mecha10-deploy 0.8.0

//! Binary Manager service for downloading and caching node binaries via `mecha10-api`
//!
//! This service implements the Node Binary Distribution architecture, providing:
//! - Downloading pre-built node binaries via the public `mecha10-api` downloads proxy
//!   (`GET /api/downloads/node/{name}`), never the private Minio instance directly
//! - Caching binaries to `~/.mecha10/bin/`
//! - Platform detection and target triple resolution
//!
//! There is a single resolution path: a cached binary if one already exists, otherwise a
//! download via `mecha10-api`. There is no `cargo install` fallback — an unsupported platform
//! or a failed download is a hard, immediate error naming what was tried and why it failed.
//!
//! # Design
//!
//! - Binaries are downloaded from `{mecha10_api}/downloads/node/{node}?os=..&arch=..&version=..`
//! - Binary naming: `{node}-{version}-{target}.tar.gz`
//! - Cached to: `~/.mecha10/bin/{node}-{version}-{target}`
//! - Symlink created: `~/.mecha10/bin/{node}` -> latest version
//!
//! # Usage
//!
//! ```no_run
//! use mecha10_deploy::services::BinaryManager;
//!
//! # async fn example() -> anyhow::Result<()> {
//! let manager = BinaryManager::new()?;
//!
//! // Resolve binary path (downloads if needed)
//! let path = manager.resolve("speaker").await?;
//!
//! // Execute the binary
//! std::process::Command::new(&path).spawn()?;
//! # Ok(())
//! # }
//! ```

#![allow(dead_code)]

use crate::paths;
use anyhow::{Context, Result};
use indicatif::{ProgressBar, ProgressStyle};
use mecha10_cli_core::utils::build_client;
use std::path::PathBuf;

const FRAMEWORK_VERSION: &str = env!("CARGO_PKG_VERSION");

pub struct BinaryManager {
    cache_dir: PathBuf,
    version: String,
    target: String,
}

impl BinaryManager {
    /// Create a new binary manager
    pub fn new() -> Result<Self> {
        let cache_dir = paths::user::bin_dir();
        let version = FRAMEWORK_VERSION.to_string();
        let target = mecha10_binary_naming::detect_target()?;

        Ok(Self {
            cache_dir,
            version,
            target,
        })
    }

    /// Create a binary manager with a specific version
    #[allow(dead_code)]
    pub fn with_version(version: String) -> Result<Self> {
        let cache_dir = paths::user::bin_dir();
        let target = mecha10_binary_naming::detect_target()?;

        Ok(Self {
            cache_dir,
            version,
            target,
        })
    }

    /// Check if pre-built binaries are available for current platform
    pub fn is_prebuilt_available(&self) -> bool {
        mecha10_binary_naming::is_prebuilt_available(&self.target)
    }

    /// Get the binary cache directory
    #[allow(dead_code)]
    pub fn cache_dir(&self) -> &PathBuf {
        &self.cache_dir
    }

    /// Get the current version
    #[allow(dead_code)]
    pub fn version(&self) -> &str {
        &self.version
    }

    /// Get the current target
    #[allow(dead_code)]
    pub fn target(&self) -> &str {
        &self.target
    }

    /// Resolve binary path for a node, downloading if needed
    ///
    /// Resolution strategy:
    /// 1. Check if a cached binary exists for the current version/target
    /// 2. If not, download it from `mecha10-api`
    ///
    /// There is no further fallback: if the platform has no pre-built binary, or the
    /// download fails, this returns an error immediately instead of silently degrading to
    /// a slower/older resolution path.
    ///
    /// # Arguments
    ///
    /// * `node_name` - Name of the node (e.g., "speaker", "motor")
    ///
    /// # Returns
    ///
    /// Path to the executable binary
    pub async fn resolve(&self, node_name: &str) -> Result<PathBuf> {
        self.resolve_with_version(node_name, None).await
    }

    /// Resolve binary path for a node with a specific version
    ///
    /// Resolution strategy (`LAB-4558`: the ordered-tiers-with-aggregate-error control flow
    /// below is shared via `mecha10_binary_naming::try_resolution_tiers!` with
    /// `NodeResolver::resolve_with_version` and the CLI's `resolve_cli_binary` - only the
    /// concrete tiers here are specific to this type):
    /// 1. Check if a cached binary exists for the current version/target
    /// 2. If not, download it from `mecha10-api`
    ///
    /// There is no further fallback: if the platform has no pre-built binary, or the
    /// download fails, this returns an error immediately instead of silently degrading to
    /// a slower/older resolution path.
    ///
    /// # Arguments
    ///
    /// * `node_name` - Name of the node (e.g., "speaker", "motor")
    /// * `version` - Optional specific version to download (e.g., "0.1.48").
    ///   If None, downloads the latest available version.
    ///
    /// # Returns
    ///
    /// Path to the executable binary
    pub async fn resolve_with_version(&self, node_name: &str, version: Option<&str>) -> Result<PathBuf> {
        mecha10_binary_naming::try_resolution_tiers!(node_name, {
            "cached binary" => match version {
                Some(v) => self.find_cached_version(node_name, v),
                None => self.find_cached(node_name),
            }
            .inspect(|path| {
                tracing::debug!("Using cached binary: {}", path.display());
            })
            .ok_or_else(|| "no cached binary found for this version/target".to_string()),

            "mecha10-api download" => {
                if !self.is_prebuilt_available() {
                    Err(format!(
                        "No pre-built binary available for '{}' on platform '{}' (supported targets: {}). \
                         Binaries are resolved solely via mecha10-api downloads ({}); there is no \
                         cargo-install or build-from-source fallback.",
                        node_name,
                        self.target,
                        mecha10_binary_naming::SUPPORTED_TARGETS.join(", "),
                        paths::urls::mecha10_api_base_url(),
                    ))
                } else {
                    let result = if let Some(v) = version {
                        self.download_version(node_name, Some(v)).await
                    } else {
                        self.download(node_name).await
                    };

                    result
                        .inspect(|path| {
                            tracing::info!("Downloaded binary for {}: {}", node_name, path.display());
                        })
                        .map_err(|e| {
                            format!(
                                "Failed to resolve binary for '{}' via mecha10-api download: {:#}",
                                node_name, e
                            )
                        })
                }
            },
        })
        .map_err(|e| anyhow::anyhow!(e))
    }

    /// Check for cached binary with specific version
    fn find_cached_version(&self, node_name: &str, version: &str) -> Option<PathBuf> {
        mecha10_binary_naming::find_cached_version(&self.cache_dir, node_name, version, &self.target)
    }

    /// Check for cached binary (any version)
    ///
    /// Looks for any cached version of the binary, preferring the symlink which
    /// points to the most recently downloaded version.
    fn find_cached(&self, node_name: &str) -> Option<PathBuf> {
        mecha10_binary_naming::find_cached(&self.cache_dir, node_name, &self.target)
    }

    /// Build the binary name for a node with a specific version
    fn binary_name_with_version(&self, node_name: &str, version: &str) -> String {
        mecha10_binary_naming::binary_name(node_name, version, &self.target)
    }

    /// Build the binary name for a node (uses current version)
    fn binary_name(&self, node_name: &str) -> String {
        self.binary_name_with_version(node_name, &self.version)
    }

    /// Build the tarball name for a node with a specific version
    fn tarball_name_with_version(&self, node_name: &str, version: &str) -> String {
        mecha10_binary_naming::tarball_name(node_name, version, &self.target)
    }

    /// Build the tarball name for a node (uses current version)
    #[allow(dead_code)]
    fn tarball_name(&self, node_name: &str) -> String {
        self.tarball_name_with_version(node_name, &self.version)
    }

    /// Download the latest published binary for a node via mecha10-api.
    ///
    /// Deliberately does NOT request `version=<Self::version>` (this CLI's own framework
    /// version) - node binaries are versioned independently by `mecha10-nodes` (see that
    /// repo's README "Versioning" section), not guaranteed to equal this crate's
    /// `CARGO_PKG_VERSION`. Omitting `version` lets `mecha10-api` resolve "latest" itself
    /// (`binaries/latest.txt`), matching the one other caller that already needs this
    /// (`resolve_cli_binary`'s "no override" case) rather than guessing a version client-side
    /// that may not match what was actually published.
    ///
    /// Confirmed live (2026-10-15): assuming node version == framework version made every
    /// single node binary 404 the moment the two repos' versions drifted (this crate at
    /// `0.7.0`, `mecha10-nodes` still at `0.6.5`) - fixed both by automating the version
    /// lockstep CI-side (mecha10-nodes PR ci/bump-version-on-mecha10-release) and by removing
    /// this client-side assumption entirely.
    async fn download(&self, node_name: &str) -> Result<PathBuf> {
        self.download_version(node_name, None).await
    }

    /// Download a node binary via `mecha10-api`. `version`: `Some` pins an exact version
    /// (`resolve_with_version`'s explicit-version tier); `None` asks mecha10-api for whatever
    /// is latest (see [`Self::download`]'s doc comment for why that's the right default).
    /// Either way, the version actually downloaded is read back from the response's
    /// `Content-Disposition` filename rather than assumed - that's the version used to name
    /// the cached file, so a `None` download caches under the real resolved version, not a
    /// guess.
    async fn download_version(&self, node_name: &str, version: Option<&str>) -> Result<PathBuf> {
        let (os, arch) = mecha10_binary_naming::os_arch_query(&self.target)?;
        let mut url = format!(
            "{}/downloads/node/{}?os={}&arch={}",
            paths::urls::mecha10_api_base_url(),
            node_name,
            os,
            arch
        );
        if let Some(v) = version {
            url.push_str(&format!("&version={}", v));
        }

        println!(
            "📦 Downloading {} {}...",
            node_name,
            version.map(|v| format!("v{v}")).unwrap_or_else(|| "latest".to_string())
        );
        tracing::info!("Downloading binary from mecha10-api: {}", url);

        let client = build_client()?;
        let response = client
            .get(&url)
            .send()
            .await
            .context(format!("Failed to connect to mecha10-api for binary '{}'", node_name))?;

        if !response.status().is_success() {
            return Err(anyhow::anyhow!(
                "Binary '{}' not found: HTTP {}\n\
                 URL: {}",
                node_name,
                response.status(),
                url
            ));
        }

        let resolved_version = version
            .map(|v| v.to_string())
            .or_else(|| self.parse_resolved_version(node_name, &response))
            .ok_or_else(|| {
                anyhow::anyhow!(
                    "mecha10-api did not report which version it resolved for '{}' \
                     (missing/unparseable Content-Disposition header)",
                    node_name
                )
            })?;

        let size = response.content_length().unwrap_or(0);
        self.download_and_extract_versioned(node_name, &resolved_version, response, size)
            .await
    }

    /// Extracts the actual resolved version out of a download response's
    /// `Content-Disposition` filename (`"{node_name}-{version}-{self.target}.tar.gz"` - see
    /// `mecha10-api`'s `node_key`), for the `version: None` ("give me latest") case where the
    /// caller doesn't already know what version it's getting.
    fn parse_resolved_version(&self, node_name: &str, response: &reqwest::Response) -> Option<String> {
        let header = response
            .headers()
            .get(reqwest::header::CONTENT_DISPOSITION)?
            .to_str()
            .ok()?;
        let filename = header.split("filename=\"").nth(1)?.strip_suffix('"')?;
        filename
            .strip_prefix(&format!("{node_name}-"))?
            .strip_suffix(&format!("-{}.tar.gz", self.target))
            .map(str::to_string)
    }

    /// Download and extract a binary tarball with a specific version
    async fn download_and_extract_versioned(
        &self,
        node_name: &str,
        version: &str,
        response: reqwest::Response,
        size: u64,
    ) -> Result<PathBuf> {
        let pb = ProgressBar::new(size);
        pb.set_style(
            ProgressStyle::default_bar()
                .template("{spinner:.green} [{bar:40.cyan/blue}] {bytes}/{total_bytes} ({eta})")
                .unwrap()
                .progress_chars("#>-"),
        );

        let temp_dir = tempfile::tempdir()?;
        let temp_file = temp_dir.path().join("binary.tar.gz");

        let mut file = tokio::fs::File::create(&temp_file).await?;
        let mut stream = response.bytes_stream();

        use futures_util::StreamExt;
        use tokio::io::AsyncWriteExt;

        while let Some(chunk) = stream.next().await {
            let chunk = chunk.context("Error downloading chunk")?;
            file.write_all(&chunk).await?;
            pb.inc(chunk.len() as u64);
        }

        file.flush().await?;
        pb.finish_with_message("Download complete");

        tokio::fs::create_dir_all(&self.cache_dir).await?;

        let tar_gz = std::fs::File::open(&temp_file)?;
        let tar = flate2::read::GzDecoder::new(tar_gz);
        let mut archive = tar::Archive::new(tar);

        let extract_dir = temp_dir.path().join("extract");
        std::fs::create_dir_all(&extract_dir)?;
        archive.unpack(&extract_dir)?;

        let extracted_binary = extract_dir.join(node_name);
        if !extracted_binary.exists() {
            return Err(anyhow::anyhow!("Binary '{}' not found in tarball", node_name));
        }

        let binary_name = self.binary_name_with_version(node_name, version);
        let dest_path = self.cache_dir.join(&binary_name);

        tokio::fs::copy(&extracted_binary, &dest_path).await?;

        #[cfg(unix)]
        {
            use std::os::unix::fs::PermissionsExt;
            let mut perms = tokio::fs::metadata(&dest_path).await?.permissions();
            perms.set_mode(0o755);
            tokio::fs::set_permissions(&dest_path, perms).await?;
        }

        let symlink_path = self.cache_dir.join(node_name);
        if symlink_path.exists() || symlink_path.is_symlink() {
            tokio::fs::remove_file(&symlink_path).await.ok();
        }

        #[cfg(unix)]
        {
            std::os::unix::fs::symlink(&binary_name, &symlink_path)?;
        }

        #[cfg(windows)]
        {
            std::os::windows::fs::symlink_file(&dest_path, &symlink_path)?;
        }

        println!("✅ Installed {} v{} to {}", node_name, version, dest_path.display());

        Ok(dest_path)
    }

    /// Remove a cached binary
    pub async fn remove(&self, node_name: &str) -> Result<()> {
        let binary_name = self.binary_name(node_name);
        let binary_path = self.cache_dir.join(&binary_name);
        let symlink_path = self.cache_dir.join(node_name);

        if binary_path.exists() {
            tokio::fs::remove_file(&binary_path).await?;
            println!("Removed {}", binary_path.display());
        }

        if symlink_path.exists() || symlink_path.is_symlink() {
            tokio::fs::remove_file(&symlink_path).await?;
            println!("Removed symlink {}", symlink_path.display());
        }

        Ok(())
    }

    /// Clear all cached binaries
    pub async fn clear_cache(&self) -> Result<()> {
        if self.cache_dir.exists() {
            tokio::fs::remove_dir_all(&self.cache_dir).await?;
            println!("Cleared binary cache at {}", self.cache_dir.display());
        }
        Ok(())
    }
}

impl Default for BinaryManager {
    fn default() -> Self {
        Self::new().expect("Failed to create BinaryManager")
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_binary_name() {
        let manager = BinaryManager {
            cache_dir: PathBuf::from("/tmp"),
            version: "0.1.44".to_string(),
            target: "aarch64-apple-darwin".to_string(),
        };

        assert_eq!(manager.binary_name("speaker"), "speaker-0.1.44-aarch64-apple-darwin");
    }

    #[test]
    fn test_tarball_name() {
        let manager = BinaryManager {
            cache_dir: PathBuf::from("/tmp"),
            version: "0.1.44".to_string(),
            target: "x86_64-apple-darwin".to_string(),
        };

        assert_eq!(manager.tarball_name("motor"), "motor-0.1.44-x86_64-apple-darwin.tar.gz");
    }

    #[tokio::test]
    async fn resolve_errors_immediately_on_unsupported_platform_with_no_cargo_install_fallback() {
        let manager = BinaryManager {
            cache_dir: PathBuf::from("/tmp/mecha10-binary-manager-test-does-not-exist"),
            version: "0.1.44".to_string(),
            target: "aarch64-unknown-linux-musl".to_string(),
        };

        let err = manager
            .resolve("speaker")
            .await
            .expect_err("unsupported platform must error, not silently fall back");

        let message = err.to_string();
        assert!(
            message.contains("No pre-built binary available"),
            "error should name the missing source, got: {message}"
        );
        assert!(
            message.contains("no cargo-install or build-from-source fallback"),
            "error must make clear there is no fallback path, got: {message}"
        );
    }

    #[test]
    fn test_prebuilt_available() {
        let manager = BinaryManager {
            cache_dir: PathBuf::from("/tmp"),
            version: "0.1.44".to_string(),
            target: "aarch64-apple-darwin".to_string(),
        };
        assert!(manager.is_prebuilt_available());

        let manager_arm_linux = BinaryManager {
            cache_dir: PathBuf::from("/tmp"),
            version: "0.1.44".to_string(),
            target: "aarch64-unknown-linux-gnu".to_string(),
        };
        assert!(manager_arm_linux.is_prebuilt_available());

        let manager_unsupported = BinaryManager {
            cache_dir: PathBuf::from("/tmp"),
            version: "0.1.44".to_string(),
            target: "aarch64-unknown-linux-musl".to_string(),
        };
        assert!(!manager_unsupported.is_prebuilt_available());
    }
}