"""REST API for packages (distinct packages across scans)."""

import csv
import io

from fastapi import APIRouter, Depends, Query, Response
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from guarddog_nexus.constants import (
    CSV_MEDIA_TYPE,
    DEFAULT_OFFSET,
    DEFAULT_PAGE_SIZE,
    DEFAULT_SORT_BY_PACKAGES,
    DEFAULT_SORT_DIR,
    MAX_PAGE_SIZE,
)
from guarddog_nexus.database import get_session
from guarddog_nexus.models import Finding, Scan
from guarddog_nexus.queries import build_package_list_query

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


@router.get("")
async def list_packages(
    limit: int = Query(DEFAULT_PAGE_SIZE, le=MAX_PAGE_SIZE),
    offset: int = Query(DEFAULT_OFFSET, ge=0),
    ecosystem: str | None = Query(None),
    flagged: bool | None = Query(None),
    search: str | None = Query(None),
    repository: str | None = Query(None),
    sort_by: str = Query(DEFAULT_SORT_BY_PACKAGES),
    sort_dir: str = Query(DEFAULT_SORT_DIR),
    session: AsyncSession = Depends(get_session),
):
    rows_q, total_q = build_package_list_query(
        flagged=flagged,
        ecosystem=ecosystem,
        repository=repository,
        search=search,
        sort_by=sort_by,
        sort_dir=sort_dir,
        limit=limit,
        offset=offset,
    )
    total = await session.scalar(total_q)
    rows = (await session.execute(rows_q)).all()

    return {
        "total": total,
        "limit": limit,
        "offset": offset,
        "packages": [
            {
                "name": r.pkg_name,
                "version": r.pkg_ver,
                "ecosystem": r.ecosystem,
                "repository": r.repository,
                "last_scanned_at": r.last_scan.isoformat() if r.last_scan else None,
                "flagged": bool(r.is_flagged),
                "total_findings": r.findings_sum,
                "latest_scan_id": r.sid,
            }
            for r in rows
        ],
    }


@router.get("/export")
async def export_packages_csv(
    flagged: bool | None = Query(None),
    search: str | None = Query(None),
    session: AsyncSession = Depends(get_session),
):
    rows_q, _total_q = build_package_list_query(
        flagged=flagged,
        search=search,
        sort_by=DEFAULT_SORT_BY_PACKAGES,
        sort_dir=DEFAULT_SORT_DIR,
        limit=MAX_PAGE_SIZE,
        offset=0,
    )
    rows = (await session.execute(rows_q)).all()

    output = io.StringIO()
    writer = csv.writer(output)
    writer.writerow(
        [
            "name", "version", "ecosystem", "repository",
            "last_scanned_at", "flagged", "total_findings",
        ]
    )
    for r in rows:
        writer.writerow(
            [
                r.pkg_name, r.pkg_ver, r.ecosystem, r.repository,
                r.last_scan.isoformat() if r.last_scan else "",
                bool(r.is_flagged),
                r.findings_sum,
            ]
        )

    return Response(
        content=output.getvalue(),
        media_type=CSV_MEDIA_TYPE,
        headers={"Content-Disposition": "attachment; filename=packages_export.csv"},
    )


@router.get("/{name}/{version}")
async def get_package(
    name: str,
    version: str,
    session: AsyncSession = Depends(get_session),
):
    scans = (
        (
            await session.execute(
                select(Scan)
                .where(Scan.package_name == name, Scan.package_version == version)
                .order_by(Scan.started_at.desc())
            )
        )
        .scalars()
        .all()
    )

    if not scans:
        return {"detail": "Not found"}

    all_findings: list[dict] = []
    for s in scans:
        findings = (
            (await session.execute(select(Finding).where(Finding.scan_id == s.id)))
            .scalars()
            .all()
        )
        for f in findings:
            all_findings.append({"id": f.id, **f.data, "report": f.report})

    return {
        "name": scans[0].package_name,
        "version": scans[0].package_version,
        "ecosystem": scans[0].ecosystem,
        "repository": scans[0].repository,
        "flagged": any(s.flagged for s in scans),
        "scans": [
            {
                "id": s.id,
                "status": s.status,
                "total_findings": s.total_findings,
                "flagged": s.flagged,
                "started_at": s.started_at.isoformat() if s.started_at else None,
            }
            for s in scans
        ],
        "findings": all_findings,
    }