"""
lib/hiring_intent.py — V6 Hiring Intent Engine

Infers WHY the company is hiring, not just WHAT skills they need.
A hiring manager doesn't think "I want Python" — they think
"I need someone who can own production systems" or "I need a founding engineer."

The intent drives downstream weight adjustments, feature emphasis,
and reasoning quality.

Outputs a HiringIntent dataclass with:
  - philosophy: list of hiring philosophy tags
  - ownership_expectation: how much ownership is expected
  - shipping_culture: scrappy vs methodical
  - depth_requirement: specialist vs generalist
  - scale_requirement: startup vs large scale
  - team_context: founding vs established
  - independence: how independently they expect work
  - mentorship: whether they expect mentoring
  - primary_need: the core thing this hire must deliver
"""
from __future__ import annotations
import re
from dataclasses import dataclass, field
from lib.jd_parser import get_jd, JDUnderstanding


@dataclass
class HiringIntent:
    """Structured inference of WHY the company is hiring."""
    # Hiring philosophy tags (multiple can apply)
    philosophy: list[str] = field(default_factory=list)

    # Primary thing this hire must deliver
    primary_need: str = "general"

    # How much ownership is expected (0.0-1.0)
    ownership_expectation: float = 0.5

    # Shipping culture
    shipping_culture: str = "balanced"  # scrappy, methodical, balanced

    # Depth vs breadth
    depth_requirement: str = "generalist"  # specialist, generalist, t_shaped

    # Scale context
    scale_requirement: str = "mid_scale"  # startup_scale, mid_scale, large_scale

    # Team context
    team_context: str = "established"  # founding, early, growing, established

    # Independence expected (0.0-1.0)
    independence: float = 0.5

    # Whether they expect mentoring juniors
    mentorship: bool = False

    # Raw signals extracted from JD
    raw_signals: dict = field(default_factory=dict)


# ---------------------------------------------------------------------------
# Intent signal detectors
# ---------------------------------------------------------------------------

_PHILOSOPHY_PATTERNS = {
    "startup_builder": [
        r"founding", r"first\s+hire", r"early\s+stage", r"build\s+from\s+scratch",
        r"ship\s+a\s+working", r"scrappy", r"0\s+to\s+1", r"ground\s+up",
    ],
    "hands_on_ic": [
        r"hands\s+on", r"write\s+code", r"coding", r"implement",
        r"no\s+pure\s+research", r"not\s+a\s+research", r"product.engineering",
    ],
    "fast_shipper": [
        r"ship\s+in\s+a\s+week", r"fast", r"quickly", r"rapid",
        r"iterate", r"agile", r"move\s+fast",
    ],
    "research_heavy": [
        r"research", r"paper", r"publication", r"novel", r"state.of.the.art",
        r"cutting.edge", r"advance\s+the\s+field",
    ],
    "platform_engineer": [
        r"platform", r"infrastructure", r"scalable", r"system\s+design",
        r"architecture", r"end.to.end",
    ],
    "specialist_depth": [
        r"deep\s+technical\s+depth", r"expertise\s+in", r"specialist",
        r"deep\s+knowledge", r"domain\s+expert",
    ],
    "team_leader": [
        r"mentor", r"lead", r"senior", r"guide", r"coach",
        r"team\s+of", r"manage\s+engineers",
    ],
    "customer_facing": [
        r"customer", r"user.facing", r"production", r"real\s+users",
        r"live\s+traffic", r"on.call",
    ],
    "scale_focused": [
        r"at\s+scale", r"large.scale", r"millions?\s+of\s+users", r"high\s+throughput",
        r"low\s+latency", r"distributed",
    ],
}

_OWNERSHIP_PATTERNS = {
    "founding": [r"founding", r"first\s+hire", r"build\s+the", r"own\s+the"],
    "senior_ic": [r"senior", r"staff", r"lead", r"own", r"independent"],
    "team_lead": [r"lead\s+a\s+team", r"manage", r"mentor", r"guide"],
    "contributor": [r"contribute", r"part\s+of", r"join", r"work\s+with"],
}

_SHIPPING_PATTERNS = {
    "scrappy": [r"ship\s+in\s+a\s+week", r"scrappy", r"just\s+ship\s+it", r"willing\s+to\s+ship"],
    "methodical": [r"rigorous", r"systematic", r"process", r"methodology", r"thorough"],
    "balanced": [],  # default
}

_DEPTH_PATTERNS = {
    "specialist": [r"deep\s+technical\s+depth", r"specialist", r"expert\s+in", r"deep\s+dive"],
    "generalist": [r"full\s+stack", r"generalist", r"versatile", r"broad"],
    "t_shaped": [r"deep\s+in\s+one", r"broad\s+knowledge", r"t.shaped", r"depth.*breadth"],
}

_SCALE_PATTERNS = {
    "startup_scale": [r"startup", r"early\s+stage", r"small\s+team", r"series\s+[ab]"],
    "mid_scale": [r"scale", r"growing", r"product.company", r"thousands"],
    "large_scale": [r"millions", r"enterprise", r"global", r"large.scale"],
}

_TEAM_PATTERNS = {
    "founding": [r"founding\s+team", r"first\s+engineer", r"employee\s+#"],
    "early": [r"early\s+team", r"small\s+team", r"core\s+team"],
    "growing": [r"growing\s+team", r"scaling\s+team", r"hiring\s+team"],
    "established": [r"team\s+of\s+\d+", r"large\s+team", r"department"],
}


def _detect_signals(jd_text: str) -> dict[str, list[str]]:
    """Detect all intent signals from JD text."""
    signals = {}

    # Philosophy
    signals["philosophy"] = []
    for tag, patterns in _PHILOSOPHY_PATTERNS.items():
        if any(re.search(p, jd_text, re.IGNORECASE) for p in patterns):
            signals["philosophy"].append(tag)

    # Ownership
    signals["ownership"] = []
    for level, patterns in _OWNERSHIP_PATTERNS.items():
        if any(re.search(p, jd_text, re.IGNORECASE) for p in patterns):
            signals["ownership"].append(level)

    # Shipping culture
    signals["shipping"] = []
    for culture, patterns in _SHIPPING_PATTERNS.items():
        if culture == "balanced":
            continue
        if any(re.search(p, jd_text, re.IGNORECASE) for p in patterns):
            signals["shipping"].append(culture)

    # Depth
    signals["depth"] = []
    for depth, patterns in _DEPTH_PATTERNS.items():
        if any(re.search(p, jd_text, re.IGNORECASE) for p in patterns):
            signals["depth"].append(depth)

    # Scale
    signals["scale"] = []
    for scale, patterns in _SCALE_PATTERNS.items():
        if any(re.search(p, jd_text, re.IGNORECASE) for p in patterns):
            signals["scale"].append(scale)

    # Team context
    signals["team"] = []
    for ctx, patterns in _TEAM_PATTERNS.items():
        if any(re.search(p, jd_text, re.IGNORECASE) for p in patterns):
            signals["team"].append(ctx)

    return signals


def _compute_ownership_expectation(signals: dict) -> float:
    """Compute ownership expectation level from signals."""
    levels = signals.get("ownership", [])
    if "founding" in levels:
        return 0.95
    if "senior_ic" in levels:
        return 0.80
    if "team_lead" in levels:
        return 0.70
    return 0.50


def _determine_primary_need(jd: JDUnderstanding, signals: dict) -> str:
    """Determine the primary thing this hire must deliver."""
    # Check for explicit production ownership
    if "customer_facing" in signals.get("philosophy", []):
        return "production_systems"
    if "platform_engineer" in signals.get("philosophy", []):
        return "platform_engineering"
    if "research_heavy" in signals.get("philosophy", []):
        return "research"
    if "startup_builder" in signals.get("philosophy", []):
        return "build_from_scratch"
    if "specialist_depth" in signals.get("philosophy", []):
        return "specialist_contribution"
    return "general"


def _compute_independence(jd_text: str, signals: dict) -> float:
    """How independently is this person expected to work?"""
    score = 0.5  # baseline
    indie_patterns = [
        (r"independently", 0.15), (r"own\s+initiative", 0.10),
        (r"async", 0.08), (r"self.directed", 0.10),
        (r"decides?\s+quickly", 0.08), (r"disagrees?\s+openly", 0.05),
        (r"minimal\s+supervision", 0.10), (r"autonom", 0.10),
    ]
    for pattern, bonus in indie_patterns:
        if re.search(pattern, jd_text, re.IGNORECASE):
            score = min(1.0, score + bonus)
    return score


# ---------------------------------------------------------------------------
# Main API
# ---------------------------------------------------------------------------

def analyze(jd: JDUnderstanding | None = None) -> HiringIntent:
    """
    Analyze a JD to infer hiring intent.

    Returns a HiringIntent dataclass that drives downstream weight adjustments,
    feature emphasis, and reasoning.
    """
    if jd is None:
        jd = get_jd()

    jd_text = jd.raw_text.lower()
    signals = _detect_signals(jd_text)

    # Build the intent
    philosophy = signals.get("philosophy", [])
    if not philosophy:
        philosophy = ["general"]

    ownership_levels = signals.get("ownership", [])
    ownership_expectation = _compute_ownership_expectation(signals)

    shipping_cultures = signals.get("shipping", [])
    shipping_culture = shipping_cultures[0] if shipping_cultures else "balanced"

    depths = signals.get("depth", [])
    depth_requirement = depths[0] if depths else "generalist"

    scales = signals.get("scale", [])
    scale_requirement = scales[0] if scales else "mid_scale"

    teams = signals.get("team", [])
    team_context = teams[0] if teams else "established"

    independence = _compute_independence(jd_text, signals)

    mentorship = bool(
        re.search(r"mentor|guide|coach|senior\s+to|teach", jd_text, re.IGNORECASE)
    )

    primary_need = _determine_primary_need(jd, signals)

    return HiringIntent(
        philosophy=philosophy,
        primary_need=primary_need,
        ownership_expectation=ownership_expectation,
        shipping_culture=shipping_culture,
        depth_requirement=depth_requirement,
        scale_requirement=scale_requirement,
        team_context=team_context,
        independence=independence,
        mentorship=mentorship,
        raw_signals=signals,
    )


# Singleton
_intent_cache: HiringIntent | None = None

def get_intent() -> HiringIntent:
    """Get the hiring intent (cached after first analysis)."""
    global _intent_cache
    if _intent_cache is None:
        _intent_cache = analyze()
    return _intent_cache