#!/usr/bin/env python3
"""OpenAlex + Crossref — Phase 0 identity/ISBN resolution (free, no key).

Usage:
  oa.py "Exact EN Title"               # OpenAlex work search (names, year, DOI, ISBN via locations)
  oa.py --crossref "Title words"       # Crossref bibliographic search (author, ISBN, publisher)
  oa.py --author "Last, First"         # OpenAlex author entity (ID, works count, cited)
  oa.py both "Title"                   # both APIs in one go

OpenAlex: https://api.openalex.org/works?search=...  (no key, 10 req/s pool)
Crossref: https://api.crossref.org/works?query.bibliographic=... (polite pool ok)

Notes:
- OpenAlex 'display_name' + authorships[].author.display_name = full EN names
  (better than OL for modern academic books; OL still primary for pre-1990).
- Crossref ISBN list = direct EN ISBN candidates (13-digit, Routledge/Springer/Karnac).
- DNS here is flaky for python sockets in some contexts; use urllib (works).
"""
import json, sys, time, urllib.parse, urllib.request

UA = "jung-ru-editions-research/1.0 (mailto:dmitry@kokorin.org)"

def get(url):
    req = urllib.request.Request(url, headers={"User-Agent": UA})
    with urllib.request.urlopen(req, timeout=45) as r:
        return json.loads(r.read().decode("utf-8", "replace"))

def openalex_works(q, n=5):
    url = "https://api.openalex.org/works?search=%s&per-page=%d" % (urllib.parse.quote(q), n)
    d = get(url)
    out = []
    for w in d.get("results", []):
        auths = [a["author"]["display_name"] for a in w.get("authorships", [])]
        isbns = set()
        for l in w.get("locations", []):
            if l.get("pdf") or l.get("landing_page_url"):
                pass
            # ISBNs often in biblio
        bib = w.get("biblio") or {}
        ids = w.get("ids", {})
        doi = ids.get("doi")
        out.append({
            "title": w.get("display_name"),
            "authors": auths,
            "year": w.get("publication_year"),
            "doi": doi,
            "publisher": (((w.get("primary_location") or {}).get("source")) or {}).get("display_name"),
            "openalex_id": w.get("id"),
        })
    return out

def crossref(q, n=3):
    url = "https://api.crossref.org/works?query.bibliographic=%s&rows=%d" % (urllib.parse.quote(q), n)
    d = get(url)
    out = []
    for m in d.get("message", {}).get("items", []):
        auths = [("%s %s" % (a.get("given", ""), a.get("family", ""))).strip() for a in m.get("author", [])]
        out.append({
            "title": (m.get("title") or ["?"])[0],
            "authors": auths,
            "isbn": m.get("ISBN") or [],
            "issn": m.get("ISSN") or [],
            "publisher": m.get("publisher"),
            "year": (m.get("issued", {}).get("date-parts") or [[None]])[0][0],
            "doi": m.get("DOI"),
        })
    return out

def openalex_author(q):
    url = "https://api.openalex.org/authors?search=%s&per-page=5" % urllib.parse.quote(q)
    d = get(url)
    out = []
    for a in d.get("results", []):
        out.append({
            "name": a.get("display_name"),
            "id": a.get("id"),
            "works": a.get("works_count"),
            "cited": a.get("cited_by_count"),
        })
    return out

def main():
    if len(sys.argv) < 3:
        print(__doc__); sys.exit(1)
    mode, q = sys.argv[1], " ".join(sys.argv[2:])
    if mode == "both":
        for r in openalex_works(q): print("OA ", r)
        time.sleep(1)
        for r in crossref(q): print("CR ", r)
    elif mode == "--crossref":
        for r in crossref(q): print(r)
    elif mode == "--author":
        for r in openalex_author(q): print(r)
    else:
        for r in openalex_works(q): print(r)

if __name__ == "__main__":
    main()