"""Data sources management endpoints (admin only).

Provides a centralized panel for managing all external data sources
(Atomic Red Team, Sigma, LOLBAS, GTFOBins, CALDERA, Elastic, etc.)
including sync triggers, enable/disable toggles, and statistics.
"""

import logging
from datetime import datetime
from typing import Optional

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

from app.database import get_db
from app.dependencies.auth import require_role
from app.models.user import User
from app.models.data_source import DataSource
from app.services.audit_service import log_action


# ---------------------------------------------------------------------------
# Pydantic schemas for request validation
# ---------------------------------------------------------------------------

class DataSourceUpdate(BaseModel):
    """Payload for updating a data source — only allowed fields."""
    is_enabled: Optional[bool] = None
    sync_frequency: Optional[str] = None
    config: Optional[dict] = None

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/data-sources", tags=["data-sources"])


# ---------------------------------------------------------------------------
# Sync dispatcher — maps source name → import function
# ---------------------------------------------------------------------------

def _get_sync_handler(source_name: str):
    """Lazily import and return the sync function for *source_name*.

    We import lazily to avoid circular imports and to only load the
    modules that are actually needed.
    """
    handlers = {
        "atomic_red_team": ("app.services.atomic_import_service", "import_atomic_red_team"),
        "sigma": ("app.services.sigma_import_service", "sync"),
        "lolbas": ("app.services.lolbas_import_service", "sync"),
        "gtfobins": ("app.services.lolbas_import_service", "sync_gtfobins"),
        "caldera": ("app.services.caldera_import_service", "sync"),
        "elastic_rules": ("app.services.elastic_import_service", "sync"),
        "mitre_cti": ("app.services.threat_actor_import_service", "sync"),
        "d3fend": ("app.services.d3fend_import_service", "sync"),
    }

    if source_name not in handlers:
        return None

    module_path, func_name = handlers[source_name]
    import importlib
    mod = importlib.import_module(module_path)
    return getattr(mod, func_name)


# ---------------------------------------------------------------------------
# Endpoints
# ---------------------------------------------------------------------------


@router.get("")
def list_data_sources(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """List all registered data sources.

    **Requires** the ``admin`` role.
    """
    sources = db.query(DataSource).order_by(DataSource.name).all()
    return [
        {
            "id": str(s.id),
            "name": s.name,
            "display_name": s.display_name,
            "type": s.type,
            "url": s.url,
            "description": s.description,
            "is_enabled": s.is_enabled,
            "last_sync_at": s.last_sync_at.isoformat() if s.last_sync_at else None,
            "last_sync_status": s.last_sync_status,
            "last_sync_stats": s.last_sync_stats,
            "sync_frequency": s.sync_frequency,
            "config": s.config,
            "created_at": s.created_at.isoformat() if s.created_at else None,
        }
        for s in sources
    ]


@router.patch("/{source_id}")
def update_data_source(
    source_id: str,
    body: DataSourceUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Update a data source (enable/disable, change config).

    **Requires** the ``admin`` role.
    """
    ds = db.query(DataSource).filter(DataSource.id == source_id).first()
    if not ds:
        raise HTTPException(status_code=404, detail="Data source not found")

    update_data = body.model_dump(exclude_unset=True)

    if "is_enabled" in update_data:
        ds.is_enabled = update_data["is_enabled"]
    if "sync_frequency" in update_data:
        ds.sync_frequency = update_data["sync_frequency"]
    if "config" in update_data:
        ds.config = update_data["config"]

    db.commit()

    log_action(
        db,
        user_id=current_user.id,
        action="update_data_source",
        entity_type="data_source",
        entity_id=str(ds.id),
        details={"updates": update_data},
    )

    return {"message": "Data source updated", "id": str(ds.id)}


@router.post("/{source_id}/sync")
def sync_data_source(
    source_id: str,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Trigger sync/import for a specific data source.

    **Requires** the ``admin`` role.
    """
    ds = db.query(DataSource).filter(DataSource.id == source_id).first()
    if not ds:
        raise HTTPException(status_code=404, detail="Data source not found")

    handler = _get_sync_handler(ds.name)
    if handler is None:
        raise HTTPException(
            status_code=400,
            detail=f"No sync handler available for '{ds.name}'",
        )

    # Mark as in_progress
    ds.last_sync_status = "in_progress"
    db.commit()

    try:
        summary = handler(db)
    except Exception as exc:
        logger.error("Sync failed for %s: %s", ds.name, exc, exc_info=True)
        ds.last_sync_status = "error"
        ds.last_sync_at = datetime.utcnow()
        ds.last_sync_stats = {"error": str(exc)}
        db.commit()
        raise HTTPException(
            status_code=500,
            detail=f"Sync failed for '{ds.display_name}'. Check server logs for details.",
        )

    # Update DS record (the handler may already have done this,
    # but we ensure it here as well)
    ds.last_sync_at = datetime.utcnow()
    ds.last_sync_status = "success"
    ds.last_sync_stats = summary
    db.commit()

    return {
        "message": f"Sync complete for {ds.display_name}",
        "source": ds.name,
        "stats": summary,
    }


@router.post("/sync-all")
def sync_all_data_sources(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Trigger sync for all enabled data sources (sequentially).

    **Requires** the ``admin`` role.
    """
    enabled_sources = (
        db.query(DataSource)
        .filter(DataSource.is_enabled == True)
        .order_by(DataSource.name)
        .all()
    )

    results = []
    for ds in enabled_sources:
        handler = _get_sync_handler(ds.name)
        if handler is None:
            results.append({
                "source": ds.name,
                "status": "skipped",
                "detail": "No sync handler available",
            })
            continue

        ds.last_sync_status = "in_progress"
        db.commit()

        try:
            summary = handler(db)
            ds.last_sync_at = datetime.utcnow()
            ds.last_sync_status = "success"
            ds.last_sync_stats = summary
            db.commit()
            results.append({
                "source": ds.name,
                "status": "success",
                "stats": summary,
            })
        except Exception as exc:
            logger.error("Sync failed for %s: %s", ds.name, exc, exc_info=True)
            ds.last_sync_status = "error"
            ds.last_sync_at = datetime.utcnow()
            ds.last_sync_stats = {"error": str(exc)}
            db.commit()
            results.append({
                "source": ds.name,
                "status": "error",
                "detail": "Sync failed. Check server logs for details.",
            })

    log_action(
        db,
        user_id=current_user.id,
        action="sync_all_data_sources",
        entity_type="data_source",
        entity_id=None,
        details={"results": results},
    )

    return {"message": "Sync all complete", "results": results}


@router.get("/{source_id}/stats")
def get_data_source_stats(
    source_id: str,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_role("admin")),
):
    """Get detailed statistics for a specific data source.

    **Requires** the ``admin`` role.
    """
    ds = db.query(DataSource).filter(DataSource.id == source_id).first()
    if not ds:
        raise HTTPException(status_code=404, detail="Data source not found")

    # Count items from this source
    from app.models.test_template import TestTemplate
    from app.models.detection_rule import DetectionRule

    template_count = 0
    rule_count = 0

    if ds.type == "attack_procedure":
        template_count = (
            db.query(TestTemplate)
            .filter(TestTemplate.source == ds.name)
            .count()
        )
    elif ds.type == "detection_rule":
        rule_count = (
            db.query(DetectionRule)
            .filter(DetectionRule.source == ds.name)
            .count()
        )

    return {
        "id": str(ds.id),
        "name": ds.name,
        "display_name": ds.display_name,
        "type": ds.type,
        "is_enabled": ds.is_enabled,
        "last_sync_at": ds.last_sync_at.isoformat() if ds.last_sync_at else None,
        "last_sync_status": ds.last_sync_status,
        "last_sync_stats": ds.last_sync_stats,
        "total_templates": template_count,
        "total_rules": rule_count,
    }