"""
Output-side guardrails for V2.5.

The goal is not to prove clinical correctness. The guard catches obvious demo
and safety failures: pure validation, dependency language, ungrounded contact
claims, unsafe agreement, and crisis responses that keep coaching normally.
"""

from __future__ import annotations

from dataclasses import dataclass
import re


@dataclass(frozen=True)
class OutputGuardResult:
    allowed: bool
    reason: str
    flags: list[str]
    fallback_required: bool
    corrected_response: str | None = None


NEXT_ACTION_MARKERS = (
    "next step",
    "next action",
    "best next",
    "recommended",
    "contact",
    "call",
    "text",
    "office hours",
    "office-hours",
    "email",
    "use ",
    "route",
    "send ",
    "take ",
    "pick ",
    "start ",
    "write ",
    "ask ",
    "tell ",
    "choose ",
    "make ",
    "decide ",
    "identify ",
    "do one",
    "do a",
    "stay ",
    "involve ",
    "try ",
    "keep it",
    "talk ",
    "talk to",
    "schedule ",
    "review ",
    "bring ",
    "file ",
)

DEPENDENCY_PATTERNS = (
    r"\bi am always here\b",
    r"\bi will never leave\b",
    r"\byou only need me\b",
    r"\bi understand you better than anyone\b",
)

HARMFUL_AGREEMENT_PATTERNS = (
    r"\byou are right[, ]+no one can help\b",
    r"\byou are worthless\b",
    r"\byour future is over\b",
    r"\beveryone would be better off\b",
    r"\bkeep this secret\b",
    r"\bdon'?t tell anyone\b",
    r"\bquit immediately\b",
    r"\bdrop out right now\b",
)

NORMAL_COACHING_IN_CRISIS = (
    "study plan",
    "office hours",
    "professor",
    "time management",
    "productivity",
)


def validate_output(
    response: str,
    retrieved_sources: list[dict],
    safety_tier: str,
    route: str,
    conversation_history: list[dict] | list[str] | None = None,
) -> OutputGuardResult:
    text = response.lower()
    flags: list[str] = []

    if safety_tier == "imminent_safety" and any(marker in text for marker in NORMAL_COACHING_IN_CRISIS):
        flags.append("normal_coaching_in_crisis")

    if safety_tier != "imminent_safety" and not any(marker in text for marker in NEXT_ACTION_MARKERS):
        flags.append("missing_recommended_next_action")

    if _looks_like_pure_validation(text):
        flags.append("pure_validation_no_redirect")

    if any(re.search(pattern, text) for pattern in DEPENDENCY_PATTERNS):
        flags.append("dependency_reinforcement")

    if any(re.search(pattern, text) for pattern in HARMFUL_AGREEMENT_PATTERNS):
        flags.append("harmful_or_sycophantic_agreement")

    if _self_degrading_compliance(text):
        flags.append("self_degrading_compliance")

    if _has_ungrounded_contact_claim(response, retrieved_sources):
        flags.append("ungrounded_contact_claim")

    if _has_unsupported_resource_recommendation(response, retrieved_sources):
        flags.append("unsupported_resource_recommendation")

    if flags:
        return OutputGuardResult(
            allowed=False,
            reason=";".join(flags),
            flags=flags,
            fallback_required=True,
            corrected_response=_fallback_response(safety_tier, route),
        )

    return OutputGuardResult(
        allowed=True,
        reason="passed_output_guard",
        flags=[],
        fallback_required=False,
    )


def _looks_like_pure_validation(text: str) -> bool:
    validation_words = ("that sounds", "makes sense", "i hear", "valid", "understandable", "painful")
    has_validation = any(word in text for word in validation_words)
    has_action = any(marker in text for marker in NEXT_ACTION_MARKERS)
    return has_validation and not has_action


def _self_degrading_compliance(text: str) -> bool:
    return bool(re.search(r"\byou are (worthless|a failure|pathetic|stupid|unlovable)\b", text))


def _has_ungrounded_contact_claim(response: str, retrieved_sources: list[dict]) -> bool:
    phone_like = re.findall(r"\b(?:\+?1[-. ]?)?\(?\d{3}\)?[-. ]?\d{3}[-. ]?\d{4}\b|\b\d{3}\b", response)
    if not phone_like:
        return False
    grounded_blob = " ".join(
        str(value)
        for source in retrieved_sources
        for value in source.values()
        if value is not None
    )
    for claim in phone_like:
        if claim == "988":
            continue
        if claim not in grounded_blob:
            return True
    return False


def _has_unsupported_resource_recommendation(response: str, retrieved_sources: list[dict]) -> bool:
    text = response.lower()
    if "will not invent" in text or "not invent" in text:
        return False
    if "source-grounded option:" not in text and "grounded support:" not in text:
        return False
    known_names = {
        str(source.get("source_name", "")).lower()
        for source in retrieved_sources
        if source.get("source_name")
    }
    known_titles = {
        str(source.get("title", "")).lower()
        for source in retrieved_sources
        if source.get("title")
    }
    known_blob = " ".join(known_names | known_titles)
    flagged_resources = ("campus pantry", "thrive", "mheart", "help center", "care to stop violence")
    return any(resource in text and resource not in known_blob for resource in flagged_resources)


def _fallback_response(safety_tier: str, route: str) -> str:
    if safety_tier == "imminent_safety":
        return (
            "I am concerned this may be an immediate safety moment. Please call or text 988 now, "
            "or call emergency services if there is immediate danger. If someone nearby can stay with you, "
            "move near them while you get help."
        )
    return (
        "That sounds difficult, and I do not want to turn it into empty reassurance. "
        "Recommended next action: make this smaller and use one relevant campus or human support option now. "
        "If safety becomes urgent, use 988 or emergency services instead of continuing here."
    )