// file: crates/knowledge-git-lib/tests/git_write_candidate.rs
// version: 2

//! Integration tests for isolated real Git candidate creation using local temporary repositories.

fn test_root(label: &str) -> std::path::PathBuf {
    let nanos_result = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH);
    let nanos = match nanos_result {
        Ok(value) => value.as_nanos(),
        Err(_) => 0,
    };
    let mut path = std::env::temp_dir();
    path.push(format!("sasedev-knowledge-git-write-{label}-{}-{nanos}", std::process::id()));
    let _ = std::fs::remove_dir_all(&path);
    return path;
}

fn run_git(repository: &std::path::Path, arguments: &[&str]) -> bool {
    let mut command = std::process::Command::new("git");
    command.current_dir(repository);
    command.args(arguments);
    command.env("GIT_TERMINAL_PROMPT", "0");
    let status_result = command.status();
    match status_result {
        Ok(status) => return status.success(),
        Err(_) => return false,
    }
}

fn run_git_output(arguments: Vec<std::ffi::OsString>) -> Option<Vec<u8>> {
    let mut command = std::process::Command::new("git");
    command.args(arguments);
    command.env("GIT_TERMINAL_PROMPT", "0");
    let output_result = command.output();
    let output = match output_result {
        Ok(value) => value,
        Err(_) => return None,
    };
    if !output.status.success() {
        return None;
    }
    return Some(output.stdout);
}

fn prepare_source(root: &std::path::Path) -> Option<std::path::PathBuf> {
    let source = root.join("source");
    if std::fs::create_dir_all(&source).is_err() {
        return None;
    }
    if !run_git(&source, &["init", "-b", "main"]) {
        return None;
    }
    if !run_git(&source, &["config", "user.name", "Ambient Identity"]) {
        return None;
    }
    if !run_git(&source, &["config", "user.email", "ambient@example.invalid"]) {
        return None;
    }
    if !run_git(&source, &["config", "commit.gpgsign", "false"]) {
        return None;
    }
    if std::fs::write(source.join("content.txt"), "first\n").is_err() {
        return None;
    }
    if std::fs::write(source.join("delete.txt"), "delete me\n").is_err() {
        return None;
    }
    if !run_git(&source, &["add", "content.txt", "delete.txt"]) {
        return None;
    }
    if !run_git(&source, &["commit", "-m", "first"]) {
        return None;
    }
    return Some(source);
}

fn configured_backend(root: &std::path::Path, source: &std::path::Path) -> Option<(knowledge_git_lib::GitBackend, knowledge_domain_lib::SourceId)> {
    let source_id_result = knowledge_domain_lib::SourceId::new("integration-write-source");
    let source_id = match source_id_result {
        Ok(value) => value,
        Err(_) => return None,
    };
    let config_result = knowledge_git_lib::GitBackendConfig::new(root.join("state"));
    let config = match config_result {
        Ok(value) => value,
        Err(_) => return None,
    };
    let source_result = knowledge_git_lib::GitSourceConfig::local(source_id.clone(), source.to_path_buf());
    let source_config = match source_result {
        Ok(value) => value,
        Err(_) => return None,
    };
    let mut backend = knowledge_git_lib::GitBackend::new(config);
    if backend.register_source(source_config).is_err() {
        return None;
    }
    return Some((backend, source_id));
}

fn resolved_main(backend: &mut knowledge_git_lib::GitBackend, source_id: &knowledge_domain_lib::SourceId) -> Option<knowledge_git_api::GitRevision> {
    if knowledge_git_api::GitRepository::refresh(backend, source_id).is_err() {
        return None;
    }
    let reference = knowledge_git_api::GitReference::new("refs/heads/main");
    let revision_result = knowledge_git_api::GitRepository::resolve_revision(backend, source_id, &reference);
    match revision_result {
        Ok(value) => return Some(value),
        Err(_) => return None,
    }
}

fn mutation_path(value: &str) -> Option<knowledge_git_api::GitMutationPath> {
    let result = knowledge_git_api::GitMutationPath::new(value);
    match result {
        Ok(value) => return Some(value),
        Err(_) => return None,
    }
}

fn commit_identity() -> Option<knowledge_git_api::GitCommitIdentity> {
    let result = knowledge_git_api::GitCommitIdentity::new("Knowledge Writer", "writer@example.invalid");
    match result {
        Ok(value) => return Some(value),
        Err(_) => return None,
    }
}

#[test]
fn candidate_commit_applies_exact_mutations_uses_explicit_identity_and_cleans_worktree() {
    let root = test_root("candidate");
    let source_result = prepare_source(&root);
    assert!(source_result.is_some());
    let source = match source_result {
        Some(value) => value,
        None => return,
    };
    let backend_result = configured_backend(&root, &source);
    assert!(backend_result.is_some());
    let (mut backend, source_id) = match backend_result {
        Some(value) => value,
        None => return,
    };
    let base_result = resolved_main(&mut backend, &source_id);
    assert!(base_result.is_some());
    let base = match base_result {
        Some(value) => value,
        None => return,
    };
    let snapshot_result = knowledge_git_api::GitRepository::prepare_snapshot(&backend, &source_id, &base);
    assert!(snapshot_result.is_ok());
    let snapshot = match snapshot_result {
        Ok(value) => value,
        Err(_) => return,
    };
    let content_path = match mutation_path("content.txt") {
        Some(value) => value,
        None => return,
    };
    let nested_path = match mutation_path("nested/new.txt") {
        Some(value) => value,
        None => return,
    };
    let delete_path = match mutation_path("delete.txt") {
        Some(value) => value,
        None => return,
    };
    let identity = match commit_identity() {
        Some(value) => value,
        None => return,
    };
    let request_result = knowledge_git_api::GitWriteRequest::new(
        base.clone(),
        vec![
            knowledge_git_api::GitFileMutation::Write { path: content_path, content: b"second\n".to_vec() },
            knowledge_git_api::GitFileMutation::Write { path: nested_path, content: b"nested\n".to_vec() },
            knowledge_git_api::GitFileMutation::Delete { path: delete_path },
        ],
        identity,
        "candidate commit",
    );
    assert!(request_result.is_ok());
    let request = match request_result {
        Ok(value) => value,
        Err(_) => return,
    };
    let candidate_result = backend.create_candidate(&source_id, &request);
    assert!(candidate_result.is_ok());
    let candidate = match candidate_result {
        Ok(value) => value,
        Err(_) => return,
    };
    assert_ne!(candidate, base);
    let repository_path = backend.repository_path(&source_id);
    let parent_output = run_git_output(vec![
        std::ffi::OsString::from("--git-dir"),
        repository_path.as_os_str().to_os_string(),
        std::ffi::OsString::from("rev-parse"),
        std::ffi::OsString::from(format!("{}^1", candidate.as_str())),
    ]);
    assert!(parent_output.is_some());
    let parent = match parent_output {
        Some(value) => String::from_utf8_lossy(&value).trim().to_owned(),
        None => return,
    };
    assert_eq!(parent, base.as_str());
    let content_output = run_git_output(vec![
        std::ffi::OsString::from("--git-dir"),
        repository_path.as_os_str().to_os_string(),
        std::ffi::OsString::from("show"),
        std::ffi::OsString::from(format!("{}:content.txt", candidate.as_str())),
    ]);
    assert_eq!(content_output, Some(b"second\n".to_vec()));
    let nested_output = run_git_output(vec![
        std::ffi::OsString::from("--git-dir"),
        repository_path.as_os_str().to_os_string(),
        std::ffi::OsString::from("show"),
        std::ffi::OsString::from(format!("{}:nested/new.txt", candidate.as_str())),
    ]);
    assert_eq!(nested_output, Some(b"nested\n".to_vec()));
    let deleted_output = run_git_output(vec![
        std::ffi::OsString::from("--git-dir"),
        repository_path.as_os_str().to_os_string(),
        std::ffi::OsString::from("show"),
        std::ffi::OsString::from(format!("{}:delete.txt", candidate.as_str())),
    ]);
    assert!(deleted_output.is_none());
    let identity_output = run_git_output(vec![
        std::ffi::OsString::from("--git-dir"),
        repository_path.as_os_str().to_os_string(),
        std::ffi::OsString::from("show"),
        std::ffi::OsString::from("-s"),
        std::ffi::OsString::from("--format=%an%x00%ae%x00%cn%x00%ce"),
        std::ffi::OsString::from(candidate.as_str()),
    ]);
    assert!(identity_output.is_some());
    let identity_text = match identity_output {
        Some(value) => String::from_utf8_lossy(&value).trim().to_owned(),
        None => return,
    };
    assert_eq!(identity_text, "Knowledge Writer\0writer@example.invalid\0Knowledge Writer\0writer@example.invalid");
    let candidate_ref = format!("refs/knowledge/candidates/{}", candidate.as_str());
    let retained = run_git_output(vec![
        std::ffi::OsString::from("--git-dir"),
        repository_path.as_os_str().to_os_string(),
        std::ffi::OsString::from("show-ref"),
        std::ffi::OsString::from("--verify"),
        std::ffi::OsString::from(candidate_ref),
    ]);
    assert!(retained.is_some());
    let source_key = knowledge_git_lib::GitSourceKey::from_source_id(&source_id);
    assert!(!backend.config().write_worktrees_path().join(source_key.as_str()).join("candidate").exists());
    let snapshot_content = std::fs::read_to_string(snapshot.path().join("content.txt"));
    assert!(matches!(snapshot_content.as_deref(), Ok("first\n")));
    assert!(snapshot.path().join("delete.txt").is_file());
    let _ = std::fs::remove_dir_all(&root);
    return;
}

#[cfg(unix)]
#[test]
fn candidate_rejects_symlink_escape_and_removes_owned_failed_worktree() {
    let root = test_root("symlink");
    let source_result = prepare_source(&root);
    assert!(source_result.is_some());
    let source = match source_result {
        Some(value) => value,
        None => return,
    };
    let outside = root.join("outside");
    assert!(std::fs::create_dir_all(&outside).is_ok());
    assert!(std::os::unix::fs::symlink(&outside, source.join("escape")).is_ok());
    assert!(run_git(&source, &["add", "escape"]));
    assert!(run_git(&source, &["commit", "-m", "add escape symlink"]));
    let backend_result = configured_backend(&root, &source);
    assert!(backend_result.is_some());
    let (mut backend, source_id) = match backend_result {
        Some(value) => value,
        None => return,
    };
    let base_result = resolved_main(&mut backend, &source_id);
    assert!(base_result.is_some());
    let base = match base_result {
        Some(value) => value,
        None => return,
    };
    let path = match mutation_path("escape/pwned.txt") {
        Some(value) => value,
        None => return,
    };
    let identity = match commit_identity() {
        Some(value) => value,
        None => return,
    };
    let request_result = knowledge_git_api::GitWriteRequest::new(
        base,
        vec![knowledge_git_api::GitFileMutation::Write { path, content: b"forbidden\n".to_vec() }],
        identity,
        "must fail",
    );
    assert!(request_result.is_ok());
    let request = match request_result {
        Ok(value) => value,
        Err(_) => return,
    };
    let result = backend.create_candidate(&source_id, &request);
    assert_eq!(result, Err(knowledge_git_lib::GitBackendError::UnsafeMutationTarget));
    assert!(!outside.join("pwned.txt").exists());
    let source_key = knowledge_git_lib::GitSourceKey::from_source_id(&source_id);
    assert!(!backend.config().write_worktrees_path().join(source_key.as_str()).join("candidate").exists());
    let _ = std::fs::remove_dir_all(&root);
    return;
}