"""Early Termination / Doom Detector: Stop runs unlikely to succeed."""
from typing import Dict, List, Optional
from dataclasses import dataclass

@dataclass
class DoomSignal:
    signal_type: str
    severity: float  # 0-1
    evidence: str

@dataclass
class DoomAssessment:
    doomed: bool
    severity: float  # 0-1
    signals: List[DoomSignal]
    recommended_action: str  # "continue","stop","mark_blocked","ask_question","switch_strategy"
    reasoning: str

DOOM_THRESHOLDS = {
    "max_failed_tool_calls": 3,
    "max_repeated_planning": 2,
    "max_cost_without_progress": 2.0,
    "max_context_confusion": 0.7,
    "max_escalation_loops": 2,
}

class DoomDetector:
    def __init__(self, doom_threshold: float = 0.7):
        self.doom_threshold = doom_threshold
        self.assessments: List[DoomAssessment] = []

    def assess(self, steps: List[Dict], current_cost: float, max_cost: float,
               model_tier: int, verifier_disagreements: int = 0) -> DoomAssessment:
        signals = []
        severity = 0.0
        # Check signals
        failed_tools = sum(1 for s in steps for tc in s.get("tool_calls",[])
                          if not tc.get("success", True))
        if failed_tools >= DOOM_THRESHOLDS["max_failed_tool_calls"]:
            signals.append(DoomSignal("failed_tool_calls", 0.6,
                          f"{failed_tools} failed tool calls"))
            severity += 0.3

        no_progress = all(not s.get("artifacts_created") for s in steps)
        if no_progress and len(steps) > 3:
            signals.append(DoomSignal("no_artifact_progress", 0.5,
                          "no artifacts after 3+ steps"))
            severity += 0.25

        if current_cost > DOOM_THRESHOLDS["max_cost_without_progress"] and no_progress:
            signals.append(DoomSignal("growing_cost_no_progress", 0.7,
                          f"cost={current_cost:.2f} with no progress"))
            severity += 0.35

        planning_steps = sum(1 for s in steps if s.get("retry_num",0) > 0)
        if planning_steps >= DOOM_THRESHOLDS["max_repeated_planning"]:
            signals.append(DoomSignal("repeated_planning", 0.4,
                          f"{planning_steps} retry steps"))
            severity += 0.2

        if verifier_disagreements >= 2:
            signals.append(DoomSignal("verifier_disagreement", 0.6,
                          f"{verifier_disagreements} verifier disagreements"))
            severity += 0.3

        if current_cost >= max_cost * 0.9:
            signals.append(DoomSignal("approaching_cost_limit", 0.5,
                          f"cost={current_cost:.2f} / {max_cost:.2f}"))
            severity += 0.4

        severity = min(severity, 1.0)
        doomed = severity >= self.doom_threshold
        # Determine action
        if not doomed:
            action = "continue"
            reasoning = f"severity={severity:.2f} < threshold={self.doom_threshold}"
        elif failed_tools >= 3 and no_progress:
            action = "mark_blocked"
            reasoning = "too many failures with no progress"
        elif current_cost >= max_cost * 0.9:
            action = "stop"
            reasoning = "approaching cost limit"
        elif verifier_disagreements >= 2:
            action = "switch_strategy"
            reasoning = "verifier disagreement suggests wrong approach"
        else:
            action = "ask_question"
            reasoning = "run may be recoverable with user input"
        assessment = DoomAssessment(doomed, severity, signals, action, reasoning)
        self.assessments.append(assessment)
        return assessment