Analyzing Sbom For Supply Chain Vulnerabilities

                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).

      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to the Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."

      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by the Licensor and
      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.

   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding any notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

   END OF TERMS AND CONDITIONS

   APPENDIX: How to apply the Apache License to your work.

      To apply the Apache License to your work, attach the following
      boilerplate notice, with the fields enclosed by brackets "[]"
      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. Please do not remove or change
      the license header comment from a contributed file except when
      necessary.

   Copyright 2026 mukul975

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

#!/usr/bin/env python3
"""SBOM supply chain vulnerability analysis agent.

Parses CycloneDX and SPDX JSON SBOMs, correlates components against the NVD 2.0 API
for known CVEs, builds dependency graphs with networkx, calculates risk scores, and
generates compliance reports.
"""

import os
import sys
import json
import time
import argparse
from pathlib import Path
from datetime import datetime
from collections import defaultdict

try:
    import requests
    HAS_REQUESTS = True
except ImportError:
    HAS_REQUESTS = False

try:
    import networkx as nx
    HAS_NETWORKX = True
except ImportError:
    HAS_NETWORKX = False

try:
    from packaging.version import Version, InvalidVersion
    HAS_PACKAGING = True
except ImportError:
    HAS_PACKAGING = False

# NVD API 2.0 configuration
NVD_CVE_API = "https://services.nvd.nist.gov/rest/json/cves/2.0"
NVD_CPE_API = "https://services.nvd.nist.gov/rest/json/cpes/2.0"
NVD_RATE_LIMIT_NO_KEY = 6.0   # seconds between requests without API key
NVD_RATE_LIMIT_WITH_KEY = 0.6  # seconds between requests with API key
NVD_RESULTS_PER_PAGE = 50

# CVSS severity thresholds
SEVERITY_THRESHOLDS = {
    "CRITICAL": 9.0,
    "HIGH": 7.0,
    "MEDIUM": 4.0,
    "LOW": 0.1,
}


class SBOMComponent:
    """Represents a single software component extracted from an SBOM."""

    def __init__(self, name, version, purl=None, cpe=None, component_type="library",
                 licenses=None, supplier=None):
        self.name = name
        self.version = version
        self.purl = purl
        self.cpe = cpe
        self.component_type = component_type
        self.licenses = licenses or []
        self.supplier = supplier
        self.cves = []
        self.max_cvss = 0.0
        self.risk_level = "NONE"

    def to_dict(self):
        return {
            "name": self.name,
            "version": self.version,
            "purl": self.purl,
            "cpe": self.cpe,
            "type": self.component_type,
            "licenses": self.licenses,
            "cves": self.cves,
            "max_cvss": self.max_cvss,
            "risk_level": self.risk_level,
        }


def detect_sbom_format(sbom_data):
    """Detect whether the SBOM is CycloneDX or SPDX format."""
    if isinstance(sbom_data, dict):
        if sbom_data.get("bomFormat") == "CycloneDX":
            return "cyclonedx"
        if "spdxVersion" in sbom_data:
            return "spdx"
        if "components" in sbom_data and any(
            "purl" in c for c in sbom_data.get("components", [])
        ):
            return "cyclonedx"
        if "packages" in sbom_data:
            return "spdx"
    return "unknown"


def parse_cyclonedx(sbom_data):
    """Parse CycloneDX JSON SBOM and extract components and dependencies."""
    components = []
    dependencies = {}

    spec_version = sbom_data.get("specVersion", "unknown")
    print(f"  Format: CycloneDX v{spec_version}")

    for comp in sbom_data.get("components", []):
        name = comp.get("name", "unknown")
        version = comp.get("version", "unknown")
        purl = comp.get("purl")
        cpe = None

        # Extract CPE from multiple possible locations
        if "cpe" in comp:
            cpe = comp["cpe"]
        for prop in comp.get("properties", []):
            if prop.get("name") == "syft:cpe23" or "cpe" in prop.get("name", "").lower():
                cpe = prop.get("value")
                break

        # Extract licenses
        licenses = []
        for lic_entry in comp.get("licenses", []):
            lic = lic_entry.get("license", {})
            if "id" in lic:
                licenses.append(lic["id"])
            elif "name" in lic:
                licenses.append(lic["name"])

        component = SBOMComponent(
            name=name,
            version=version,
            purl=purl,
            cpe=cpe,
            component_type=comp.get("type", "library"),
            licenses=licenses,
            supplier=comp.get("supplier", {}).get("name"),
        )
        components.append(component)

    # Parse dependency graph
    for dep_entry in sbom_data.get("dependencies", []):
        ref = dep_entry.get("ref", "")
        depends_on = dep_entry.get("dependsOn", [])
        dependencies[ref] = depends_on

    return components, dependencies


def parse_spdx(sbom_data):
    """Parse SPDX JSON SBOM and extract components and dependencies."""
    components = []
    dependencies = {}

    spdx_version = sbom_data.get("spdxVersion", "unknown")
    print(f"  Format: SPDX {spdx_version}")

    spdx_id_to_purl = {}

    for pkg in sbom_data.get("packages", []):
        name = pkg.get("name", "unknown")
        version = pkg.get("versionInfo", "unknown")
        spdx_id = pkg.get("SPDXID", "")
        purl = None
        cpe = None

        for ref in pkg.get("externalRefs", []):
            ref_type = ref.get("referenceType", "")
            locator = ref.get("referenceLocator", "")
            if ref_type == "purl" or "purl" in ref_type.lower():
                purl = locator
            elif ref_type == "cpe23Type" or "cpe" in ref_type.lower():
                cpe = locator

        licenses = []
        concluded = pkg.get("licenseConcluded", "NOASSERTION")
        if concluded and concluded != "NOASSERTION":
            licenses.append(concluded)
        declared = pkg.get("licenseDeclared", "NOASSERTION")
        if declared and declared != "NOASSERTION" and declared not in licenses:
            licenses.append(declared)

        component = SBOMComponent(
            name=name,
            version=version,
            purl=purl,
            cpe=cpe,
            component_type="library",
            licenses=licenses,
            supplier=pkg.get("supplier"),
        )
        components.append(component)
        spdx_id_to_purl[spdx_id] = purl or f"{name}@{version}"

    # Parse relationships
    for rel in sbom_data.get("relationships", []):
        rel_type = rel.get("relationshipType", "")
        if rel_type == "DEPENDS_ON":
            parent_id = rel.get("spdxElementId", "")
            child_id = rel.get("relatedSpdxElement", "")
            parent_ref = spdx_id_to_purl.get(parent_id, parent_id)
            child_ref = spdx_id_to_purl.get(child_id, child_id)
            if parent_ref not in dependencies:
                dependencies[parent_ref] = []
            dependencies[parent_ref].append(child_ref)

    return components, dependencies


def parse_sbom(sbom_path):
    """Load and parse an SBOM file, auto-detecting the format."""
    if not os.path.isfile(sbom_path):
        raise FileNotFoundError(f"SBOM file not found: {sbom_path}")

    with open(sbom_path, "r", encoding="utf-8") as f:
        sbom_data = json.load(f)

    fmt = detect_sbom_format(sbom_data)
    print(f"\n[INFO] Parsing SBOM: {sbom_path}")

    if fmt == "cyclonedx":
        return parse_cyclonedx(sbom_data), fmt
    elif fmt == "spdx":
        return parse_spdx(sbom_data), fmt
    else:
        raise ValueError(
            f"Unrecognized SBOM format. Expected CycloneDX or SPDX JSON. "
            f"Keys found: {list(sbom_data.keys())[:10]}"
        )


def query_nvd_by_cpe(cpe_name, api_key=None):
    """Query NVD 2.0 API for CVEs matching a CPE name."""
    if not HAS_REQUESTS:
        return []

    params = {"cpeName": cpe_name, "resultsPerPage": NVD_RESULTS_PER_PAGE}
    headers = {}
    if api_key:
        headers["apiKey"] = api_key

    try:
        resp = requests.get(NVD_CVE_API, params=params, headers=headers, timeout=30)
        if resp.status_code == 403:
            print(f"    [WARN] NVD API rate limited. Waiting...", file=sys.stderr)
            time.sleep(NVD_RATE_LIMIT_NO_KEY * 2)
            resp = requests.get(NVD_CVE_API, params=params, headers=headers, timeout=30)
        resp.raise_for_status()
        return resp.json().get("vulnerabilities", [])
    except requests.RequestException as e:
        print(f"    [WARN] NVD API error for {cpe_name}: {e}", file=sys.stderr)
        return []


def query_nvd_by_keyword(keyword, api_key=None):
    """Query NVD 2.0 API for CVEs matching a keyword search."""
    if not HAS_REQUESTS:
        return []

    params = {"keywordSearch": keyword, "resultsPerPage": NVD_RESULTS_PER_PAGE}
    headers = {}
    if api_key:
        headers["apiKey"] = api_key

    try:
        resp = requests.get(NVD_CVE_API, params=params, headers=headers, timeout=30)
        resp.raise_for_status()
        return resp.json().get("vulnerabilities", [])
    except requests.RequestException as e:
        print(f"    [WARN] NVD keyword search error for '{keyword}': {e}", file=sys.stderr)
        return []


def extract_cve_info(vuln_entry):
    """Extract structured CVE information from an NVD API response entry."""
    cve_data = vuln_entry.get("cve", {})
    cve_id = cve_data.get("id", "UNKNOWN")

    # Extract CVSS score (prefer v3.1, fallback to v3.0, then v2.0)
    cvss_score = 0.0
    cvss_version = "none"
    metrics = cve_data.get("metrics", {})

    for version_key in ["cvssMetricV31", "cvssMetricV30", "cvssMetricV2"]:
        metric_list = metrics.get(version_key, [])
        if metric_list:
            cvss_data = metric_list[0].get("cvssData", {})
            cvss_score = cvss_data.get("baseScore", 0.0)
            cvss_version = cvss_data.get("version", version_key)
            break

    # Extract description
    descriptions = cve_data.get("descriptions", [])
    description = ""
    for desc in descriptions:
        if desc.get("lang") == "en":
            description = desc.get("value", "")
            break

    # Determine severity
    severity = "LOW"
    for level, threshold in sorted(SEVERITY_THRESHOLDS.items(),
                                    key=lambda x: x[1], reverse=True):
        if cvss_score >= threshold:
            severity = level
            break

    # Check for known exploited (CISA KEV indicator)
    is_kev = False
    for ref in cve_data.get("references", []):
        if "cisa.gov" in ref.get("url", "").lower():
            is_kev = True
            break

    return {
        "cve_id": cve_id,
        "cvss_score": cvss_score,
        "cvss_version": cvss_version,
        "severity": severity,
        "description": description[:300],
        "is_kev": is_kev,
        "published": cve_data.get("published", ""),
    }


def correlate_cves(components, api_key=None, skip_nvd=False):
    """Correlate all SBOM components against NVD for known vulnerabilities."""
    rate_limit = NVD_RATE_LIMIT_WITH_KEY if api_key else NVD_RATE_LIMIT_NO_KEY
    total = len(components)
    vuln_count = 0

    print(f"\n[INFO] Correlating {total} components against NVD CVE database...")
    if not api_key:
        print(f"  [NOTE] No NVD API key. Rate limited to 1 request per {rate_limit}s.")
        print(f"  Get a free key at: https://nvd.nist.gov/developers/request-an-api-key")

    if skip_nvd:
        print(f"  [NOTE] NVD queries skipped (--skip-nvd flag). Using offline mode.")
        return components

    for idx, comp in enumerate(components):
        print(f"  [{idx+1}/{total}] {comp.name}@{comp.version}...", end="", flush=True)

        vulns = []
        # Try CPE-based search first (most precise)
        if comp.cpe:
            vulns = query_nvd_by_cpe(comp.cpe, api_key)

        # Fallback to keyword search if no CPE or no results
        if not vulns:
            keyword = f"{comp.name} {comp.version}"
            vulns = query_nvd_by_keyword(keyword, api_key)

        # Process results
        for v in vulns:
            cve_info = extract_cve_info(v)
            if cve_info["cvss_score"] > 0:
                comp.cves.append(cve_info)
                if cve_info["cvss_score"] > comp.max_cvss:
                    comp.max_cvss = cve_info["cvss_score"]

        # Assign risk level
        if comp.max_cvss >= SEVERITY_THRESHOLDS["CRITICAL"]:
            comp.risk_level = "CRITICAL"
        elif comp.max_cvss >= SEVERITY_THRESHOLDS["HIGH"]:
            comp.risk_level = "HIGH"
        elif comp.max_cvss >= SEVERITY_THRESHOLDS["MEDIUM"]:
            comp.risk_level = "MEDIUM"
        elif comp.max_cvss > 0:
            comp.risk_level = "LOW"

        cve_count = len(comp.cves)
        vuln_count += cve_count
        status = f" {cve_count} CVEs (max CVSS: {comp.max_cvss})" if cve_count else " clean"
        print(status)

        # Rate limiting
        if idx < total - 1:
            time.sleep(rate_limit)

    print(f"\n[INFO] Correlation complete. Found {vuln_count} total CVEs across all components.")
    return components


def build_dependency_graph(components, dependencies):
    """Build a directed dependency graph using networkx."""
    if not HAS_NETWORKX:
        print("[WARN] networkx not installed. Dependency graph analysis skipped.", file=sys.stderr)
        return None

    G = nx.DiGraph()

    # Build lookup for components by purl or name@version
    comp_lookup = {}
    for comp in components:
        ref = comp.purl or f"{comp.name}@{comp.version}"
        G.add_node(ref, name=comp.name, version=comp.version,
                   max_cvss=comp.max_cvss, risk_level=comp.risk_level,
                   cve_count=len(comp.cves))
        comp_lookup[ref] = comp

    # Add edges from dependency relationships
    for parent_ref, children in dependencies.items():
        if parent_ref not in G:
            G.add_node(parent_ref)
        for child_ref in children:
            if child_ref not in G:
                G.add_node(child_ref)
            G.add_edge(parent_ref, child_ref)

    return G


def analyze_dependency_graph(G):
    """Analyze the dependency graph for risk metrics."""
    if G is None or len(G.nodes) == 0:
        return {}

    analysis = {
        "total_nodes": G.number_of_nodes(),
        "total_edges": G.number_of_edges(),
        "is_dag": nx.is_directed_acyclic_graph(G),
    }

    # Find most depended-on components (highest in-degree)
    in_degrees = sorted(G.in_degree(), key=lambda x: x[1], reverse=True)
    analysis["most_depended_on"] = [
        {"ref": node, "dependents": deg, **G.nodes[node]}
        for node, deg in in_degrees[:10] if deg > 0
    ]

    # Find root nodes (no incoming edges - likely the application itself)
    roots = [n for n, d in G.in_degree() if d == 0]
    analysis["root_components"] = len(roots)

    # Find leaf nodes (no outgoing edges - no dependencies)
    leaves = [n for n, d in G.out_degree() if d == 0]
    analysis["leaf_components"] = len(leaves)

    # Calculate longest dependency chain
    if analysis["is_dag"] and len(G.nodes) > 0:
        try:
            longest_path = nx.dag_longest_path(G)
            analysis["deepest_chain_length"] = len(longest_path)
            analysis["deepest_chain"] = longest_path
        except nx.NetworkXError:
            analysis["deepest_chain_length"] = 0

    # Identify vulnerable components with high in-degree (blast radius)
    high_risk_hubs = []
    for node, deg in in_degrees:
        node_data = G.nodes.get(node, {})
        if node_data.get("max_cvss", 0) >= SEVERITY_THRESHOLDS["HIGH"] and deg > 0:
            high_risk_hubs.append({
                "ref": node,
                "dependents": deg,
                "max_cvss": node_data.get("max_cvss", 0),
                "risk_level": node_data.get("risk_level", "UNKNOWN"),
            })
    analysis["high_risk_hubs"] = high_risk_hubs

    # Betweenness centrality for bottleneck identification
    if len(G.nodes) > 1:
        centrality = nx.betweenness_centrality(G)
        top_central = sorted(centrality.items(), key=lambda x: x[1], reverse=True)[:5]
        analysis["bottleneck_components"] = [
            {"ref": node, "centrality": round(cent, 4)} for node, cent in top_central if cent > 0
        ]

    return analysis


def check_license_compliance(components):
    """Check for potentially problematic licenses in SBOM components."""
    copyleft_licenses = {
        "GPL-2.0", "GPL-2.0-only", "GPL-2.0-or-later",
        "GPL-3.0", "GPL-3.0-only", "GPL-3.0-or-later",
        "AGPL-3.0", "AGPL-3.0-only", "AGPL-3.0-or-later",
        "LGPL-2.1", "LGPL-2.1-only", "LGPL-2.1-or-later",
        "LGPL-3.0", "LGPL-3.0-only", "LGPL-3.0-or-later",
        "MPL-2.0", "EUPL-1.2", "CPAL-1.0", "OSL-3.0",
    }

    findings = {
        "copyleft_components": [],
        "unknown_license_components": [],
        "license_distribution": defaultdict(int),
    }

    for comp in components:
        if not comp.licenses or comp.licenses == ["NOASSERTION"]:
            findings["unknown_license_components"].append(
                {"name": comp.name, "version": comp.version}
            )
        for lic in comp.licenses:
            findings["license_distribution"][lic] += 1
            if lic in copyleft_licenses:
                findings["copyleft_components"].append({
                    "name": comp.name,
                    "version": comp.version,
                    "license": lic,
                })

    findings["license_distribution"] = dict(findings["license_distribution"])
    return findings


def generate_report(components, dependencies, graph_analysis, license_info,
                    sbom_path, sbom_format, output_path=None):
    """Generate a comprehensive vulnerability analysis report."""
    # Aggregate statistics
    vuln_components = [c for c in components if c.cves]
    total_cves = sum(len(c.cves) for c in components)
    severity_counts = defaultdict(lambda: {"components": 0, "cves": 0})

    for comp in components:
        if comp.risk_level != "NONE":
            severity_counts[comp.risk_level]["components"] += 1
            severity_counts[comp.risk_level]["cves"] += len(comp.cves)

    report_lines = []
    report_lines.append("=" * 60)
    report_lines.append("SBOM VULNERABILITY ANALYSIS REPORT")
    report_lines.append("=" * 60)
    report_lines.append(f"SBOM File:          {sbom_path}")
    report_lines.append(f"Format:             {sbom_format}")
    report_lines.append(f"Analysis Date:      {datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S UTC')}")
    report_lines.append(f"Total Components:   {len(components)}")

    direct_deps = len(dependencies)
    transitive = len(components) - direct_deps if direct_deps < len(components) else 0
    report_lines.append(f"Dependencies:       {len(dependencies)} direct, ~{transitive} transitive")
    report_lines.append("")

    report_lines.append("VULNERABILITY SUMMARY")
    report_lines.append("-" * 40)
    for level in ["CRITICAL", "HIGH", "MEDIUM", "LOW"]:
        counts = severity_counts.get(level, {"components": 0, "cves": 0})
        report_lines.append(
            f"  {level:10s}: {counts['components']:3d} components / {counts['cves']:3d} CVEs"
        )
    report_lines.append(f"  {'TOTAL':10s}: {len(vuln_components):3d} components / {total_cves:3d} CVEs")
    report_lines.append("")

    # Critical and high findings detail
    critical_high = sorted(
        [c for c in components if c.risk_level in ("CRITICAL", "HIGH")],
        key=lambda c: c.max_cvss, reverse=True
    )

    if critical_high:
        report_lines.append("CRITICAL & HIGH FINDINGS")
        report_lines.append("-" * 40)
        for i, comp in enumerate(critical_high[:20], 1):
            report_lines.append(f"\n  {i}. {comp.name}@{comp.version} [{comp.risk_level}]")
            for cve in sorted(comp.cves, key=lambda c: c["cvss_score"], reverse=True)[:5]:
                kev_flag = " [CISA KEV]" if cve.get("is_kev") else ""
                report_lines.append(
                    f"     {cve['cve_id']} (CVSS {cve['cvss_score']:.1f}){kev_flag}"
                )
                if cve["description"]:
                    desc_short = cve["description"][:120]
                    report_lines.append(f"       {desc_short}...")

    # Dependency graph analysis
    if graph_analysis:
        report_lines.append("")
        report_lines.append("DEPENDENCY GRAPH ANALYSIS")
        report_lines.append("-" * 40)
        report_lines.append(f"  Nodes: {graph_analysis.get('total_nodes', 0)}")
        report_lines.append(f"  Edges: {graph_analysis.get('total_edges', 0)}")
        report_lines.append(f"  DAG: {graph_analysis.get('is_dag', 'N/A')}")
        chain_len = graph_analysis.get("deepest_chain_length", 0)
        if chain_len:
            report_lines.append(f"  Deepest dependency chain: {chain_len} levels")

        hubs = graph_analysis.get("high_risk_hubs", [])
        if hubs:
            report_lines.append(f"\n  HIGH-RISK HUBS (vulnerable + many dependents):")
            for hub in hubs[:5]:
                report_lines.append(
                    f"    {hub['ref']}: {hub['dependents']} dependents, "
                    f"CVSS {hub['max_cvss']:.1f} [{hub['risk_level']}]"
                )

    # License compliance
    if license_info:
        report_lines.append("")
        report_lines.append("LICENSE COMPLIANCE")
        report_lines.append("-" * 40)
        copyleft = license_info.get("copyleft_components", [])
        unknown = license_info.get("unknown_license_components", [])
        report_lines.append(f"  Copyleft licenses found: {len(copyleft)}")
        for cl in copyleft[:10]:
            report_lines.append(f"    {cl['name']}@{cl['version']}: {cl['license']}")
        report_lines.append(f"  Unknown/missing licenses: {len(unknown)}")

    report_text = "\n".join(report_lines)
    print(f"\n{report_text}")

    # Build JSON result
    result = {
        "sbom_file": sbom_path,
        "sbom_format": sbom_format,
        "analysis_timestamp": datetime.utcnow().isoformat(),
        "summary": {
            "total_components": len(components),
            "vulnerable_components": len(vuln_components),
            "total_cves": total_cves,
            "severity_counts": dict(severity_counts),
        },
        "components": [c.to_dict() for c in components],
        "dependency_graph": graph_analysis or {},
        "license_compliance": license_info or {},
    }

    if output_path:
        with open(output_path, "w", encoding="utf-8") as f:
            json.dump(result, f, indent=2, default=str)
        print(f"\n[OK] Full report saved to {output_path}")

    return result


def analyze_sbom(sbom_path, api_key=None, output_path=None, skip_nvd=False):
    """Full SBOM analysis pipeline: parse, correlate CVEs, graph analysis, report."""
    (components, dependencies), sbom_format = parse_sbom(sbom_path)
    print(f"  Components: {len(components)}")
    print(f"  Dependency entries: {len(dependencies)}")

    # Correlate with NVD
    components = correlate_cves(components, api_key=api_key, skip_nvd=skip_nvd)

    # Build and analyze dependency graph
    G = build_dependency_graph(components, dependencies)
    graph_analysis = analyze_dependency_graph(G)

    # License compliance check
    license_info = check_license_compliance(components)

    # Generate report
    result = generate_report(
        components, dependencies, graph_analysis, license_info,
        sbom_path, sbom_format, output_path
    )

    return result


def compare_sboms(sbom_path_old, sbom_path_new, api_key=None):
    """Compare two SBOMs to identify added, removed, and changed components."""
    (comps_old, _), _ = parse_sbom(sbom_path_old)
    (comps_new, _), _ = parse_sbom(sbom_path_new)

    old_set = {f"{c.name}@{c.version}" for c in comps_old}
    new_set = {f"{c.name}@{c.version}" for c in comps_new}
    old_names = {c.name for c in comps_old}
    new_names = {c.name for c in comps_new}

    added = new_set - old_set
    removed = old_set - new_set

    # Version changes: same name, different version
    old_versions = {c.name: c.version for c in comps_old}
    new_versions = {c.name: c.version for c in comps_new}
    version_changes = []
    for name in old_names & new_names:
        if old_versions[name] != new_versions[name]:
            version_changes.append({
                "name": name,
                "old_version": old_versions[name],
                "new_version": new_versions[name],
            })

    print(f"\n{'='*60}")
    print(f"SBOM DIFF REPORT")
    print(f"{'='*60}")
    print(f"Old: {sbom_path_old} ({len(comps_old)} components)")
    print(f"New: {sbom_path_new} ({len(comps_new)} components)")
    print(f"\nAdded:   {len(added)} components")
    for a in sorted(added):
        print(f"  + {a}")
    print(f"\nRemoved: {len(removed)} components")
    for r in sorted(removed):
        print(f"  - {r}")
    print(f"\nVersion Changes: {len(version_changes)}")
    for vc in version_changes:
        print(f"  ~ {vc['name']}: {vc['old_version']} -> {vc['new_version']}")

    return {"added": sorted(added), "removed": sorted(removed),
            "version_changes": version_changes}


def main():
    parser = argparse.ArgumentParser(
        description="SBOM Supply Chain Vulnerability Analysis Agent"
    )
    subparsers = parser.add_subparsers(dest="command", help="Available commands")

    # Analyze SBOM
    analyze_parser = subparsers.add_parser("analyze", help="Analyze an SBOM for vulnerabilities")
    analyze_parser.add_argument("sbom_path", help="Path to SBOM file (CycloneDX or SPDX JSON)")
    analyze_parser.add_argument("--api-key", help="NVD API key for higher rate limits")
    analyze_parser.add_argument("--output", "-o", help="Save full report to JSON file")
    analyze_parser.add_argument("--skip-nvd", action="store_true",
                                help="Skip NVD API queries (offline mode)")

    # Compare two SBOMs
    diff_parser = subparsers.add_parser("diff", help="Compare two SBOMs for changes")
    diff_parser.add_argument("old_sbom", help="Path to old/baseline SBOM")
    diff_parser.add_argument("new_sbom", help="Path to new/current SBOM")
    diff_parser.add_argument("--api-key", help="NVD API key")

    # Parse only (no NVD queries)
    parse_parser = subparsers.add_parser("parse", help="Parse SBOM and list components")
    parse_parser.add_argument("sbom_path", help="Path to SBOM file")
    parse_parser.add_argument("--output", "-o", help="Save component list to JSON")

    # License check
    license_parser = subparsers.add_parser("licenses", help="Check license compliance")
    license_parser.add_argument("sbom_path", help="Path to SBOM file")

    args = parser.parse_args()

    if args.command == "analyze":
        if not HAS_REQUESTS:
            print("[ERROR] requests library required. Install: pip install requests",
                  file=sys.stderr)
            sys.exit(1)
        api_key = args.api_key or os.environ.get("NVD_API_KEY")
        analyze_sbom(args.sbom_path, api_key=api_key, output_path=args.output,
                     skip_nvd=args.skip_nvd)

    elif args.command == "diff":
        compare_sboms(args.old_sbom, args.new_sbom, api_key=args.api_key)

    elif args.command == "parse":
        (components, dependencies), fmt = parse_sbom(args.sbom_path)
        print(f"\n  Total components: {len(components)}")
        for comp in components:
            print(f"    {comp.name}@{comp.version} [{comp.component_type}] "
                  f"licenses={comp.licenses}")
        if args.output:
            data = {"format": fmt, "component_count": len(components),
                    "components": [c.to_dict() for c in components]}
            with open(args.output, "w") as f:
                json.dump(data, f, indent=2)
            print(f"\n[OK] Component list saved to {args.output}")

    elif args.command == "licenses":
        (components, _), _ = parse_sbom(args.sbom_path)
        info = check_license_compliance(components)
        print(f"\nLicense Distribution:")
        for lic, count in sorted(info["license_distribution"].items(),
                                  key=lambda x: x[1], reverse=True):
            print(f"  {lic}: {count}")
        if info["copyleft_components"]:
            print(f"\nCopyleft Components ({len(info['copyleft_components'])}):")
            for cl in info["copyleft_components"]:
                print(f"  {cl['name']}@{cl['version']}: {cl['license']}")
        if info["unknown_license_components"]:
            print(f"\nUnknown License ({len(info['unknown_license_components'])}):")
            for ul in info["unknown_license_components"]:
                print(f"  {ul['name']}@{ul['version']}")

    else:
        parser.print_help()


if __name__ == "__main__":
    main()