"""Self-improvement models — signals, patterns, proposals, impact measurements.

All models are real SQLAlchemy models with TenantMixin (no dataclasses).
Tables get RLS via migration.
"""
from __future__ import annotations

import uuid
from datetime import datetime

from sqlalchemy import (
    DateTime,
    Float,
    ForeignKey,
    Index,
    Integer,
    String,
    Text,
    func,
)
from sqlalchemy.dialects.postgresql import JSONB, UUID as PGUUID
from sqlalchemy.orm import Mapped, mapped_column

from app.core.db import Base, TenantMixin
from app.models.owned_mixin import OwnedMixin

# Constants
SIGNAL_KINDS = ("failure", "retry", "dismissal", "correction", "observation", "handoff")
SEVERITY_LEVELS = ("info", "warning", "error")
PATTERN_KINDS = ("retry_bottleneck", "manual_correction", "suggestion_dismissal", "repetitive_handoff")
PATTERN_STATUSES = ("detected", "proposal_created", "resolved", "ignored")
PROPOSAL_STATUSES = (
    "draft", "evaluating", "evaluated", "pending_approval",
    "approved", "active", "rolled_back", "rejected", "expired",
)
PROPOSAL_TARGET_TYPES = ("agent", "skill", "trigger", "workflow", "miniapp_template", "plugin_patch")


class ImprovementSignal(Base, TenantMixin):
    """A single improvement signal collected from real system usage.

    References source data (AgentRun, WorkflowInstance, ProactiveSuggestion,
    AuditLog) by ID — stores no personal data copies.
    """
    __tablename__ = "improvement_signals"
    __table_args__ = (
        Index("ix_impr_signals_tenant_kind", "tenant_id", "signal_kind"),
        Index("ix_impr_signals_tenant_source", "tenant_id", "source_type"),
        Index("ix_impr_signals_tenant_pattern", "tenant_id", "pattern_id"),
    )

    id: Mapped[uuid.UUID] = mapped_column(PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    source_type: Mapped[str] = mapped_column(String(50), nullable=False)
    source_ref_id: Mapped[uuid.UUID | None] = mapped_column(PGUUID(as_uuid=True), nullable=True)
    source_metadata: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    summary: Mapped[str] = mapped_column(Text, nullable=False)
    signal_kind: Mapped[str] = mapped_column(String(30), nullable=False)
    severity: Mapped[str] = mapped_column(String(20), nullable=False, default="info")
    confidence: Mapped[float] = mapped_column(Float, nullable=False, default=0.5)
    pattern_id: Mapped[uuid.UUID | None] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("improvement_patterns.id", ondelete="SET NULL"), nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())


class ImprovementPattern(Base, TenantMixin):
    """A detected pattern from grouped improvement signals."""
    __tablename__ = "improvement_patterns"
    __table_args__ = (
        Index("ix_impr_patterns_tenant_status", "tenant_id", "status"),
        Index("ix_impr_patterns_tenant_target", "tenant_id", "target_type"),
    )

    id: Mapped[uuid.UUID] = mapped_column(PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    pattern_kind: Mapped[str] = mapped_column(String(40), nullable=False)
    title: Mapped[str] = mapped_column(String(300), nullable=False)
    description: Mapped[str] = mapped_column(Text, nullable=False, default="")
    target_type: Mapped[str] = mapped_column(String(30), nullable=False)
    target_name: Mapped[str] = mapped_column(String(200), nullable=False, default="unknown")
    evidence_refs: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
    occurrence_count: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
    confidence: Mapped[float] = mapped_column(Float, nullable=False, default=0.5)
    status: Mapped[str] = mapped_column(String(20), nullable=False, default="detected")
    proposed_action: Mapped[str] = mapped_column(Text, nullable=False, default="")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now())


class ImprovementProposal(Base, TenantMixin, OwnedMixin):
    """A versioned improvement proposal with lifecycle.

    Status flow:
    draft -> evaluating -> evaluated -> pending_approval -> approved -> active
                                                                     -> rolled_back
                                  rejected <- pending_approval
                                  expired <- pending_approval
    """
    __tablename__ = "improvement_proposals"
    __table_args__ = (
        Index("ix_impr_proposals_tenant_status", "tenant_id", "status"),
        Index("ix_impr_proposals_tenant_target", "tenant_id", "target_type"),
        Index("ix_impr_proposals_tenant_pattern", "tenant_id", "pattern_id"),
    )

    id: Mapped[uuid.UUID] = mapped_column(PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    pattern_id: Mapped[uuid.UUID | None] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("improvement_patterns.id", ondelete="SET NULL"), nullable=True
    )
    title: Mapped[str] = mapped_column(String(300), nullable=False)
    description: Mapped[str] = mapped_column(Text, nullable=False, default="")
    target_type: Mapped[str] = mapped_column(String(30), nullable=False)
    target_ref_id: Mapped[uuid.UUID | None] = mapped_column(PGUUID(as_uuid=True), nullable=True)
    target_name: Mapped[str | None] = mapped_column(String(200), nullable=True)
    version_number: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
    proposed_config: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    previous_config: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    evidence_refs: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
    rationale: Mapped[str] = mapped_column(Text, nullable=False, default="")
    expected_benefit: Mapped[str] = mapped_column(Text, nullable=False, default="")
    risk_assessment: Mapped[str] = mapped_column(Text, nullable=False, default="")
    evaluation_result: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    evaluated_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    approval_request_id: Mapped[uuid.UUID | None] = mapped_column(PGUUID(as_uuid=True), nullable=True)
    approved_by: Mapped[uuid.UUID | None] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )
    approved_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    activated_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    rolled_back_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    rollback_reason: Mapped[str | None] = mapped_column(Text, nullable=True)
    status: Mapped[str] = mapped_column(String(20), nullable=False, default="draft")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now())


class ImpactMeasurement(Base, TenantMixin):
    """Pre/post impact measurement for an activated proposal."""
    __tablename__ = "improvement_impact_measurements"
    __table_args__ = (
        Index("ix_impr_impact_tenant_proposal", "tenant_id", "proposal_id"),
    )

    id: Mapped[uuid.UUID] = mapped_column(PGUUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    proposal_id: Mapped[uuid.UUID] = mapped_column(
        PGUUID(as_uuid=True), ForeignKey("improvement_proposals.id", ondelete="CASCADE"), nullable=False
    )
    pre_metrics: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    post_metrics: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    delta: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    assessment: Mapped[str] = mapped_column(Text, nullable=False, default="")
    is_positive: Mapped[str] = mapped_column(String(20), nullable=False, default="neutral")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())