"""Deterministic, source-grounded ATS criterion extraction — NO external LLM.

This is the PRIMARY extraction path for V1. It turns a cleaned job description
into a full criterion inventory (schema below) using only local, deterministic
signals: the curated gazetteers + cue-word requirement classification in
`jd_analyzer.analyze_jd` (llm=None), plus section detection, years/title/cert
patterns, importance scoring, verbatim traceability, and longest-first dedup.

An external LLM is NEVER required for extraction, ranking, evidence matching,
coverage, or scoring — it is optional wording polish only (see resume_rewrite).
"""
from __future__ import annotations

import re
from typing import Dict, List

from .jd_analyzer import analyze_jd, _BUZZWORDS, _TOOLS
from .jd_preprocess import preprocess_jd

# Generic fragments never promoted on their own when a specific phrase exists.
_GENERIC_ALONE = {
    "work", "problem", "performance", "manage", "communicate", "process",
    "team", "teams", "skills", "experience", "ability", "knowledge", "understanding",
    "responsibilities", "requirements", "role", "job", "candidate", "years",
    "solutions", "environment", "priorities", "impact", "results", "data",
    "products", "product", "business", "customers", "users", "stakeholders",
    "execution", "delivery", "quality", "success", "goals", "partners",
    # title/seniority modifiers + generic action verbs — low standalone ATS value
    "staff", "senior", "lead", "principal", "junior", "associate", "director",
    "collaborate", "collaboration", "influence", "mentor", "communication",
    "competitors", "vision", "strategy", "systems", "engineering", "design",
    "legal", "autonomy", "acumen", "empathy", "passion", "trust", "joy",
    "growth", "services", "programs", "decisions", "network", "initiatives",
    "outcomes", "field", "programs", "complex programs",
}

# Importance signal weights (sum 1.0) — Step "Keyword importance".
_W = {
    "mandatory_wording": 0.25, "required_section": 0.20, "centrality": 0.15,
    "title_summary": 0.10, "repetition": 0.10, "specificity": 0.10,
    "recruiter_filter": 0.05, "outcome": 0.05,
}

_YEARS_RE = re.compile(r"\b(\d{1,2})\s*\+?\s*years?\b", re.I)
_MUST_CUES = ("required", "must have", "must-have", "minimum", "essential",
              "mandatory", "at least", "you must", "strong")
_RESP_SECTIONS = ("responsibilit", "requirement", "qualification", "what you")
_OUTCOME_HINTS = ("revenue", "conversion", "growth", "retention", "roi",
                  "impact", "kpi", "metric", "margin", "adoption", "engagement")


# Locally-stored professional synonym map: JD concept -> résumé-side surface forms
# a candidate might genuinely use for the SAME capability. Powers curated-synonym
# evidence matching AND deterministic terminology alignment (swap weaker->exact).
_SYNONYMS = {
    "stakeholder management": ["stakeholder communication", "stakeholder comms",
                               "stakeholder engagement", "managing stakeholders"],
    "roadmap prioritization": ["roadmap planning", "product roadmap planning",
                               "prioritization", "roadmapping"],
    "product experimentation": ["experiments", "experimentation", "a/b testing",
                                "ab testing", "a/b experimentation"],
    "cross-functional collaboration": ["cross-functional teams", "cross functional",
                                       "cross-functional", "worked with teams"],
    "product analytics": ["analytics", "product data", "data analysis"],
    "go-to-market": ["gtm", "launch", "go to market"],
    "product strategy": ["product vision", "strategy and vision"],
    "conversion rate optimization": ["cro", "conversion optimization", "funnel optimization"],
    "demand generation": ["demand gen", "lead generation", "lead gen"],
    "data visualization": ["dashboards", "dashboarding", "visualization"],
    "statistical modeling": ["statistics", "statistical analysis", "modeling"],
    "distributed systems": ["distributed backends", "scalable systems"],
    "inventory management": ["stock management", "inventory control"],
    "process optimization": ["process improvement", "operational efficiency"],
    "risk management": ["risk mitigation", "risk assessment"],
    "campaign management": ["campaigns", "campaign execution"],
}
# reverse index: any surface form -> canonical concept (for fast enrichment)
_SYN_REVERSE = {}
for _canon, _forms in _SYNONYMS.items():
    for _f in _forms:
        _SYN_REVERSE.setdefault(_f.lower(), set()).add(_canon)


def _synonyms_for(concept: str) -> list:
    c = (concept or "").lower().strip()
    out = list(_SYNONYMS.get(c, []))
    # also include forms whose canonical shares this concept's head tokens
    for canon, forms in _SYNONYMS.items():
        if canon != c and (c in canon or canon in c):
            out += forms
    return list(dict.fromkeys(out))[:6]


def _band(score: float) -> str:
    return ("critical" if score >= 0.7 else "high" if score >= 0.5
            else "medium" if score >= 0.3 else "low")


def _sentences(text: str) -> List[str]:
    parts = re.split(r"(?<=[.;:!?])\s+|\n+", text or "")
    return [p.strip() for p in parts if p and p.strip()]


def _section_of(sentence: str, sections: Dict[str, str]) -> str:
    for name, body in (sections or {}).items():
        if sentence and sentence[:40] in body:
            return name
    return "body"


def _is_required(source_sentence: str, section: str) -> bool:
    low = (source_sentence or "").lower()
    if any(k in section for k in ("requirement", "minimum", "must", "qualification")):
        return True
    return any(c in low for c in _MUST_CUES)


def _importance(term: str, jd_low: str, source_sentence: str, section: str,
                category: str, is_required: bool) -> float:
    s = source_sentence.lower()
    score = 0.0
    if is_required or any(c in s for c in _MUST_CUES):
        score += _W["mandatory_wording"]
    if any(k in section for k in _RESP_SECTIONS):
        score += _W["required_section"]
    # centrality: multi-word skill/responsibility/tool phrase
    if category in ("responsibility", "hard_skill", "core_skill", "tool") and " " in term:
        score += _W["centrality"]
    # title/summary presence
    if term in jd_low[:400]:
        score += _W["title_summary"]
    # repetition across the JD
    if len(re.findall(r"(?<![a-z0-9])" + re.escape(term) + r"(?![a-z0-9])", jd_low)) >= 2:
        score += _W["repetition"]
    # role specificity: not a generic single token
    if " " in term or category in ("tool", "domain", "certification"):
        score += _W["specificity"]
    # recruiter-filter usefulness: tools/domains/certs/hard skills
    if category in ("tool", "domain", "certification", "hard_skill", "core_skill"):
        score += _W["recruiter_filter"]
    if any(h in s for h in _OUTCOME_HINTS):
        score += _W["outcome"]
    return round(min(score, 1.0), 3)


# Cues that introduce a list of skills/responsibilities in a requirement sentence.
_LIST_CUES = re.compile(
    r"\b(?:own|owns|owning|drive|drives|driving|build|builds|building|run|runs|"
    r"running|manage|manages|managing|lead|leads|leading|define|defines|defining|"
    r"develop|develops|developing|deliver|delivers|conduct|design|designs|"
    r"experience (?:with|in)|proficiency (?:with|in)|expertise (?:with|in)|"
    r"skills? (?:with|in)|knowledge of|strong|hands-on|familiarity with)\b",
    re.I)
_LEAD_TRIM = re.compile(
    r"^(?:the|a|an|and|our|your|their|strong|deep|solid|excellent|proven|"
    r"cross[- ]|end[- ]to[- ]end|both|other|new|complex|scalable)\s+", re.I)
_STOP_EDGE = {"and", "or", "the", "a", "an", "to", "of", "for", "with", "in",
              "on", "across", "using", "including", "etc", "such", "as", "e.g",
              "i.e", "you", "we", "they", "our", "your", "their", "will", "must"}


def _list_phrases(sent: str) -> List[str]:
    """Extract multi-word professional phrases from a requirement/responsibility
    sentence: the comma/'and'-separated items following a list cue (e.g. 'own
    product strategy, roadmap prioritization, and stakeholder management')."""
    out: List[str] = []
    m = _LIST_CUES.search(sent)
    tail = sent[m.end():] if m else sent
    # split into candidate items
    for raw in re.split(r"\s*(?:,|;|\band\b|\bor\b|\bacross\b|\bvia\b|\bthrough\b|/|\||•)\s*", tail):
        item = _LEAD_TRIM.sub("", raw.strip().strip(".:—-()").strip()).strip()
        item = re.sub(r"\s+", " ", item)
        toks = item.split()
        # trim generic edge words
        while toks and toks[0].lower() in _STOP_EDGE:
            toks = toks[1:]
        while toks and toks[-1].lower() in _STOP_EDGE:
            toks = toks[:-1]
        if not (1 <= len(toks) <= 4):
            continue
        phrase = " ".join(toks)
        pl = phrase.lower()
        if pl in _GENERIC_ALONE or pl in _BUZZWORDS:
            continue
        # must contain at least one content token not in the generic/stop sets and
        # be multi-word OR a known-ish single technical token (kept multi-word only)
        content = [t for t in toks if t.lower() not in _STOP_EDGE
                   and t.lower() not in _GENERIC_ALONE]
        if len(toks) >= 2 and content:
            out.append(phrase)
        elif len(toks) == 1:
            # accept a single-word item only if it's a known tool or an acronym
            # (SEO, SQL, AWS, Docker) — not a generic noun.
            t = toks[0]
            if t.lower() in _TOOLS or re.fullmatch(r"[A-Z][A-Za-z0-9]{1,5}", t) \
                    and t.lower() not in _GENERIC_ALONE:
                out.append(t)
    return out


def extract_criteria(clean_jd: str, sections: Dict[str, str] | None = None) -> List[dict]:
    """Return the full deterministic criterion inventory for a CLEANED JD.

    Each item: exact_phrase, normalized_concept, source_sentence, source_section,
    source_start, source_end, requirement_type, category, importance_score.
    """
    jd = clean_jd or ""
    jd_low = jd.lower()
    req = analyze_jd(jd, llm=None)          # deterministic gazetteer engine, NO LLM
    sents = _sentences(jd)

    def _src(term: str) -> tuple:
        m = re.search(r"(?<![a-z0-9])" + re.escape(term.lower()) + r"(?![a-z0-9])", jd_low)
        if not m:
            return None
        start = m.start()
        # containing sentence
        sent = next((s for s in sents if term.lower() in s.lower()), jd[max(0, start-40):start+80])
        return start, start + len(term), sent

    out: List[dict] = []
    seen = set()
    for r in req.all_requirements():
        term = (r.term or "").strip()
        tl = term.lower()
        if not term or tl in seen:
            continue
        if tl in _GENERIC_ALONE or tl in _BUZZWORDS:
            continue
        sr0 = _src(term)
        if sr0 is None:               # traceability: must be verbatim in the JD
            continue
        start, end, sent = sr0
        section = _section_of(sent, sections or {})
        is_req = (r.importance == "must_have") or _is_required(sent, section)
        if r.category == "seniority":     # title modifiers, not ATS keywords
            continue
        cat = r.category if r.category in (
            "tool", "domain", "responsibility", "soft_skill", "hard_skill",
            "core_skill", "certification", "education") else "hard_skill"
        iscore = _importance(tl, jd_low, sent, section, cat, is_req)
        out.append({
            "exact_phrase": term,
            "normalized_concept": tl,
            "source_sentence": sent[:200],
            "source_text": sent[:200],           # scorer/validator compatibility
            "source_section": section,
            "source_start": start,
            "source_end": end,
            "requirement_type": "required" if is_req else "preferred",
            "category": cat,
            "importance_score": iscore,
            "importance": _band(iscore),          # critical|high|medium|low
            "confidence": iscore,
            "requires_resume_evidence": True,
            "semantic_variants": (list(getattr(r, "aliases", []) or [])
                                  + _synonyms_for(tl))[:6],
        })
        seen.add(tl)

    # multi-word professional phrases from requirement/responsibility sentences
    # (comma-lists after a cue) — captures domain phrases the gazetteers miss
    # (e.g. distributed systems, demand generation, inventory management).
    for sent in sents:
        section = _section_of(sent, sections or {})
        if not (any(k in section for k in _RESP_SECTIONS) or _LIST_CUES.search(sent)):
            continue
        is_req = _is_required(sent, section)
        for phrase in _list_phrases(sent):
            pl = phrase.lower()
            if pl in seen:
                continue
            sr = _src(phrase)
            if sr is None:
                continue
            start, end, s2 = sr
            cat = "responsibility" if " " in phrase and any(
                v in sent.lower() for v in ("own", "drive", "lead", "manage", "run")) else "hard_skill"
            iscore = _importance(pl, jd_low, sent, section, cat, is_req)
            out.append({
                "exact_phrase": phrase, "normalized_concept": pl,
                "source_sentence": sent[:200], "source_text": sent[:200],
                "source_section": section, "source_start": start, "source_end": end,
                "requirement_type": "required" if is_req else "preferred",
                "category": cat, "importance_score": iscore, "importance": _band(iscore),
                "confidence": iscore, "requires_resume_evidence": True,
                "semantic_variants": _synonyms_for(pl),
            })
            seen.add(pl)

    # explicit years-of-experience requirement (a distinct criterion)
    ym = _YEARS_RE.search(jd)
    if ym and not any("year" in o["normalized_concept"] for o in out):
        start = ym.start()
        sent = next((s for s in sents if ym.group(0).lower() in s.lower()), ym.group(0))
        out.append({
            "exact_phrase": ym.group(0), "normalized_concept": ym.group(0).lower(),
            "source_sentence": sent[:200], "source_text": sent[:200],
            "source_section": _section_of(sent, sections or {}),
            "source_start": start, "source_end": ym.end(),
            "requirement_type": "required", "category": "experience_signal",
            "importance_score": 0.6, "importance": "high", "confidence": 0.6,
            "requires_resume_evidence": True, "semantic_variants": [],
        })

    # longest-phrase-first dedup: drop a shorter phrase fully contained in a longer
    out.sort(key=lambda o: len(o["exact_phrase"]), reverse=True)
    kept: List[dict] = []
    for o in out:
        c = o["normalized_concept"]
        if any(c != k["normalized_concept"] and c in k["normalized_concept"].split()
               and len(c.split()) == 1 for k in kept):
            continue    # single generic token already covered by a longer phrase
        kept.append(o)
    # stable order by importance desc
    kept.sort(key=lambda o: o["importance_score"], reverse=True)
    return kept


def extract_from_raw(raw_jd: str, company: str = "") -> tuple:
    """Preprocess (untrusted) + deterministic extraction. Returns
    (PreprocessResult, criteria_list). criteria is [] when JD isolation fails."""
    pre = preprocess_jd(raw_jd, company=company)
    if not pre.ok:
        return pre, []
    return pre, extract_criteria(pre.clean_text, pre.sections)


if __name__ == "__main__":  # ponytail: runnable self-check
    JD = """About the Role
We seek a Product Manager to own the roadmap and drive product-led growth.

Responsibilities
- You will own product strategy, roadmap prioritization, and stakeholder management.
- Run A/B testing and product analytics to improve activation and conversion.

Minimum requirements
- 5+ years of product management experience.
- Strong SQL and experience with payments and fintech.
"""
    crit = extract_criteria(JD, None)
    concepts = {c["normalized_concept"] for c in crit}
    assert "product management" in concepts or "product manager" in concepts
    assert any("sql" == c["normalized_concept"] for c in crit)
    assert any(c["requirement_type"] == "required" for c in crit)
    # generic bare tokens excluded
    assert "work" not in concepts and "team" not in concepts
    # every phrase is traceable + has the full schema
    for c in crit:
        assert JD.lower().find(c["normalized_concept"]) >= 0
        assert set(c) >= {"exact_phrase", "requirement_type", "category",
                          "importance_score", "source_start"}
    print(f"deterministic_extract self-check PASSED — {len(crit)} criteria")
    for c in crit[:8]:
        print(f"  [{c['requirement_type']:<9} {c['importance_score']:.2f}] "
              f"{c['exact_phrase']} ({c['category']})")