//! Async worktree creation and component setup/teardown commands.
use crate::config::ProjectConfig;
use crate::slog;
use std::path::Path;
use std::process::Command;

use super::git::{
    branch_name, configure_sparse_checkout, create_worktree_sync, detect_base_branch,
};
use super::{WorktreeInfo, worktree_path, write_mcp_json};

/// Create a git worktree for the given story.
///
/// - Creates the worktree at `{project_root}/.huskies/worktrees/{story_id}`
///   on branch `feature/story-{story_id}`.
/// - Writes `.mcp.json` in the worktree pointing to the MCP server at `port`.
/// - Runs setup commands from the config for each component.
/// - If the worktree/branch already exists, reuses rather than errors.
pub async fn create_worktree(
    project_root: &Path,
    story_id: &str,
    config: &ProjectConfig,
    port: u16,
) -> Result<WorktreeInfo, String> {
    let wt_path = worktree_path(project_root, story_id);
    let branch = branch_name(story_id);
    let base_branch = config
        .base_branch
        .clone()
        .unwrap_or_else(|| detect_base_branch(project_root));
    let root = project_root.to_path_buf();

    // Already exists — reuse (ensure sparse checkout is configured)
    if wt_path.exists() {
        let wt_clone = wt_path.clone();
        tokio::task::spawn_blocking(move || configure_sparse_checkout(&wt_clone))
            .await
            .map_err(|e| format!("spawn_blocking: {e}"))??;
        write_mcp_json(&wt_path, port)?;
        run_setup_commands(&wt_path, config).await;
        return Ok(WorktreeInfo {
            path: wt_path,
            branch,
            base_branch,
        });
    }

    let wt = wt_path.clone();
    let br = branch.clone();

    tokio::task::spawn_blocking(move || create_worktree_sync(&root, &wt, &br))
        .await
        .map_err(|e| format!("spawn_blocking: {e}"))??;

    write_mcp_json(&wt_path, port)?;
    run_setup_commands(&wt_path, config).await;

    Ok(WorktreeInfo {
        path: wt_path,
        branch,
        base_branch,
    })
}

pub(crate) async fn run_setup_commands(wt_path: &Path, config: &ProjectConfig) {
    for component in &config.component {
        let cmd_dir = wt_path.join(&component.path);
        for cmd in &component.setup {
            if let Err(e) = run_shell_command(cmd, &cmd_dir).await {
                slog!("[worktree] setup warning for {}: {e}", component.name);
            }
        }
    }
}

pub(crate) async fn run_teardown_commands(
    wt_path: &Path,
    config: &ProjectConfig,
) -> Result<(), String> {
    for component in &config.component {
        let cmd_dir = wt_path.join(&component.path);
        for cmd in &component.teardown {
            // Best effort — don't fail teardown
            if let Err(e) = run_shell_command(cmd, &cmd_dir).await {
                slog!("[worktree] teardown warning for {}: {e}", component.name);
            }
        }
    }
    Ok(())
}

/// Install a pre-commit git hook in an agent worktree.
///
/// Creates `{wt_path}/.git-hooks/pre-commit` containing a shell script that
/// runs `script/check` and aborts the commit if it fails. Configures the
/// worktree's `core.hooksPath` (via `git config --worktree`) so only this
/// worktree uses the per-worktree hooks directory.
pub fn install_pre_commit_hook(wt_path: &Path) -> Result<(), String> {
    #[cfg(unix)]
    use std::os::unix::fs::PermissionsExt;

    let hooks_dir = wt_path.join(".git-hooks");
    std::fs::create_dir_all(&hooks_dir).map_err(|e| format!("create .git-hooks dir: {e}"))?;

    let hook = "#!/bin/sh\n\
        #\n\
        # Pre-commit hook installed by huskies.\n\
        # Runs script/check (fmt-check, clippy, cargo check, source-map-check)\n\
        # before every commit. Aborts if any gate fails.\n\
        #\n\
        # Emergency bypass: git commit --no-verify  (see AGENT.md — avoid this)\n\
        \n\
        REPO_ROOT=\"$(git rev-parse --show-toplevel)\"\n\
        \n\
        printf '[pre-commit] Running script/check ...\\n'\n\
        OUTPUT=$(\"$REPO_ROOT/script/check\" 2>&1)\n\
        STATUS=$?\n\
        \n\
        if [ \"$STATUS\" -ne 0 ]; then\n\
            printf '\\n=== PRE-COMMIT HOOK FAILED ===\\n\\n'\n\
            printf '%s\\n' \"$OUTPUT\"\n\
            printf '\\nFix the issues above, then re-validate with:\\n'\n\
            printf '    script/check\\n'\n\
            printf '\\nEmergency bypass (see AGENT.md -- avoid this):\\n'\n\
            printf '    git commit --no-verify\\n\\n'\n\
            exit 1\n\
        fi\n";

    let hook_path = hooks_dir.join("pre-commit");
    std::fs::write(&hook_path, hook).map_err(|e| format!("write pre-commit hook: {e}"))?;

    #[cfg(unix)]
    std::fs::set_permissions(&hook_path, std::fs::Permissions::from_mode(0o755))
        .map_err(|e| format!("chmod pre-commit hook: {e}"))?;

    // Point git at the per-worktree hooks dir so only this worktree uses
    // these hooks (not the main repo or other worktrees).
    // Requires extensions.worktreeConfig = true in the repository config.
    let output = std::process::Command::new("git")
        .args(["config", "--worktree", "core.hooksPath", ".git-hooks"])
        .current_dir(wt_path)
        .output()
        .map_err(|e| format!("git config --worktree core.hooksPath: {e}"))?;

    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        return Err(format!(
            "git config --worktree core.hooksPath failed: {stderr}"
        ));
    }

    Ok(())
}

pub(crate) async fn run_shell_command(cmd: &str, cwd: &Path) -> Result<(), String> {
    let cmd = cmd.to_string();
    let cwd = cwd.to_path_buf();

    tokio::task::spawn_blocking(move || {
        slog!("[worktree] Running: {cmd} in {}", cwd.display());
        let output = Command::new("sh")
            .args(["-c", &cmd])
            .current_dir(&cwd)
            .output()
            .map_err(|e| format!("Run '{cmd}': {e}"))?;

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            return Err(format!("Command '{cmd}' failed: {stderr}"));
        }
        Ok(())
    })
    .await
    .map_err(|e| format!("spawn_blocking: {e}"))?
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::config::{ComponentConfig, WatcherConfig};
    use std::fs;
    use std::process::Command;
    use tempfile::TempDir;

    fn init_git_repo(dir: &Path) {
        Command::new("git")
            .args(["init"])
            .current_dir(dir)
            .output()
            .expect("git init");
        Command::new("git")
            .args(["commit", "--allow-empty", "-m", "init"])
            .current_dir(dir)
            .output()
            .expect("git commit");
    }

    fn empty_config() -> ProjectConfig {
        ProjectConfig {
            component: vec![],
            agent: vec![],
            watcher: WatcherConfig::default(),
            default_qa: "server".to_string(),
            default_coder_model: None,
            max_coders: None,
            max_retries: 2,
            base_branch: None,
            rate_limit_notifications: true,
            web_ui_status_consumer: true,
            matrix_status_consumer: true,
            slack_status_consumer: true,
            discord_status_consumer: true,
            whatsapp_status_consumer: true,
            timezone: None,
            rendezvous: None,
            trusted_keys: Vec::new(),
            crdt_require_token: false,
            crdt_tokens: Vec::new(),
            max_mesh_peers: 3,
            gateway_url: None,
            gateway_project: None,
            status_push_enabled: true,
        }
    }

    fn failing_setup_config() -> ProjectConfig {
        ProjectConfig {
            component: vec![ComponentConfig {
                name: "broken-build".to_string(),
                path: ".".to_string(),
                setup: vec!["exit 1".to_string()],
                teardown: vec![],
            }],
            ..empty_config()
        }
    }

    #[tokio::test]
    async fn run_shell_command_succeeds_for_echo() {
        let tmp = TempDir::new().unwrap();
        let result = run_shell_command("echo hello", tmp.path()).await;
        assert!(result.is_ok(), "Expected success: {:?}", result.err());
    }

    #[tokio::test]
    async fn run_shell_command_fails_for_nonzero_exit() {
        let tmp = TempDir::new().unwrap();
        let result = run_shell_command("exit 1", tmp.path()).await;
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("failed"));
    }

    #[tokio::test]
    async fn run_setup_commands_no_components_succeeds() {
        let tmp = TempDir::new().unwrap();
        // Should complete without panic
        run_setup_commands(tmp.path(), &empty_config()).await;
    }

    #[tokio::test]
    async fn run_setup_commands_runs_each_command_successfully() {
        let tmp = TempDir::new().unwrap();
        let config = ProjectConfig {
            component: vec![ComponentConfig {
                name: "test".to_string(),
                path: ".".to_string(),
                setup: vec!["echo setup_ok".to_string()],
                teardown: vec![],
            }],
            ..empty_config()
        };
        // Should complete without panic
        run_setup_commands(tmp.path(), &config).await;
    }

    #[tokio::test]
    async fn run_setup_commands_ignores_failures() {
        let tmp = TempDir::new().unwrap();
        let config = ProjectConfig {
            component: vec![ComponentConfig {
                name: "test".to_string(),
                path: ".".to_string(),
                setup: vec!["exit 1".to_string()],
                teardown: vec![],
            }],
            ..empty_config()
        };
        // Setup command failures are non-fatal — should not panic or propagate
        run_setup_commands(tmp.path(), &config).await;
    }

    #[tokio::test]
    async fn run_teardown_commands_ignores_failures() {
        let tmp = TempDir::new().unwrap();
        let config = ProjectConfig {
            component: vec![ComponentConfig {
                name: "test".to_string(),
                path: ".".to_string(),
                setup: vec![],
                teardown: vec!["exit 1".to_string()],
            }],
            ..empty_config()
        };
        // Teardown failures are best-effort — should not propagate
        assert!(run_teardown_commands(tmp.path(), &config).await.is_ok());
    }

    #[tokio::test]
    async fn create_worktree_fresh_creates_dir_and_mcp_json() {
        let tmp = TempDir::new().unwrap();
        let project_root = tmp.path().join("my-project");
        fs::create_dir_all(&project_root).unwrap();
        init_git_repo(&project_root);

        let info = create_worktree(&project_root, "42_fresh_test", &empty_config(), 3001)
            .await
            .unwrap();

        assert!(info.path.exists());
        assert!(info.path.join(".mcp.json").exists());
        let mcp = fs::read_to_string(info.path.join(".mcp.json")).unwrap();
        assert!(mcp.contains("3001"));
        assert_eq!(info.branch, "feature/story-42_fresh_test");
    }

    #[tokio::test]
    async fn create_worktree_reuses_existing_path_and_updates_port() {
        let tmp = TempDir::new().unwrap();
        let project_root = tmp.path().join("my-project");
        fs::create_dir_all(&project_root).unwrap();
        init_git_repo(&project_root);

        // First creation
        let _info1 = create_worktree(&project_root, "43_reuse_test", &empty_config(), 3001)
            .await
            .unwrap();
        // Second call — worktree already exists, reuse path, update port
        let info2 = create_worktree(&project_root, "43_reuse_test", &empty_config(), 3002)
            .await
            .unwrap();

        let mcp = fs::read_to_string(info2.path.join(".mcp.json")).unwrap();
        assert!(
            mcp.contains("3002"),
            "MCP json should be updated to new port"
        );
    }

    #[tokio::test]
    async fn create_worktree_succeeds_despite_setup_failure() {
        let tmp = TempDir::new().unwrap();
        let project_root = tmp.path().join("my-project");
        fs::create_dir_all(&project_root).unwrap();
        init_git_repo(&project_root);

        // Even though setup commands fail, create_worktree must succeed
        // so the agent can start and fix the problem itself.
        let result = create_worktree(
            &project_root,
            "172_setup_fail",
            &failing_setup_config(),
            3001,
        )
        .await;
        assert!(
            result.is_ok(),
            "create_worktree must succeed even if setup commands fail: {:?}",
            result.err()
        );
        let info = result.unwrap();
        assert!(info.path.exists());
        assert!(info.path.join(".mcp.json").exists());
    }

    #[tokio::test]
    async fn create_worktree_reuse_succeeds_despite_setup_failure() {
        let tmp = TempDir::new().unwrap();
        let project_root = tmp.path().join("my-project");
        fs::create_dir_all(&project_root).unwrap();
        init_git_repo(&project_root);

        // First creation — no setup commands, should succeed
        create_worktree(&project_root, "173_reuse_fail", &empty_config(), 3001)
            .await
            .unwrap();

        // Second call — worktree exists, setup commands fail, must still succeed
        let result = create_worktree(
            &project_root,
            "173_reuse_fail",
            &failing_setup_config(),
            3002,
        )
        .await;
        assert!(
            result.is_ok(),
            "create_worktree reuse must succeed even if setup commands fail: {:?}",
            result.err()
        );
    }

    #[test]
    fn install_pre_commit_hook_creates_executable_hook_and_sets_hookspath() {
        let tmp = TempDir::new().unwrap();
        let project_root = tmp.path().join("main-repo");
        fs::create_dir_all(&project_root).unwrap();
        init_git_repo(&project_root);

        // Enable per-worktree config so git config --worktree works.
        Command::new("git")
            .args(["config", "extensions.worktreeConfig", "true"])
            .current_dir(&project_root)
            .output()
            .expect("enable extensions.worktreeConfig");

        // Create a linked worktree to simulate what huskies does for agents.
        let wt_path = tmp.path().join("linked-wt");
        let out = Command::new("git")
            .args([
                "worktree",
                "add",
                wt_path.to_str().unwrap(),
                "-b",
                "feature/hook-test",
            ])
            .current_dir(&project_root)
            .output()
            .expect("git worktree add");
        assert!(
            out.status.success(),
            "git worktree add failed: {}",
            String::from_utf8_lossy(&out.stderr)
        );

        install_pre_commit_hook(&wt_path).expect("install_pre_commit_hook must succeed");

        // Hook file must exist.
        let hook_path = wt_path.join(".git-hooks").join("pre-commit");
        assert!(hook_path.exists(), "pre-commit hook must be created");

        // Hook must be executable.
        #[cfg(unix)]
        {
            use std::os::unix::fs::PermissionsExt;
            let mode = fs::metadata(&hook_path).unwrap().permissions().mode();
            assert!(mode & 0o111 != 0, "pre-commit hook must be executable");
        }

        // Hook content must reference script/check and --no-verify.
        let content = fs::read_to_string(&hook_path).unwrap();
        assert!(
            content.contains("script/check"),
            "hook must invoke script/check; got:\n{content}"
        );
        assert!(
            content.contains("--no-verify"),
            "hook must mention --no-verify bypass; got:\n{content}"
        );

        // git config core.hooksPath for the worktree must be .git-hooks.
        let cfg_out = Command::new("git")
            .args(["config", "--worktree", "core.hooksPath"])
            .current_dir(&wt_path)
            .output()
            .expect("git config --worktree core.hooksPath");
        assert!(
            cfg_out.status.success(),
            "git config --worktree core.hooksPath lookup failed"
        );
        let value = String::from_utf8_lossy(&cfg_out.stdout).trim().to_string();
        assert_eq!(
            value, ".git-hooks",
            "core.hooksPath must be set to .git-hooks"
        );
    }
}