"""Self-improvement services — signal collection, pattern detection,
proposal lifecycle, evaluation, activation, impact measurement.

Builds on existing systems:
- ai_proactive: ContextLog, ProactiveSuggestion
- automation: AgentRun, AgentRunStep, AgentVersion
- app.core.approval: create_approval_request
- app.models.audit: AuditLog
- app.models.workflow: WorkflowInstance
- app.ai.llm_client: llm_complete
"""
from __future__ import annotations

import logging
import uuid
from datetime import UTC, datetime, timedelta
from typing import Any

from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.ai.llm_client import llm_complete
from app.plugins.builtins.self_improvement.models import (
    ImprovementPattern,
    ImprovementProposal,
    ImprovementSignal,
    ImpactMeasurement,
    PROPOSAL_STATUSES,
)

logger = logging.getLogger(__name__)


# ──────────────────────────────────────────────────────────────────────────
# J-SIGNAL: Signal Collection
# ──────────────────────────────────────────────────────────────────────────

async def collect_signals(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    since: datetime | None = None,
    limit: int = 100,
) -> dict[str, Any]:
    """Collect improvement signals from existing system data.

    Queries real usage data from AgentRun, WorkflowInstance,
    ProactiveSuggestion, AuditLog — stores references/summaries,
    not personal data copies.
    """
    if since is None:
        since = datetime.now(UTC) - timedelta(days=7)

    collected: list[ImprovementSignal] = []

    # 1. Agent runs with failures or retries
    try:
        from app.plugins.builtins.automation.models import AgentRun, AgentRunStep

        # Failed agent runs
        result = await db.execute(
            select(AgentRun)
            .where(
                AgentRun.tenant_id == tenant_id,
                AgentRun.created_at >= since,
                AgentRun.status.in_(["failed", "error", "timeout"]),
            )
            .order_by(AgentRun.created_at.desc())
            .limit(limit)
        )
        for run in result.scalars().all():
            sig = ImprovementSignal(
                tenant_id=tenant_id,
                source_type="agent_run",
                source_ref_id=run.id,
                source_metadata={
                    "agent_id": str(run.agent_id) if run.agent_id else None,
                    "status": run.status,
                    "duration_seconds": getattr(run, "duration_seconds", None),
                },
                summary=f"Agent run failed with status '{run.status}'",
                signal_kind="failure",
                severity="error",
                confidence=0.8,
            )
            db.add(sig)
            collected.append(sig)

        # Agent runs with many steps (potential retry/bottleneck)
        result = await db.execute(
            select(AgentRunStep.agent_run_id, func.count(AgentRunStep.id).label("step_count"))
            .where(
                AgentRunStep.tenant_id == tenant_id,
                AgentRunStep.created_at >= since,
            )
            .group_by(AgentRunStep.agent_run_id)
            .having(func.count(AgentRunStep.id) >= 5)
            .limit(limit)
        )
        for row in result.all():
            sig = ImprovementSignal(
                tenant_id=tenant_id,
                source_type="agent_run",
                source_ref_id=row.agent_run_id,
                source_metadata={"step_count": row.step_count},
                summary=f"Agent run had {row.step_count} steps (potential bottleneck)",
                signal_kind="retry",
                severity="warning",
                confidence=0.6,
            )
            db.add(sig)
            collected.append(sig)
    except Exception:
        logger.warning("Failed to collect agent run signals", exc_info=True)

    # 2. Workflow instances with failures
    try:
        from app.models.workflow import WorkflowInstance

        result = await db.execute(
            select(WorkflowInstance)
            .where(
                WorkflowInstance.tenant_id == tenant_id,
                WorkflowInstance.created_at >= since,
                WorkflowInstance.status.in_(["failed", "error", "cancelled"]),
            )
            .order_by(WorkflowInstance.created_at.desc())
            .limit(limit)
        )
        for wf in result.scalars().all():
            sig = ImprovementSignal(
                tenant_id=tenant_id,
                source_type="workflow_run",
                source_ref_id=wf.id,
                source_metadata={
                    "workflow_id": str(wf.workflow_id) if hasattr(wf, "workflow_id") else None,
                    "status": wf.status,
                },
                summary=f"Workflow instance failed with status '{wf.status}'",
                signal_kind="failure",
                severity="error",
                confidence=0.7,
            )
            db.add(sig)
            collected.append(sig)
    except Exception:
        logger.warning("Failed to collect workflow signals", exc_info=True)

    # 3. Dismissed proactive suggestions
    try:
        from app.plugins.builtins.ai_proactive.models import ProactiveSuggestion

        result = await db.execute(
            select(ProactiveSuggestion)
            .where(
                ProactiveSuggestion.tenant_id == tenant_id,
                ProactiveSuggestion.created_at >= since,
                ProactiveSuggestion.is_dismissed.is_(True),
            )
            .order_by(ProactiveSuggestion.created_at.desc())
            .limit(limit)
        )
        for sug in result.scalars().all():
            sig = ImprovementSignal(
                tenant_id=tenant_id,
                source_type="proactive_suggestion",
                source_ref_id=sug.id,
                source_metadata={
                    "suggestion_type": sug.suggestion_type,
                    "entity_type": sug.entity_type,
                },
                summary=f"Proactive suggestion '{sug.title}' was dismissed",
                signal_kind="dismissal",
                severity="info",
                confidence=0.5,
            )
            db.add(sig)
            collected.append(sig)
    except Exception:
        logger.warning("Failed to collect proactive suggestion signals", exc_info=True)

    # 4. Audit log entries with corrections (update/delete patterns)
    try:
        from app.models.audit import AuditLog

        result = await db.execute(
            select(AuditLog.entity_type, AuditLog.action, func.count(AuditLog.id).label("cnt"))
            .where(
                AuditLog.tenant_id == tenant_id,
                AuditLog.created_at >= since,
                AuditLog.action.in_(["update", "delete"]),
            )
            .group_by(AuditLog.entity_type, AuditLog.action)
            .having(func.count(AuditLog.id) >= 3)
            .limit(limit)
        )
        for row in result.all():
            sig = ImprovementSignal(
                tenant_id=tenant_id,
                source_type="audit_log",
                source_ref_id=None,
                source_metadata={
                    "entity_type": row.entity_type,
                    "action": row.action,
                    "count": row.cnt,
                },
                summary=f"{row.cnt} '{row.action}' operations on '{row.entity_type}' (potential correction pattern)",
                signal_kind="correction",
                severity="info",
                confidence=0.5,
            )
            db.add(sig)
            collected.append(sig)
    except Exception:
        logger.warning("Failed to collect audit log signals", exc_info=True)

    await db.flush()
    return {
        "collected": len(collected),
        "signals": [
            {
                "id": str(s.id),
                "source_type": s.source_type,
                "signal_kind": s.signal_kind,
                "severity": s.severity,
                "summary": s.summary,
                "confidence": s.confidence,
            }
            for s in collected
        ],
    }


# ──────────────────────────────────────────────────────────────────────────
# J-PATTERN: Pattern Detection
# ──────────────────────────────────────────────────────────────────────────

async def detect_patterns(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    min_occurrences: int = 2,
) -> dict[str, Any]:
    """Detect recurring patterns from collected signals.

    Groups signals by source_type + signal_kind + target metadata
    to find bottlenecks, repetitive corrections, dismissed suggestions.
    """
    # Get unpatterned signals
    result = await db.execute(
        select(ImprovementSignal)
        .where(
            ImprovementSignal.tenant_id == tenant_id,
            ImprovementSignal.pattern_id.is_(None),
        )
        .order_by(ImprovementSignal.created_at.desc())
    )
    signals = result.scalars().all()

    if not signals:
        return {"patterns_created": 0, "patterns": []}

    # Group signals by (source_type, signal_kind, target identifier from metadata)
    groups: dict[str, list[ImprovementSignal]] = {}
    for sig in signals:
        # Create a grouping key from source type + kind + a target identifier
        meta = sig.source_metadata or {}
        target_key = meta.get("agent_id") or meta.get("workflow_id") or meta.get("entity_type") or meta.get("suggestion_type") or "unknown"
        key = f"{sig.source_type}:{sig.signal_kind}:{target_key}"
        groups.setdefault(key, []).append(sig)

    patterns_created: list[ImprovementPattern] = []
    for key, group_signals in groups.items():
        if len(group_signals) < min_occurrences:
            continue

        parts = key.split(":", 2)
        source_type = parts[0] if len(parts) > 0 else "unknown"
        signal_kind = parts[1] if len(parts) > 1 else "observation"
        target_name = parts[2] if len(parts) > 2 else "unknown"

        # Determine target_type from source
        target_type_map = {
            "agent_run": "agent",
            "workflow_run": "workflow",
            "proactive_suggestion": "trigger",
            "audit_log": "agent",
        }
        target_type = target_type_map.get(source_type, "agent")

        # Build evidence refs (references, not data copies)
        evidence_refs = [
            {
                "signal_id": str(s.id),
                "source_type": s.source_type,
                "source_ref_id": str(s.source_ref_id) if s.source_ref_id else None,
                "summary": s.summary,
            }
            for s in group_signals
        ]

        avg_confidence = sum(s.confidence for s in group_signals) / len(group_signals)

        pattern_kind_map = {
            "failure": "retry_bottleneck",
            "retry": "retry_bottleneck",
            "correction": "manual_correction",
            "dismissal": "suggestion_dismissal",
        }
        pattern_kind = pattern_kind_map.get(signal_kind, "repetitive_handoff")

        pattern = ImprovementPattern(
            tenant_id=tenant_id,
            pattern_kind=pattern_kind,
            title=f"{pattern_kind.replace('_', ' ').title()}: {target_name} ({len(group_signals)} occurrences)",
            description=f"Detected {len(group_signals)} '{signal_kind}' signals for '{target_name}' from '{source_type}'. "
            + "; ".join(s.summary for s in group_signals[:3]),
            target_type=target_type,
            target_name=target_name,
            evidence_refs=evidence_refs,
            occurrence_count=len(group_signals),
            confidence=avg_confidence,
            status="detected",
            proposed_action=_suggest_action(pattern_kind, target_type, target_name, len(group_signals)),
        )
        db.add(pattern)
        await db.flush()

        # Link signals to pattern
        for sig in group_signals:
            sig.pattern_id = pattern.id

        patterns_created.append(pattern)

    await db.flush()
    return {
        "patterns_created": len(patterns_created),
        "patterns": [
            {
                "id": str(p.id),
                "pattern_kind": p.pattern_kind,
                "title": p.title,
                "target_type": p.target_type,
                "target_name": p.target_name,
                "occurrence_count": p.occurrence_count,
                "confidence": p.confidence,
                "proposed_action": p.proposed_action,
            }
            for p in patterns_created
        ],
    }


def _suggest_action(pattern_kind: str, target_type: str, target_name: str, count: int) -> str:
    """Generate a human-readable proposed action for a pattern."""
    if pattern_kind == "retry_bottleneck":
        return f"Review {target_type} '{target_name}': {count} retries/failures detected. Consider adjusting system prompt, tools, or timeout settings."
    elif pattern_kind == "manual_correction":
        return f"Review {target_type} '{target_name}': {count} manual corrections detected. Consider improving output quality or adding validation."
    elif pattern_kind == "suggestion_dismissal":
        return f"Review trigger '{target_name}': {count} dismissed suggestions. Consider adjusting confidence threshold or suggestion relevance."
    else:
        return f"Review {target_type} '{target_name}': {count} repetitive handoffs detected. Consider automation or workflow adjustment."


# ──────────────────────────────────────────────────────────────────────────
# J-PROP: Improvement Proposals
# ──────────────────────────────────────────────────────────────────────────

async def create_proposal(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    *,
    pattern_id: uuid.UUID | None = None,
    title: str,
    description: str,
    target_type: str,
    target_ref_id: uuid.UUID | None = None,
    target_name: str | None = None,
    proposed_config: dict | None = None,
    rationale: str = "",
    expected_benefit: str = "",
    risk_assessment: str = "",
    user_id: uuid.UUID | None = None,
) -> ImprovementProposal:
    """Create a new improvement proposal in draft status."""
    # Capture previous config for rollback
    previous_config: dict[str, Any] = {}
    if target_ref_id and target_type == "agent":
        try:
            from app.plugins.builtins.automation.models import AgentDefinition
            result = await db.execute(
                select(AgentDefinition).where(
                    AgentDefinition.tenant_id == tenant_id,
                    AgentDefinition.id == target_ref_id,
                )
            )
            agent = result.scalar_one_or_none()
            if agent:
                previous_config = {
                    "system_prompt": agent.system_prompt,
                    "tool_ids": agent.tool_ids,
                    "temperature": agent.temperature,
                    "max_tokens": agent.max_tokens,
                    "max_steps": agent.max_steps,
                }
        except Exception:
            logger.warning("Failed to capture previous agent config", exc_info=True)

    # Get evidence from pattern if linked
    evidence_refs: list = []
    if pattern_id:
        pat_result = await db.execute(
            select(ImprovementPattern).where(
                ImprovementPattern.tenant_id == tenant_id,
                ImprovementPattern.id == pattern_id,
            )
        )
        pattern = pat_result.scalar_one_or_none()
        if pattern:
            evidence_refs = pattern.evidence_refs
            # Update pattern status
            pattern.status = "proposal_created"

    proposal = ImprovementProposal(
        tenant_id=tenant_id,
        owner_id=user_id,
        pattern_id=pattern_id,
        title=title,
        description=description,
        target_type=target_type,
        target_ref_id=target_ref_id,
        target_name=target_name,
        proposed_config=proposed_config or {},
        previous_config=previous_config,
        evidence_refs=evidence_refs,
        rationale=rationale,
        expected_benefit=expected_benefit,
        risk_assessment=risk_assessment,
        status="draft",
    )
    db.add(proposal)
    await db.flush()
    return proposal


# ──────────────────────────────────────────────────────────────────────────
# J-EVAL: Evaluation / Dry-Run
# ──────────────────────────────────────────────────────────────────────────

async def evaluate_proposal(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    proposal_id: uuid.UUID,
) -> dict[str, Any]:
    """Evaluate a proposal via LLM-based dry-run assessment.

    No external side effects — the LLM assesses the proposed change
    against the evidence and expected benefit.
    """
    result = await db.execute(
        select(ImprovementProposal).where(
            ImprovementProposal.tenant_id == tenant_id,
            ImprovementProposal.id == proposal_id,
        )
    )
    proposal = result.scalar_one_or_none()
    if not proposal:
        return {"error": "Proposal not found"}

    proposal.status = "evaluating"
    await db.flush()

    # Build evaluation prompt
    eval_prompt = f"""You are an AI improvement evaluator for a CRM system.
Assess the following improvement proposal. Consider:
1. Is the rationale sound?
2. Is the expected benefit realistic?
3. Are there risks not mentioned?
4. Would you recommend approval?

Return JSON:
{{
  "score": 0.0-1.0,
  "assessment": "...",
  "risks_identified": ["..."],
  "recommendation": "approve" | "reject" | "needs_review",
  "test_scenarios": ["..."]
}}

Proposal:
- Title: {proposal.title}
- Target: {proposal.target_type} ({proposal.target_name or 'N/A'})
- Description: {proposal.description}
- Rationale: {proposal.rationale}
- Expected Benefit: {proposal.expected_benefit}
- Risk Assessment: {proposal.risk_assessment}
- Evidence Count: {len(proposal.evidence_refs)}
- Proposed Config: {proposal.proposed_config}
"""

    try:
        response = await llm_complete(
            model="openai/gpt-4o-mini",
            messages=[
                {"role": "system", "content": "You are an improvement evaluator. Return only valid JSON."},
                {"role": "user", "content": eval_prompt},
            ],
            temperature=0.2,
            max_tokens=1000,
            tenant_id=tenant_id,
            db=db,
        )
        import json
        eval_result = json.loads(response.get("content", "{}"))
    except Exception:
        logger.warning("LLM evaluation failed, using basic assessment", exc_info=True)
        eval_result = {
            "score": 0.5,
            "assessment": "LLM evaluation unavailable. Manual review required.",
            "risks_identified": [],
            "recommendation": "needs_review",
            "test_scenarios": [],
        }

    proposal.evaluation_result = eval_result
    proposal.evaluated_at = datetime.now(UTC)
    proposal.status = "evaluated"
    await db.flush()

    return {
        "proposal_id": str(proposal.id),
        "status": proposal.status,
        "evaluation": eval_result,
    }


# ──────────────────────────────────────────────────────────────────────────
# J-APPROVAL: Human Approval (uses existing approval system)
# ──────────────────────────────────────────────────────────────────────────

async def request_approval(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    proposal_id: uuid.UUID,
    requested_by: uuid.UUID,
    approver_id: uuid.UUID | None = None,
) -> dict[str, Any]:
    """Create an approval request for a proposal using the existing approval system."""
    from app.core.approval import create_approval_request

    result = await db.execute(
        select(ImprovementProposal).where(
            ImprovementProposal.tenant_id == tenant_id,
            ImprovementProposal.id == proposal_id,
        )
    )
    proposal = result.scalar_one_or_none()
    if not proposal:
        return {"error": "Proposal not found"}
    if proposal.status not in ("evaluated", "draft"):
        return {"error": f"Proposal must be in 'evaluated' or 'draft' status, got '{proposal.status}'"}

    req = await create_approval_request(
        db=db,
        tenant_id=tenant_id,
        entity_type="improvement_proposal",
        entity_id=proposal.id,
        action="activate",
        requested_by=requested_by,
        requested_by_type="system",
        approver_id=approver_id,
        metadata={
            "proposal_title": proposal.title,
            "target_type": proposal.target_type,
            "target_name": proposal.target_name,
            "evaluation_score": proposal.evaluation_result.get("score", 0.0),
            "expected_benefit": proposal.expected_benefit,
        },
    )
    proposal.approval_request_id = req.id
    await db.flush()

    # Post to Communication via KommunikationContract (ARCH-013: contract
    # only — no direct plugin imports; skip cleanly when contract is absent)
    try:
        from app.plugins.builtins.contracts import get_contract
        _komm = get_contract("kommunikation")
        if not _komm or not hasattr(_komm, "create_plugin_room"):
            logger.warning("kommunikation contract unavailable - skipping proposal notification")
        else:
            room = await _komm.create_plugin_room(
                db=db, tenant_id=tenant_id, user_id=requested_by,
                plugin_name="self_improvement", title="Improvement Proposals",
                participant_type="system",
            )
            conversation_id = room.get("conversation_id") if isinstance(room, dict) else None
            if not conversation_id and hasattr(room, "id"):
                conversation_id = room.id
            if conversation_id:
                await _komm.send_message(
                    db=db,
                    tenant_id=tenant_id,
                    conversation_id=conversation_id,
                    sender_id=requested_by,
                    sender_type="system",
                    content=f"Improvement Proposal: {proposal.title}",
                blocks=[
                    {
                        "type": "action_card",
                        "title": f"Improvement Proposal: {proposal.title}",
                        "content": proposal.description,
                        "actions": [
                            {"label": "Approve", "action": "approve", "proposal_id": str(proposal.id), "approval_id": str(req.id)},
                            {"label": "Reject", "action": "reject", "proposal_id": str(proposal.id), "approval_id": str(req.id)},
                        ],
                        "metadata": {
                            "target_type": proposal.target_type,
                            "target_name": proposal.target_name,
                            "evaluation_score": proposal.evaluation_result.get("score", 0.0),
                            "expected_benefit": proposal.expected_benefit,
                        },
                    }
                ],
            )
    except Exception:
        logger.warning("Failed to post proposal to Communication", exc_info=True)

    return {
        "proposal_id": str(proposal.id),
        "approval_request_id": str(req.id),
        "status": "pending_approval",
    }


# ──────────────────────────────────────────────────────────────────────────
# J-ACTIVATE: Controlled Activation + Rollback
# ──────────────────────────────────────────────────────────────────────────

async def activate_proposal(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    proposal_id: uuid.UUID,
    approved_by: uuid.UUID,
) -> dict[str, Any]:
    """Activate an approved proposal — apply the proposed config to the target.

    Only applies to agent configurations (system_prompt, tools, temperature, etc.).
    Code/plugin patches go through the normal engineering way (J-CODE).
    """
    result = await db.execute(
        select(ImprovementProposal).where(
            ImprovementProposal.tenant_id == tenant_id,
            ImprovementProposal.id == proposal_id,
        )
    )
    proposal = result.scalar_one_or_none()
    if not proposal:
        return {"error": "Proposal not found"}
    if proposal.status not in ("approved", "evaluated"):
        return {"error": f"Proposal must be 'approved' or 'evaluated', got '{proposal.status}'"}

    # Apply config change to target
    applied = False
    if proposal.target_type == "agent" and proposal.target_ref_id and proposal.proposed_config:
        try:
            from app.plugins.builtins.automation.models import AgentDefinition
            agent_result = await db.execute(
                select(AgentDefinition).where(
                    AgentDefinition.tenant_id == tenant_id,
                    AgentDefinition.id == proposal.target_ref_id,
                )
            )
            agent = agent_result.scalar_one_or_none()
            if agent:
                # Create a version snapshot before applying (reuse existing versioning)
                from app.plugins.builtins.automation.models import AgentVersion
                version_result = await db.execute(
                    select(func.max(AgentVersion.version_number))
                    .where(AgentVersion.tenant_id == tenant_id, AgentVersion.agent_id == agent.id)
                )
                max_ver = version_result.scalar() or 0
                version = AgentVersion(
                    tenant_id=tenant_id,
                    agent_id=agent.id,
                    version_number=max_ver + 1,
                    snapshot={
                        "system_prompt": agent.system_prompt,
                        "tool_ids": agent.tool_ids,
                        "temperature": agent.temperature,
                        "max_tokens": agent.max_tokens,
                        "max_steps": agent.max_steps,
                    },
                    changed_by=approved_by,
                )
                db.add(version)

                # Apply proposed config
                cfg = proposal.proposed_config
                if "system_prompt" in cfg:
                    agent.system_prompt = cfg["system_prompt"]
                if "tool_ids" in cfg:
                    agent.tool_ids = cfg["tool_ids"]
                if "temperature" in cfg:
                    agent.temperature = cfg["temperature"]
                if "max_tokens" in cfg:
                    agent.max_tokens = cfg["max_tokens"]
                if "max_steps" in cfg:
                    agent.max_steps = cfg["max_steps"]
                applied = True
        except Exception:
            logger.exception("Failed to apply proposal to agent")

    proposal.status = "active"
    proposal.approved_by = approved_by
    proposal.approved_at = datetime.now(UTC)
    proposal.activated_at = datetime.now(UTC)
    await db.flush()

    return {
        "proposal_id": str(proposal.id),
        "status": proposal.status,
        "applied": applied,
        "activated_at": proposal.activated_at.isoformat() if proposal.activated_at else None,
    }


async def rollback_proposal(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    proposal_id: uuid.UUID,
    reason: str = "",
) -> dict[str, Any]:
    """Rollback an active proposal — restore previous config."""
    result = await db.execute(
        select(ImprovementProposal).where(
            ImprovementProposal.tenant_id == tenant_id,
            ImprovementProposal.id == proposal_id,
        )
    )
    proposal = result.scalar_one_or_none()
    if not proposal:
        return {"error": "Proposal not found"}
    if proposal.status != "active":
        return {"error": f"Proposal must be 'active' to rollback, got '{proposal.status}'"}

    # Restore previous config
    restored = False
    if proposal.target_type == "agent" and proposal.target_ref_id and proposal.previous_config:
        try:
            from app.plugins.builtins.automation.models import AgentDefinition
            agent_result = await db.execute(
                select(AgentDefinition).where(
                    AgentDefinition.tenant_id == tenant_id,
                    AgentDefinition.id == proposal.target_ref_id,
                )
            )
            agent = agent_result.scalar_one_or_none()
            if agent:
                cfg = proposal.previous_config
                if "system_prompt" in cfg:
                    agent.system_prompt = cfg["system_prompt"]
                if "tool_ids" in cfg:
                    agent.tool_ids = cfg["tool_ids"]
                if "temperature" in cfg:
                    agent.temperature = cfg["temperature"]
                if "max_tokens" in cfg:
                    agent.max_tokens = cfg["max_tokens"]
                if "max_steps" in cfg:
                    agent.max_steps = cfg["max_steps"]
                restored = True
        except Exception:
            logger.exception("Failed to rollback agent config")

    proposal.status = "rolled_back"
    proposal.rolled_back_at = datetime.now(UTC)
    proposal.rollback_reason = reason
    await db.flush()

    return {
        "proposal_id": str(proposal.id),
        "status": proposal.status,
        "restored": restored,
        "rolled_back_at": proposal.rolled_back_at.isoformat() if proposal.rolled_back_at else None,
    }


# ──────────────────────────────────────────────────────────────────────────
# J-MEASURE: Impact Measurement
# ──────────────────────────────────────────────────────────────────────────

async def measure_impact(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    proposal_id: uuid.UUID,
) -> dict[str, Any]:
    """Measure pre/post impact of an activated proposal.

    Compares agent run metrics before and after activation.
    """
    result = await db.execute(
        select(ImprovementProposal).where(
            ImprovementProposal.tenant_id == tenant_id,
            ImprovementProposal.id == proposal_id,
        )
    )
    proposal = result.scalar_one_or_none()
    if not proposal:
        return {"error": "Proposal not found"}
    if proposal.status not in ("active", "rolled_back"):
        return {"error": "Proposal must be 'active' or 'rolled_back' to measure"}

    # Collect pre-activation metrics (7 days before activation)
    pre_metrics: dict[str, Any] = {}
    post_metrics: dict[str, Any] = {}
    delta: dict[str, Any] = {}

    if proposal.target_type == "agent" and proposal.target_ref_id:
        try:
            from app.plugins.builtins.automation.models import AgentRun

            activated = proposal.activated_at or datetime.now(UTC)
            pre_start = activated - timedelta(days=7)

            # Pre-activation metrics
            pre_result = await db.execute(
                select(
                    func.count(AgentRun.id).label("total_runs"),
                    func.count(AgentRun.id).filter(AgentRun.status.in_(["failed", "error", "timeout"])).label("failed_runs"),
                ).where(
                    AgentRun.tenant_id == tenant_id,
                    AgentRun.agent_id == proposal.target_ref_id,
                    AgentRun.created_at >= pre_start,
                    AgentRun.created_at < activated,
                )
            )
            pre_row = pre_result.one_or_none()
            pre_total = pre_row.total_runs if pre_row else 0
            pre_failed = pre_row.failed_runs if pre_row else 0
            pre_metrics = {
                "total_runs": pre_total,
                "failed_runs": pre_failed,
                "failure_rate": (pre_failed / pre_total) if pre_total > 0 else 0.0,
            }

            # Post-activation metrics
            post_result = await db.execute(
                select(
                    func.count(AgentRun.id).label("total_runs"),
                    func.count(AgentRun.id).filter(AgentRun.status.in_(["failed", "error", "timeout"])).label("failed_runs"),
                ).where(
                    AgentRun.tenant_id == tenant_id,
                    AgentRun.agent_id == proposal.target_ref_id,
                    AgentRun.created_at >= activated,
                )
            )
            post_row = post_result.one_or_none()
            post_total = post_row.total_runs if post_row else 0
            post_failed = post_row.failed_runs if post_row else 0
            post_metrics = {
                "total_runs": post_total,
                "failed_runs": post_failed,
                "failure_rate": (post_failed / post_total) if post_total > 0 else 0.0,
            }

            # Compute delta
            delta = {
                "total_runs_change": post_total - pre_total,
                "failure_rate_change": post_metrics["failure_rate"] - pre_metrics["failure_rate"],
            }
        except Exception:
            logger.warning("Failed to collect agent run metrics", exc_info=True)

    # Determine if impact is positive
    failure_rate_improved = delta.get("failure_rate_change", 0) < 0
    is_positive = "positive" if failure_rate_improved else ("neutral" if delta.get("failure_rate_change", 0) == 0 else "negative")

    assessment = f"Failure rate changed from {pre_metrics.get('failure_rate', 0):.1%} to {post_metrics.get('failure_rate', 0):.1%}. "
    assessment += "Improvement detected." if failure_rate_improved else "No improvement or regression detected."

    measurement = ImpactMeasurement(
        tenant_id=tenant_id,
        proposal_id=proposal_id,
        pre_metrics=pre_metrics,
        post_metrics=post_metrics,
        delta=delta,
        assessment=assessment,
        is_positive=is_positive,
    )
    db.add(measurement)
    await db.flush()

    return {
        "measurement_id": str(measurement.id),
        "proposal_id": str(proposal_id),
        "pre_metrics": pre_metrics,
        "post_metrics": post_metrics,
        "delta": delta,
        "assessment": assessment,
        "is_positive": is_positive,
    }


# ──────────────────────────────────────────────────────────────────────────
# Query helpers
# ──────────────────────────────────────────────────────────────────────────

async def list_signals(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    page: int = 1,
    page_size: int = 20,
    source_type: str | None = None,
) -> dict[str, Any]:
    """List improvement signals with pagination."""
    q = select(ImprovementSignal).where(
        ImprovementSignal.tenant_id == tenant_id,
    )
    if source_type:
        q = q.where(ImprovementSignal.source_type == source_type)
    q = q.order_by(ImprovementSignal.created_at.desc())

    count_q = select(func.count()).select_from(q.subquery())
    total = (await db.execute(count_q)).scalar() or 0

    offset = (page - 1) * page_size
    result = await db.execute(q.offset(offset).limit(page_size))
    items = [
        {
            "id": str(s.id),
            "source_type": s.source_type,
            "signal_kind": s.signal_kind,
            "severity": s.severity,
            "summary": s.summary,
            "confidence": s.confidence,
            "pattern_id": str(s.pattern_id) if s.pattern_id else None,
            "created_at": s.created_at.isoformat() if s.created_at else None,
        }
        for s in result.scalars().all()
    ]
    return {"items": items, "total": total, "page": page, "page_size": page_size}


async def list_patterns(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    page: int = 1,
    page_size: int = 20,
) -> dict[str, Any]:
    """List detected patterns with pagination."""
    q = select(ImprovementPattern).where(
        ImprovementPattern.tenant_id == tenant_id,
    ).order_by(ImprovementPattern.created_at.desc())

    count_q = select(func.count()).select_from(q.subquery())
    total = (await db.execute(count_q)).scalar() or 0

    offset = (page - 1) * page_size
    result = await db.execute(q.offset(offset).limit(page_size))
    items = [
        {
            "id": str(p.id),
            "pattern_kind": p.pattern_kind,
            "title": p.title,
            "description": p.description,
            "target_type": p.target_type,
            "target_name": p.target_name,
            "occurrence_count": p.occurrence_count,
            "confidence": p.confidence,
            "status": p.status,
            "proposed_action": p.proposed_action,
            "created_at": p.created_at.isoformat() if p.created_at else None,
        }
        for p in result.scalars().all()
    ]
    return {"items": items, "total": total, "page": page, "page_size": page_size}


async def list_proposals(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    page: int = 1,
    page_size: int = 20,
    status: str | None = None,
) -> dict[str, Any]:
    """List improvement proposals with pagination."""
    q = select(ImprovementProposal).where(
        ImprovementProposal.tenant_id == tenant_id,
    )
    if status:
        q = q.where(ImprovementProposal.status == status)
    q = q.order_by(ImprovementProposal.created_at.desc())

    count_q = select(func.count()).select_from(q.subquery())
    total = (await db.execute(count_q)).scalar() or 0

    offset = (page - 1) * page_size
    result = await db.execute(q.offset(offset).limit(page_size))
    items = [
        {
            "id": str(p.id),
            "title": p.title,
            "description": p.description,
            "target_type": p.target_type,
            "target_name": p.target_name,
            "status": p.status,
            "version_number": p.version_number,
            "rationale": p.rationale,
            "expected_benefit": p.expected_benefit,
            "risk_assessment": p.risk_assessment,
            "evaluation_score": p.evaluation_result.get("score", 0.0) if p.evaluation_result else 0.0,
            "pattern_id": str(p.pattern_id) if p.pattern_id else None,
            "created_at": p.created_at.isoformat() if p.created_at else None,
            "activated_at": p.activated_at.isoformat() if p.activated_at else None,
        }
        for p in result.scalars().all()
    ]
    return {"items": items, "total": total, "page": page, "page_size": page_size}


async def get_proposal_detail(
    db: AsyncSession,
    tenant_id: uuid.UUID,
    proposal_id: uuid.UUID,
) -> dict[str, Any]:
    """Get full proposal detail."""
    result = await db.execute(
        select(ImprovementProposal).where(
            ImprovementProposal.tenant_id == tenant_id,
            ImprovementProposal.id == proposal_id,
        )
    )
    p = result.scalar_one_or_none()
    if not p:
        return {"error": "Proposal not found"}
    return {
        "id": str(p.id),
        "title": p.title,
        "description": p.description,
        "target_type": p.target_type,
        "target_ref_id": str(p.target_ref_id) if p.target_ref_id else None,
        "target_name": p.target_name,
        "proposed_config": p.proposed_config,
        "previous_config": p.previous_config,
        "evidence_refs": p.evidence_refs,
        "rationale": p.rationale,
        "expected_benefit": p.expected_benefit,
        "risk_assessment": p.risk_assessment,
        "status": p.status,
        "version_number": p.version_number,
        "evaluation_result": p.evaluation_result,
        "evaluated_at": p.evaluated_at.isoformat() if p.evaluated_at else None,
        "approval_request_id": str(p.approval_request_id) if p.approval_request_id else None,
        "approved_by": str(p.approved_by) if p.approved_by else None,
        "approved_at": p.approved_at.isoformat() if p.approved_at else None,
        "activated_at": p.activated_at.isoformat() if p.activated_at else None,
        "rolled_back_at": p.rolled_back_at.isoformat() if p.rolled_back_at else None,
        "rollback_reason": p.rollback_reason,
        "pattern_id": str(p.pattern_id) if p.pattern_id else None,
        "created_at": p.created_at.isoformat() if p.created_at else None,
    }