mollify-cli 0.1.1

//! Live OSV advisory fetch for `mollify supply-chain`. Network I/O lives here so
//! `mollify-core` stays pure, offline, and deterministic. Best-effort: callers
//! fall back to the local advisory DB on any error.
//!
//! Uses OSV's `/v1/query` endpoint, which returns the vulnerabilities affecting
//! a specific `(package, version)` — so OSV does the version matching and we
//! pin each resulting advisory to the exact queried version.

use mollify_core::supplychain::{Advisory, PinnedDep};
use serde_json::Value;
use std::time::Duration;

const OSV_QUERYBATCH: &str = "https://api.osv.dev/v1/querybatch";
const OSV_VULN: &str = "https://api.osv.dev/v1/vulns/";

fn build_agent() -> ureq::Agent {
    let mut b = ureq::AgentBuilder::new().timeout(Duration::from_secs(20));
    // Honor a corporate/CI proxy if one is configured.
    if let Ok(p) = std::env::var("HTTPS_PROXY").or_else(|_| std::env::var("https_proxy")) {
        if !p.is_empty() {
            if let Ok(proxy) = ureq::Proxy::new(&p) {
                b = b.proxy(proxy);
            }
        }
    }
    b.build()
}

/// Query OSV for each distinct `(package, version)` pin and return advisories.
/// Each advisory's spec pins the exact queried version, so the offline matcher
/// in `mollify-core` reproduces the same result deterministically.
pub fn fetch_for_pins(pins: &[PinnedDep]) -> anyhow::Result<Vec<Advisory>> {
    if pins.is_empty() {
        return Ok(Vec::new());
    }
    let agent = build_agent();
    // Distinct (name, version) pins, order preserved for result alignment.
    let mut seen = std::collections::HashSet::new();
    let distinct: Vec<&PinnedDep> = pins
        .iter()
        .filter(|p| seen.insert((p.name.clone(), p.version.clone())))
        .collect();

    // One batched discovery request returns vuln IDs per query (aligned order).
    let queries: Vec<Value> = distinct
        .iter()
        .map(|p| serde_json::json!({ "package": { "name": p.name, "ecosystem": "PyPI" }, "version": p.version }))
        .collect();
    let resp = agent
        .post(OSV_QUERYBATCH)
        .send_json(serde_json::json!({ "queries": queries }))?;
    let val: Value = resp.into_json()?;
    let results = val
        .get("results")
        .and_then(|r| r.as_array())
        .cloned()
        .unwrap_or_default();

    // Fetch each unique advisory's details once (batch gives only IDs).
    let mut detail_cache: std::collections::HashMap<String, (String, Vec<String>)> =
        std::collections::HashMap::new();
    let mut out = Vec::new();
    for (pin, result) in distinct.iter().zip(results.iter()) {
        let Some(vulns) = result.get("vulns").and_then(|v| v.as_array()) else {
            continue;
        };
        for v in vulns {
            let Some(id) = v.get("id").and_then(|x| x.as_str()) else {
                continue;
            };
            let (summary, aliases) = detail_cache
                .entry(id.to_string())
                .or_insert_with(|| fetch_vuln_detail(&agent, id))
                .clone();
            out.push(Advisory {
                id: id.to_string(),
                package: pin.name.clone(),
                specs: vec![format!("=={}", pin.version)],
                summary,
                aliases,
                severity: None,
            });
        }
    }
    Ok(out)
}

/// Fetch one OSV advisory's summary (first line) and CVE aliases by id.
/// Best-effort: returns empty strings on any failure.
fn fetch_vuln_detail(agent: &ureq::Agent, id: &str) -> (String, Vec<String>) {
    let url = format!("{OSV_VULN}{id}");
    let Ok(resp) = agent.get(&url).call() else {
        return (String::new(), Vec::new());
    };
    let Ok(v) = resp.into_json::<Value>() else {
        return (String::new(), Vec::new());
    };
    let summary = v
        .get("summary")
        .and_then(|x| x.as_str())
        .or_else(|| v.get("details").and_then(|x| x.as_str()))
        .unwrap_or("")
        .lines()
        .next()
        .unwrap_or("")
        .chars()
        .take(200)
        .collect::<String>();
    let aliases = v
        .get("aliases")
        .and_then(|a| a.as_array())
        .map(|a| {
            a.iter()
                .filter_map(|x| x.as_str())
                .filter(|s| s.starts_with("CVE-"))
                .map(String::from)
                .collect()
        })
        .unwrap_or_default();
    (summary, aliases)
}

/// Serialize advisories into the `mollify-advisories/1` schema and write to
/// `path` (used by `--refresh` to cache the live feed for later offline runs).
pub fn write_db(path: &camino::Utf8Path, advisories: &[Advisory]) -> std::io::Result<()> {
    if let Some(parent) = path.parent() {
        if !parent.as_str().is_empty() {
            std::fs::create_dir_all(parent)?;
        }
    }
    let db = serde_json::json!({
        "schema": "mollify-advisories/1",
        "source": "osv.dev /v1/query (live)",
        "advisories": advisories,
    });
    std::fs::write(path, serde_json::to_string_pretty(&db).unwrap())
}