use super::{stash::is_stash_commit, utils::repo, CommitId};
use crate::{
    error::Error, error::Result, StatusItem, StatusItemType,
};
use git2::{Diff, DiffDelta, DiffOptions, Repository};
use scopetime::scope_time;

/// get all files that are part of a commit
pub fn get_commit_files(
    repo_path: &str,
    id: CommitId,
) -> Result<Vec<StatusItem>> {
    scope_time!("get_commit_files");

    let repo = repo(repo_path)?;

    let diff = get_commit_diff(&repo, id, None)?;

    let mut res = Vec::new();

    diff.foreach(
        &mut |delta: DiffDelta<'_>, _progress| {
            res.push(StatusItem {
                path: delta
                    .new_file()
                    .path()
                    .map(|p| p.to_str().unwrap_or("").to_string())
                    .unwrap_or_default(),
                status: StatusItemType::from(delta.status()),
            });
            true
        },
        None,
        None,
        None,
    )?;

    Ok(res)
}

#[allow(clippy::redundant_pub_crate)]
pub(crate) fn get_commit_diff(
    repo: &Repository,
    id: CommitId,
    pathspec: Option<String>,
) -> Result<Diff<'_>> {
    // scope_time!("get_commit_diff");

    let commit = repo.find_commit(id.into())?;
    let commit_tree = commit.tree()?;
    let parent = if commit.parent_count() > 0 {
        Some(repo.find_commit(commit.parent_id(0)?)?.tree()?)
    } else {
        None
    };

    let mut opts = DiffOptions::new();
    if let Some(p) = &pathspec {
        opts.pathspec(p.clone());
    }
    opts.show_binary(true);

    let mut diff = repo.diff_tree_to_tree(
        parent.as_ref(),
        Some(&commit_tree),
        Some(&mut opts),
    )?;

    if is_stash_commit(
        repo.path().to_str().map_or_else(
            || Err(Error::Generic("repo path utf8 err".to_owned())),
            Ok,
        )?,
        &id,
    )? {
        if let Ok(untracked_commit) = commit.parent_id(2) {
            let untracked_diff = get_commit_diff(
                repo,
                CommitId::new(untracked_commit),
                pathspec,
            )?;

            diff.merge(&untracked_diff)?;
        }
    }

    Ok(diff)
}

#[cfg(test)]
mod tests {
    use super::get_commit_files;
    use crate::{
        error::Result,
        sync::{
            commit, stage_add_file, stash_save,
            tests::{get_statuses, repo_init},
        },
        StatusItemType,
    };
    use std::{fs::File, io::Write, path::Path};

    #[test]
    fn test_smoke() -> Result<()> {
        let file_path = Path::new("file1.txt");
        let (_td, repo) = repo_init()?;
        let root = repo.path().parent().unwrap();
        let repo_path = root.as_os_str().to_str().unwrap();

        File::create(&root.join(file_path))?
            .write_all(b"test file1 content")?;

        stage_add_file(repo_path, file_path)?;

        let id = commit(repo_path, "commit msg")?;

        let diff = get_commit_files(repo_path, id)?;

        assert_eq!(diff.len(), 1);
        assert_eq!(diff[0].status, StatusItemType::New);

        Ok(())
    }

    #[test]
    fn test_stashed_untracked() -> Result<()> {
        let file_path = Path::new("file1.txt");
        let (_td, repo) = repo_init()?;
        let root = repo.path().parent().unwrap();
        let repo_path = root.as_os_str().to_str().unwrap();

        File::create(&root.join(file_path))?
            .write_all(b"test file1 content")?;

        let id = stash_save(repo_path, None, true, false)?;

        let diff = get_commit_files(repo_path, id)?;

        assert_eq!(diff.len(), 1);
        assert_eq!(diff[0].status, StatusItemType::New);

        Ok(())
    }

    #[test]
    fn test_stashed_untracked_and_modified() -> Result<()> {
        let file_path1 = Path::new("file1.txt");
        let file_path2 = Path::new("file2.txt");
        let (_td, repo) = repo_init()?;
        let root = repo.path().parent().unwrap();
        let repo_path = root.as_os_str().to_str().unwrap();

        File::create(&root.join(file_path1))?.write_all(b"test")?;
        stage_add_file(repo_path, file_path1)?;
        commit(repo_path, "c1")?;

        File::create(&root.join(file_path1))?
            .write_all(b"modified")?;
        File::create(&root.join(file_path2))?.write_all(b"new")?;

        assert_eq!(get_statuses(repo_path), (2, 0));

        let id = stash_save(repo_path, None, true, false)?;

        let diff = get_commit_files(repo_path, id)?;

        assert_eq!(diff.len(), 2);
        assert_eq!(diff[0].status, StatusItemType::Modified);
        assert_eq!(diff[1].status, StatusItemType::New);

        Ok(())
    }
}