"""
Source Policy Router — Manages allowed compliance data sources.

Controls which legal sources the RAG corpus may use,
operations matrix, PII rules, and provides audit trail.

Endpoints:
  GET    /api/v1/admin/sources              — List all sources
  POST   /api/v1/admin/sources              — Add new source
  GET    /api/v1/admin/sources/{id}         — Get source by ID
  PUT    /api/v1/admin/sources/{id}         — Update source
  DELETE /api/v1/admin/sources/{id}         — Remove source
  GET    /api/v1/admin/operations-matrix    — Operations matrix
  PUT    /api/v1/admin/operations/{id}      — Update operation
  GET    /api/v1/admin/pii-rules            — List PII rules
  POST   /api/v1/admin/pii-rules            — Create PII rule
  PUT    /api/v1/admin/pii-rules/{id}       — Update PII rule
  DELETE /api/v1/admin/pii-rules/{id}       — Delete PII rule
  GET    /api/v1/admin/policy-audit         — Audit trail
  GET    /api/v1/admin/policy-stats         — Dashboard statistics
  GET    /api/v1/admin/compliance-report    — Compliance report
"""

import uuid
from datetime import datetime
from typing import Optional, List

from fastapi import APIRouter, HTTPException, Depends, Query
from pydantic import BaseModel, Field
from sqlalchemy.orm import Session

from database import get_db
from compliance.db.source_policy_models import (
    AllowedSourceDB,
    BlockedContentDB,
    SourceOperationDB,
    PIIRuleDB,
    SourcePolicyAuditDB,
)


router = APIRouter(prefix="/v1/admin", tags=["source-policy"])


# =============================================================================
# Pydantic Schemas
# =============================================================================

class SourceCreate(BaseModel):
    domain: str
    name: str
    description: Optional[str] = None
    license: Optional[str] = None
    legal_basis: Optional[str] = None
    trust_boost: float = Field(default=0.5, ge=0.0, le=1.0)
    source_type: str = "legal"
    active: bool = True
    metadata: Optional[dict] = None


class SourceUpdate(BaseModel):
    domain: Optional[str] = None
    name: Optional[str] = None
    description: Optional[str] = None
    license: Optional[str] = None
    legal_basis: Optional[str] = None
    trust_boost: Optional[float] = Field(default=None, ge=0.0, le=1.0)
    source_type: Optional[str] = None
    active: Optional[bool] = None
    metadata: Optional[dict] = None


class SourceResponse(BaseModel):
    id: str
    domain: str
    name: str
    description: Optional[str] = None
    license: Optional[str] = None
    legal_basis: Optional[str] = None
    trust_boost: float
    source_type: str
    active: bool
    metadata: Optional[dict] = None
    created_at: str
    updated_at: Optional[str] = None

    class Config:
        from_attributes = True


class OperationUpdate(BaseModel):
    allowed: bool
    conditions: Optional[str] = None


class PIIRuleCreate(BaseModel):
    name: str
    description: Optional[str] = None
    pattern: Optional[str] = None
    category: str
    action: str = "mask"
    active: bool = True


class PIIRuleUpdate(BaseModel):
    name: Optional[str] = None
    description: Optional[str] = None
    pattern: Optional[str] = None
    category: Optional[str] = None
    action: Optional[str] = None
    active: Optional[bool] = None


# =============================================================================
# Helper: Audit logging
# =============================================================================

def _log_audit(db: Session, action: str, entity_type: str, entity_id, old_values=None, new_values=None):
    audit = SourcePolicyAuditDB(
        action=action,
        entity_type=entity_type,
        entity_id=entity_id,
        old_values=old_values,
        new_values=new_values,
        user_id="system",
    )
    db.add(audit)


def _source_to_dict(source: AllowedSourceDB) -> dict:
    return {
        "id": str(source.id),
        "domain": source.domain,
        "name": source.name,
        "description": source.description,
        "license": source.license,
        "legal_basis": source.legal_basis,
        "trust_boost": source.trust_boost,
        "source_type": source.source_type,
        "active": source.active,
    }


# =============================================================================
# Sources CRUD
# =============================================================================

@router.get("/sources")
async def list_sources(
    active_only: bool = Query(False),
    source_type: Optional[str] = Query(None),
    license: Optional[str] = Query(None),
    db: Session = Depends(get_db),
):
    """List all allowed sources with optional filters."""
    query = db.query(AllowedSourceDB)
    if active_only:
        query = query.filter(AllowedSourceDB.active == True)
    if source_type:
        query = query.filter(AllowedSourceDB.source_type == source_type)
    if license:
        query = query.filter(AllowedSourceDB.license == license)
    sources = query.order_by(AllowedSourceDB.name).all()
    return {
        "sources": [
            {
                "id": str(s.id),
                "domain": s.domain,
                "name": s.name,
                "description": s.description,
                "license": s.license,
                "legal_basis": s.legal_basis,
                "trust_boost": s.trust_boost,
                "source_type": s.source_type,
                "active": s.active,
                "metadata": s.metadata_,
                "created_at": s.created_at.isoformat() if s.created_at else None,
                "updated_at": s.updated_at.isoformat() if s.updated_at else None,
            }
            for s in sources
        ],
        "count": len(sources),
    }


@router.post("/sources")
async def create_source(
    data: SourceCreate,
    db: Session = Depends(get_db),
):
    """Add a new allowed source."""
    existing = db.query(AllowedSourceDB).filter(AllowedSourceDB.domain == data.domain).first()
    if existing:
        raise HTTPException(status_code=409, detail=f"Source with domain '{data.domain}' already exists")

    source = AllowedSourceDB(
        domain=data.domain,
        name=data.name,
        description=data.description,
        license=data.license,
        legal_basis=data.legal_basis,
        trust_boost=data.trust_boost,
        source_type=data.source_type,
        active=data.active,
        metadata_=data.metadata,
    )
    db.add(source)
    _log_audit(db, "create", "source", source.id, new_values=_source_to_dict(source))
    db.commit()
    db.refresh(source)

    return {
        "id": str(source.id),
        "domain": source.domain,
        "name": source.name,
        "created_at": source.created_at.isoformat(),
    }


@router.get("/sources/{source_id}")
async def get_source(source_id: str, db: Session = Depends(get_db)):
    """Get a specific source."""
    source = db.query(AllowedSourceDB).filter(AllowedSourceDB.id == source_id).first()
    if not source:
        raise HTTPException(status_code=404, detail="Source not found")
    return {
        "id": str(source.id),
        "domain": source.domain,
        "name": source.name,
        "description": source.description,
        "license": source.license,
        "legal_basis": source.legal_basis,
        "trust_boost": source.trust_boost,
        "source_type": source.source_type,
        "active": source.active,
        "metadata": source.metadata_,
        "created_at": source.created_at.isoformat() if source.created_at else None,
        "updated_at": source.updated_at.isoformat() if source.updated_at else None,
    }


@router.put("/sources/{source_id}")
async def update_source(
    source_id: str,
    data: SourceUpdate,
    db: Session = Depends(get_db),
):
    """Update an existing source."""
    source = db.query(AllowedSourceDB).filter(AllowedSourceDB.id == source_id).first()
    if not source:
        raise HTTPException(status_code=404, detail="Source not found")

    old_values = _source_to_dict(source)
    update_data = data.model_dump(exclude_unset=True)

    # Rename metadata to metadata_ for the DB column
    if "metadata" in update_data:
        update_data["metadata_"] = update_data.pop("metadata")

    for key, value in update_data.items():
        setattr(source, key, value)

    _log_audit(db, "update", "source", source.id, old_values=old_values, new_values=update_data)
    db.commit()
    db.refresh(source)

    return {"status": "updated", "id": str(source.id)}


@router.delete("/sources/{source_id}")
async def delete_source(source_id: str, db: Session = Depends(get_db)):
    """Remove an allowed source."""
    source = db.query(AllowedSourceDB).filter(AllowedSourceDB.id == source_id).first()
    if not source:
        raise HTTPException(status_code=404, detail="Source not found")

    old_values = _source_to_dict(source)
    _log_audit(db, "delete", "source", source.id, old_values=old_values)

    # Also delete associated operations
    db.query(SourceOperationDB).filter(SourceOperationDB.source_id == source_id).delete()
    db.delete(source)
    db.commit()

    return {"status": "deleted", "id": source_id}


# =============================================================================
# Operations Matrix
# =============================================================================

@router.get("/operations-matrix")
async def get_operations_matrix(db: Session = Depends(get_db)):
    """Get the full operations matrix."""
    operations = db.query(SourceOperationDB).all()
    return {
        "operations": [
            {
                "id": str(op.id),
                "source_id": str(op.source_id),
                "operation": op.operation,
                "allowed": op.allowed,
                "conditions": op.conditions,
            }
            for op in operations
        ],
        "count": len(operations),
    }


@router.put("/operations/{operation_id}")
async def update_operation(
    operation_id: str,
    data: OperationUpdate,
    db: Session = Depends(get_db),
):
    """Update an operation in the matrix."""
    op = db.query(SourceOperationDB).filter(SourceOperationDB.id == operation_id).first()
    if not op:
        raise HTTPException(status_code=404, detail="Operation not found")

    op.allowed = data.allowed
    if data.conditions is not None:
        op.conditions = data.conditions

    _log_audit(db, "update", "operation", op.id, new_values={"allowed": data.allowed})
    db.commit()

    return {"status": "updated", "id": str(op.id)}


# =============================================================================
# PII Rules
# =============================================================================

@router.get("/pii-rules")
async def list_pii_rules(
    category: Optional[str] = Query(None),
    db: Session = Depends(get_db),
):
    """List all PII rules with optional category filter."""
    query = db.query(PIIRuleDB)
    if category:
        query = query.filter(PIIRuleDB.category == category)
    rules = query.order_by(PIIRuleDB.category, PIIRuleDB.name).all()
    return {
        "rules": [
            {
                "id": str(r.id),
                "name": r.name,
                "description": r.description,
                "pattern": r.pattern,
                "category": r.category,
                "action": r.action,
                "active": r.active,
                "created_at": r.created_at.isoformat() if r.created_at else None,
            }
            for r in rules
        ],
        "count": len(rules),
    }


@router.post("/pii-rules")
async def create_pii_rule(data: PIIRuleCreate, db: Session = Depends(get_db)):
    """Create a new PII rule."""
    rule = PIIRuleDB(
        name=data.name,
        description=data.description,
        pattern=data.pattern,
        category=data.category,
        action=data.action,
        active=data.active,
    )
    db.add(rule)
    _log_audit(db, "create", "pii_rule", rule.id, new_values={"name": data.name, "category": data.category})
    db.commit()
    db.refresh(rule)

    return {"id": str(rule.id), "name": rule.name}


@router.put("/pii-rules/{rule_id}")
async def update_pii_rule(rule_id: str, data: PIIRuleUpdate, db: Session = Depends(get_db)):
    """Update a PII rule."""
    rule = db.query(PIIRuleDB).filter(PIIRuleDB.id == rule_id).first()
    if not rule:
        raise HTTPException(status_code=404, detail="PII rule not found")

    update_data = data.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(rule, key, value)

    _log_audit(db, "update", "pii_rule", rule.id, new_values=update_data)
    db.commit()

    return {"status": "updated", "id": str(rule.id)}


@router.delete("/pii-rules/{rule_id}")
async def delete_pii_rule(rule_id: str, db: Session = Depends(get_db)):
    """Delete a PII rule."""
    rule = db.query(PIIRuleDB).filter(PIIRuleDB.id == rule_id).first()
    if not rule:
        raise HTTPException(status_code=404, detail="PII rule not found")

    _log_audit(db, "delete", "pii_rule", rule.id, old_values={"name": rule.name, "category": rule.category})
    db.delete(rule)
    db.commit()

    return {"status": "deleted", "id": rule_id}


# =============================================================================
# Blocked Content
# =============================================================================

@router.get("/blocked-content")
async def list_blocked_content(
    limit: int = Query(50, ge=1, le=500),
    offset: int = Query(0, ge=0),
    domain: Optional[str] = None,
    date_from: Optional[str] = Query(None, alias="from"),
    date_to: Optional[str] = Query(None, alias="to"),
    db: Session = Depends(get_db),
):
    """List blocked content entries."""
    query = db.query(BlockedContentDB)

    if domain:
        query = query.filter(BlockedContentDB.domain == domain)

    if date_from:
        try:
            from_dt = datetime.fromisoformat(date_from)
            query = query.filter(BlockedContentDB.created_at >= from_dt)
        except ValueError:
            pass

    if date_to:
        try:
            to_dt = datetime.fromisoformat(date_to)
            query = query.filter(BlockedContentDB.created_at <= to_dt)
        except ValueError:
            pass

    total = query.count()
    entries = query.order_by(BlockedContentDB.created_at.desc()).offset(offset).limit(limit).all()

    return {
        "blocked": [
            {
                "id": str(e.id),
                "url": e.url,
                "domain": e.domain,
                "block_reason": e.block_reason,
                "rule_id": str(e.rule_id) if e.rule_id else None,
                "details": e.details,
                "created_at": e.created_at.isoformat() if e.created_at else None,
            }
            for e in entries
        ],
        "total": total,
    }


# =============================================================================
# Audit Trail
# =============================================================================

@router.get("/policy-audit")
async def get_policy_audit(
    limit: int = Query(50, ge=1, le=500),
    offset: int = Query(0, ge=0),
    entity_type: Optional[str] = None,
    date_from: Optional[str] = Query(None, alias="from"),
    date_to: Optional[str] = Query(None, alias="to"),
    db: Session = Depends(get_db),
):
    """Get the audit trail for source policy changes."""
    query = db.query(SourcePolicyAuditDB)
    if entity_type:
        query = query.filter(SourcePolicyAuditDB.entity_type == entity_type)

    if date_from:
        try:
            from_dt = datetime.fromisoformat(date_from)
            query = query.filter(SourcePolicyAuditDB.created_at >= from_dt)
        except ValueError:
            pass

    if date_to:
        try:
            to_dt = datetime.fromisoformat(date_to)
            query = query.filter(SourcePolicyAuditDB.created_at <= to_dt)
        except ValueError:
            pass

    total = query.count()
    entries = query.order_by(SourcePolicyAuditDB.created_at.desc()).offset(offset).limit(limit).all()

    return {
        "entries": [
            {
                "id": str(e.id),
                "action": e.action,
                "entity_type": e.entity_type,
                "entity_id": str(e.entity_id) if e.entity_id else None,
                "old_values": e.old_values,
                "new_values": e.new_values,
                "user_id": e.user_id,
                "created_at": e.created_at.isoformat() if e.created_at else None,
            }
            for e in entries
        ],
        "total": total,
        "limit": limit,
        "offset": offset,
    }


# =============================================================================
# Dashboard Statistics
# =============================================================================

@router.get("/policy-stats")
async def get_policy_stats(db: Session = Depends(get_db)):
    """Get dashboard statistics for source policy."""
    total_sources = db.query(AllowedSourceDB).count()
    active_sources = db.query(AllowedSourceDB).filter(AllowedSourceDB.active == True).count()
    pii_rules = db.query(PIIRuleDB).filter(PIIRuleDB.active == True).count()

    # Count blocked content entries from today
    today_start = datetime.utcnow().replace(hour=0, minute=0, second=0, microsecond=0)
    blocked_today = db.query(BlockedContentDB).filter(
        BlockedContentDB.created_at >= today_start,
    ).count()

    blocked_total = db.query(BlockedContentDB).count()

    return {
        "active_policies": active_sources,
        "allowed_sources": total_sources,
        "pii_rules": pii_rules,
        "blocked_today": blocked_today,
        "blocked_total": blocked_total,
    }


@router.get("/compliance-report")
async def get_compliance_report(db: Session = Depends(get_db)):
    """Generate a compliance report for source policies."""
    sources = db.query(AllowedSourceDB).filter(AllowedSourceDB.active == True).all()
    pii_rules = db.query(PIIRuleDB).filter(PIIRuleDB.active == True).all()

    return {
        "report_date": datetime.utcnow().isoformat(),
        "summary": {
            "active_sources": len(sources),
            "active_pii_rules": len(pii_rules),
            "source_types": list(set(s.source_type for s in sources)),
            "licenses": list(set(s.license for s in sources if s.license)),
        },
        "sources": [
            {
                "domain": s.domain,
                "name": s.name,
                "license": s.license,
                "legal_basis": s.legal_basis,
                "trust_boost": s.trust_boost,
            }
            for s in sources
        ],
        "pii_rules": [
            {
                "name": r.name,
                "category": r.category,
                "action": r.action,
            }
            for r in pii_rules
        ],
    }