cleanlib-client 0.3.0

//! HTTP transport — `Client` wraps reqwest with auth header injection +
//! timeout + per Client spec rev1 §2 + Rev 2 amendment §2 + §4.
//!
//! Phase 1 substrate: `fetch_verdict` is the first transport consumer
//! (CLEANLIB-30); subsequent CLEANLIB-N PRs add `scan` / `audit` /
//! `policy preview` / `fetch` verb impls reusing this `Client`.

use std::time::Duration;

use reqwest::{header, Client as ReqwestClient, Method, Url};

use crate::attestation_verify::PinnedKeyMap;
use crate::config::Config;
use crate::errors::{from_http, CleanLibraryError, TransportError};
use crate::types::{
    AuditResponse, PolicyPreviewRequest, PolicyPreviewResponse, ScanRequest, ScanResponse, Verdict,
};

/// Default HTTP timeout per Rev 2 amendment §4.1 — allows 1-5s GCS-catalog
/// first-request-ingest + buffer.
const DEFAULT_TIMEOUT_SECS: u64 = 30;

/// `Client` is the cleanlib-client HTTP transport handle. Cheap to clone;
/// share across verbs in the same process.
#[derive(Debug, Clone)]
pub struct Client {
    http: ReqwestClient,
    base_url: Url,
    api_key: Option<String>,
    api_version: String,
}

/// Outcome of a remediation fetch (CLEANLIB-733 Rust remediation client).
/// Mirrors the sdk-py/js/go `RemediationOrAbsent` discriminated union: a 404 is
/// a distinct, cacheable "no data" answer — never collapsed into a transient.
#[derive(Debug, Clone)]
pub enum RemediationOutcome {
    /// `2xx` — the sparse remediation composite (loosely-typed JSON, matching
    /// the envelope `remediation` field shape).
    Present(serde_json::Value),
    /// `404 REMEDIATION_NOT_FOUND` — a true, final "no remediation data for this
    /// coordinate" answer, distinct from a transient failure.
    NotInSubstrate,
    /// `5xx` / transport — a transient failure; a retry may succeed.
    Transient(String),
}

/// Filters for [`Client::audit`] (CLEANLIB-813). All fields are optional —
/// `AuditFilters::default()` (or any `..Default::default()` spread)
/// queries the full audit log, matching the prior `audit(None, None,
/// None)` shape byte-for-byte.
///
/// Deliberately an options struct rather than positional parameters:
/// `until` is the filter this ticket adds (the real server already
/// accepts it — `cleanlib-app/src/verbs.rs` — and Go's SDK already
/// exposes it; this SDK never did). A 4th positional parameter would
/// have been ANOTHER breaking signature change on top of the one this
/// struct already is, and the same problem recurs at the 5th filter.
/// Every field here is purely additive from a caller's perspective when
/// built via `AuditFilters { since: Some(x), ..Default::default() }` —
/// a future filter lands as one new field, never another migration.
#[derive(Debug, Clone, Copy, Default)]
pub struct AuditFilters<'a> {
    /// Only entries at or after this RFC 3339 timestamp.
    pub since: Option<&'a str>,
    /// CLEANLIB-813: only entries at or before this RFC 3339 timestamp —
    /// bounds the END of the query window. The gap this ticket closes.
    pub until: Option<&'a str>,
    /// Only entries with this decision (`ALLOW` / `INSUFFICIENT` / `DENY`
    /// — see `cleanlib-cli`'s `VALID_DECISION_FILTERS` for the
    /// client-side-validated domain).
    pub decision: Option<&'a str>,
    /// Only entries for this ecosystem.
    pub ecosystem: Option<&'a str>,
}

impl Client {
    /// Construct from a loaded `Config`. TLS required for non-localhost
    /// endpoints. Returns `TlsRequired` for `http://` on remote hosts.
    pub fn from_config(config: &Config) -> Result<Self, CleanLibraryError> {
        Self::build(&config.endpoint.url, config.auth.api_key.clone(), &config.endpoint.api_version)
    }

    /// Construct with explicit endpoint + api_key. Intended for integration
    /// tests + ad-hoc invocations (e.g., CLI `--endpoint=` flag future).
    pub fn new(endpoint: &str, api_key: Option<String>) -> Result<Self, CleanLibraryError> {
        Self::build(endpoint, api_key, "v1")
    }

    fn build(
        endpoint: &str,
        api_key: Option<String>,
        api_version: &str,
    ) -> Result<Self, CleanLibraryError> {
        let base_url = Url::parse(endpoint)
            .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", endpoint, e)))?;

        let is_localhost = matches!(
            base_url.host_str(),
            Some("localhost") | Some("127.0.0.1") | Some("::1")
        );
        if base_url.scheme() != "https" && !is_localhost {
            return Err(TransportError::TlsRequired(endpoint.to_string()).into());
        }

        let http = ReqwestClient::builder()
            .timeout(Duration::from_secs(DEFAULT_TIMEOUT_SECS))
            .user_agent(concat!("cleanlib-cli/", env!("CARGO_PKG_VERSION")))
            .build()
            .map_err(TransportError::Network)?;

        Ok(Self {
            http,
            base_url,
            api_key,
            api_version: api_version.to_string(),
        })
    }

    /// Cosign gate 3 (Q6=a): verify a `Verdict`'s signed attestation.
    ///
    /// Q14 (capability parity, not policy) — this is opt-in. Nothing else in
    /// `Client` calls this; a caller that never invokes it sees no behavior
    /// change. Returns `Err(AttestationInvalid { reason_code:
    /// "ATTESTATION_ABSENT", .. })` when the verdict carries no attestation
    /// at all (distinct from a present-but-invalid one) so callers can tell
    /// "nothing to verify" apart from "verification failed".
    ///
    /// Post gate-3 redesign (2026-09-13, BD-ratified per Jira CLEANLIB-379
    /// comment 804236): verifies against [`PinnedKeyMap`] — a compiled-in,
    /// fail-closed key set — NOT a `/v1/pubkeys` fetch. See
    /// [`crate::attestation_verify`]'s module doc for why the earlier
    /// fetch-by-`key_id` design (PR #536) was architecturally circular and
    /// got redesigned before any release shipped it as a default. No lazy
    /// network object to build here anymore — `PinnedKeyMap::default()` is
    /// a cheap, synchronous, in-memory construction.
    pub async fn verify_attestation(&self, verdict: &Verdict) -> Result<(), CleanLibraryError> {
        let envelope = verdict.attestation.as_ref().ok_or_else(|| {
            CleanLibraryError::AttestationInvalid {
                reason_code: "ATTESTATION_ABSENT".to_string(),
                message: "verdict carries no attestation (attestation_status = \
                          signature_absent, or a v1/pre-attestation response)"
                    .to_string(),
            }
        })?;
        let lookup = PinnedKeyMap::default();
        crate::attestation_verify::verify_attestation(envelope, &lookup).await
    }

    /// Fetch a single verdict per App Rev 4 §9.3 +
    /// `GET /v1/customer/verdicts/{ecosystem}/{package}/{version}`.
    pub async fn fetch_verdict(
        &self,
        ecosystem: &str,
        package: &str,
        version: &str,
    ) -> Result<Verdict, CleanLibraryError> {
        let path = format!(
            "{}/customer/verdicts/{}/{}/{}",
            self.api_version,
            urlencode(ecosystem),
            urlencode(package),
            urlencode(version),
        );
        let url = self
            .base_url
            .join(&path)
            .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))?;

        let response = self.send(Method::GET, url).await?;
        let status = response.status();
        let headers = response.headers().clone();
        let body = response.text().await.map_err(TransportError::Network)?;

        if !status.is_success() {
            return Err(from_http(status.as_u16(), &headers, &body));
        }

        serde_json::from_str(&body)
            .map_err(|e| CleanLibraryError::Parse(format!("verdict response: {}", e)))
    }

    /// Submit a packages + optional-policy request to
    /// `POST /v1/scan` — batch-resolve verdicts for a set of packages against
    /// the customer's active policy. Used by `cleanlib scan`. The App resolves
    /// each package independently (partial-success: a per-package miss lands as
    /// `ScanResult.error`, not a whole-batch failure), so the caller derives
    /// the gating decision per `ScanResult.verdict` and aggregates the exit
    /// code (`commands::scan`).
    ///
    /// Distinct endpoint from [`Self::policy_preview`]: `/v1/scan` needs no
    /// `policy_yaml`. Routing scan through `/v1/policy/preview` produced a
    /// `422 missing field policy_yaml`, and the old `PolicyPreviewResponse`
    /// (`{decisions}`, `#[serde(default)]`) silently parsed the App's
    /// `{results}` body into an empty vec → `scan_exit_code(&[]) == 0`, a
    /// fail-open on the security gate. Both are closed here.
    pub async fn scan(&self, req: &ScanRequest) -> Result<ScanResponse, CleanLibraryError> {
        let path = format!("{}/scan", self.api_version);
        let url = self
            .base_url
            .join(&path)
            .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))?;

        let body = serde_json::to_vec(req)
            .map_err(|e| CleanLibraryError::Parse(format!("scan body: {}", e)))?;

        let response = self
            .send_with_body(Method::POST, url, body, "application/json")
            .await?;
        let status = response.status();
        let headers = response.headers().clone();
        let body = response.text().await.map_err(TransportError::Network)?;

        if !status.is_success() {
            return Err(from_http(status.as_u16(), &headers, &body));
        }

        let mut resp: ScanResponse = serde_json::from_str(&body)
            .map_err(|e| CleanLibraryError::Parse(format!("scan response: {}", e)))?;
        // CLEANLIB-480 · stamp the `x-request-id` from the response header onto
        // the parsed body so SDK callers can `resp.request_id` for correlation
        // debugging without a raw HTTP bypass.
        resp.request_id = extract_request_id(&headers);
        Ok(resp)
    }

    /// `POST /v1/policy/preview`. Used by `cleanlib policy preview` (with an
    /// explicit candidate policy override). NOTE: `cleanlib scan` uses
    /// [`Self::scan`] (`/v1/scan`), NOT this endpoint.
    ///
    /// CLEANLIB-305 DX-fix: corrected from `/v1/customer/policy/preview`
    /// (which 404s) to `/v1/policy/preview` (which the App mounts via
    /// `verbs_router`). Same class of bug as the cycle-14 `/v1/audit`
    /// fix (see `audit` below): the `/customer/` prefix is used only by
    /// `customer_verdicts_router` (`/v1/customer/verdicts/*`); the
    /// cycle-6 verb surface (`scan`, `audit`, `policy/preview`,
    /// `risk-accept`, `fetch/*`) mounts flat under `/v1`.
    pub async fn policy_preview(
        &self,
        req: &PolicyPreviewRequest,
    ) -> Result<PolicyPreviewResponse, CleanLibraryError> {
        let path = format!("{}/policy/preview", self.api_version);
        let url = self
            .base_url
            .join(&path)
            .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))?;

        let body = serde_json::to_vec(req)
            .map_err(|e| CleanLibraryError::Parse(format!("policy_preview body: {}", e)))?;

        let response = self.send_with_body(Method::POST, url, body, "application/json").await?;
        let status = response.status();
        let headers = response.headers().clone();
        let body = response.text().await.map_err(TransportError::Network)?;

        if !status.is_success() {
            return Err(from_http(status.as_u16(), &headers, &body));
        }

        let mut resp: PolicyPreviewResponse = serde_json::from_str(&body)
            .map_err(|e| CleanLibraryError::Parse(format!("policy_preview response: {}", e)))?;
        // CLEANLIB-480 · stamp `x-request-id` from the response header.
        resp.request_id = extract_request_id(&headers);
        Ok(resp)
    }

    /// Fetch the raw artifact bytes for `(ecosystem, package, version)` via
    /// App's unified catalog-proxy `GET /v1/fetch/{ecosystem}/{package}/{version}`
    /// (CLEANLIB-302 / CLEANLIB-368). Returns owned `Vec<u8>` — caller decides
    /// write target. Emits decision + reason headers to stderr for visibility
    /// (binary stdout stays clean).
    ///
    /// **CLEANLIB-368 route pivot**: prior cycles built per-ecosystem registry
    /// paths (`/npm/<pkg>/-/<pkg>-<ver>.tgz`, `/go/<pkg>/@v/<ver>.zip`, …)
    /// against the App's cycle-3 §C.8 nested per-eco routers. Those paths are
    /// legacy registry-mimic shapes that never surfaced the CLEANLIB-302 audit
    /// row (`gcs_hit` / `gcs_object_path` / `bytes_served`) and hard-coded
    /// pypi wheel-variant assumptions that diverge from the real serve path.
    /// The App unifies both under `verbs_router` at `/v1/fetch/*` — that is
    /// now the sole client-side route.
    pub async fn fetch_artifact(
        &self,
        ecosystem: &str,
        package: &str,
        version: &str,
    ) -> Result<Vec<u8>, CleanLibraryError> {
        let url = build_fetch_url(&self.base_url, &self.api_version, ecosystem, package, version)?;
        let response = self.send(Method::GET, url).await?;
        let status = response.status();
        let headers = response.headers().clone();

        if !status.is_success() {
            let body = response.text().await.map_err(TransportError::Network)?;
            return Err(from_http(status.as_u16(), &headers, &body));
        }

        emit_decision_headers(&headers);

        let bytes = response.bytes().await.map_err(TransportError::Network)?;
        Ok(bytes.to_vec())
    }

    /// CLEANLIB-733 / step-4 Rust remediation client — fetch the sparse
    /// remediation composite via the cleanapp CUSTOMER-BOUNDARY FACADE
    /// (`GET /v1/customer/remediation/{eco}/{pkg}`, the same customer key that
    /// opens the verdict surface). Sister of the sdk-py / sdk-js / sdk-go
    /// `HttpRemediationClient`.
    ///
    /// Status mapping mirrors the other SDKs: `404` → [`RemediationOutcome::NotInSubstrate`]
    /// (a true, final "no remediation data" answer — never conflated with a
    /// transient, the [Degr≡Real] guard the facade 404-passthrough fix restored),
    /// `5xx`/transport → [`RemediationOutcome::Transient`], `2xx` →
    /// [`RemediationOutcome::Present`]. Internal/producer-bearer callers hit the
    /// direct enrich host — construct the `Client` with that endpoint and use
    /// [`Self::get_remediation_direct`]. Scoped npm packages (`@scope/name`) are
    /// percent-encoded to a single `%2F` segment (CLEANLIB-737 guard; see
    /// `urlencode`).
    pub async fn get_remediation(
        &self,
        ecosystem: &str,
        package: &str,
    ) -> Result<RemediationOutcome, CleanLibraryError> {
        self.remediation_with_mode(ecosystem, package, true).await
    }

    /// Direct-mode remediation for internal/producer-bearer callers: hits the
    /// pre-facade `GET /api/v1/remediation/{eco}/{pkg}` path on the configured
    /// (enrich-host) endpoint. Preserves the direct path per the un-park item-3.
    pub async fn get_remediation_direct(
        &self,
        ecosystem: &str,
        package: &str,
    ) -> Result<RemediationOutcome, CleanLibraryError> {
        self.remediation_with_mode(ecosystem, package, false).await
    }

    async fn remediation_with_mode(
        &self,
        ecosystem: &str,
        package: &str,
        facade: bool,
    ) -> Result<RemediationOutcome, CleanLibraryError> {
        let url = build_remediation_url(&self.base_url, &self.api_version, facade, ecosystem, package)?;
        let response = self.send(Method::GET, url).await?;
        let status = response.status();
        if status.as_u16() == 404 {
            return Ok(RemediationOutcome::NotInSubstrate);
        }
        if status.is_server_error() {
            return Ok(RemediationOutcome::Transient(format!("HTTP {}", status.as_u16())));
        }
        if !status.is_success() {
            let headers = response.headers().clone();
            let body = response.text().await.map_err(TransportError::Network)?;
            return Err(from_http(status.as_u16(), &headers, &body));
        }
        let body = response.text().await.map_err(TransportError::Network)?;
        let json: serde_json::Value =
            serde_json::from_str(&body).map_err(|e| CleanLibraryError::Parse(e.to_string()))?;
        Ok(RemediationOutcome::Present(json))
    }

    /// Streaming variant of [`Self::fetch_artifact`] — writes chunks to
    /// `writer` without buffering the full body in memory. Per Client Rev 2
    /// amendment §9.4 cycle-4 §D.5 streaming substrate. Returns total bytes
    /// written. Decision + reason headers surface to stderr before stream.
    /// Hits the same unified `/v1/fetch/{ecosystem}/{package}/{version}`
    /// proxy as [`Self::fetch_artifact`] — see the CLEANLIB-368 route pivot
    /// note there.
    pub async fn fetch_artifact_stream<W>(
        &self,
        ecosystem: &str,
        package: &str,
        version: &str,
        writer: &mut W,
    ) -> Result<u64, CleanLibraryError>
    where
        W: tokio::io::AsyncWrite + Unpin,
    {
        use futures_util::StreamExt;
        use tokio::io::AsyncWriteExt;

        let url = build_fetch_url(&self.base_url, &self.api_version, ecosystem, package, version)?;
        let response = self.send(Method::GET, url).await?;
        let status = response.status();
        let headers = response.headers().clone();

        if !status.is_success() {
            let body = response.text().await.map_err(TransportError::Network)?;
            return Err(from_http(status.as_u16(), &headers, &body));
        }

        emit_decision_headers(&headers);

        let mut total: u64 = 0;
        let mut stream = response.bytes_stream();
        while let Some(chunk) = stream.next().await {
            let bytes = chunk.map_err(TransportError::Network)?;
            writer
                .write_all(&bytes)
                .await
                .map_err(|e| CleanLibraryError::Parse(format!("write artifact chunk: {}", e)))?;
            total += bytes.len() as u64;
        }
        writer
            .flush()
            .await
            .map_err(|e| CleanLibraryError::Parse(format!("flush artifact stream: {}", e)))?;
        Ok(total)
    }

    /// Query customer audit log via `GET /v1/audit` with optional filters.
    /// Caller passes already-validated filter values.
    ///
    /// Cycle-14 DX-fix: corrected from `/v1/customer/audit` (which 404s) to
    /// `/v1/audit` (which the App mounts via `verbs_router`). Verified live
    /// against cleanapp.clnstrt.dev 2026-06-05 — direct probe returns 200
    /// with `{window, records, backend_status}`.
    ///
    /// CLEANLIB-813: takes an [`AuditFilters`] options struct rather than
    /// positional `Option<&str>` params. The real server
    /// (`cleanlib-app/src/verbs.rs`) accepts a fourth filter, `until`, that
    /// this SDK never exposed — Go's SDK already supports it. Adding it as
    /// a 4th positional parameter would have been a breaking signature
    /// change today AND set up another one the next time a filter is
    /// added; an options struct absorbs `until` now and any future filter
    /// later as a purely additive field, so every existing
    /// `..Default::default()`-built call site keeps compiling. This IS a
    /// breaking change for existing positional callers (Rust has no
    /// source-compat path from 3 positional params to a struct) — the
    /// migration cost is paid once, here, rather than deferred to the next
    /// filter add.
    pub async fn audit(
        &self,
        filters: AuditFilters<'_>,
    ) -> Result<AuditResponse, CleanLibraryError> {
        let path = format!("{}/audit", self.api_version);
        let mut url = self
            .base_url
            .join(&path)
            .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))?;
        {
            let mut q = url.query_pairs_mut();
            if let Some(s) = filters.since {
                q.append_pair("since", s);
            }
            // CLEANLIB-813: the one genuinely new filter this ticket exists
            // for — bounds the END of the audit query's time window, mirroring
            // Go's SDK. `cleanlib-app/src/verbs.rs` already accepts it; only
            // this SDK's `audit()` never threaded it through.
            if let Some(u) = filters.until {
                q.append_pair("until", u);
            }
            if let Some(d) = filters.decision {
                q.append_pair("decision", d);
            }
            if let Some(e) = filters.ecosystem {
                q.append_pair("ecosystem", e);
            }
        }

        let response = self.send(Method::GET, url).await?;
        let status = response.status();
        let headers = response.headers().clone();
        let body = response.text().await.map_err(TransportError::Network)?;

        if !status.is_success() {
            return Err(from_http(status.as_u16(), &headers, &body));
        }

        let mut resp: AuditResponse = serde_json::from_str(&body)
            .map_err(|e| CleanLibraryError::Parse(format!("audit response: {}", e)))?;
        // CLEANLIB-480 · stamp `x-request-id` from the response header — the
        // per-CALL identifier, distinct from `AuditEntry::request_id` (which
        // is the record-scoped per-row id persisted in the audit log).
        resp.request_id = extract_request_id(&headers);
        Ok(resp)
    }

        pub async fn probe_auth(&self) -> Result<(), CleanLibraryError> {
        let path = format!("{}/audit", self.api_version);
        let url = self
            .base_url
            .join(&path)
            .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))?;
        let response = self.send(Method::GET, url).await?;
        let status = response.status();
        let headers = response.headers().clone();
        let body = response.text().await.map_err(TransportError::Network)?;
        if status.is_success() {
            return Ok(());
        }
        Err(from_http(status.as_u16(), &headers, &body))
    }

    /// Low-level: send a request with body + content-type + auth header.
    async fn send_with_body(
        &self,
        method: Method,
        url: Url,
        body: Vec<u8>,
        content_type: &str,
    ) -> Result<reqwest::Response, CleanLibraryError> {
        let mut req = self.http.request(method, url).body(body);
        req = req.header(header::CONTENT_TYPE, content_type);
        if let Some(key) = &self.api_key {
            req = req.header(header::AUTHORIZATION, format!("Bearer {}", key));
        }
        req.send().await.map_err(|e| {
            if e.is_timeout() {
                CleanLibraryError::Transport(TransportError::Timeout)
            } else {
                CleanLibraryError::Transport(TransportError::Network(e))
            }
        })
    }

    /// Low-level: send a request with auth header. Used internally by verb
    /// methods; public for advanced consumers (future).
    pub async fn send(
        &self,
        method: Method,
        url: Url,
    ) -> Result<reqwest::Response, CleanLibraryError> {
        let mut req = self.http.request(method, url);
        if let Some(key) = &self.api_key {
            req = req.header(header::AUTHORIZATION, format!("Bearer {}", key));
        }
        req.send().await.map_err(|e| {
            if e.is_timeout() {
                CleanLibraryError::Transport(TransportError::Timeout)
            } else {
                CleanLibraryError::Transport(TransportError::Network(e))
            }
        })
    }

    /// Expose the base URL for diagnostics + integration tests.
    pub fn base_url(&self) -> &Url {
        &self.base_url
    }

    /// Fetch supported ecosystems from GET /health ecosystems_mounted field.
    pub async fn get_ecosystems(&self) -> Result<Vec<String>, CleanLibraryError> {
        let url = self.base_url.join("/health")
            .map_err(|e| CleanLibraryError::Transport(
                TransportError::InvalidUrl(e.to_string())
            ))?;
        let resp = self.http.get(url).send().await.map_err(|e| {
            CleanLibraryError::Transport(TransportError::Network(e))
        })?;
        let body_text = resp.text().await.map_err(|e| {
            CleanLibraryError::Transport(TransportError::Network(e))
        })?;
        let body: serde_json::Value = serde_json::from_str(&body_text)
            .map_err(|e| CleanLibraryError::Parse(e.to_string()))?;
        let ecosystems = body["ecosystems_mounted"]
            .as_array()
            .unwrap_or(&vec![])
            .iter()
            .filter_map(|v| v.as_str().map(|s| s.to_string()))
            .collect();
        Ok(ecosystems)
    }
}

/// CLEANLIB-480 · pull the `x-request-id` header off a response. Returns
/// `None` when the header is absent (older App builds pre-CLEANLIB-470) or
/// when the value is not UTF-8 (defence-in-depth — App always emits ASCII
/// ULIDs, so this is unreachable on a well-behaved server). HTTP header
/// names are case-insensitive so `x-request-id` matches `X-Request-Id`
/// either way. Free-standing so both the transport verbs and the tests
/// can share it.
pub(crate) fn extract_request_id(
    headers: &reqwest::header::HeaderMap,
) -> Option<String> {
    headers
        .get("x-request-id")
        .and_then(|v| v.to_str().ok())
        .map(|s| s.to_string())
}

/// Emit App's verdict + reason headers (when present) to stderr. Keeps
/// stdout clean for binary content + scripted consumers; visible to TTY
/// users for verdict awareness.
fn emit_decision_headers(headers: &reqwest::header::HeaderMap) {
    if let Some(decision) = headers
        .get("X-CleanLibrary-Decision")
        .and_then(|v| v.to_str().ok())
    {
        eprintln!("# decision: {}", decision);
    }
    if let Some(reason) = headers
        .get("X-CleanLibrary-Reason")
        .and_then(|v| v.to_str().ok())
    {
        eprintln!("# reason: {}", reason);
    }
}

/// Build the App-side catalog-proxy URL for a triple. Post-CLEANLIB-368 this
/// is the ONLY fetch URL shape the client emits: `GET /{api_version}/fetch/
/// {ecosystem}/{package}/{version}` — the unified verb the App mounts in
/// `verbs_router` (see `cleanlib-app/src/verbs.rs`), which returns
/// `application/octet-stream` on catalog-hit and a structured JSON 404 on
/// miss. Per CLEANLIB-302 this is the surface that emits the fetch-audit
/// `AuditRow` with `gcs_hit` / `gcs_object_path` / `bytes_served`
/// populated from the real catalog outcome — the substrate the
/// `/v1/audit` cache-hit-ratio metric consumes.
///
/// Every triple component is percent-encoded so path-embedded slashes
/// (npm-scoped `@scope/name`, go-module `github.com/…/…`) survive the
/// App's axum `Path<(String, String, String)>` extractor as a single
/// segment each.
fn build_fetch_url(
    base: &Url,
    api_version: &str,
    ecosystem: &str,
    package: &str,
    version: &str,
) -> Result<Url, TransportError> {
    let path = format!(
        "{}/fetch/{}/{}/{}",
        api_version,
        urlencode(ecosystem),
        urlencode(package),
        urlencode(version),
    );
    base.join(&path)
        .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))
}

/// Build the remediation URL. `facade` (customer) → `{api_version}/customer/
/// remediation/{eco}/{pkg}` on the cleanapp base; `!facade` (internal) → the
/// pre-facade `api/{api_version}/remediation/{eco}/{pkg}` direct path. Segments
/// go through `urlencode`, so a scoped npm package (`@scope/name`) becomes a
/// single `%2F`-encoded segment (CLEANLIB-737 guard) rather than a split path.
fn build_remediation_url(
    base: &Url,
    api_version: &str,
    facade: bool,
    ecosystem: &str,
    package: &str,
) -> Result<Url, TransportError> {
    let path = if facade {
        format!(
            "{}/customer/remediation/{}/{}",
            api_version,
            urlencode(ecosystem),
            urlencode(package),
        )
    } else {
        format!(
            "api/{}/remediation/{}/{}",
            api_version,
            urlencode(ecosystem),
            urlencode(package),
        )
    };
    base.join(&path)
        .map_err(|e| TransportError::InvalidUrl(format!("{}: {}", path, e)))
}

/// URL-encode a path segment. Covers `@` + `/` + reserved chars + unicode.
/// Avoids pulling the full `url` crate as a separate dep (re-export is via
/// `reqwest::Url`).
fn urlencode(s: &str) -> String {
    let mut out = String::with_capacity(s.len());
    for c in s.chars() {
        match c {
            'A'..='Z' | 'a'..='z' | '0'..='9' | '-' | '_' | '.' | '~' => out.push(c),
            _ => {
                let mut buf = [0u8; 4];
                let encoded = c.encode_utf8(&mut buf);
                for b in encoded.bytes() {
                    out.push_str(&format!("%{:02X}", b));
                }
            }
        }
    }
    out
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::config::{Config, EndpointConfig};

    fn cfg(url: &str) -> Config {
        let mut c = Config::default();
        c.endpoint = EndpointConfig {
            url: url.to_string(),
            api_version: "v1".to_string(),
        };
        c
    }

    #[test]
    fn refuses_remote_plaintext() {
        let err = Client::from_config(&cfg("http://cleanapp.clnstrt.dev")).unwrap_err();
        assert!(matches!(
            err,
            CleanLibraryError::Transport(TransportError::TlsRequired(_))
        ));
    }

    #[test]
    fn allows_localhost_plaintext_for_testing() {
        let client = Client::new("http://localhost:8080", None).unwrap();
        assert_eq!(client.base_url().host_str(), Some("localhost"));
    }

    #[test]
    fn allows_127_loopback_plaintext() {
        let client = Client::new("http://127.0.0.1:8080", None).unwrap();
        assert_eq!(client.base_url().host_str(), Some("127.0.0.1"));
    }

    #[test]
    fn accepts_https_endpoint() {
        let client = Client::from_config(&cfg("https://cleanapp.clnstrt.dev")).unwrap();
        assert_eq!(client.base_url().as_str(), "https://cleanapp.clnstrt.dev/");
    }

    #[test]
    fn rejects_invalid_url() {
        let err = Client::from_config(&cfg("not a url")).unwrap_err();
        assert!(matches!(
            err,
            CleanLibraryError::Transport(TransportError::InvalidUrl(_))
        ));
    }

    #[test]
    fn urlencode_npm_scoped_pkg() {
        // @scope/pkg → %40scope%2Fpkg for safe URL embedding
        assert_eq!(urlencode("@my-org/foo"), "%40my-org%2Ffoo");
    }

    // ─── CLEANLIB-733 Rust remediation client (step 4) ──────────────────────
    #[test]
    fn remediation_url_facade_is_customer_path() {
        let base = Url::parse("https://cleanapp.clnstrt.dev").unwrap();
        let u = build_remediation_url(&base, "v1", true, "npm", "cors").unwrap();
        assert_eq!(u.path(), "/v1/customer/remediation/npm/cors");
    }

    #[test]
    fn remediation_url_direct_is_api_v1_path() {
        // Internal/producer-bearer mode preserves the pre-facade path (item-3).
        let base = Url::parse("https://cleanlib-enrich.clnstrt.dev").unwrap();
        let u = build_remediation_url(&base, "v1", false, "npm", "cors").unwrap();
        assert_eq!(u.path(), "/api/v1/remediation/npm/cors");
    }

    #[test]
    fn remediation_url_scoped_package_slash_is_percent_encoded() {
        // CLEANLIB-737 guard: a scoped npm package reaches the wire as a SINGLE
        // %2F-encoded segment, never a bare "/" that would split into an extra
        // segment and bind the wrong upstream coordinate.
        let base = Url::parse("https://cleanapp.clnstrt.dev").unwrap();
        let u = build_remediation_url(&base, "v1", true, "npm", "@babel/core").unwrap();
        assert!(u.as_str().contains("%2F"), "scope slash not encoded: {u}");
        assert!(
            u.as_str().ends_with("/npm/%40babel%2Fcore"),
            "want a single %2F-encoded scoped segment, got {u}"
        );
    }

    #[test]
    fn urlencode_passes_simple() {
        assert_eq!(urlencode("lodash"), "lodash");
        assert_eq!(urlencode("4.17.21"), "4.17.21");
        assert_eq!(urlencode("github.com/sirupsen/logrus"), "github.com%2Fsirupsen%2Flogrus");
    }

    #[test]
    fn urlencode_maven_coordinate_encodes_colon() {
        // CLEANLIB S3 / A3 Maven contract: maven package = groupId:artifactId;
        // the colon must percent-encode to %3A so the wire coordinate is
        // byte-identical across all 4 SDKs (sdk-go escapePathSeg / js
        // encodeURIComponent / py quote(safe='')). The allowlist urlencode
        // already does this — this test locks it against regression.
        assert_eq!(
            urlencode("org.springframework:spring-beans"),
            "org.springframework%3Aspring-beans"
        );
        assert_eq!(
            urlencode("org.apache.logging.log4j:log4j-core"),
            "org.apache.logging.log4j%3Alog4j-core"
        );
    }

    #[test]
    fn urlencode_handles_unicode() {
        // UTF-8 multi-byte chars get percent-encoded byte-by-byte
        assert_eq!(urlencode("é"), "%C3%A9");
    }

    fn base() -> Url {
        Url::parse("https://cleanapp.clnstrt.dev").unwrap()
    }

    // CLEANLIB-368 route pivot: every ecosystem now resolves to the App's
    // unified `/{api_version}/fetch/{ecosystem}/{package}/{version}` catalog
    // proxy. The client no longer emits registry-mimic per-ecosystem paths
    // (`/npm/…/-/….tgz`, `/go/…/@v/….zip`, `/pypi/…/…-….tar.gz`) — those
    // URL-shape assertions are retired because they are the pre-pivot bug.
    #[test]
    fn fetch_url_routes_through_app_v1_fetch_for_npm_bare() {
        let url = build_fetch_url(&base(), "v1", "npm", "lodash", "4.17.21").unwrap();
        assert_eq!(
            url.as_str(),
            "https://cleanapp.clnstrt.dev/v1/fetch/npm/lodash/4.17.21"
        );
    }

    #[test]
    fn fetch_url_npm_scoped_encodes_at_and_slash() {
        // `@my-org/foo` must survive the App's Path extractor as a single
        // `{package}` segment — so `@` → `%40` and `/` → `%2F`.
        let url = build_fetch_url(&base(), "v1", "npm", "@my-org/foo", "1.0.0").unwrap();
        assert_eq!(
            url.as_str(),
            "https://cleanapp.clnstrt.dev/v1/fetch/npm/%40my-org%2Ffoo/1.0.0"
        );
    }

    #[test]
    fn fetch_url_go_module_path_slashes_encoded() {
        // `github.com/sirupsen/logrus` is one package identifier; its
        // internal `/`s must not split into extra path segments.
        let url = build_fetch_url(&base(), "v1", "go", "github.com/sirupsen/logrus", "v1.9.0")
            .unwrap();
        assert_eq!(
            url.as_str(),
            "https://cleanapp.clnstrt.dev/v1/fetch/go/github.com%2Fsirupsen%2Flogrus/v1.9.0"
        );
    }

    #[test]
    fn fetch_url_pypi_routes_through_v1_fetch_not_registry_mimic() {
        let url = build_fetch_url(&base(), "v1", "pypi", "requests", "2.31.0").unwrap();
        assert_eq!(
            url.as_str(),
            "https://cleanapp.clnstrt.dev/v1/fetch/pypi/requests/2.31.0"
        );
        // Explicitly assert the legacy pypi shape is NOT emitted.
        assert!(!url.as_str().contains("/pypi/requests/requests-"));
    }

    #[test]
    fn fetch_url_ecosystem_client_side_unopinionated() {
        // Post-pivot the client no longer rejects any ecosystem name; the
        // App owns catalog-lookup + returns a structured 404 on miss. This
        // closes the CLEANLIB-368 gap that had maven/crates/nuget/rubygems
        // failing at the client with `Phase 1 Tier A` before even hitting
        // the wire.
        for eco in ["maven", "crates", "nuget", "rubygems", "composer"] {
            let url = build_fetch_url(&base(), "v1", eco, "somepkg", "1.0.0").unwrap();
            assert_eq!(
                url.as_str(),
                format!("https://cleanapp.clnstrt.dev/v1/fetch/{}/somepkg/1.0.0", eco)
            );
        }
    }

    #[test]
    fn fetch_url_maven_coordinates_group_id_encoded() {
        // Maven coordinates use `group:artifact` (no `/`), but the `:` is a
        // reserved char in URL segments — urlencode covers it.
        let url = build_fetch_url(&base(), "v1", "maven", "junit:junit", "4.13.2").unwrap();
        assert_eq!(
            url.as_str(),
            "https://cleanapp.clnstrt.dev/v1/fetch/maven/junit%3Ajunit/4.13.2"
        );
    }

    #[test]
    fn fetch_url_honors_configured_api_version() {
        // Future-proof: if the config carries `api_version = "v2"`, the
        // client picks it up — no hard-coded `v1` in transport.
        let url = build_fetch_url(&base(), "v2", "npm", "lodash", "4.17.21").unwrap();
        assert_eq!(
            url.as_str(),
            "https://cleanapp.clnstrt.dev/v2/fetch/npm/lodash/4.17.21"
        );
    }

    // ── CLEANLIB-480 · x-request-id header extraction ────────────────────

    fn header_map(pairs: &[(&str, &str)]) -> reqwest::header::HeaderMap {
        let mut m = reqwest::header::HeaderMap::new();
        for (k, v) in pairs {
            m.insert(
                reqwest::header::HeaderName::from_bytes(k.as_bytes()).unwrap(),
                reqwest::header::HeaderValue::from_str(v).unwrap(),
            );
        }
        m
    }

    #[test]
    fn cleanlib_480_extract_request_id_reads_lowercase_header() {
        // App emit is lowercase per CLEANLIB-470 wire; extract must match.
        let h = header_map(&[("x-request-id", "01M1KWQ41SPRAP551FGW5ZN4RF")]);
        assert_eq!(
            extract_request_id(&h).as_deref(),
            Some("01M1KWQ41SPRAP551FGW5ZN4RF")
        );
    }

    #[test]
    fn cleanlib_480_extract_request_id_reads_mixed_case_header() {
        // HTTP header names are case-insensitive per RFC; the client must
        // read `X-Request-Id` identically to `x-request-id` so a future App
        // header casing change doesn't silently drop the id.
        let h = header_map(&[("X-Request-Id", "01ABC")]);
        assert_eq!(extract_request_id(&h).as_deref(), Some("01ABC"));
    }

    #[test]
    fn cleanlib_480_extract_request_id_absent_returns_none() {
        // Older App builds pre-CLEANLIB-470 emit no header — SDK callers
        // see `None`, not an error.
        let h = header_map(&[("content-type", "application/json")]);
        assert!(extract_request_id(&h).is_none());
    }

    #[test]
    fn cleanlib_480_extract_request_id_non_utf8_value_returns_none() {
        // Defence-in-depth: a non-UTF-8 header value (never emitted by the
        // App, but a proxy could inject one) must not panic or corrupt the
        // returned Option — the client returns None and the SDK caller
        // falls back to a null request_id.
        let mut h = reqwest::header::HeaderMap::new();
        h.insert(
            reqwest::header::HeaderName::from_static("x-request-id"),
            reqwest::header::HeaderValue::from_bytes(&[0x80, 0xFF]).unwrap(),
        );
        assert!(extract_request_id(&h).is_none());
    }
}