from __future__ import annotations

from dataclasses import asdict, dataclass
from datetime import date
from typing import Any
from normative_status import NormativeStatus


DecisionStatus = NormativeStatus


@dataclass(frozen=True)
class DecisionResult:
    status: str
    decision_type: str
    outcome: Any = None
    reason: str = ""
    contract_ids: tuple[str, ...] = ()
    matched_rule_ids: tuple[str, ...] = ()
    source_refs: tuple[str, ...] = ()
    missing_facts: tuple[str, ...] = ()
    judgment_requirements: tuple[str, ...] = ()
    trace: tuple[dict[str, Any], ...] = ()

    def to_dict(self) -> dict[str, Any]:
        return asdict(self)


class NormativeDecisionRuntime:
    """Deterministic evaluator for expert-approved MCKF decision contracts.

    Natural language, embeddings and LLM output never enter this evaluator.
    The same package version and structured facts always produce the same
    result and proof trace.
    """

    def __init__(self, contracts: list[dict[str, Any]] | None = None, build_id: str = "") -> None:
        self.contracts = [dict(item) for item in (contracts or [])]
        self.build_id = build_id

    @classmethod
    def from_corpus(cls, corpus: dict[str, Any] | None) -> "NormativeDecisionRuntime":
        import json
        from pathlib import Path
        corpus = corpus or {}
        contracts = list(corpus.get("decision_contracts", []) or [])
        registry_path = Path(__file__).parent / "data" / "registry" / "normative_decision_contracts.json"
        if registry_path.exists():
            try:
                registry_data = json.loads(registry_path.read_text(encoding="utf-8"))
                registry_contracts = registry_data.get("contracts", []) or []
                existing_ids = {c.get("contract_id") for c in contracts if c.get("contract_id")}
                for rc in registry_contracts:
                    if rc.get("contract_id") not in existing_ids:
                        contracts.append(rc)
                        existing_ids.add(rc.get("contract_id"))
            except Exception:
                pass
        return cls(contracts, str(corpus.get("build_id", "") or ""))


    def evaluate(
        self,
        decision_type: str,
        facts: dict[str, Any] | None,
        as_of_date: str = "",
    ) -> dict[str, Any]:
        decision_type = str(decision_type or "").strip()
        facts = facts if isinstance(facts, dict) else {}
        candidates = [
            item for item in self.contracts
            if str(item.get("decision_type", "") or "") == decision_type
            and _is_effective(item, as_of_date)
        ]
        if not candidates:
            return DecisionResult(
                status=DecisionStatus.OUT_OF_SCOPE.value,
                decision_type=decision_type,
                reason="Yayınlanmış MCKF paketinde bu karar türü ve tarih için çalıştırılabilir sözleşme yok.",
            ).to_dict()

        evaluations = [_evaluate_contract(contract, facts, decision_type) for contract in candidates]
        decided = [item for item in evaluations if item.status == DecisionStatus.DECIDED.value]
        distinct_outcomes = {_stable_value(item.outcome) for item in decided}
        if len(distinct_outcomes) > 1:
            return DecisionResult(
                status=DecisionStatus.CONFLICT.value,
                decision_type=decision_type,
                reason="Aynı olay verileri yürürlükteki karar sözleşmelerinde farklı sonuçlar üretti.",
                contract_ids=tuple(item.contract_ids[0] for item in decided),
                matched_rule_ids=tuple(rule for item in decided for rule in item.matched_rule_ids),
                source_refs=tuple(dict.fromkeys(ref for item in decided for ref in item.source_refs)),
                trace=tuple(step for item in evaluations for step in item.trace),
            ).to_dict()
        if decided:
            winner = decided[0]
            return winner.to_dict()

        for status in (
            DecisionStatus.REQUIRES_JUDGMENT.value,
            DecisionStatus.UNKNOWN.value,
            DecisionStatus.CONFLICT.value,
        ):
            matching = [item for item in evaluations if item.status == status]
            if matching:
                merged = matching[0]
                return DecisionResult(
                    status=status,
                    decision_type=decision_type,
                    reason=merged.reason,
                    contract_ids=tuple(item.contract_ids[0] for item in matching),
                    source_refs=tuple(dict.fromkeys(ref for item in matching for ref in item.source_refs)),
                    missing_facts=tuple(dict.fromkeys(fact for item in matching for fact in item.missing_facts)),
                    judgment_requirements=tuple(
                        dict.fromkeys(req for item in matching for req in item.judgment_requirements)
                    ),
                    trace=tuple(step for item in evaluations for step in item.trace),
                ).to_dict()
        return DecisionResult(
            status=DecisionStatus.OUT_OF_SCOPE.value,
            decision_type=decision_type,
            reason="Sözleşme kapsamı bulundu ancak verilen olay için uygulanabilir karar kolu yok.",
            contract_ids=tuple(str(item.get("contract_id", "")) for item in candidates),
        ).to_dict()

    def governance_report(self) -> dict[str, Any]:
        warnings = []
        for contract in self.contracts:
            contract_id = str(contract.get("contract_id", "") or "")
            for requirement in contract.get("judgment_requirements", []) or []:
                warnings.append({
                    "status": DecisionStatus.REQUIRES_JUDGMENT.value,
                    "contract_id": contract_id,
                    "fact": requirement.get("fact", ""),
                    "message": requirement.get("reason", "İnsan değerlendirmesi gereken açık normatif kavram."),
                    "source_refs": _source_refs(contract),
                })
            conflicts = _static_conflicts(contract)
            warnings.extend(conflicts)
            if not contract.get("rules"):
                warnings.append({
                    "status": DecisionStatus.OUT_OF_SCOPE.value,
                    "contract_id": contract_id,
                    "message": "Karar sözleşmesinde çalıştırılabilir kural bulunmuyor.",
                    "source_refs": _source_refs(contract),
                })
        return {
            "schema": "MCKF-DecisionGovernanceReport-v1.0",
            "build_id": self.build_id,
            "contract_count": len(self.contracts),
            "warning_count": len(warnings),
            "warnings": warnings,
        }


def _evaluate_contract(contract: dict[str, Any], facts: dict[str, Any], decision_type: str) -> DecisionResult:
    contract_id = str(contract.get("contract_id", "") or "")
    source_refs = tuple(_source_refs(contract))
    schema_fields = (contract.get("input_schema", {}) or {}).get("fields", {}) or {}
    required = [name for name, spec in schema_fields.items() if (spec or {}).get("required")]
    judgment_requirements = contract.get("judgment_requirements", []) or []
    unresolved_judgment = [
        item for item in judgment_requirements
        if _fact_value(facts, str(item.get("fact", "") or ""), _MISSING) is _MISSING
    ]
    if unresolved_judgment:
        return DecisionResult(
            status=DecisionStatus.REQUIRES_JUDGMENT.value,
            decision_type=decision_type,
            reason="Hukukun açık bıraktığı değerlendirme alanı insan kararı gerektiriyor.",
            contract_ids=(contract_id,),
            source_refs=source_refs,
            judgment_requirements=tuple(
                str(item.get("reason", "") or item.get("fact", "")) for item in unresolved_judgment
            ),
        )

    missing = [name for name in required if _fact_value(facts, name, _MISSING) is _MISSING]
    if missing:
        return DecisionResult(
            status=DecisionStatus.UNKNOWN.value,
            decision_type=decision_type,
            reason="Deterministik karar için zorunlu olay verileri eksik.",
            contract_ids=(contract_id,),
            source_refs=source_refs,
            missing_facts=tuple(missing),
        )

    matched = []
    trace = []
    for rule in contract.get("rules", []) or []:
        conditions = rule.get("when", {}) or {}
        applies, condition_trace = _conditions_match(conditions, facts)
        trace.append({
            "contract_id": contract_id,
            "rule_id": rule.get("rule_id", ""),
            "applies": applies,
            "conditions": condition_trace,
        })
        if applies:
            matched.append(rule)
    if not matched and "default_outcome" in contract:
        return DecisionResult(
            status=DecisionStatus.DECIDED.value,
            decision_type=decision_type,
            outcome=contract.get("default_outcome"),
            reason="Hiçbir özel kural eşleşmedi; uzman onaylı varsayılan sonuç uygulandı.",
            contract_ids=(contract_id,),
            source_refs=source_refs,
            trace=tuple(trace),
        )
    if not matched:
        return DecisionResult(
            status=DecisionStatus.OUT_OF_SCOPE.value,
            decision_type=decision_type,
            reason="Girdiler tam olsa da bu olay için sözleşmede uygulanabilir kural bulunmuyor.",
            contract_ids=(contract_id,),
            source_refs=source_refs,
            trace=tuple(trace),
        )

    highest = max(int(item.get("priority", 0) or 0) for item in matched)
    winners = [item for item in matched if int(item.get("priority", 0) or 0) == highest]
    outcomes = {_stable_value(item.get("outcome")) for item in winners}
    if len(outcomes) > 1:
        return DecisionResult(
            status=DecisionStatus.CONFLICT.value,
            decision_type=decision_type,
            reason="Aynı öncelikte birden fazla kural farklı sonuç üretti.",
            contract_ids=(contract_id,),
            matched_rule_ids=tuple(str(item.get("rule_id", "")) for item in winners),
            source_refs=source_refs,
            trace=tuple(trace),
        )
    winner = sorted(winners, key=lambda item: str(item.get("rule_id", "")))[0]
    return DecisionResult(
        status=DecisionStatus.DECIDED.value,
        decision_type=decision_type,
        outcome=winner.get("outcome"),
        reason=str(winner.get("explanation", "") or "Uzman onaylı normatif kural uygulandı."),
        contract_ids=(contract_id,),
        matched_rule_ids=(str(winner.get("rule_id", "")),),
        source_refs=source_refs,
        trace=tuple(trace),
    )


def _conditions_match(conditions: dict[str, Any], facts: dict[str, Any]) -> tuple[bool, list[dict[str, Any]]]:
    mode = "any" if "any" in conditions else "all"
    rows = conditions.get(mode, []) or []
    if not rows:
        return True, []
    trace = []
    results = []
    for condition in rows:
        fact = str(condition.get("fact", "") or "")
        actual = _fact_value(facts, fact, _MISSING)
        operator = str(condition.get("operator", "eq") or "eq")
        expected = condition.get("value")
        result = False if actual is _MISSING else _compare(actual, operator, expected)
        results.append(result)
        trace.append({"fact": fact, "operator": operator, "expected": expected, "actual": None if actual is _MISSING else actual, "result": result})
    return (any(results) if mode == "any" else all(results)), trace


def _compare(actual: Any, operator: str, expected: Any) -> bool:
    operations = {
        "eq": lambda: actual == expected,
        "ne": lambda: actual != expected,
        "gt": lambda: actual > expected,
        "gte": lambda: actual >= expected,
        "lt": lambda: actual < expected,
        "lte": lambda: actual <= expected,
        "in": lambda: actual in expected,
        "not_in": lambda: actual not in expected,
        "truthy": lambda: bool(actual),
        "falsy": lambda: not bool(actual),
    }
    try:
        return bool(operations[operator]())
    except (KeyError, TypeError, ValueError):
        return False


def _fact_value(facts: dict[str, Any], path: str, default: Any) -> Any:
    value: Any = facts
    for part in path.split("."):
        if not isinstance(value, dict) or part not in value:
            return default
        value = value[part]
    return value


def _source_refs(contract: dict[str, Any]) -> list[str]:
    return [
        f"{item.get('document_id', '')}::{item.get('article_id', '')}"
        for item in contract.get("source_refs", []) or []
        if item.get("document_id") and item.get("article_id")
    ]


def _is_effective(contract: dict[str, Any], value: str) -> bool:
    if not value:
        return True
    try:
        target = date.fromisoformat(value)
        start = date.fromisoformat(contract["effective_from"]) if contract.get("effective_from") else None
        end = date.fromisoformat(contract["effective_to"]) if contract.get("effective_to") else None
    except (TypeError, ValueError):
        return False
    return (not start or target >= start) and (not end or target <= end)


def _static_conflicts(contract: dict[str, Any]) -> list[dict[str, Any]]:
    signatures: dict[str, dict[str, Any]] = {}
    warnings = []
    for rule in contract.get("rules", []) or []:
        signature = _stable_value({"priority": rule.get("priority", 0), "when": rule.get("when", {})})
        previous = signatures.get(signature)
        if previous and _stable_value(previous.get("outcome")) != _stable_value(rule.get("outcome")):
            warnings.append({
                "status": DecisionStatus.CONFLICT.value,
                "contract_id": contract.get("contract_id", ""),
                "rule_ids": [previous.get("rule_id", ""), rule.get("rule_id", "")],
                "message": "Aynı koşul ve öncelik için farklı sonuçlar tanımlanmış.",
                "source_refs": _source_refs(contract),
            })
        signatures[signature] = rule
    return warnings


def _stable_value(value: Any) -> str:
    import json

    return json.dumps(value, ensure_ascii=False, sort_keys=True, separators=(",", ":"))


_MISSING = object()