"""REST API for scans."""

from fastapi import APIRouter, Depends, Query
from sqlalchemy import func, select, text
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from guarddog_nexus.database import get_session
from guarddog_nexus.models import Finding, Scan

router = APIRouter(prefix="/api/v1/scans", tags=["scans"])

VALID_SORT_FIELDS = {
    "id": Scan.id,
    "package_name": Scan.package_name,
    "started_at": Scan.started_at,
    "status": Scan.status,
    "total_findings": Scan.total_findings,
    "flagged": Scan.flagged,
}


@router.get("")
async def list_scans(
    limit: int = Query(50, le=200),
    offset: int = Query(0, ge=0),
    flagged: bool | None = Query(None),
    search: str | None = Query(None),
    status: str | None = Query(None),
    repository: str | None = Query(None),
    sort_by: str = Query("started_at"),
    sort_dir: str = Query("desc"),
    session: AsyncSession = Depends(get_session),
):
    q = select(Scan)

    if flagged is not None:
        q = q.where(Scan.flagged == flagged)
    if status:
        q = q.where(Scan.status == status)
    if repository:
        q = q.where(Scan.repository == repository)
    if search:
        pattern = f"%{search}%"
        q = q.where(
            Scan.package_name.ilike(pattern) | Scan.package_version.ilike(pattern)
        )

    sort_field = VALID_SORT_FIELDS.get(sort_by, Scan.started_at)
    sort_dir = "asc" if sort_dir.lower() == "asc" else "desc"
    q = q.order_by(sort_field.desc() if sort_dir == "desc" else sort_field.asc())

    q = q.offset(offset).limit(limit)

    total = await session.scalar(select(func.count(Scan.id)))

    scans = (await session.execute(q)).scalars().all()
    return {
        "total": total,
        "limit": limit,
        "offset": offset,
        "scans": [
            {
                "id": s.id,
                "package_name": s.package_name,
                "package_version": s.package_version,
                "ecosystem": s.ecosystem,
                "repository": s.repository,
                "status": s.status,
                "total_findings": s.total_findings,
                "flagged": s.flagged,
                "started_at": s.started_at.isoformat() if s.started_at else None,
                "finished_at": s.finished_at.isoformat() if s.finished_at else None,
                "error_message": s.error_message,
            }
            for s in scans
        ],
    }


@router.get("/stats")
async def scan_stats(session: AsyncSession = Depends(get_session)):
    total_scans = await session.scalar(select(func.count(Scan.id)))
    flagged_scans = await session.scalar(select(func.count(Scan.id)).where(Scan.flagged == True))
    recent_flagged = await session.scalar(
        select(func.count(Scan.id)).where(
            Scan.flagged == True,
            Scan.started_at >= func.datetime("now", "-7 days"),
        )
    )
    total_findings = await session.scalar(select(func.count(Finding.id)))

    top_rules = (
        await session.execute(
            select(
                func.json_extract(Finding.data, "$.rule").label("rule"),
                func.count(Finding.id).label("cnt"),
            )
            .group_by(text("rule"))
            .order_by(text("cnt DESC"))
            .limit(10)
        )
    ).all()

    latest_scan = await session.scalar(select(Scan).order_by(Scan.started_at.desc()).limit(1))

    return {
        "total_scans": total_scans,
        "flagged_scans": flagged_scans,
        "recent_flagged": recent_flagged,
        "total_findings": total_findings,
        "top_rules": [{"rule": r.rule, "count": r.cnt} for r in top_rules],
        "latest_scan_at": latest_scan.started_at.isoformat() if latest_scan else None,
    }


@router.get("/{scan_id}")
async def get_scan(scan_id: int, session: AsyncSession = Depends(get_session)):
    scan = await session.scalar(
        select(Scan).where(Scan.id == scan_id).options(selectinload(Scan.findings))
    )
    if not scan:
        return {"detail": "Not found"}
    return {
        "id": scan.id,
        "package_name": scan.package_name,
        "package_version": scan.package_version,
        "ecosystem": scan.ecosystem,
        "repository": scan.repository,
        "nexus_asset_url": scan.nexus_asset_url,
        "sha256": scan.sha256,
        "status": scan.status,
        "total_findings": scan.total_findings,
        "flagged": scan.flagged,
        "started_at": scan.started_at.isoformat() if scan.started_at else None,
        "finished_at": scan.finished_at.isoformat() if scan.finished_at else None,
        "error_message": scan.error_message,
        "findings": [{"id": f.id, **f.data} for f in scan.findings],
    }