#!/usr/bin/env python3
"""Ingest a repo's lockfile into the State Hub SBOM store.

Usage:
    python ingest_sbom.py --repo <slug> [--lockfile <path>] [--api-base <url>]

Auto-detects lockfile type:
  uv.lock            → Python ecosystem
  requirements.txt   → Python ecosystem (basic)
  package-lock.json  → Node ecosystem
  yarn.lock          → Node ecosystem
  Cargo.lock         → Rust ecosystem
"""
from __future__ import annotations

import argparse
import json
import os
import re
import sys
import urllib.error
import urllib.request
from pathlib import Path

API_BASE = os.environ.get("API_BASE", "http://127.0.0.1:8000").rstrip("/")


# ---------------------------------------------------------------------------
# Lockfile parsers
# ---------------------------------------------------------------------------

def _parse_uv_lock(path: Path) -> list[dict]:
    """Parse uv.lock TOML format (v0.1 — [[package]] blocks)."""
    entries = []
    current: dict | None = None

    for line in path.read_text().splitlines():
        stripped = line.strip()
        if stripped == "[[package]]":
            if current:
                entries.append(current)
            current = {}
        elif current is not None:
            if stripped.startswith("name = "):
                current["package_name"] = stripped.split("=", 1)[1].strip().strip('"')
            elif stripped.startswith("version = "):
                current["package_version"] = stripped.split("=", 1)[1].strip().strip('"')

    if current:
        entries.append(current)

    return [
        {
            "package_name": e.get("package_name", "unknown"),
            "package_version": e.get("package_version"),
            "ecosystem": "python",
            "license_spdx": None,
            "is_direct": False,  # uv.lock doesn't distinguish; treat all as transitive
            "is_dev": False,
        }
        for e in entries
        if "package_name" in e
    ]


def _parse_requirements_txt(path: Path) -> list[dict]:
    """Parse requirements.txt (basic — name==version lines)."""
    entries = []
    for line in path.read_text().splitlines():
        line = line.strip()
        if not line or line.startswith("#") or line.startswith("-"):
            continue
        # Handle: pkg==1.2.3, pkg>=1.2, pkg
        m = re.match(r"^([A-Za-z0-9_.\-]+)(?:[>=<!~^]+([^\s;]+))?", line)
        if m:
            entries.append({
                "package_name": m.group(1),
                "package_version": m.group(2),
                "ecosystem": "python",
                "license_spdx": None,
                "is_direct": True,
                "is_dev": False,
            })
    return entries


def _parse_package_lock_json(path: Path) -> list[dict]:
    """Parse package-lock.json (npm) — packages dict."""
    try:
        data = json.loads(path.read_text())
    except json.JSONDecodeError as e:
        print(f"Warning: cannot parse {path}: {e}", file=sys.stderr)
        return []

    packages = data.get("packages", {})
    entries = []
    for pkg_path, info in packages.items():
        if not pkg_path:  # root package
            continue
        name = info.get("name") or pkg_path.split("node_modules/")[-1]
        entries.append({
            "package_name": name,
            "package_version": info.get("version"),
            "ecosystem": "node",
            "license_spdx": info.get("license"),
            "is_direct": not info.get("indirect", False),
            "is_dev": bool(info.get("dev", False)),
        })
    return entries


def _parse_yarn_lock(path: Path) -> list[dict]:
    """Parse yarn.lock — basic name extraction."""
    entries = []
    current_names: list[str] = []
    current_version: str | None = None

    for line in path.read_text().splitlines():
        stripped = line.strip()
        if not stripped or stripped.startswith("#"):
            continue
        if not line.startswith(" ") and stripped.endswith(":"):
            # New package block header: "name@version::" or "\"name@version\":"
            # May list multiple versions: "name@^1.0, name@~1.0:"
            current_names = []
            current_version = None
            for part in stripped.rstrip(":").split(","):
                m = re.match(r'"?([^@"]+)@', part.strip())
                if m:
                    current_names.append(m.group(1).strip())
        elif stripped.startswith("version "):
            current_version = stripped.split('"')[1] if '"' in stripped else None
        elif not stripped and current_names and current_version:
            for name in current_names:
                entries.append({
                    "package_name": name,
                    "package_version": current_version,
                    "ecosystem": "node",
                    "license_spdx": None,
                    "is_direct": False,
                    "is_dev": False,
                })
            current_names = []
            current_version = None

    return entries


def _parse_cargo_lock(path: Path) -> list[dict]:
    """Parse Cargo.lock TOML format ([[package]] blocks)."""
    entries = []
    current: dict | None = None

    for line in path.read_text().splitlines():
        stripped = line.strip()
        if stripped == "[[package]]":
            if current:
                entries.append(current)
            current = {}
        elif current is not None:
            if stripped.startswith("name = "):
                current["package_name"] = stripped.split("=", 1)[1].strip().strip('"')
            elif stripped.startswith("version = "):
                current["package_version"] = stripped.split("=", 1)[1].strip().strip('"')

    if current:
        entries.append(current)

    return [
        {
            "package_name": e.get("package_name", "unknown"),
            "package_version": e.get("package_version"),
            "ecosystem": "rust",
            "license_spdx": None,
            "is_direct": False,
            "is_dev": False,
        }
        for e in entries
        if "package_name" in e
    ]


_LOCKFILE_PARSERS = {
    "uv.lock": _parse_uv_lock,
    "requirements.txt": _parse_requirements_txt,
    "package-lock.json": _parse_package_lock_json,
    "yarn.lock": _parse_yarn_lock,
    "Cargo.lock": _parse_cargo_lock,
}


def detect_lockfile(repo_path: Path) -> tuple[Path, str] | None:
    """Return (lockfile_path, ecosystem) for the first recognised lockfile found."""
    for name in _LOCKFILE_PARSERS:
        candidate = repo_path / name
        if candidate.exists():
            return candidate, name
    return None


def parse_lockfile(lockfile_path: Path) -> list[dict]:
    filename = lockfile_path.name
    parser = _LOCKFILE_PARSERS.get(filename)
    if parser is None:
        print(f"Error: unsupported lockfile type '{filename}'", file=sys.stderr)
        sys.exit(1)
    return parser(lockfile_path)


# ---------------------------------------------------------------------------
# API submission
# ---------------------------------------------------------------------------

def post_ingest(api_base: str, repo_slug: str, entries: list[dict]) -> dict:
    payload = json.dumps({"repo_slug": repo_slug, "entries": entries}).encode()
    req = urllib.request.Request(
        f"{api_base}/sbom/ingest/",
        data=payload,
        headers={"Content-Type": "application/json"},
        method="POST",
    )
    try:
        with urllib.request.urlopen(req, timeout=30) as resp:
            return json.loads(resp.read())
    except urllib.error.HTTPError as e:
        body = e.read().decode(errors="replace")
        print(f"HTTP {e.code} from API: {body}", file=sys.stderr)
        sys.exit(1)
    except urllib.error.URLError as e:
        print(f"API unreachable: {e}", file=sys.stderr)
        sys.exit(1)


# ---------------------------------------------------------------------------
# Entry point
# ---------------------------------------------------------------------------

def main() -> None:
    parser = argparse.ArgumentParser(description="Ingest a lockfile into the State Hub SBOM store.")
    parser.add_argument("--repo", required=True, help="Managed-repo slug (e.g. 'the-custodian')")
    parser.add_argument("--lockfile", help="Path to lockfile (auto-detected if omitted)")
    parser.add_argument("--repo-path", default=".", help="Repo root for auto-detection (default: cwd)")
    parser.add_argument("--api-base", default=API_BASE, help="State Hub API base URL")
    parser.add_argument("--dry-run", action="store_true", help="Parse only — do not submit")
    args = parser.parse_args()

    if args.lockfile:
        lockfile_path = Path(args.lockfile).resolve()
    else:
        found = detect_lockfile(Path(args.repo_path).resolve())
        if not found:
            print(
                f"No recognised lockfile found in '{args.repo_path}'. "
                "Supported: " + ", ".join(_LOCKFILE_PARSERS),
                file=sys.stderr,
            )
            sys.exit(1)
        lockfile_path, _ = found
        print(f"Auto-detected: {lockfile_path}")

    entries = parse_lockfile(lockfile_path)
    print(f"Parsed {len(entries)} packages from {lockfile_path.name}")

    if args.dry_run:
        print(json.dumps(entries[:5], indent=2))
        if len(entries) > 5:
            print(f"  … and {len(entries) - 5} more")
        return

    result = post_ingest(args.api_base, args.repo, entries)
    print(f"Ingested {result.get('ingested', '?')} entries for repo '{args.repo}'")
    print(f"Snapshot at: {result.get('snapshot_at', '?')}")


if __name__ == "__main__":
    main()