"""Web UI routes — Jinja2 + htmx pages."""

import datetime

from fastapi import APIRouter, Depends, Request
from fastapi.responses import HTMLResponse
from jinja2 import Environment, PackageLoader, select_autoescape
from sqlalchemy import Integer, cast, func, select, text
from sqlalchemy.ext.asyncio import AsyncSession

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

router = APIRouter(tags=["web"])

_jinja_env = Environment(
    loader=PackageLoader("guarddog_nexus", "web/templates"),
    autoescape=select_autoescape(),
)

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

PACKAGE_SORT_FIELDS = {
    "name": Scan.package_name,
    "last_scanned_at": Scan.started_at,
    "total_findings": Scan.total_findings,
    "flagged": Scan.flagged,
}


def _render(name: str, **context) -> HTMLResponse:
    template = _jinja_env.get_template(name)
    return HTMLResponse(template.render(**context))


@router.get("/", response_class=HTMLResponse)
async def dashboard(request: Request, session: AsyncSession = Depends(get_session)):
    ctx = await _dashboard_data(session)
    return _render("dashboard.html", **ctx, request=request)


@router.get("/dashboard/stats", response_class=HTMLResponse)
async def dashboard_stats_fragment(session: AsyncSession = Depends(get_session)):
    ctx = await _dashboard_data(session)
    return _render("dashboard_stats.html", **ctx)


async def _dashboard_data(session: AsyncSession) -> dict:
    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)))

    warnings_count = await session.scalar(
        select(func.count(Finding.id)).where(
            func.json_extract(Finding.data, "$.severity") == "WARNING"
        )
    )
    errors_count = await session.scalar(
        select(func.count(Finding.id)).where(
            func.json_extract(Finding.data, "$.severity") == "ERROR"
        )
    )

    latest_flagged = (
        (
            await session.execute(
                select(Scan).where(Scan.flagged == True).order_by(Scan.started_at.desc()).limit(8)
            )
        )
        .scalars()
        .all()
    )

    latest_scans = (
        (await session.execute(select(Scan).order_by(Scan.started_at.desc()).limit(10)))
        .scalars()
        .all()
    )

    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()

    most_flagged = (
        await session.execute(
            select(
                Scan.package_name,
                Scan.package_version,
                func.sum(Scan.total_findings).label("total"),
                func.max(Scan.started_at).label("last_scan"),
            )
            .where(Scan.flagged == True)
            .group_by(Scan.package_name, Scan.package_version)
            .order_by(func.sum(Scan.total_findings).desc())
            .limit(8)
        )
    ).all()

    max_findings = max((r.total for r in most_flagged), default=1)

    days_raw = (
        await session.execute(
            select(
                func.date(Scan.started_at).label("day"),
                func.count(Scan.id).label("cnt"),
                func.sum(cast(Scan.flagged, Integer)).label("flagged_cnt"),
            )
            .where(Scan.started_at >= func.datetime("now", "-14 days"))
            .group_by("day")
            .order_by("day")
        )
    ).all()

    return {
        "total_scans": total_scans or 0,
        "flagged_scans": flagged_scans or 0,
        "recent_flagged": recent_flagged or 0,
        "total_findings": total_findings or 0,
        "warnings_count": warnings_count or 0,
        "errors_count": errors_count or 0,
        "latest_flagged": latest_flagged,
        "latest_scans": latest_scans,
        "top_rules": [(r.rule, r.cnt) for r in top_rules],
        "most_flagged": most_flagged,
        "max_findings": max_findings,
        "days": [(d.day, d.cnt, d.flagged_cnt) for d in days_raw],
        "now": datetime.datetime.now(datetime.timezone.utc),
    }


@router.get("/scans", response_class=HTMLResponse)
async def scans_list(
    request: Request,
    page: int = 1,
    flagged: str = "",
    search: str = "",
    status: str = "",
    sort_by: str = "started_at",
    sort_dir: str = "desc",
    session: AsyncSession = Depends(get_session),
):
    per_page = 50
    offset = (page - 1) * per_page

    count_q = select(func.count(Scan.id))
    q = select(Scan)

    if flagged == "1":
        q = q.where(Scan.flagged == True)
        count_q = count_q.where(Scan.flagged == True)
    if status:
        q = q.where(Scan.status == status)
        count_q = count_q.where(Scan.status == status)
    if search:
        pattern = f"%{search}%"
        condition = Scan.package_name.ilike(pattern) | Scan.package_version.ilike(pattern)
        q = q.where(condition)
        count_q = count_q.where(condition)

    sort_field = SCAN_SORT_FIELDS.get(sort_by, Scan.started_at)
    q = q.order_by(sort_field.desc() if sort_dir == "desc" else sort_field.asc())
    q = q.offset(offset).limit(per_page)

    scans = (await session.execute(q)).scalars().all()
    total = await session.scalar(count_q)

    return _render(
        "scans_list.html",
        scans=scans,
        page=page,
        per_page=per_page,
        total=total,
        flagged_filter=flagged,
        search=search,
        status_filter=status,
        sort_by=sort_by,
        sort_dir=sort_dir,
        request=request,
    )


@router.get("/scans/{scan_id}", response_class=HTMLResponse)
async def scan_detail(scan_id: int, request: Request, session: AsyncSession = Depends(get_session)):
    from sqlalchemy.orm import selectinload

    scan = await session.scalar(
        select(Scan).where(Scan.id == scan_id).options(selectinload(Scan.findings))
    )
    if not scan:
        return HTMLResponse("<h1>Not found</h1>", status_code=404)

    return _render("scan_detail.html", scan=scan, request=request)


@router.get("/packages", response_class=HTMLResponse)
async def packages_list(
    request: Request,
    page: int = 1,
    flagged: str = "",
    search: str = "",
    sort_by: str = "last_scanned_at",
    sort_dir: str = "desc",
    session: AsyncSession = Depends(get_session),
):
    per_page = 50
    offset = (page - 1) * per_page

    subq = select(
        Scan.package_name.label("pkg_name"),
        Scan.package_version.label("pkg_ver"),
        Scan.ecosystem,
        Scan.repository,
        func.max(Scan.started_at).label("last_scan"),
        func.max(Scan.flagged).label("is_flagged"),
        func.sum(Scan.total_findings).label("findings_sum"),
        func.max(Scan.id).label("sid"),
    ).group_by(Scan.package_name, Scan.package_version)

    if flagged == "1":
        subq = subq.having(func.max(Scan.flagged) == True)
    if search:
        pattern = f"%{search}%"
        subq = subq.where(
            Scan.package_name.ilike(pattern) | Scan.package_version.ilike(pattern)
        )

    sort_field = PACKAGE_SORT_FIELDS.get(sort_by, Scan.started_at)
    sort_col = func.max(sort_field)
    subq = subq.order_by(
        sort_col.desc() if sort_dir == "desc" else sort_col.asc()
    )

    sq = subq.subquery()
    total = await session.scalar(select(func.count()).select_from(sq))
    rows = (
        await session.execute(
            select(sq).offset(offset).limit(per_page)
        )
    ).all()

    return _render(
        "packages_list.html",
        packages=rows,
        page=page,
        per_page=per_page,
        total=total,
        flagged_filter=flagged,
        search=search,
        sort_by=sort_by,
        sort_dir=sort_dir,
        request=request,
    )


@router.get("/packages/{name}/{version}", response_class=HTMLResponse)
async def package_detail(
    name: str,
    version: str,
    request: Request,
    session: AsyncSession = Depends(get_session),
):
    from sqlalchemy.orm import selectinload

    scans = (
        (
            await session.execute(
                select(Scan)
                .where(Scan.package_name == name, Scan.package_version == version)
                .options(selectinload(Scan.findings))
                .order_by(Scan.started_at.desc())
            )
        )
        .scalars()
        .all()
    )

    if not scans:
        return HTMLResponse("<h1>Not found</h1>", status_code=404)

    all_findings = []
    for s in scans:
        all_findings.extend(s.findings)

    return _render(
        "package_detail.html",
        pkg_name=name,
        pkg_version=version,
        scans=scans,
        findings=all_findings,
        request=request,
    )