/aa/aaafile")).unwrap(), AAA_CONTENT,);
    assert!(!dest.path().join("b").exists());
    assert_eq!(
        stats,
        CopyStats {
            files: 1,
            file_bytes: AAA_CONTENT.len() as u64,
            dirs: 2,
            symlinks: 0,
            filtered_out: 1,
        }
    );
    // The order in which entries are seen is not guaranteed, and in practice
    // will be partly determined by the unpredictable order that the filesystem
    // returns directory entries.
    //
    // "b" is seen (because the filter records it before filtering it out), but
    // b's children are not visited.
    filter_seen_paths.sort_unstable();
    assert_eq!(filter_seen_paths, ["a", "a/aa", "a/aa/aaafile", "b"]);
}

#[test]
fn after_entry_copied_callback() {
    let src = setup_a_b_src();
    let dest = tempfile::tempdir().unwrap();
    let mut progress_seen: Vec<(PathBuf, FileType)> = Vec::new();
    let mut last_stats = CopyStats::default();

    // We can't count on the entries being seen in any particular order, but there are other
    // properties we can check...
    let final_stats = CopyOptions::new()
        .after_entry_copied(|p, ft, stats| {
            assert!(
                !progress_seen.iter().any(|(pp, _)| pp == p),
                "filename has not been seen before"
            );
            progress_seen.push((p.to_owned(), *ft));
            if ft.is_file() {
                assert_eq!(stats.files, last_stats.files + 1);
            } else if ft.is_dir() {
                assert_eq!(stats.dirs, last_stats.dirs + 1);
            } else {
                panic!("unexpected file type {:?}", ft);
            }
            last_stats = stats.clone();
            Ok(())
        })
        .copy_tree(src.path(), dest.path())
        .unwrap();
    assert_eq!(
        last_stats, final_stats,
        "progress after the final copy include stats equal to the overall final stats"
    );
}

#[test]
fn after_entry_callback_error_terminates_copy() {
    let src = setup_a_b_src();
    let dest = tempfile::tempdir().unwrap();

    // Stop after copying one file. The order in which files are copied is not defined, but we should see
    // exactly one in the result.
    let options = CopyOptions::new().after_entry_copied(|p, ft, _stats| {
        if ft.is_file() {
            Err(Error::new(ErrorKind::Interrupted, p))
        } else {
            Ok(())
        }
    });
    let result = options.copy_tree(src.path(), dest.path());

    let err = result.unwrap_err();
    let err_str = err.to_string();
    assert!(
        err_str.starts_with("interrupted"),
        "unexpected err_str: {:?}",
        err_str
    );

    let err_debug = format!("{:?}", err);
    assert!(
        err_debug.starts_with("Error") && err_debug.contains("kind: Interrupted"),
        "unexpected err_debug: {:?}",
        err_debug
    );
}