#![allow(unused_labels)]

use std::path::{Path, PathBuf};
use std::collections::{BTreeMap, HashMap};
use std::io::{self, prelude::*};
use std::time::*;

use serde::{Serialize, Deserialize};
use clap::Parser;
use tracing::{debug, error, info, trace, warn};
use tracing_subscriber::filter::EnvFilter;
use url::Url;
use anyhow::{anyhow, bail, Error, Context};
use semver::Version;
use futures::stream::StreamExt;
use tokio::io::AsyncBufReadExt;
use reqwest::header::AUTHORIZATION;
use tempfile::TempDir;
use rayon::prelude::*;
use chrono::prelude::*;
use convert_case::{Case, Casing};

#[derive(Parser, Debug)]
#[clap(author, version, global_setting(clap::AppSettings::DeriveDisplayOrder))]
struct Opt {
    /// Config file with source directories and destination registry info
    #[clap(short, long, value_name = "PATH")]
    pub config_file: PathBuf,
    /// Perform all the work of generating `cargo publish` payloads,
    /// but don't send them to the destination registry server
    #[clap(long)]
    pub dry_run: bool,
    /// Load config file, validate the settings, and display the final loaded content
    /// to stdout, then exit
    #[clap(long)]
    pub validate: bool,

    /// Use to limit which crates from the source registry are published to the
    /// destination registry. Expects a regular expression which will be matched
    /// against the names of crates. Only crates with names that match the regex
    /// will be published. This field may also be specified at the top level of
    /// the config file.
    #[clap(long, value_name = "REGEX", alias = "filter")]
    pub filter_crates: Option<String>,
}

#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub struct DestinationRegistryConfig {
    #[serde(alias = "api")]
    pub api_url: Url,
    /// Registry index url, i.e. the url provided to Cargo via configuration
    /// to identify where to pull the index metadata from.
    #[serde(alias = "index")]
    pub index_url: String,
    #[serde(alias = "token")]
    pub auth_token: String,
    /// The name the registry should have in the Cargo.toml files published to
    /// the destination registry. This can be a rename (i.e. different than the
    /// registry name provided in `SourceRegistryConfig`) or the same name.
    pub registry_name: String,
}

#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub struct SourceRegistryConfig {
    #[serde(alias = "index")]
    pub index_dir: PathBuf,
    #[serde(alias = "crate-files")]
    pub crate_files_dir: PathBuf,
    /// Name used in Cargo.toml for dependencies from the registry.
    pub registry_name: String,
    /// Path of CSV file with log of when each crate version was published.
    pub publish_history_csv: PathBuf,
}

#[derive(Deserialize, Debug, Clone)]
#[serde(rename_all = "kebab-case")]
pub struct HttpConfig {
    /// Value of user-agent HTTP header
    #[serde(default = "default_user_agent")]
    pub user_agent: String,
}

const DEFAULT_USER_AGENT: &str = concat!("shipyard.rs-publish-tool/v", env!("CARGO_PKG_VERSION"));

fn default_user_agent() -> String {
    DEFAULT_USER_AGENT.to_string()
}

impl Default for HttpConfig {
    fn default() -> Self {
        Self {
            user_agent: default_user_agent(),
        }
    }
}

#[derive(Debug, Clone, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub struct Config {
    /// Do everything except actually publish to the destination registry. Can also be
    /// toggled using the --dry-run command line flag.
    #[serde(default)]
    pub dry_run: bool,
    /// Local directories with source registry files
    #[serde(alias = "source")]
    pub src: SourceRegistryConfig,
    /// Server information and authentication needed to publish to the
    /// destination registry
    #[serde(alias = "destination")]
    pub dst: DestinationRegistryConfig,
    /// Settings controlling the HTTP publish requests to the destination registry
    #[serde(default)]
    pub http: HttpConfig,
    /// Use to limit which crates from the source registry are published to the
    /// destination registry. Expects a regular expression which will be matched
    /// against the names of crates. Only crates with names that match the regex
    /// will be published.
    #[serde(default, alias = "filter")]
    pub filter_crates: Option<String>,
}

impl Config {
    pub fn compile_filter(&self) -> Result<Option<regex::Regex>, Error> {
        match self.filter_crates.as_ref() {
            Some(regex) => {
                let compiled = regex::Regex::new(regex).map_err(|e| {
                    error!(%regex, err = ?e, "regex failed to compile: {}", e);
                    e
                })?;
                Ok(Some(compiled))
            }
            None => Ok(None),
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct PublishLogRow {
    pub crate_name: String,
    pub version: Version,
    pub path: PathBuf,
    pub commit: String,
    pub author: String,
    pub time: DateTime<Utc>,
    pub unix_nanos: u64,
}

struct CsvSetup {
    pub rdr: csv::Reader<io::BufReader<std::fs::File>>,
    pub headers: csv::ByteRecord,
    pub row: csv::ByteRecord,
}

fn csv_setup(path: &Path) -> Result<CsvSetup, Error> {
    verify_file_exists(path)?;
    let file = std::fs::File::open(path)?;
    let buf = std::io::BufReader::new(file);
    let mut rdr = csv::Reader::from_reader(buf);
    let headers =
        rdr.byte_headers()
            .map_err(|e| anyhow!("failed to parse csv headers: {}", e))?
            .clone();
    let row = csv::ByteRecord::new();
    Ok(CsvSetup { rdr, headers, row })
}



/// fields we need from Cargo.toml [package] section to combine with IndexMeta
/// to form a PublishMeta.
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct PackageStub {
    pub name: String,
    pub version: Version,
    #[serde(default)]
    pub authors: Vec<String>,
    pub description: Option<String>,
    pub license: Option<String>,
    pub license_file: Option<PathBuf>,
    #[serde(default)]
    pub categories: Vec<String>,
    #[serde(default)]
    pub keywords: Vec<String>,
    pub readme: Option<PathBuf>,
    pub repository: Option<String>,
    pub homepage: Option<String>,
    pub documentation: Option<String>,
    pub links: Option<String>,
}


/// Example from post-cargo publish Cargo.toml
/// ```toml,ignore
/// [dependencies.docyard]
/// version = "0.31.0"
/// registry-index = "ssh://git@ssh.shipyard.rs/shipyard-rs/crate-index.git"
/// features = [
///     "auth",
///     "storage",
/// ]
/// default-features = false
/// ```
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct GeneratedManifestDependency {
    #[serde(rename = "registry-index")]
    pub registry_index: Option<String>,
}

/// for parsing Cargo.toml to extract missing PublishMeta fields that do not appear
/// in IndexMeta
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct ManifestStub {
    pub package: PackageStub,

    // TODO: parse + modify the generated Cargo.toml (not Cargo.toml.original)
    // to rewrite the `registry-index` fields.
    //
    // we will also need to recompute the cksum
}

/// full definition of cargo publish json
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct PublishMeta {
    pub name: String,
    #[serde(alias = "version")]
    pub vers: semver::Version,
    #[serde(alias = "dependencies")]
    #[serde(default)]
    pub deps: Vec<PublishDependency>,
    #[serde(default)]
    pub features: BTreeMap<String, Vec<String>>,
    #[serde(default)]
    pub authors: Vec<String>,
    pub description: Option<String>,
    pub documentation: Option<String>,
    pub homepage: Option<String>,
    pub readme: Option<String>,
    pub readme_file: Option<PathBuf>,
    #[serde(default)]
    pub keywords: Vec<String>,
    #[serde(default)]
    pub categories: Vec<String>,
    pub license: Option<String>,
    pub license_file: Option<PathBuf>,
    pub repository: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub links: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub badges: Option<BTreeMap<String, String>>,
    /// from ancient cargo versions
    #[serde(skip_serializing_if = "Option::is_none")]
    pub features2: Option<BTreeMap<String, Vec<String>>>,
    /// from ancient cargo versions
    #[serde(skip_serializing_if = "Option::is_none")]
    pub v: Option<u8>,
}

#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct PublishDependency {
    pub optional: bool,
    pub default_features: bool,
    pub name: String,
    pub features: Vec<String>,
    // cargo and crates-io have this as string
    #[serde(alias = "req")]
    pub version_req: semver::VersionReq,
    pub target: Option<String>,
    // crates-io has this as option
    pub kind: DependencyKind,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub registry: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub explicit_name_in_toml: Option<String>,
}

impl From<IndexDependency> for PublishDependency {
    fn from(dep: IndexDependency) -> Self {
        Self {
            name: dep.name,
            features: dep.features,
            default_features: dep.default_features,
            optional: dep.optional,
            target: dep.target,
            kind: dep.kind,
            registry: dep.registry,
            version_req: dep.req,
            explicit_name_in_toml: dep.package,
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct IndexMeta {
    // same everything as publish metadata
    pub name: String,
    #[serde(alias = "version")]
    pub vers: semver::Version,
    #[serde(alias = "dependencies")]
    pub features: BTreeMap<String, Vec<String>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub links: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub badges: Option<BTreeMap<String, String>>,

    // modified format/field names
    pub deps: Vec<IndexDependency>,

    // fields that don't appear in publish metadata
    pub cksum: String,
    pub yanked: bool,

    // ancient fields, these were actually written
    // on sanskrit on stone tablets
    #[serde(skip_serializing_if = "Option::is_none")]
    pub features2: Option<BTreeMap<String, Vec<String>>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub v: Option<u8>,
}

#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct IndexDependency {
    /// corresponds to `explicit_name_in_toml` field in `publish::Dependency`
    /// when a dep is renamed in Cargo.toml, otherwise same as `package`.
    pub name: String,
    /// corresponds to `name` in `publish::Dependency`
    #[serde(skip_serializing_if = "Option::is_none")]
    pub package: Option<String>,
    /// in publish meta, this field is called `version_req`, and the index
    /// format requires it to be renamed to `req`
    #[serde(alias = "version_req")]
    pub req: semver::VersionReq,
    pub features: Vec<String>,
    pub optional: bool,
    pub default_features: bool,
    pub target: Option<String>,
    pub kind: DependencyKind,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub registry: Option<String>,
}

/// Section in which this dependency was defined
#[derive(Copy, Clone, Serialize, Deserialize, Debug, PartialEq, PartialOrd, Ord, Eq, Hash)]
#[serde(rename_all = "lowercase")]
pub enum DependencyKind {
    /// Used at run time
    Normal,
    /// Used at build time, not available at run time
    Build,
    /// Not fetched and not used, except for when used direclty in a workspace
    Dev,
}

impl PublishMeta {
    pub fn new(
        index_meta: IndexMeta,
        manifest: ManifestStub,
        readme: Option<String>,
    ) -> Self {
        let ManifestStub { package } = manifest;
        PublishMeta {
            name: package.name,
            vers: package.version,
            deps: index_meta.deps.into_iter().map(From::from).collect(),
            features: index_meta.features,
            authors: package.authors,
            description: package.description,
            documentation: package.documentation,
            homepage: package.homepage,
            readme,
            readme_file: package.readme,
            keywords: package.keywords,
            categories: package.categories,
            license: package.license,
            license_file: package.license_file,
            repository: package.repository,
            links: package.links,
            badges: index_meta.badges,
            features2: index_meta.features2,
            v: index_meta.v,
        }
    }
}

fn serialize_publish_payload(
    publish_meta_json: &[u8],
    dot_crate_bytes: &[u8],
) -> Vec<u8> {
    assert!(publish_meta_json.len() <= u32::MAX as usize);
    assert!(dot_crate_bytes.len() <= u32::MAX as usize);

    let mut out: Vec<u8> = Vec::with_capacity(
        publish_meta_json.len()
        + dot_crate_bytes.len()
        + 8 // 2x u32 lengths
    );

    out.extend_from_slice(&(publish_meta_json.len() as u32).to_le_bytes()[..]);
    out.extend_from_slice(publish_meta_json);
    out.extend_from_slice(&(dot_crate_bytes.len() as u32).to_le_bytes()[..]);
    out.extend_from_slice(dot_crate_bytes);

    out
}

fn extract_manifest_files_from_tar<R: Read>(rdr: R) -> Result<ManifestFiles, Error> {
    let mut archive = tar::Archive::new(rdr);

    let mut cargo_toml = None;
    let mut cargo_toml_orig = None;
    let mut cargo_lock = None;

    for entry in archive.entries()? {
        let mut entry = entry?;
        let path = entry.path()?;

        if path.ends_with("Cargo.toml.orig") {
            let mut data = String::new();
            entry.read_to_string(&mut data)?;
            cargo_toml_orig = Some(data);
        } else if path.ends_with("Cargo.toml") {
            let mut data = String::new();
            entry.read_to_string(&mut data)?;
            cargo_toml = Some(data);
        } else if path.ends_with("Cargo.lock") {
            let mut data = String::new();
            entry.read_to_string(&mut data)?;
            cargo_lock = Some(data);
        }

        if cargo_toml.is_some()
            && cargo_toml_orig.is_some()
            && cargo_lock.is_some()
        {
            break
        }
    }

    if !(cargo_toml.is_some() && cargo_toml_orig.is_some())
    {
        anyhow::bail!("some required manifest files missing in .crate archive \
            (cargo_toml={:?} cargo_toml_orig={:?} cargo_lock={:?})",
            cargo_toml.is_some(),
            cargo_toml_orig.is_some(),
            cargo_lock.is_some(),
        );
    }

    Ok(ManifestFiles {
        cargo_toml: cargo_toml.unwrap(),
        cargo_toml_orig: cargo_toml_orig.unwrap(),
        cargo_lock,
    })
}

fn extract_readme_from_tar<R: Read>(rdr: R, readme_path: &Path) -> Result<Option<String>, Error> {
    let mut archive = tar::Archive::new(rdr);
    for entry in archive.entries()? {
        let mut entry = entry?;
        let path = entry.path()?;
        if path == readme_path || path.ends_with(readme_path) {
            let mut out = String::new();
            entry.read_to_string(&mut out)?;
            return Ok(Some(out))
        }
    }
    Ok(None)
}

fn setup_logger() {
    let env_filter = EnvFilter::from_default_env();
    let builder = tracing_subscriber::fmt()
        .with_env_filter(env_filter)
        .with_ansi(true);
    builder.init();
}

fn load_config_file(opt: &Opt) -> Result<Config, Error> {
    if !opt.config_file.exists() {
        bail!("path does not exist: {:?}", opt.config_file);
    }
    let toml = std::fs::read_to_string(&opt.config_file)?;
    let mut config: Config = toml::from_str(&toml)
        .context("read config file, but unable to parse toml - check \
                  format against example config")?;
    // augment using command line opts
    config.filter_crates = config.filter_crates.or_else(|| opt.filter_crates.clone());
    config.dry_run |= opt.dry_run;
    Ok(config)
}

fn is_hidden(entry: &walkdir::DirEntry) -> bool {
    entry
        .file_name()
        .to_str()
        .map(|s| s.starts_with('.'))
        .unwrap_or(false)
}

async fn get_index_metas(
    config: &Config,
) -> Result<HashMap<String, Vec<IndexMeta>>, Error> {
    let filter = config.compile_filter()?;
    let mut n_excl = 0;

    let files: Vec<(String, PathBuf)> = walkdir::WalkDir::new(&config.src.index_dir)
        .max_depth(3)
        .into_iter()
        .filter_entry(|e| !is_hidden(e))
        .filter_map(|res| match res {
            Ok(entry) => {
                if entry.file_type().is_file() && entry.depth() >= 2 && entry.depth() <= 3 {
                    let path = entry.into_path();
                    let crate_name: &str = path.file_name().and_then(|x| x.to_str()).unwrap_or("");
                    if let Some(filter) = filter.as_ref() {
                        if !filter.is_match(crate_name.as_ref()) {
                            trace!(%crate_name, "crate excluded by filter");
                            n_excl += 1;
                            return None;
                        }
                    }

                    debug!(?path, "found crate index metadata file to parse");
                    Some((crate_name.to_owned(), path))
                } else {
                    None
                }
            }
            Err(e) => {
                warn!(error = ?e, "walkdir result is error");
                None
            }
        })
        .collect();

    let n_files = files.len();
    info!("found {} crate index metadata files to parse", n_files);

    if n_excl > 0 {
        warn!(
            regex = %config.filter_crates.as_deref().unwrap_or(""),
            n_files,
            n_excl,
            "regex filter (--filter-crates) excluded {} crates", n_excl,
        );
    }

    let crate_versions: Vec<Result<(String, Vec<IndexMeta>), Error>> =
        futures::stream::iter(files.into_iter().map(|(crate_name, path)| {
            async move {
                let file = tokio::fs::File::open(&path).await.map_err(|e| {
                    error!(err = ?e, ?path, "failed to open file");
                    e
                })?;
                let buf = tokio::io::BufReader::new(file);
                let mut out = Vec::new();
                let mut lines = buf.lines();
                'lines: while let Some(line) = lines.next_line().await? {
                    let index_meta: IndexMeta = serde_json::from_str(&line)
                        .map_err(|e| {
                            error!(err = ?e, ?path, "failed to parse line");
                            e
                        })?;
                    out.push(index_meta);
                }
                debug!(crate_name = %out.first().map(|x| x.name.as_str()).unwrap_or("na"),
                    "parsed {} crate versions from metadata file", out.len()
                );

                Ok((crate_name, out))
            }
        }))
        .buffer_unordered(num_cpus::get())
        .collect()
        .await;

    let mut total_number_of_crate_versions = 0;

    // map of crate-name => [IndexMeta] (one per published version)
    let crate_versions: HashMap<String, Vec<IndexMeta>> = crate_versions
        .into_iter()
        .filter_map(|result| match result {
            Ok((crate_name, xs)) => {
                total_number_of_crate_versions += xs.len();
                Some((crate_name, xs))
            }
            Err(e) => {
                error!(err = ?e, "parsing metadata failed, skipping file");
                None
            }
        })
        .collect();

    info!(
        n_files,
        n_excl,
        n_crates = crate_versions.len(),
        total_number_of_crate_versions,
        "parsed {} crate version metadata entries from index",
        total_number_of_crate_versions,
    );

    Ok(crate_versions)
}

#[derive(Debug, Clone, Deserialize, Eq, PartialEq, Default)]
pub struct PublishWarnings {
    #[serde(default)]
    pub invalid_categories: Vec<String>,
    #[serde(default)]
    pub invalid_badges: Vec<String>,
    #[serde(default)]
    pub other: Vec<String>,
}

#[derive(Debug, Clone, Deserialize, Eq, PartialEq, Default)]
pub struct PublishResponse {
    #[serde(default)]
    pub warnings: PublishWarnings,
}

struct ManifestFiles {
    cargo_toml: String,
    cargo_toml_orig: String,
    cargo_lock: Option<String>,
}

struct VersionMeta {
    index_meta: IndexMeta,
    manifest_files: ManifestFiles,
    dot_crate_path: PathBuf,
    manifest: ManifestStub,
    readme: Option<String>,
    tmp: TempDir,
    modified_manifest_toml: Option<String>,
    // meta: cargo_metadata::Metadata,
}

impl VersionMeta {
    pub fn source_dir(&self) -> PathBuf {
        self.tmp.path().join(&format!("{}-{}", self.index_meta.name, self.index_meta.vers))
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
struct Node<'a> {
    name: &'a str,
    vers: Version,
}

// async fn process_crates(
//     config: &Config,
//     crate_versions: HashMap<String, Vec<IndexMeta>>,
// ) -> Result<(), Error> {
//     let http_client = reqwest::Client::builder()
//         .user_agent(&config.http.user_agent)
//         .build()?;
// 
//     let publish_url = config.dst.api_url.join("/api/v1/crates/new")?;
//             let publish_meta = PublishMeta::new(index_meta, manifest, readme);
// 
//             debug!("built publish meta using crate index json and the Cargo.toml manifest in the .crate targz archive:\n{:#?}\n", publish_meta);
// 
//             let publish_meta_json = serde_json::to_vec(&publish_meta)?;
//             let payload = serialize_publish_payload(&publish_meta_json, &dot_crate_bytes);
//             debug!(
//                 n_bytes = payload.len(),
//                 %crate_name,
//                 %version,
//                 "serialized publish payload",
//             );
// 
//             if config.dry_run {
//                 debug!(
//                     %crate_name,
//                     %version,
//                     %publish_url,
//                     "skipping publish (--dry-run mode)",
//                 );
//                 continue;
//             }
// 
//             let resp = http_client.put(publish_url.clone())
//                 .header(AUTHORIZATION, &config.dst.auth_token)
//                 .body(payload)
//                 .send()
//                 .await?;
// 
//             debug!(status = ?resp.status(), "rcvd server response to publish request");
// 
//             let resp: PublishResponse = resp
//                 .error_for_status()?
//                 .json()
//                 .await?;
//             let PublishResponse { warnings } = resp;
// 
//             let mut any_warnings = false;
// 
//             for warning in warnings.invalid_categories.iter() {
//                 warn!(%crate_name, %version, "registry server invalid category warning: {}", warning);
//                 any_warnings = true;
//             }
// 
//             for warning in warnings.invalid_badges.iter() {
//                 warn!(%crate_name, %version, "registry server invalid badge warning: {}", warning);
//                 any_warnings = true;
//             }
// 
//             for warning in warnings.other.iter() {
//                 warn!(%crate_name, %version, "registry server 'other' warning: {}", warning);
//                 any_warnings = true;
//             }
// 
//             trace!("server response body:\n{warnings:#?}");
// 
//             info!(
//                 %crate_name,
//                 %version,
//                 any_warnings,
//                 "published crate version in {:?}!",
//                 begin.elapsed(),
//             );

fn parse_manifests(
    config: &Config,
    crate_versions: HashMap<String, Vec<IndexMeta>>,
) -> Result<HashMap<String, Vec<VersionMeta>>, Error> {
    let begin = Instant::now();

    let out: HashMap<String, Vec<VersionMeta>> = crate_versions
        .into_par_iter()
        // .into_iter()
        .map(|(crate_name, versions)| -> Result<(String, Vec<VersionMeta>), Error> {
            let begin = Instant::now();
            let mut version_metas = Vec::new();
            for index_meta in versions {
                let version = index_meta.vers.clone();
                trace!(%crate_name, %version, "processing crate version");
                let dot_crate_path = config.src.crate_files_dir
                    .join(&format!("{}/{}/download", crate_name, index_meta.vers));
                verify_file_exists(&dot_crate_path)?;

                trace!(path = ?dot_crate_path, "reading .crate file");
                let dot_crate_bytes = std::fs::read(&dot_crate_path)
                    .with_context(|| {
                        format!("failed to read .crate file for \
                            {crate_name} v{0} with path {dot_crate_path:?}",
                            index_meta.vers,
                        )
                    })?;

                trace!("extracting Cargo.toml from .crate targz archive");
                let decoder = flate2::read::GzDecoder::new(&dot_crate_bytes[..]);
                let manifest_files = extract_manifest_files_from_tar(decoder)?;
                if manifest_files.cargo_lock.is_none() {
                    debug!(%crate_name, %version, "Cargo.lock not present in .crate archive");
                }
                let manifest: ManifestStub = toml::from_str(&manifest_files.cargo_toml)?;
                let mut readme: Option<String> = None;
                if let Some(readme_path) = manifest.package.readme.as_ref() {
                    let decoder = flate2::read::GzDecoder::new(&dot_crate_bytes[..]);
                    if let Some(readme_content) = extract_readme_from_tar(decoder, readme_path)? {
                        trace!(length = readme_content.len(), "extracted readme file content from .crate targz archive");
                        readme = Some(readme_content);
                    }
                }
                let tmp = TempDir::new()?;
                let decoder = flate2::read::GzDecoder::new(&dot_crate_bytes[..]);
                tar::Archive::new(decoder).unpack(tmp.path())?;
                trace!(tmpdir = ?tmp.path(), "unpacked .crate archive to temp dir");
                let target_dir = tmp.path().join("target");
                std::fs::create_dir(&target_dir)?;

                // let meta = cargo_metadata::MetadataCommand::new()
                //     .manifest_path(tmp.path().join(&format!("{crate_name}-{version}/Cargo.toml")))
                //     //.env("CARGO_TARGET_DIR", &target_dir)
                //     .other_options(vec!["-vv".to_string()])
                //     .verbose(true)
                //     // .other_options(["--frozen"].into_iter().map(|x| x.to_owned()).collect::<Vec<_>>())
                //     .exec()?;

                version_metas.push(VersionMeta {
                    index_meta,
                    manifest_files,
                    dot_crate_path,
                    manifest,
                    readme,
                    tmp,
                    modified_manifest_toml: None,
                    // meta,
                });
            }
            debug!(%crate_name, "parsed {} manifests in {:?}", version_metas.len(), begin.elapsed());
            Ok((crate_name, version_metas))
        }).collect::<Result<_, Error>>()?;

    info!("parsed crate version manifests in {:?}", begin.elapsed());

    Ok(out)
}

// fn get_registry_dep<'a>(index_dep: &'a IndexDependency) -> Option<Node<'a>> {
//     match index_dep.registry.as_ref() {
//         None => Some(Node { name: index_dep.name.as_str(), vers: index_dep.vers.clone() }),
//         Some(index) if index.contains("github.com/rust-lang/crates.io-index") => None,
//         Some(other) => panic!("unexpected registry value: {}", other),
//     }
// }

fn edit_dep_registries(
    dep_key: &str,
    manifest: &mut toml_edit::Document,
    src_registry_name: &str,
    dst_registry_name: &str,
) -> Result<(), Error> {
    let Some(deps) = manifest.get_mut(dep_key).and_then(|item| item.as_table_like_mut()) else {
        trace!("missing key in manifest toml: {}", dep_key);
        return Ok(())
    };

    for (k, v) in deps.iter_mut() {
        let Some(t) = v.as_table_like_mut() else { continue };
        if t.contains_key("registry-index") {
            warn!(dep_name = ?k, "dep table contains registry-index key!");
        }
        if let Some(registry_item) = t.get_mut("registry") {
            if registry_item.as_str().unwrap_or("") == src_registry_name {
                trace!(dep_name = ?k, %dep_key, ?src_registry_name, ?dst_registry_name, "modifying registry in Cargo.toml");
                *registry_item = toml_edit::value(dst_registry_name);
            }
        }
    }
    Ok(())
}

fn edit_publish_registry_if_present(
    manifest: &mut toml_edit::Document,
    src_registry_name: &str,
    dst_registry_name: &str,
) -> Result<(), Error> {
    let Some(package) = manifest.get_mut("package").and_then(|item| item.as_table_like_mut()) else {
        anyhow::bail!("package key not found in manifest toml");
    };

    let Some(publish_item) = package.get_mut("publish") else {
        trace!("no 'publish' key in Cargo.toml package section");
        return Ok(())
    };

    let Some(publish_array) = publish_item.as_array_mut() else {
        anyhow::bail!("failed to cast publish item as array");
    };

    let Some(i) = publish_array.iter().position(|x| x.as_str().map(|s| s == src_registry_name).unwrap_or(false)) else {
        anyhow::bail!("publish key exists, but source registry name does not appear in it! (`{}`)", publish_array.to_string());
    };

    let item_i = publish_array.get_mut(i).unwrap();
    *item_i = toml_edit::Value::from(dst_registry_name);

    Ok(())
}

fn prepare_source_dir_for_publish(config: &Config, meta: &mut VersionMeta) -> Result<(), Error> {
    let source_dir = meta.source_dir();
    let mut modified_manifest = meta.manifest_files.cargo_toml_orig.parse::<toml_edit::Document>()?;

    edit_dep_registries("dependencies", &mut modified_manifest, &config.src.registry_name, &config.dst.registry_name)?;
    edit_dep_registries("dev-dependencies", &mut modified_manifest, &config.src.registry_name, &config.dst.registry_name)?;
    edit_dep_registries("build-dependencies", &mut modified_manifest, &config.src.registry_name, &config.dst.registry_name)?;

    edit_publish_registry_if_present(&mut modified_manifest, &config.src.registry_name, &config.dst.registry_name)?;

    // write modified manifest over Cargo.toml (leaves Cargo.toml.orig as is)
    let modified_manifest_toml = modified_manifest.to_string();
    let cargo_toml_path = source_dir.join("Cargo.toml");
    std::fs::write(&cargo_toml_path, modified_manifest_toml.as_bytes())?;
    debug!(
        crate_name = %meta.index_meta.name,
        vers = %meta.index_meta.vers,
        path = ?cargo_toml_path,
        "wrote modified manifest file",
    );
    meta.modified_manifest_toml = Some(modified_manifest_toml);

    let cargo_toml_orig_path = source_dir.join("Cargo.toml.orig");
    if cargo_toml_orig_path.exists() {
        std::fs::remove_file(&cargo_toml_orig_path)?;
        trace!(
            crate_name = %meta.index_meta.name,
            vers = %meta.index_meta.vers,
            path = ?cargo_toml_orig_path,
            "removed Cargo.toml.orig file",
        );
    }

    let cargo_lock_path = source_dir.join("Cargo.lock");
    if cargo_lock_path.exists() {
        std::fs::remove_file(&cargo_lock_path)?;
        trace!(
            crate_name = %meta.index_meta.name,
            vers = %meta.index_meta.vers,
            path = ?cargo_lock_path,
            "removed Cargo.lock file",
        );
    }
    Ok(())
}

fn prepare_source_dirs_for_publish(config: &Config, manifests: &mut HashMap<String, Vec<VersionMeta>>) -> Result<(), Error> {
    let begin = Instant::now();
    manifests.par_iter_mut()
        .map(|(name, versions)| -> Result<(), Error> {
            for meta in versions.iter_mut() {
                prepare_source_dir_for_publish(&config, meta)
                    .map_err(|err| {
                        error!(%name, vers = %meta.index_meta.vers, ?err, "prepare_source_dir_for_publish failed");
                        err
                    })?;
            }
            Ok(())
        }).collect::<Result<Vec<()>, Error>>()?;
    info!("modified Cargo.toml manifests in {:?}", begin.elapsed());
    Ok(())
}

fn cargo_publish_modified_source_dir(config: &Config, meta: &VersionMeta) -> Result<(), Error> {
    let begin = Instant::now();
    info!(name = %meta.index_meta.name, vers = %meta.index_meta.vers, "publishing crate version");
    let index_env_key = format!("CARGO_REGISTRIES_{}_INDEX", config.dst.registry_name.to_case(Case::ScreamingSnake));
    let token_env_key = format!("CARGO_REGISTRIES_{}_TOKEN", config.dst.registry_name.to_case(Case::ScreamingSnake));

    let source_dir = meta.source_dir();
    let manifest_path = source_dir.join("Cargo.toml");
    let manifest_path_str = manifest_path.display().to_string();

    let mut args: Vec<&str> = vec!["publish"];
    args.extend_from_slice(&["--registry", &config.dst.registry_name][..]);
    // args.extend_from_slice(&["--index", &config.dst.index_url][..]);
    args.extend_from_slice(&["--token", &config.dst.auth_token][..]);
    args.extend_from_slice(&["--manifest-path", manifest_path_str.as_str()][..]);
    args.extend_from_slice(&["--no-verify", "--allow-dirty", "-vv"][..]);

    debug!(name = %meta.index_meta.name, vers = %meta.index_meta.vers, "executing `cargo {}`", args.join(" "));
    let output = std::process::Command::new("cargo")
        .env(&index_env_key, &config.dst.index_url)
        .env(&token_env_key, &config.dst.auth_token)
        .args(&args)
        .output()?;

    debug!(name = %meta.index_meta.name, vers = %meta.index_meta.vers, exit_status = ?output.status, "finished executing `cargo publish` command");

    if !output.status.success() {
        let stdout = std::str::from_utf8(&output.stdout).unwrap_or("utf8err");
        let stderr = std::str::from_utf8(&output.stderr).unwrap_or("utf8err");
        error!(exit_status = ?output.status, "cargo publish error!\nstdout:\n{}\nstderr:\n:{}\n\n", stdout, stderr);
        debug!("cargo publish error - original Cargo.toml:\n***\n{}\n***", meta.manifest_files.cargo_toml_orig);
        debug!("cargo publish error - modified Cargo.toml:\n***\n{}\n***", meta.modified_manifest_toml.as_ref().unwrap());
    }

    info!(name = %meta.index_meta.name, vers = %meta.index_meta.vers, "finished cargo publish in {:?}", begin.elapsed());
    Ok(())
}

async fn verify_dir_exists<P: AsRef<std::path::Path>>(path: P) -> Result<(), Error> {
    match tokio::fs::metadata(path.as_ref()).await {
        Ok(meta) if meta.is_dir() => Ok(()),
        Ok(meta) /* if ! meta.is_dir() */ => {
            debug_assert!( ! meta.is_dir());
            bail!("path exists, but is not a directory: {:?}", path.as_ref())
        }
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
            bail!("path does not exist: {}", path.as_ref().display());
        }
        Err(e) => Err(e.into()),
    }
}

fn verify_file_exists<P: AsRef<std::path::Path>>(path: P) -> Result<(), Error> {
    match std::fs::metadata(path.as_ref()) {
        Ok(meta) if meta.is_file() => Ok(()),
        Ok(meta) /* if ! meta.is_file() */ => {
            debug_assert!( ! meta.is_file());
            bail!("path exists, but is not a file: {:?}", path.as_ref())
        }
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
            bail!("path does not exist: {}", path.as_ref().display());
        }
        Err(e) => Err(e.into()),
    }
}

fn read_publish_log_csv(path: &Path) -> Result<Vec<PublishLogRow>, Error> {
    let begin = Instant::now();
    let CsvSetup { mut rdr, headers, mut row } = csv_setup(path)?;
    let mut out = Vec::new();
    while rdr.read_byte_record(&mut row)? {
        // only partially deserialized after this
        let parsed: PublishLogRow = row.deserialize(Some(&headers))
            .map_err(|err| {
                error!(?row, ?headers, ?err, "deserializing row failed");
                err
            })?;
        out.push(parsed);
    }
    info!(?path, "parsed publish log csv in {:?}", begin.elapsed());
    Ok(out)
}

fn main() -> Result<(), Error> {
    let begin = Instant::now();

    dotenvy::dotenv().ok();

    let opt = Opt::parse();

    setup_logger();

    let config = load_config_file(&opt)?;

    let rt = tokio::runtime::Runtime::new()?;
    rt.block_on(verify_dir_exists(&config.src.index_dir))?;
    rt.block_on(verify_dir_exists(&config.src.crate_files_dir))?;

    verify_file_exists(&config.src.publish_history_csv)?;

    if opt.validate {
        println!("{:#?}", config);
        return Ok(())
    }

    let mut publish_log = read_publish_log_csv(&config.src.publish_history_csv)?;
    publish_log.sort_by_key(|x| x.unix_nanos);
    assert!(!publish_log.is_empty());
    info!(n_rows = publish_log.len(), "parsed publish log csv");

    let krates = rt.block_on(get_index_metas(&config))?;

    let mut manifests = parse_manifests(&config, krates)?;

    prepare_source_dirs_for_publish(&config, &mut manifests)?;

    let mut by_name_vers: HashMap<(&str, &Version), &VersionMeta> = manifests.iter()
        .flat_map(|(k, v)| {
            v.iter().map(|m| ((k.as_str(), &m.index_meta.vers), m))
        }).collect();


    for row in publish_log.iter() {
        let Some(meta) = by_name_vers.remove(&(row.crate_name.as_str(), &row.version)) else {
            warn!(?row, "crate version in publish log not found in index versions");
            continue
        };

        if let Err(err) = cargo_publish_modified_source_dir(&config, meta) {
            error!(?err, name = %meta.index_meta.name, vers = %meta.index_meta.vers, "failed to publish crate version");
        }
    }
    info!("finished publishing crates to destination registry");

    // let (graph, ix) = build_dependency_graph(&manifests);

    drop(manifests);
    drop(rt);

    info!("finished in {:?}", begin.elapsed());
    Ok(())
}