cotis-cli 0.1.0-alpha

//! Install routines from local projects, crates.io, or GitHub releases.
//!
//! Parses `path:`, `crate:`, and `gh:` install specs, builds or downloads cdylibs, validates the
//! plugin ABI, writes `descriptor.json`, and optionally runs `cotis_plugin_finish_installation`.
//!
//! ## Version naming
//!
//! | Source | Cache version directory | Routine name |
//! |--------|-------------------------|--------------|
//! | `path:` | Always `"dev"` | cdylib stem or alias |
//! | `crate:` | Crate version string | cdylib stem (alias ignored) |
//! | `gh:` | Release `tag_name` | repo name or alias |
//!
//! ## Overwrite
//!
//! Unless `overwrite` is true, install fails if the target plugin file already exists.
//! Use `-f` / `--overwrite` / `--fo` on the CLI, or `update` / `reinstall` which always overwrite.

use std::fs;
use std::io::{Read, Write};
use std::path::{Path, PathBuf};
use std::process::{Command, Stdio};

use directories::ProjectDirs;
use log::{debug, info};
use reqwest::blocking::Client;
use serde::Deserialize;
use tempfile::TempDir;

use crate::plugin::{LoadedPlugin, PluginDescriptor};
use crate::routines::{
    descriptor_path, host_target_triple, platform_library_filename, plugin_library_path,
};

/// Parsed install source for [`install`].
#[derive(Debug, Clone)]
pub enum InstallSpec {
    /// Local Cargo project directory (`path:<dir>`).
    LocalPath(PathBuf),
    /// crates.io crate (`crate:<name>@<version>`).
    Crate {
        /// Crate name on crates.io.
        name: String,
        /// Exact crate version to download and build.
        version: String,
    },
    /// GitHub release (`gh:<owner>/<repo>@<tag|latest>`).
    Github {
        /// Repository owner.
        owner: String,
        /// Repository name.
        repo: String,
        /// Release tag, or `"latest"` for the newest release.
        tag: String,
    },
}

/// Parse an install spec string into [`InstallSpec`].
///
/// Accepted forms:
/// - `path:<directory>`
/// - `crate:<name>@<version>`
/// - `gh:<owner>/<repo>@<tagOrLatest>`
///
/// # Errors
///
/// Returns an error if the prefix is unknown or required components are missing.
///
/// # Examples
///
/// ```
/// use cotis_cli::install::{parse_install_spec, InstallSpec};
/// use std::path::PathBuf;
///
/// match parse_install_spec("path:./my-routine").unwrap() {
///     InstallSpec::LocalPath(p) => assert_eq!(p, PathBuf::from("./my-routine")),
///     _ => panic!("expected LocalPath"),
/// }
///
/// match parse_install_spec("crate:my-routine@0.2.0").unwrap() {
///     InstallSpec::Crate { name, version } => {
///         assert_eq!(name, "my-routine");
///         assert_eq!(version, "0.2.0");
///     }
///     _ => panic!("expected Crate"),
/// }
///
/// match parse_install_spec("gh:org/repo@latest").unwrap() {
///     InstallSpec::Github { owner, repo, tag } => {
///         assert_eq!(owner, "org");
///         assert_eq!(repo, "repo");
///         assert_eq!(tag, "latest");
///     }
///     _ => panic!("expected Github"),
/// }
///
/// assert!(parse_install_spec("invalid").is_err());
/// ```
pub fn parse_install_spec(s: &str) -> Result<InstallSpec, String> {
    if let Some(rest) = s.strip_prefix("path:") {
        return Ok(InstallSpec::LocalPath(PathBuf::from(rest)));
    }
    if let Some(rest) = s.strip_prefix("crate:") {
        let (name, version) = rest
            .split_once('@')
            .ok_or_else(|| "Expected crate:<name>@<version>".to_string())?;
        return Ok(InstallSpec::Crate {
            name: name.to_string(),
            version: version.to_string(),
        });
    }
    if let Some(rest) = s.strip_prefix("gh:") {
        let (repo_part, tag) = rest
            .split_once('@')
            .ok_or_else(|| "Expected gh:<owner>/<repo>@<tagOrLatest>".to_string())?;
        let (owner, repo) = repo_part
            .split_once('/')
            .ok_or_else(|| "Expected gh:<owner>/<repo>@...".to_string())?;
        return Ok(InstallSpec::Github {
            owner: owner.to_string(),
            repo: repo.to_string(),
            tag: tag.to_string(),
        });
    }
    Err("Unknown install spec. Use path:, crate:, or gh:".to_string())
}

/// Normalizes `--cdylib-name` / `--dll-name`: trim and strip a trailing platform suffix if present.
///
/// # Errors
///
/// Returns an error if the stem is empty before or after stripping.
///
/// # Examples
///
/// ```
/// use cotis_cli::install::normalize_cdylib_stem;
///
/// assert_eq!(normalize_cdylib_stem("my_plugin").unwrap(), "my_plugin");
/// assert_eq!(normalize_cdylib_stem("my_plugin.dll").unwrap(), "my_plugin");
/// assert_eq!(normalize_cdylib_stem("  libfoo.so  ").unwrap(), "libfoo");
/// assert!(normalize_cdylib_stem("").is_err());
/// assert!(normalize_cdylib_stem(".dll").is_err());
/// ```
pub fn normalize_cdylib_stem(s: &str) -> Result<String, String> {
    let s = s.trim();
    if s.is_empty() {
        return Err("cdylib name must not be empty".to_string());
    }
    let lower = s.to_ascii_lowercase();
    let base = if lower.ends_with(".dll") {
        &s[..s.len() - 4]
    } else if lower.ends_with(".dylib") {
        &s[..s.len() - 6]
    } else if lower.ends_with(".so") {
        &s[..s.len() - 3]
    } else {
        s
    };
    let base = base.trim();
    if base.is_empty() {
        return Err("cdylib name must not be empty after stripping suffix".to_string());
    }
    Ok(base.to_string())
}

/// Install a routine into the cotis-cli cache.
///
/// Builds or downloads the cdylib, copies it to the cache, validates the plugin ABI, writes
/// `descriptor.json`, and runs `cotis_plugin_finish_installation` when requested by the descriptor.
///
/// `alias_override` sets the routine cache name for `path:` and `gh:` installs (ignored for `crate:`).
/// `cdylib_name_override` overrides cargo metadata cdylib detection for `path:` and `crate:` only.
///
/// # Errors
///
/// Returns an error for missing paths, failed cargo builds, HTTP failures, missing cdylib artifacts,
/// already-installed routines (when `overwrite` is false), incompatible plugins, or failed
/// finish-installation hooks.
pub fn install(
    proj_dirs: &ProjectDirs,
    spec: InstallSpec,
    alias_override: Option<&str>,
    cdylib_name_override: Option<&str>,
    overwrite: bool,
) -> Result<PluginDescriptor, String> {
    match spec {
        InstallSpec::LocalPath(path) => install_from_local_project(
            proj_dirs,
            &path,
            alias_override,
            cdylib_name_override,
            overwrite,
        ),
        InstallSpec::Crate { name, version } => {
            install_from_crates_io(proj_dirs, &name, &version, cdylib_name_override, overwrite)
        }
        InstallSpec::Github { owner, repo, tag } => {
            if cdylib_name_override.is_some() {
                return Err(
                    "--cdylib-name applies only to path: and crate: installs (GitHub uses release assets)."
                        .to_string(),
                );
            }
            install_from_github_release(proj_dirs, &owner, &repo, &tag, alias_override, overwrite)
        }
    }
}

fn install_from_local_project(
    proj_dirs: &ProjectDirs,
    path: &Path,
    alias_override: Option<&str>,
    cdylib_name_override: Option<&str>,
    overwrite: bool,
) -> Result<PluginDescriptor, String> {
    if !path.exists() {
        return Err(format!("Local path does not exist: {}", path.display()));
    }
    let path =
        fs::canonicalize(path).map_err(|e| format!("Failed to resolve project path: {e}"))?;
    debug!("Installing from local project {}", path.display());

    let target = host_target_triple()?;

    let build_target_dir = proj_dirs.cache_dir().join("installs").join("local-project");
    fs::create_dir_all(&build_target_dir)
        .map_err(|e| format!("Failed to create build dir: {e}"))?;

    let cdylib_name = match cdylib_name_override {
        Some(stem) => stem.to_string(),
        None => cargo_cdylib_name(&path)?,
    };
    let routine_name = alias_override.unwrap_or(&cdylib_name).to_string();

    cargo_build_cdylib(&path, &build_target_dir, true)?;

    let src = build_target_dir
        .join("release")
        .join(platform_library_filename(&cdylib_name));
    if !src.exists() {
        return Err(format!(
            "Expected built library not found at {}",
            src.display()
        ));
    }

    let dest = plugin_library_path(proj_dirs, &routine_name, "dev", &target);
    if dest.exists() && !overwrite {
        return Err(format!(
            "{routine_name} already installed (use -f / --overwrite / --fo to overwrite)"
        ));
    }
    fs::create_dir_all(dest.parent().unwrap())
        .map_err(|e| format!("Failed to create plugin dir: {e}"))?;
    fs::copy(&src, &dest).map_err(|e| format!("Failed to copy plugin: {e}"))?;

    let plugin = unsafe { LoadedPlugin::load(&dest) }?;
    plugin.ensure_compatible()?;
    let desc = plugin.descriptor()?;
    let desc_path = descriptor_path(proj_dirs, &routine_name, "dev", &target);
    fs::write(&desc_path, serde_json::to_vec_pretty(&desc).unwrap())
        .map_err(|e| format!("Failed to write descriptor: {e}"))?;

    run_finish_installation(proj_dirs, &plugin, &desc, Some(path.as_path()))?;

    info!("Installed {routine_name} ({}) for {target}", desc.version);
    Ok(desc)
}

fn install_from_crates_io(
    proj_dirs: &ProjectDirs,
    crate_name: &str,
    version: &str,
    cdylib_name_override: Option<&str>,
    overwrite: bool,
) -> Result<PluginDescriptor, String> {
    let target = host_target_triple()?;
    debug!("Installing from crates.io {crate_name}@{version}");

    let tmp = TempDir::new().map_err(|e| format!("Failed to create temp dir: {e}"))?;
    let tarball = download_crates_io(crate_name, version, tmp.path())?;
    let src_dir = extract_crate_tarball(&tarball, tmp.path())?;

    let build_target_dir = proj_dirs
        .cache_dir()
        .join("installs")
        .join(format!("crate-{crate_name}-{version}"));
    fs::create_dir_all(&build_target_dir)
        .map_err(|e| format!("Failed to create build dir: {e}"))?;
    cargo_build_cdylib(&src_dir, &build_target_dir, true)?;

    let cdylib_name = match cdylib_name_override {
        Some(stem) => stem.to_string(),
        None => cargo_cdylib_name(&src_dir)?,
    };
    let src = build_target_dir
        .join("release")
        .join(platform_library_filename(&cdylib_name));
    if !src.exists() {
        return Err(format!(
            "Expected built library not found at {}",
            src.display()
        ));
    }

    let routine_name = cdylib_name.clone();
    let dest = plugin_library_path(proj_dirs, &routine_name, version, &target);
    if dest.exists() && !overwrite {
        return Err(format!(
            "{routine_name}@{version} already installed (use -f / --overwrite / --fo to overwrite)"
        ));
    }
    fs::create_dir_all(dest.parent().unwrap())
        .map_err(|e| format!("Failed to create plugin dir: {e}"))?;
    fs::copy(&src, &dest).map_err(|e| format!("Failed to copy plugin: {e}"))?;

    let plugin = unsafe { LoadedPlugin::load(&dest) }?;
    plugin.ensure_compatible()?;
    let desc = plugin.descriptor()?;
    let desc_path = descriptor_path(proj_dirs, &routine_name, version, &target);
    fs::write(&desc_path, serde_json::to_vec_pretty(&desc).unwrap())
        .map_err(|e| format!("Failed to write descriptor: {e}"))?;

    run_finish_installation(proj_dirs, &plugin, &desc, None)?;

    info!("Installed {routine_name}@{version} for {target}");
    Ok(desc)
}

fn install_from_github_release(
    proj_dirs: &ProjectDirs,
    owner: &str,
    repo: &str,
    tag: &str,
    alias_override: Option<&str>,
    overwrite: bool,
) -> Result<PluginDescriptor, String> {
    let target = host_target_triple()?;
    debug!("Installing from GitHub {owner}/{repo}@{tag}");

    let client = Client::builder()
        .user_agent("cotis-cli")
        .build()
        .map_err(|e| format!("Failed to build HTTP client: {e}"))?;

    let release = github_release(&client, owner, repo, tag)?;
    let ext = if cfg!(windows) {
        ".dll"
    } else if cfg!(target_os = "macos") {
        ".dylib"
    } else {
        ".so"
    };

    // Prefer an asset whose name contains the host triple and matching extension;
    // otherwise take the first asset with a matching extension.
    let asset = release
        .assets
        .iter()
        .find(|a| a.name.contains(&target) && a.name.ends_with(ext))
        .or_else(|| release.assets.iter().find(|a| a.name.ends_with(ext)))
        .ok_or_else(|| "No matching release asset found for this platform".to_string())?;

    let routine_name = alias_override.unwrap_or(repo).to_string();
    let version = release.tag_name.clone();

    let dest = plugin_library_path(proj_dirs, &routine_name, &version, &target);
    if dest.exists() && !overwrite {
        return Err(format!(
            "{routine_name}@{version} already installed (use -f / --overwrite / --fo to overwrite)"
        ));
    }
    fs::create_dir_all(dest.parent().unwrap())
        .map_err(|e| format!("Failed to create plugin dir: {e}"))?;

    debug!("Downloading asset {} -> {}", asset.name, dest.display());
    let mut resp = client
        .get(&asset.browser_download_url)
        .send()
        .map_err(|e| format!("Failed to download asset: {e}"))?;
    if !resp.status().is_success() {
        return Err(format!("Asset download failed with HTTP {}", resp.status()));
    }
    let mut out =
        fs::File::create(&dest).map_err(|e| format!("Failed to create output file: {e}"))?;
    let mut buf = Vec::new();
    resp.read_to_end(&mut buf)
        .map_err(|e| format!("Failed to read download: {e}"))?;
    out.write_all(&buf)
        .map_err(|e| format!("Failed to write plugin file: {e}"))?;

    let plugin = unsafe { LoadedPlugin::load(&dest) }?;
    plugin.ensure_compatible()?;
    let desc = plugin.descriptor()?;
    let desc_path = descriptor_path(proj_dirs, &routine_name, &version, &target);
    fs::write(&desc_path, serde_json::to_vec_pretty(&desc).unwrap())
        .map_err(|e| format!("Failed to write descriptor: {e}"))?;

    run_finish_installation(proj_dirs, &plugin, &desc, None)?;

    info!("Installed {routine_name}@{version} for {target}");
    Ok(desc)
}

fn run_finish_installation(
    proj_dirs: &ProjectDirs,
    plugin: &LoadedPlugin,
    desc: &PluginDescriptor,
    local_install_project_dir: Option<&Path>,
) -> Result<(), String> {
    if !desc.finish_installation {
        return Ok(());
    }

    // SAFETY: `cotis-cli install` runs single-threaded; env is restored immediately after the plugin hook returns.
    unsafe {
        std::env::set_var(
            "COTIS_CLI_CACHE_DIR",
            proj_dirs.cache_dir().to_string_lossy().into_owned(),
        );
        if let Some(p) = local_install_project_dir {
            std::env::set_var(
                "COTIS_CLI_INSTALL_PROJECT_DIR",
                p.to_string_lossy().into_owned(),
            );
        } else {
            std::env::remove_var("COTIS_CLI_INSTALL_PROJECT_DIR");
        }
    }

    plugin.finish_installation_if_requested(desc)?;

    unsafe {
        std::env::remove_var("COTIS_CLI_INSTALL_PROJECT_DIR");
    }
    Ok(())
}

fn cargo_build_cdylib(project_dir: &Path, target_dir: &Path, release: bool) -> Result<(), String> {
    let mut cmd = Command::new("cargo");
    cmd.current_dir(project_dir);
    cmd.args([
        "build",
        "--lib",
        "--target-dir",
        target_dir.to_str().unwrap(),
    ]);
    if release {
        cmd.arg("--release");
    }
    cmd.stdout(Stdio::inherit());
    cmd.stderr(Stdio::inherit());
    let st = cmd
        .status()
        .map_err(|e| format!("Failed to run cargo build: {e}"))?;
    if !st.success() {
        return Err("cargo build failed".to_string());
    }
    Ok(())
}

fn cargo_cdylib_name(project_dir: &Path) -> Result<String, String> {
    #[derive(Deserialize)]
    struct Metadata {
        packages: Vec<Package>,
    }
    #[derive(Deserialize)]
    struct Package {
        manifest_path: String,
        targets: Vec<Target>,
    }
    #[derive(Deserialize)]
    struct Target {
        kind: Vec<String>,
        name: String,
    }

    let project_dir = fs::canonicalize(project_dir).map_err(|e| {
        format!(
            "Failed to resolve project directory {}: {e}",
            project_dir.display()
        )
    })?;
    let expected_manifest = fs::canonicalize(project_dir.join("Cargo.toml")).map_err(|e| {
        format!(
            "Expected Cargo.toml at {}: {e}",
            project_dir.join("Cargo.toml").display()
        )
    })?;

    let out = Command::new("cargo")
        .current_dir(&project_dir)
        .args(["metadata", "--no-deps", "--format-version", "1"])
        .stderr(Stdio::inherit())
        .output()
        .map_err(|e| format!("Failed to run cargo metadata: {e}"))?;
    if !out.status.success() {
        return Err("cargo metadata failed".to_string());
    }
    let md: Metadata = serde_json::from_slice(&out.stdout)
        .map_err(|e| format!("Failed to parse cargo metadata: {e}"))?;

    let pkg = md
        .packages
        .iter()
        .find(|p| {
            Path::new(&p.manifest_path).canonicalize().ok().as_ref() == Some(&expected_manifest)
        })
        .ok_or_else(|| {
            format!(
                "cargo metadata has no package with manifest {} (workspace root mis-detected?)",
                expected_manifest.display()
            )
        })?;

    let name = pkg
        .targets
        .iter()
        .find(|t| t.kind.iter().any(|k| k == "cdylib"))
        .map(|t| t.name.clone())
        .ok_or_else(|| {
            "No cdylib target found (is [lib] crate-type = [\"cdylib\"] set?)".to_string()
        })?;
    Ok(name)
}

fn download_crates_io(crate_name: &str, version: &str, out_dir: &Path) -> Result<PathBuf, String> {
    let url = format!("https://crates.io/api/v1/crates/{crate_name}/{version}/download");
    let client = Client::builder()
        .user_agent("cotis-cli")
        .build()
        .map_err(|e| format!("Failed to build HTTP client: {e}"))?;
    let mut resp = client
        .get(url)
        .send()
        .map_err(|e| format!("Failed to download crate: {e}"))?;
    if !resp.status().is_success() {
        return Err(format!("Crate download failed with HTTP {}", resp.status()));
    }
    let tar_path = out_dir.join(format!("{crate_name}-{version}.crate.tar.gz"));
    let mut file =
        fs::File::create(&tar_path).map_err(|e| format!("Failed to create tarball file: {e}"))?;
    let mut buf = Vec::new();
    resp.read_to_end(&mut buf)
        .map_err(|e| format!("Failed to read tarball: {e}"))?;
    file.write_all(&buf)
        .map_err(|e| format!("Failed to write tarball: {e}"))?;
    Ok(tar_path)
}

fn extract_crate_tarball(tar_gz_path: &Path, out_dir: &Path) -> Result<PathBuf, String> {
    use flate2::read::GzDecoder;
    use tar::Archive;

    let f = fs::File::open(tar_gz_path).map_err(|e| format!("Failed to open tarball: {e}"))?;
    let gz = GzDecoder::new(f);
    let mut ar = Archive::new(gz);
    ar.unpack(out_dir)
        .map_err(|e| format!("Failed to unpack tarball: {e}"))?;

    let mut dirs = fs::read_dir(out_dir)
        .map_err(|e| format!("Failed to read extracted dir: {e}"))?
        .filter_map(|e| e.ok())
        .filter(|e| e.path().is_dir())
        .collect::<Vec<_>>();
    if dirs.len() != 1 {
        return Err("Unexpected tarball layout after extract".to_string());
    }
    Ok(dirs.remove(0).path())
}

#[derive(Debug, Deserialize)]
struct GithubRelease {
    tag_name: String,
    assets: Vec<GithubAsset>,
}

#[derive(Debug, Deserialize)]
struct GithubAsset {
    name: String,
    browser_download_url: String,
}

fn github_release(
    client: &Client,
    owner: &str,
    repo: &str,
    tag: &str,
) -> Result<GithubRelease, String> {
    let url = if tag == "latest" {
        format!("https://api.github.com/repos/{owner}/{repo}/releases/latest")
    } else {
        format!("https://api.github.com/repos/{owner}/{repo}/releases/tags/{tag}")
    };
    let resp = client
        .get(url)
        .send()
        .map_err(|e| format!("Failed to query GitHub release: {e}"))?;
    if !resp.status().is_success() {
        return Err(format!("GitHub API error HTTP {}", resp.status()));
    }
    resp.json::<GithubRelease>()
        .map_err(|e| format!("Failed to parse GitHub release JSON: {e}"))
}