"""Execution policy brain for AI PMO decision runtime."""

from __future__ import annotations

import os

from .shared import (
    CanonicalIntent,
    INTENT_QUERY,
    INTENT_TASK_CREATE,
    INTENT_SIGNAL_CREATE,
    INTENT_SIGNAL_SOURCE_ONBOARD,
    re,
)


class ExecutionPolicyBrain:
    """自动执行边界。"""

    def __init__(self, *, policy_gate_rules: tuple[tuple[str, tuple[str, ...]], ...]) -> None:
        self.policy_gate_rules = policy_gate_rules

    def evaluate(
        self,
        *,
        message_text: str,
        world_model: dict[str, object],
        intent: CanonicalIntent,
        simulation: dict[str, object],
    ) -> dict[str, object]:
        warn_threshold = self._env_float("CAPACITY_WARN_THRESHOLD", 1.0)
        block_threshold = self._env_float("CAPACITY_BLOCK_THRESHOLD", 1.5)
        if block_threshold < warn_threshold:
            block_threshold = warn_threshold
        projected_capacity_ratio = float(simulation.get("projected_capacity_peak_ratio") or 0.0)
        capacity_warning: dict[str, object] | None = None
        normalized = re.sub(r"\s+", "", str(message_text or "")).lower()
        for gate_code, tokens in self.policy_gate_rules:
            if any(token.lower().replace(" ", "") in normalized for token in tokens):
                return {
                    "auto_execute": False,
                    "policy_gate_hit": True,
                    "policy_gate_code": gate_code,
                    "approval_requirement": {
                        "required": True,
                        "reason": gate_code,
                        "message": "命中硬策略边界，必须进入显式审批/人工确认。",
                    },
                }

        if intent.name == INTENT_SIGNAL_SOURCE_ONBOARD and intent.project_id is None:
            return {
                "auto_execute": False,
                "policy_gate_hit": True,
                "policy_gate_code": "missing_project_scope",
                "approval_requirement": {
                    "required": True,
                    "reason": "missing_project_scope",
                    "message": "信号源接入缺少项目归属，必须先确认项目。",
                },
            }

        if intent.name in {INTENT_QUERY, INTENT_TASK_CREATE, INTENT_SIGNAL_CREATE}:
            return {
                "auto_execute": True,
                "policy_gate_hit": False,
                "policy_gate_code": None,
                "approval_requirement": {"required": False},
            }

        budget = world_model.get("budget") if isinstance(world_model.get("budget"), dict) else {}
        if bool(budget.get("hard_limit_enabled")) and float(budget.get("usage_ratio") or 0.0) >= 1.0:
            return {
                "auto_execute": False,
                "policy_gate_hit": True,
                "policy_gate_code": "budget_hard_limit",
                "approval_requirement": {
                    "required": True,
                    "reason": "budget_hard_limit",
                    "message": "项目预算已触达硬限制，自动执行被拦截。",
                },
            }

        if float(simulation.get("projected_budget_usage_ratio") or 0.0) >= 1.0:
            return {
                "auto_execute": False,
                "policy_gate_hit": True,
                "policy_gate_code": "simulation_budget_limit",
                "approval_requirement": {
                    "required": True,
                    "reason": "simulation_budget_limit",
                    "message": "执行前仿真显示预算将触顶，自动执行被拦截。",
                },
            }

        if projected_capacity_ratio >= block_threshold:
            return {
                "auto_execute": False,
                "policy_gate_hit": True,
                "policy_gate_code": "simulation_capacity_limit",
                "approval_requirement": {
                    "required": True,
                    "reason": "simulation_capacity_limit",
                    "message": "执行前仿真显示产能严重超载，自动执行被拦截。",
                },
            }
        if projected_capacity_ratio >= warn_threshold:
            capacity_warning = {
                "enabled": True,
                "severity": "warning",
                "peak_ratio": round(projected_capacity_ratio, 4),
                "warn_threshold": round(warn_threshold, 4),
                "block_threshold": round(block_threshold, 4),
            }

        if intent.name == INTENT_SIGNAL_SOURCE_ONBOARD and int(simulation.get("missing_skill_count") or 0) > 0:
            return {
                "auto_execute": False,
                "policy_gate_hit": True,
                "policy_gate_code": "simulation_skill_gap",
                "approval_requirement": {
                    "required": True,
                    "reason": "simulation_skill_gap",
                    "message": "执行前仿真显示当前项目存在技能缺口，信号源接入先进入待确认。",
                },
            }

        if intent.name in {INTENT_SIGNAL_SOURCE_ONBOARD, INTENT_SIGNAL_CREATE} and str(simulation.get("dependency_pressure") or "") == "high":
            return {
                "auto_execute": False,
                "policy_gate_hit": True,
                "policy_gate_code": "simulation_dependency_pressure",
                "approval_requirement": {
                    "required": True,
                    "reason": "simulation_dependency_pressure",
                    "message": "执行前仿真显示关键依赖压力过高，当前先进入待人工确认。",
                },
            }

        return {
            "auto_execute": True,
            "policy_gate_hit": False,
            "policy_gate_code": None,
            "approval_requirement": {"required": False},
            "capacity_warning": capacity_warning,
        }

    @staticmethod
    def _env_float(name: str, default: float) -> float:
        raw = str(os.getenv(name, "")).strip()
        if not raw:
            return float(default)
        try:
            return float(raw)
        except (TypeError, ValueError):
            return float(default)