use anyhow::{Context as _, Result, bail};
use log::{debug, error, info, warn};
use std::path::Path;
use std::time::Duration;
use tokio::process::Command;

/// Default timeout for git operations (used when not configured).
pub const GIT_TIMEOUT_DEFAULT: Duration = Duration::from_secs(60);

/// Default git clone depth (shallow clone with 1 commit).
pub const GIT_DEPTH_DEFAULT: u32 = 1;

/// Timeout for LFS operations (longer due to large file downloads)
const LFS_TIMEOUT: Duration = Duration::from_secs(300);

/// LFS pointer file signature (per Git LFS spec)
const LFS_POINTER_SIGNATURE: &str = "version https://git-lfs.github.com/spec/v1";

/// Maximum size for a valid LFS pointer file (per spec)
const LFS_POINTER_MAX_SIZE: u64 = 1024;

/// Create a git Command with clean environment isolation.
///
/// Strips `GIT_DIR`, `GIT_WORK_TREE`, and `GIT_INDEX_FILE` so that git
/// discovers the repository from the working directory set via
/// `.current_dir()`, not from inherited environment variables.
///
/// This is defensive: in production these vars are never set, but it
/// prevents failures when tests run inside git hooks (e.g., a pre-commit
/// hook that invokes `cargo test`).
fn git_command() -> Command {
    let mut cmd = Command::new("git");
    cmd.env_remove("GIT_DIR")
        .env_remove("GIT_WORK_TREE")
        .env_remove("GIT_INDEX_FILE");
    cmd
}

/// Create a git Command that allows the file:// protocol.
///
/// Git ≥ 2.38.1 disables file:// by default (CVE-2022-39253), but the
/// restriction targets local-clone hardlink attacks, not file:// transport.
/// Submodule URLs come from the trusted config, so this is safe.
/// Used only for submodule operations whose internal clones may use file://.
fn git_command_allow_file_transport() -> Command {
    let mut cmd = git_command();
    cmd.env("GIT_CONFIG_COUNT", "1")
        .env("GIT_CONFIG_KEY_0", "protocol.file.allow")
        .env("GIT_CONFIG_VALUE_0", "always");
    cmd
}

/// Run a git command with timeout and standard error handling.
///
/// Builds a `git` `Command`, optionally sets the working directory,
/// enforces a timeout, and converts non-zero exit into an `anyhow` error.
async fn run_git(args: &[&str], dir: Option<&Path>, timeout: Duration, op: &str) -> Result<()> {
    run_git_cmd(git_command(), args, dir, timeout, op).await
}

/// Like [`run_git`] but uses a pre-built `Command` (e.g. one that allows
/// the file:// protocol for submodule clones).
async fn run_git_cmd(
    mut cmd: Command,
    args: &[&str],
    dir: Option<&Path>,
    timeout: Duration,
    op: &str,
) -> Result<()> {
    cmd.args(args);
    if let Some(d) = dir {
        cmd.current_dir(d);
    }

    let output = tokio::time::timeout(timeout, cmd.output())
        .await
        .with_context(|| format!("{op} timed out"))?
        .with_context(|| format!("failed to execute {op}"))?;

    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        bail!("{op} failed: {}", stderr.trim());
    }

    Ok(())
}

/// Synchronize a Git repository: clone if not exists, pull if exists.
/// Automatically initializes submodules and fetches LFS objects if needed.
///
/// # Errors
///
/// Returns an error if the clone, pull, submodule init, or LFS fetch fails.
pub async fn sync_repo(
    repo_url: &str,
    branch: &str,
    clone_dir: &Path,
    timeout: Duration,
    depth: u32,
) -> Result<()> {
    let is_pull = clone_dir.exists();

    if is_pull {
        pull(clone_dir, branch, timeout, depth).await?;
    } else if let Err(e) = clone(repo_url, branch, clone_dir, timeout, depth).await {
        if clone_dir.exists() {
            warn!(
                "cleaning up partial clone after failure: {}",
                clone_dir.display()
            );
            if let Err(cleanup_err) = tokio::fs::remove_dir_all(clone_dir).await {
                error!(
                    "failed to clean up partial clone: path={} error={cleanup_err}",
                    clone_dir.display()
                );
            }
        }
        return Err(e);
    }

    // Initialize submodules before LFS (submodule files may contain LFS pointers)
    maybe_init_submodules(clone_dir, timeout, depth, is_pull).await?;

    // Handle LFS after clone/pull + submodules
    maybe_fetch_lfs(clone_dir).await?;

    Ok(())
}

/// Check if the remote branch has new commits compared to local HEAD.
/// Returns `Ok(true)` if new commits are available, `Ok(false)` if up-to-date.
///
/// This function:
/// 1. Returns true if `clone_dir` doesn't exist (needs initial clone)
/// 2. Runs `git fetch` to update remote refs (with `--depth` if depth > 0)
/// 3. Compares local HEAD with `origin/{branch}`
/// 4. Does NOT modify the working directory (no reset/checkout)
///
/// # Errors
///
/// Returns an error if git fetch or rev-parse fails.
pub async fn has_remote_changes(
    clone_dir: &Path,
    branch: &str,
    timeout: Duration,
    depth: u32,
) -> Result<bool> {
    // If clone directory doesn't exist, treat as "needs update"
    if !clone_dir.exists() {
        debug!(
            "clone directory does not exist, needs initial clone: {}",
            clone_dir.display()
        );
        return Ok(true);
    }

    // Fetch from remote (update refs only, no working tree changes)
    debug!(
        "fetching remote refs: path={} branch={branch}",
        clone_dir.display()
    );
    let depth_str = depth.to_string();
    let mut fetch_args = vec!["fetch"];
    if depth > 0 {
        fetch_args.push("--depth");
        fetch_args.push(&depth_str);
    }
    fetch_args.extend_from_slice(&["origin", branch]);
    run_git(&fetch_args, Some(clone_dir), timeout, "git fetch").await?;

    // Get local HEAD commit
    let local_head = get_commit_hash(clone_dir, "HEAD").await?;

    // Get remote branch commit
    let remote_ref = format!("origin/{branch}");
    let remote_head = get_commit_hash(clone_dir, &remote_ref).await?;

    debug!(
        "comparing commits: path={} local={local_head} remote={remote_head}",
        clone_dir.display()
    );

    Ok(local_head != remote_head)
}

/// Get the full commit hash for a ref (HEAD, branch name, etc.)
async fn get_commit_hash(clone_dir: &Path, ref_name: &str) -> Result<String> {
    let output = git_command()
        .args(["rev-parse", ref_name])
        .current_dir(clone_dir)
        .output()
        .await
        .context("failed to execute git rev-parse")?;

    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        bail!("git rev-parse {} failed: {}", ref_name, stderr.trim());
    }

    Ok(String::from_utf8_lossy(&output.stdout).trim().to_owned())
}

async fn clone(
    repo_url: &str,
    branch: &str,
    clone_dir: &Path,
    timeout: Duration,
    depth: u32,
) -> Result<()> {
    info!(
        "cloning repository: repo={repo_url} branch={branch} path={}",
        clone_dir.display()
    );

    // Create parent directory if needed
    if let Some(parent) = clone_dir.parent() {
        tokio::fs::create_dir_all(parent)
            .await
            .with_context(|| format!("failed to create parent directory: {}", parent.display()))?;
    }

    let clone_dir_str = clone_dir.display().to_string();
    let depth_str = depth.to_string();
    let mut args = vec!["clone", "--branch", branch, "--single-branch"];
    if depth > 0 {
        args.push("--depth");
        args.push(&depth_str);
    }
    args.push(repo_url);
    args.push(clone_dir_str.as_str());
    run_git(&args, None, timeout, "git clone").await?;

    debug!("clone completed: {}", clone_dir.display());
    Ok(())
}

async fn pull(clone_dir: &Path, branch: &str, timeout: Duration, depth: u32) -> Result<()> {
    info!(
        "pulling latest changes: branch={branch} path={}",
        clone_dir.display()
    );

    // Fetch from origin (shallow or full depending on depth)
    let depth_str = depth.to_string();
    let mut fetch_args = vec!["fetch"];
    if depth > 0 {
        fetch_args.push("--depth");
        fetch_args.push(&depth_str);
    }
    fetch_args.extend_from_slice(&["origin", branch]);
    run_git(&fetch_args, Some(clone_dir), timeout, "git fetch").await?;

    // Reset to origin/branch to discard any local changes
    let reset_ref = format!("origin/{branch}");
    run_git(
        &["reset", "--hard", &reset_ref],
        Some(clone_dir),
        timeout,
        "git reset",
    )
    .await?;

    debug!("pull completed: {}", clone_dir.display());
    Ok(())
}

/// Check if the repository has LFS configured via .gitattributes.
async fn has_lfs_configured(clone_dir: &Path) -> bool {
    let gitattributes = clone_dir.join(".gitattributes");

    tokio::fs::read_to_string(&gitattributes)
        .await
        .is_ok_and(|content| content.contains("filter=lfs"))
}

/// Scan repository for LFS pointer files.
/// Returns true if any tracked file matches the LFS pointer signature.
async fn has_lfs_pointers(clone_dir: &Path) -> Result<bool> {
    // Use git ls-files to get tracked files
    let output = git_command()
        .args(["ls-files", "-z"]) // -z for null-separated output
        .current_dir(clone_dir)
        .output()
        .await
        .context("failed to list git files")?;

    if !output.status.success() {
        // If ls-files fails, assume pointers might exist (conservative)
        return Ok(true);
    }

    let files_str = String::from_utf8_lossy(&output.stdout);

    for file_path in files_str.split('\0').filter(|s| !s.is_empty()) {
        let full_path = clone_dir.join(file_path);

        // Check file size first (pointer files are < 1024 bytes)
        let Ok(metadata) = tokio::fs::metadata(&full_path).await else {
            continue;
        };
        if metadata.len() >= LFS_POINTER_MAX_SIZE || !metadata.is_file() {
            continue;
        }

        // Read and check for LFS signature
        let Ok(content) = tokio::fs::read_to_string(&full_path).await else {
            continue;
        };
        if content.starts_with(LFS_POINTER_SIGNATURE) {
            debug!("found LFS pointer: {file_path}");
            return Ok(true);
        }
    }

    Ok(false)
}

async fn is_lfs_available() -> bool {
    git_command()
        .args(["lfs", "version"])
        .output()
        .await
        .map(|o| o.status.success())
        .unwrap_or(false)
}

async fn lfs_pull(clone_dir: &Path) -> Result<()> {
    info!("fetching LFS objects: {}", clone_dir.display());

    run_git(
        &["lfs", "pull"],
        Some(clone_dir),
        LFS_TIMEOUT,
        "git lfs pull",
    )
    .await?;

    debug!("LFS pull completed: {}", clone_dir.display());
    Ok(())
}

/// Detect and fetch LFS objects if needed.
///
/// Detection strategy:
/// 1. Check .gitattributes for `filter=lfs`
/// 2. If configured, scan for actual pointer files
/// 3. If pointers exist, verify git-lfs is available
/// 4. Run `git lfs pull` to fetch objects
async fn maybe_fetch_lfs(clone_dir: &Path) -> Result<()> {
    // Step 1: Quick check for LFS configuration
    if !has_lfs_configured(clone_dir).await {
        debug!("no LFS configuration found: {}", clone_dir.display());
        return Ok(());
    }

    info!(
        "LFS configured, checking for pointers: {}",
        clone_dir.display()
    );

    // Step 2: Scan for actual pointer files
    match has_lfs_pointers(clone_dir).await {
        Ok(true) => {
            // Pointers found, need to fetch
        }
        Ok(false) => {
            debug!("no LFS pointers found: {}", clone_dir.display());
            return Ok(());
        }
        Err(e) => {
            // If scan fails, try to fetch anyway (conservative approach)
            debug!("LFS pointer scan failed, attempting fetch: {e}");
        }
    }

    // Step 3: Verify git-lfs is available
    if !is_lfs_available().await {
        bail!("repository requires git-lfs but git-lfs is not installed");
    }

    // Step 4: Fetch LFS objects
    lfs_pull(clone_dir).await
}

/// Check if the repository has submodules configured via .gitmodules.
async fn has_submodules(clone_dir: &Path) -> bool {
    let gitmodules = clone_dir.join(".gitmodules");
    tokio::fs::read_to_string(&gitmodules)
        .await
        .is_ok_and(|content| !content.trim().is_empty())
}

/// Detect and initialize submodules if needed.
///
/// Detection: checks for `.gitmodules` (single stat call when absent).
/// On pull: runs `git submodule sync --recursive` first to handle URL changes.
/// Then: `git submodule update --init --recursive [--depth 1]`.
async fn maybe_init_submodules(
    clone_dir: &Path,
    timeout: Duration,
    depth: u32,
    is_pull: bool,
) -> Result<()> {
    if !has_submodules(clone_dir).await {
        debug!("no submodules configured: {}", clone_dir.display());
        return Ok(());
    }

    info!("submodules detected, initializing: {}", clone_dir.display());

    // On pull, sync URLs first (handles upstream submodule URL changes)
    if is_pull {
        run_git(
            &["submodule", "sync", "--recursive"],
            Some(clone_dir),
            timeout,
            "git submodule sync",
        )
        .await?;
    }

    // Initialize and update submodules.
    // Uses file-transport-allowing command because `git submodule update`
    // internally clones each submodule, and URLs may use the file:// scheme.
    let depth_str = depth.to_string();
    let mut args = vec!["submodule", "update", "--init", "--recursive"];
    if depth > 0 {
        args.push("--depth");
        args.push(&depth_str);
    }
    run_git_cmd(
        git_command_allow_file_transport(),
        &args,
        Some(clone_dir),
        timeout,
        "git submodule update",
    )
    .await?;

    debug!(
        "submodule initialization completed: {}",
        clone_dir.display()
    );
    Ok(())
}

#[cfg(test)]
#[allow(clippy::unwrap_used, clippy::indexing_slicing, clippy::expect_used)]
mod tests {
    use super::*;
    use crate::test_support::{cleanup, temp_dir};
    use tokio::fs;
    use tokio::process::Command;

    /// Alias for `git_command_allow_file_transport()` — tests use file://
    /// URLs for bare repos, so the file protocol must be allowed.
    fn git_cmd() -> Command {
        git_command_allow_file_transport()
    }

    async fn configure_test_git_user(dir: &Path) {
        git_cmd()
            .args(["config", "user.email", "test@test.com"])
            .current_dir(dir)
            .output()
            .await
            .unwrap();
        git_cmd()
            .args(["config", "user.name", "Test"])
            .current_dir(dir)
            .output()
            .await
            .unwrap();
    }

    /// Create a local bare git repository with an initial commit on the specified branch.
    /// Returns a file:// URL that works with git clone --depth 1.
    async fn create_local_repo(temp: &Path, branch: &str) -> String {
        let bare_repo = temp.join("origin.git");
        fs::create_dir_all(&bare_repo).await.unwrap();

        // Initialize bare repo with explicit initial branch
        let output = git_cmd()
            .args(["init", "--bare", "--initial-branch", branch])
            .current_dir(&bare_repo)
            .output()
            .await
            .unwrap();
        assert!(output.status.success(), "git init failed");

        // Create a working copy to make initial commit
        let work_dir = temp.join("work");
        let output = git_cmd()
            .args([
                "clone",
                bare_repo.to_str().unwrap(),
                work_dir.to_str().unwrap(),
            ])
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "git clone failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // Configure git user for commit
        configure_test_git_user(&work_dir).await;

        // Checkout the target branch (in case clone defaulted to something else)
        let output = git_cmd()
            .args(["checkout", "-B", branch])
            .current_dir(&work_dir)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "git checkout failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // Create initial commit
        fs::write(work_dir.join("README.md"), "# Test Repo")
            .await
            .unwrap();
        let output = git_cmd()
            .args(["add", "README.md"])
            .current_dir(&work_dir)
            .output()
            .await
            .unwrap();
        assert!(output.status.success(), "git add failed");

        let output = git_cmd()
            .args(["commit", "-m", "Initial commit"])
            .current_dir(&work_dir)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "git commit failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // Push to origin
        let output = git_cmd()
            .args(["push", "-u", "origin", branch])
            .current_dir(&work_dir)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "git push failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // Clean up working copy
        let _ = fs::remove_dir_all(&work_dir).await;

        // Return file:// URL so --depth works correctly
        format!("file://{}", bare_repo.to_str().unwrap())
    }

    #[tokio::test]
    async fn clone_creates_directory_and_clones_repo() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("test-repo");

        let result = clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1).await;

        assert!(result.is_ok(), "clone should succeed: {result:?}");
        assert!(clone_dir.exists(), "clone directory should exist");
        assert!(
            clone_dir.join(".git").exists(),
            ".git directory should exist"
        );

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn clone_invalid_url_returns_error() {
        let temp = temp_dir("git-test").await;
        let clone_dir = temp.join("invalid-repo");

        let result = clone(
            "/nonexistent/path/to/repo.git",
            "main",
            &clone_dir,
            GIT_TIMEOUT_DEFAULT,
            1,
        )
        .await;

        assert!(result.is_err(), "clone should fail for invalid URL");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn clone_invalid_branch_returns_error() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("invalid-branch");

        let result = clone(
            &repo_url,
            "nonexistent-branch-xyz",
            &clone_dir,
            GIT_TIMEOUT_DEFAULT,
            1,
        )
        .await;

        assert!(result.is_err(), "clone should fail for invalid branch");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn pull_updates_existing_repo() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("pull-test");

        // First clone
        clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("initial clone should succeed");

        // Push a new commit to origin
        let work_dir = temp.join("work-pull");
        push_new_commit(&repo_url, &work_dir, "pulled.txt", "pulled content").await;

        // Pull should fetch the new commit
        pull(&clone_dir, "main", GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("pull should succeed");

        // Verify the new file appeared in the working copy
        let pulled_file = clone_dir.join("pulled.txt");
        assert!(pulled_file.exists(), "pulled file should exist after pull");
        let content = fs::read_to_string(&pulled_file).await.unwrap();
        assert_eq!(content, "pulled content");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn pull_invalid_branch_returns_error() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("pull-invalid-branch");

        // First clone
        clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("initial clone should succeed");

        // Pull with invalid branch
        let result = pull(&clone_dir, "nonexistent-branch-xyz", GIT_TIMEOUT_DEFAULT, 1).await;

        assert!(result.is_err(), "pull should fail for invalid branch");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn sync_repo_clones_when_not_exists() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("sync-clone");

        let result = sync_repo(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1).await;

        assert!(result.is_ok(), "sync should succeed: {result:?}");
        assert!(clone_dir.exists(), "clone directory should exist");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn sync_repo_pulls_when_exists() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("sync-pull");

        // First sync (clone)
        sync_repo(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("initial sync should succeed");

        // Push a new commit to origin
        let work_dir = temp.join("work-sync");
        push_new_commit(&repo_url, &work_dir, "synced.txt", "synced content").await;

        // Second sync should pull the new commit
        sync_repo(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("second sync should succeed");

        // Verify the new file appeared
        let synced_file = clone_dir.join("synced.txt");
        assert!(synced_file.exists(), "synced file should exist after pull");
        let content = fs::read_to_string(&synced_file).await.unwrap();
        assert_eq!(content, "synced content");

        cleanup(&temp).await;
    }

    // LFS tests

    #[tokio::test]
    async fn has_lfs_configured_with_lfs() {
        let temp = temp_dir("git-test").await;
        fs::write(
            temp.join(".gitattributes"),
            "*.bin filter=lfs diff=lfs merge=lfs -text\n",
        )
        .await
        .unwrap();

        assert!(has_lfs_configured(&temp).await);

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_lfs_configured_without_lfs() {
        let temp = temp_dir("git-test").await;
        fs::write(temp.join(".gitattributes"), "*.txt text\n")
            .await
            .unwrap();

        assert!(!has_lfs_configured(&temp).await);

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_lfs_configured_no_file() {
        let temp = temp_dir("git-test").await;
        // No .gitattributes file

        assert!(!has_lfs_configured(&temp).await);

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_lfs_pointers_detects_pointer() {
        let temp = temp_dir("git-test").await;

        // Initialize git repo
        init_git_repo(&temp).await;

        // Create LFS pointer file
        let pointer_content = "version https://git-lfs.github.com/spec/v1\n\
            oid sha256:4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393\n\
            size 12345\n";
        fs::write(temp.join("large.bin"), pointer_content)
            .await
            .unwrap();

        // Stage the file
        stage_file(&temp, "large.bin").await;

        let result = has_lfs_pointers(&temp).await;
        assert!(result.is_ok());
        assert!(result.unwrap());

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_lfs_pointers_ignores_non_pointers() {
        let temp = temp_dir("git-test").await;

        // Initialize git repo
        init_git_repo(&temp).await;

        // Create normal small file
        fs::write(temp.join("readme.txt"), "Hello World")
            .await
            .unwrap();
        stage_file(&temp, "readme.txt").await;

        let result = has_lfs_pointers(&temp).await;
        assert!(result.is_ok());
        assert!(!result.unwrap());

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_lfs_pointers_ignores_large_files() {
        let temp = temp_dir("git-test").await;

        init_git_repo(&temp).await;

        // Create large file that starts with LFS signature (edge case)
        let mut content = String::from("version https://git-lfs.github.com/spec/v1\n");
        content.push_str(&"x".repeat(2000)); // > 1024 bytes
        fs::write(temp.join("large.txt"), &content).await.unwrap();
        stage_file(&temp, "large.txt").await;

        let result = has_lfs_pointers(&temp).await;
        assert!(result.is_ok());
        assert!(!result.unwrap()); // Should be ignored due to size

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn maybe_fetch_lfs_no_config() {
        let temp = temp_dir("git-test").await;
        init_git_repo(&temp).await;

        // No .gitattributes = no LFS
        let result = maybe_fetch_lfs(&temp).await;
        assert!(result.is_ok());

        cleanup(&temp).await;
    }

    // Helper functions for LFS tests

    async fn init_git_repo(dir: &Path) {
        git_cmd()
            .args(["init"])
            .current_dir(dir)
            .output()
            .await
            .unwrap();
        configure_test_git_user(dir).await;
    }

    async fn stage_file(dir: &Path, filename: &str) {
        git_cmd()
            .args(["add", filename])
            .current_dir(dir)
            .output()
            .await
            .unwrap();
    }

    /// Clone a bare repo into `work_dir`, commit a new file, and push it.
    async fn push_new_commit(repo_url: &str, work_dir: &Path, filename: &str, content: &str) {
        git_cmd()
            .args(["clone", repo_url, work_dir.to_str().unwrap()])
            .output()
            .await
            .unwrap();
        configure_test_git_user(work_dir).await;

        fs::write(work_dir.join(filename), content).await.unwrap();

        git_cmd()
            .args(["add", filename])
            .current_dir(work_dir)
            .output()
            .await
            .unwrap();

        git_cmd()
            .args(["commit", "-m", "New commit"])
            .current_dir(work_dir)
            .output()
            .await
            .unwrap();

        git_cmd()
            .args(["push"])
            .current_dir(work_dir)
            .output()
            .await
            .unwrap();
    }

    // has_remote_changes tests

    #[tokio::test]
    async fn has_remote_changes_nonexistent_dir_returns_true() {
        let temp = temp_dir("git-test").await;
        let nonexistent = temp.join("does-not-exist");

        let result = has_remote_changes(&nonexistent, "main", GIT_TIMEOUT_DEFAULT, 1).await;
        assert!(result.is_ok());
        assert!(result.unwrap(), "nonexistent directory should return true");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_remote_changes_up_to_date_returns_false() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("test-clone");

        // Clone the repo
        clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .unwrap();

        // Check for changes - should be false since we just cloned
        let result = has_remote_changes(&clone_dir, "main", GIT_TIMEOUT_DEFAULT, 1).await;
        assert!(result.is_ok(), "has_remote_changes failed: {result:?}");
        assert!(!result.unwrap(), "freshly cloned repo should be up-to-date");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_remote_changes_detects_new_commits() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("test-clone");

        // Clone the repo
        clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .unwrap();

        // Push a new commit to the origin
        let work_dir = temp.join("work2");
        push_new_commit(&repo_url, &work_dir, "new-file.txt", "new content").await;

        // Now check for changes - should detect the new commit
        let result = has_remote_changes(&clone_dir, "main", GIT_TIMEOUT_DEFAULT, 1).await;
        assert!(result.is_ok(), "has_remote_changes failed: {result:?}");
        assert!(result.unwrap(), "should detect new commits on remote");

        cleanup(&temp).await;
    }

    // git_depth tests

    #[tokio::test]
    async fn clone_full_depth_creates_complete_history() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;

        // Push a second commit so we have more than 1 commit in history
        let work_dir = temp.join("work-depth");
        push_new_commit(&repo_url, &work_dir, "second.txt", "second commit").await;

        let clone_dir = temp.join("full-clone");

        // Clone with depth=0 (full clone)
        clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 0)
            .await
            .expect("full clone should succeed");

        // Verify we have more than 1 commit (full history)
        let output = git_cmd()
            .args(["rev-list", "--count", "HEAD"])
            .current_dir(&clone_dir)
            .output()
            .await
            .unwrap();
        let count: u32 = String::from_utf8_lossy(&output.stdout)
            .trim()
            .parse()
            .unwrap();
        assert!(
            count > 1,
            "full clone should have multiple commits, got {count}"
        );

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn sync_repo_full_depth_preserves_history() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;

        // Push a second commit
        let work_dir = temp.join("work-depth2");
        push_new_commit(&repo_url, &work_dir, "second.txt", "second").await;

        let clone_dir = temp.join("sync-full");

        // sync_repo with depth=0 should do a full clone
        sync_repo(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 0)
            .await
            .expect("sync with full depth should succeed");

        let output = git_cmd()
            .args(["rev-list", "--count", "HEAD"])
            .current_dir(&clone_dir)
            .output()
            .await
            .unwrap();
        let count: u32 = String::from_utf8_lossy(&output.stdout)
            .trim()
            .parse()
            .unwrap();
        assert!(
            count > 1,
            "full sync should have multiple commits, got {count}"
        );

        cleanup(&temp).await;
    }

    // Submodule tests

    #[tokio::test]
    async fn has_submodules_with_gitmodules_file() {
        let temp = temp_dir("git-test").await;
        fs::write(
            temp.join(".gitmodules"),
            "[submodule \"lib\"]\n\tpath = lib\n\turl = ../lib.git\n",
        )
        .await
        .unwrap();

        assert!(has_submodules(&temp).await);

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_submodules_without_gitmodules() {
        let temp = temp_dir("git-test").await;

        assert!(!has_submodules(&temp).await);

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn has_submodules_empty_gitmodules() {
        let temp = temp_dir("git-test").await;
        fs::write(temp.join(".gitmodules"), "").await.unwrap();

        assert!(!has_submodules(&temp).await);

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn maybe_init_submodules_no_submodules_is_noop() {
        let temp = temp_dir("git-test").await;
        let repo_url = create_local_repo(&temp, "main").await;
        let clone_dir = temp.join("no-submodules");

        clone(&repo_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("clone should succeed");

        // No .gitmodules → should be a no-op
        let result = maybe_init_submodules(&clone_dir, GIT_TIMEOUT_DEFAULT, 1, false).await;
        assert!(
            result.is_ok(),
            "noop submodule init should succeed: {result:?}"
        );

        cleanup(&temp).await;
    }

    /// Create a parent repo with a submodule wired up.
    /// Returns `(parent_url, submodule_url)`.
    async fn create_repo_with_submodule(temp: &Path, branch: &str) -> (String, String) {
        // 1. Create bare submodule repo with a file
        let sub_bare = temp.join("sub.git");
        fs::create_dir_all(&sub_bare).await.unwrap();
        git_cmd()
            .args(["init", "--bare", "--initial-branch", branch])
            .current_dir(&sub_bare)
            .output()
            .await
            .unwrap();

        let sub_work = temp.join("sub-work");
        git_cmd()
            .args([
                "clone",
                sub_bare.to_str().unwrap(),
                sub_work.to_str().unwrap(),
            ])
            .output()
            .await
            .unwrap();
        configure_test_git_user(&sub_work).await;
        git_cmd()
            .args(["checkout", "-B", branch])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        fs::write(sub_work.join("sub-file.txt"), "submodule content")
            .await
            .unwrap();
        git_cmd()
            .args(["add", "sub-file.txt"])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        let output = git_cmd()
            .args(["commit", "-m", "sub initial"])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "sub commit failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
        let output = git_cmd()
            .args(["push", "-u", "origin", branch])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "sub push failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // 2. Create bare parent repo with a submodule reference
        let parent_bare = temp.join("parent.git");
        fs::create_dir_all(&parent_bare).await.unwrap();
        git_cmd()
            .args(["init", "--bare", "--initial-branch", branch])
            .current_dir(&parent_bare)
            .output()
            .await
            .unwrap();

        let parent_work = temp.join("parent-work");
        git_cmd()
            .args([
                "clone",
                parent_bare.to_str().unwrap(),
                parent_work.to_str().unwrap(),
            ])
            .output()
            .await
            .unwrap();
        configure_test_git_user(&parent_work).await;
        git_cmd()
            .args(["checkout", "-B", branch])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        fs::write(parent_work.join("README.md"), "# Parent")
            .await
            .unwrap();
        git_cmd()
            .args(["add", "README.md"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();

        // Add submodule using file:// URL
        let sub_url = format!("file://{}", sub_bare.to_str().unwrap());
        let output = git_cmd()
            .args(["submodule", "add", &sub_url, "lib"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "git submodule add failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        git_cmd()
            .args(["commit", "-m", "add submodule"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        let output = git_cmd()
            .args(["push", "-u", "origin", branch])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "git push failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        let _ = fs::remove_dir_all(&sub_work).await;
        let _ = fs::remove_dir_all(&parent_work).await;

        let parent_url = format!("file://{}", parent_bare.to_str().unwrap());
        (parent_url, sub_url)
    }

    #[tokio::test]
    async fn sync_repo_initializes_submodules() {
        let temp = temp_dir("git-test").await;
        let (parent_url, _sub_url) = create_repo_with_submodule(&temp, "main").await;
        let clone_dir = temp.join("clone-with-sub");

        sync_repo(&parent_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("sync should succeed");

        // Verify submodule content is present
        let sub_file = clone_dir.join("lib").join("sub-file.txt");
        assert!(sub_file.exists(), "submodule file should exist after sync");
        let content = fs::read_to_string(&sub_file).await.unwrap();
        assert_eq!(content, "submodule content");

        cleanup(&temp).await;
    }

    #[tokio::test]
    async fn sync_repo_updates_submodules_on_pull() {
        let temp = temp_dir("git-test").await;
        let (parent_url, sub_url) = create_repo_with_submodule(&temp, "main").await;
        let clone_dir = temp.join("pull-sub");

        // First sync (clone + submodule init)
        sync_repo(&parent_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("initial sync should succeed");

        // Push a new commit to the submodule
        let sub_work = temp.join("sub-update");
        git_cmd()
            .args(["clone", &sub_url, sub_work.to_str().unwrap()])
            .output()
            .await
            .unwrap();
        configure_test_git_user(&sub_work).await;
        fs::write(sub_work.join("new-sub-file.txt"), "updated submodule")
            .await
            .unwrap();
        git_cmd()
            .args(["add", "new-sub-file.txt"])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        let output = git_cmd()
            .args(["commit", "-m", "update sub"])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "sub commit failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
        let output = git_cmd()
            .args(["push"])
            .current_dir(&sub_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "sub push failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // Update parent to point to new submodule commit
        let parent_work = temp.join("parent-update");
        let parent_bare = temp.join("parent.git");
        git_cmd()
            .args([
                "clone",
                parent_bare.to_str().unwrap(),
                parent_work.to_str().unwrap(),
            ])
            .output()
            .await
            .unwrap();
        configure_test_git_user(&parent_work).await;
        // Init submodule in parent work copy, then update to latest
        git_cmd()
            .args(["submodule", "update", "--init", "--remote", "lib"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        git_cmd()
            .args(["add", "lib"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        let output = git_cmd()
            .args(["commit", "-m", "bump submodule"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "parent bump commit failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
        let output = git_cmd()
            .args(["push"])
            .current_dir(&parent_work)
            .output()
            .await
            .unwrap();
        assert!(
            output.status.success(),
            "parent push failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );

        // Second sync (pull + submodule update)
        sync_repo(&parent_url, "main", &clone_dir, GIT_TIMEOUT_DEFAULT, 1)
            .await
            .expect("second sync should succeed");

        // Verify the new submodule content is present
        let new_sub_file = clone_dir.join("lib").join("new-sub-file.txt");
        assert!(
            new_sub_file.exists(),
            "updated submodule file should exist after pull"
        );
        let content = fs::read_to_string(&new_sub_file).await.unwrap();
        assert_eq!(content, "updated submodule");

        cleanup(&temp).await;
    }
}