//! MCP bridge binary self-management.
//!
//! On startup, checks if wraith-mcp-bridge exists in the data directory.
//! If missing or outdated, downloads the correct version from Gitea packages.

use std::path::PathBuf;

/// Get the expected path for the bridge binary.
pub fn bridge_path() -> PathBuf {
    let dir = crate::data_directory();
    if cfg!(windows) {
        dir.join("wraith-mcp-bridge.exe")
    } else {
        dir.join("wraith-mcp-bridge")
    }
}

/// Check if the bridge binary exists and is the correct version.
/// If not, download it from Gitea packages.
pub async fn ensure_bridge(app_version: &str) -> Result<(), String> {
    let path = bridge_path();
    let version_file = crate::data_directory().join("mcp-bridge-version");

    // Check if bridge exists and version matches
    if path.exists() {
        if let Ok(installed_ver) = std::fs::read_to_string(&version_file) {
            if installed_ver.trim() == app_version {
                wraith_log!("[MCP Bridge] v{} already installed at {}", app_version, path.display());
                return Ok(());
            }
        }
    }

    wraith_log!("[MCP Bridge] Downloading v{} to {}", app_version, path.display());

    let binary_name = if cfg!(windows) {
        "wraith-mcp-bridge.exe"
    } else {
        "wraith-mcp-bridge"
    };

    let url = format!(
        "https://git.command.vigilcyber.com/api/packages/vstockwell/generic/wraith/{}/{}",
        app_version, binary_name
    );

    let client = reqwest::Client::builder()
        .timeout(std::time::Duration::from_secs(30))
        .build()
        .map_err(|e| format!("HTTP client error: {}", e))?;

    let resp = client.get(&url).send().await
        .map_err(|e| format!("Failed to download MCP bridge: {}", e))?;

    if !resp.status().is_success() {
        return Err(format!("MCP bridge download failed: HTTP {}", resp.status()));
    }

    let bytes = resp.bytes().await
        .map_err(|e| format!("Failed to read MCP bridge response: {}", e))?;

    // Write the binary
    std::fs::write(&path, &bytes)
        .map_err(|e| format!("Failed to write MCP bridge to {}: {}", path.display(), e))?;

    // Make executable on Unix
    #[cfg(unix)]
    {
        use std::os::unix::fs::PermissionsExt;
        let mut perms = std::fs::metadata(&path)
            .map_err(|e| format!("Failed to read permissions: {}", e))?
            .permissions();
        perms.set_mode(0o755);
        std::fs::set_permissions(&path, perms)
            .map_err(|e| format!("Failed to set execute permission: {}", e))?;
    }

    // Write version marker
    std::fs::write(&version_file, app_version)
        .map_err(|e| format!("Failed to write version file: {}", e))?;

    wraith_log!("[MCP Bridge] v{} installed successfully ({} bytes)", app_version, bytes.len());

    Ok(())
}