"""
This module implements the compatibility API for Apollo V2 advisories
"""

import datetime
from typing import TypeVar, Generic, Optional, Any, Sequence

from tortoise import connections

from fastapi import APIRouter, Depends, Query, Response
from fastapi.exceptions import HTTPException
from fastapi_pagination import pagination_ctx
from fastapi_pagination.bases import BasePage
from fastapi_pagination.default import Page
from fastapi_pagination.types import GreaterEqualOne, GreaterEqualZero
from fastapi_pagination.ext.tortoise import create_page

from pydantic import BaseModel

from rssgen.feed import RssGenerator

from apollo.db import Advisory, RedHatIndexState
from apollo.db.serialize import Advisory_Pydantic_V2, Advisory_Pydantic_V2_CVE, Advisory_Pydantic_V2_Fix, Advisory_Pydantic_V2_RPMs
from apollo.server.settings import UI_URL, COMPANY_NAME, MANAGING_EDITOR, get_setting

from common.fastapi import RenderErrorTemplateException

router = APIRouter(tags=["v2_compat"])

T = TypeVar("T")


class CompatParams(BaseModel):
    page: int = Query(0, ge=0, description="Page number")
    limit: int = Query(20, ge=1, le=100, description="Page size")

    def get_offset(self) -> int:
        print(self.limit * self.page)
        return self.limit * self.page

    def get_size(self) -> int:
        return self.limit


class Pagination(BasePage[T], Generic[T]):
    lastUpdated: Optional[str]  # noqa # pylint: disable=invalid-name

    page: GreaterEqualZero
    size: GreaterEqualOne

    __params_type__ = CompatParams

    @classmethod
    def create(
        cls,
        items: Sequence[T],
        params: CompatParams,
        *,
        total: Optional[int] = None,
        **kwargs: Any,
    ) -> Page[T]:
        if not isinstance(params, CompatParams):
            raise ValueError("Pagination should be used with CompatParams")

        return cls(
            total=total,
            items=items,
            page=params.page,
            size=params.limit,
            **kwargs,
        )

    class Config:
        allow_population_by_field_name = True
        fields = {"items": {"alias": "advisories"}}


class AdvisoryResponse(BaseModel):
    advisory: Advisory_Pydantic_V2


def v3_advisory_to_v2(
    advisory: Advisory,
    include_rpms=True,
) -> Advisory_Pydantic_V2:
    kind = "TYPE_SECURITY"
    if advisory.kind == "Bug Fix":
        kind = "TYPE_BUGFIX"
    elif advisory.kind == "Enhancement":
        kind = "TYPE_ENHANCEMENT"

    affected_products = list(
        set(
            [
                f"{ap.variant} {ap.major_version}"
                for ap in advisory.affected_products
            ]
        )
    )

    cves = []
    for cve in advisory.cves:
        cves.append(
            Advisory_Pydantic_V2_CVE(
                name=cve.cve,
                cvss3ScoringVector=cve.cvss3_scoring_vector,
                cvss3BaseScore=cve.cvss3_base_score,
                cwe=cve.cwe,
                sourceBy="Red Hat",
                sourceLink=
                f"https://access.redhat.com/hydra/rest/securitydata/cve/{cve.cve}.json",
            )
        )

    fixes = []
    for fix in advisory.fixes:
        fixes.append(
            Advisory_Pydantic_V2_Fix(
                ticket=fix.ticket_id,
                sourceBy="Red Hat",
                sourceLink=fix.source,
                description=fix.description,
            )
        )

    rpms = {}
    if include_rpms:
        for pkg in advisory.packages:
            name = f"{pkg.supported_product.variant} {pkg.supported_products_rh_mirror.match_major_version}"
            if name not in rpms:
                rpms[name] = Advisory_Pydantic_V2_RPMs(nvras=[])
            if pkg.nevra not in rpms[name].nvras:
                rpms[name].nvras.append(pkg.nevra)

    published_at = advisory.published_at.isoformat("T"
                                                  ).replace("+00:00", "") + "Z"
    severity = advisory.severity.upper()
    if severity == "NONE":
        severity = "UNKNOWN"

    return Advisory_Pydantic_V2(
        id=advisory.id,
        publishedAt=published_at,
        name=advisory.name,
        synopsis=advisory.synopsis,
        description=advisory.description,
        type=kind,
        severity=f"SEVERITY_{severity}",
        shortCode=advisory.name[0:2],
        topic=advisory.topic if advisory.topic else "",
        solution=None,
        rpms=rpms,
        affectedProducts=affected_products,
        references=[],
        rebootSuggested=False,
        buildReferences=[],
        fixes=fixes,
        cves=cves,
    )


async def fetch_advisories_compat(
    params: CompatParams,
    product: str,
    before_raw: str,
    after_raw: str,
    cve: str,
    synopsis: str,
    keyword: str,
    severity: str,
    kind: str,
):
    before = None
    after = None

    try:
        if before_raw:
            before = datetime.datetime.fromisoformat(
                before_raw.removesuffix("Z")
            )
    except:
        raise RenderErrorTemplateException("Invalid before date", 400)  # noqa # pylint: disable=raise-missing-from

    try:
        if after_raw:
            after = datetime.datetime.fromisoformat(after_raw.removesuffix("Z"))
    except:
        raise RenderErrorTemplateException("Invalid after date", 400)  # noqa # pylint: disable=raise-missing-from

    q_kind = kind
    if q_kind:
        if q_kind == "TYPE_BUGFIX":
            q_kind = "Bug Fix"
        elif q_kind == "TYPE_ENHANCEMENT":
            q_kind = "Enhancement"
        elif q_kind == "TYPE_SECURITY":
            q_kind = "Security"

    q_severity = severity
    if q_severity:
        if q_severity == "SEVERITY_LOW":
            q_severity = "Low"
        elif q_severity == "SEVERITY_MEDIUM":
            q_severity = "Moderate"
        elif q_severity == "SEVERITY_IMPORTANT":
            q_severity = "Important"
        elif q_severity == "SEVERITY_CRITICAL":
            q_severity = "Critical"

    a = """
        with vars (search, size, page_offset, product, before, after, cve, synopsis, severity, kind) as (
            values ($1 :: text, $2 :: bigint, $3 :: bigint, $4 :: text, $5 :: timestamp, $6 :: timestamp, $7 :: text, $8 :: text, $9 :: text, $10 :: text)
        )
        select
            a.id,
            a.created_at,
            a.updated_at,
            a.published_at,
            a.name,
            a.synopsis,
            a.description,
            a.kind,
            a.severity,
            a.topic,
            a.red_hat_advisory_id,
            count(a.*) over () as total
        from
            advisories a
        left outer join advisory_affected_products ap on ap.advisory_id = a.id
        left outer join advisory_cves c on c.advisory_id = a.id
        left outer join advisory_fixes f on f.advisory_id = a.id
        where
            ((select product from vars) is null or exists (select name from advisory_affected_products where advisory_id = a.id and name like '%' || (select product from vars) || '%'))
            and ((select before from vars) is null or a.published_at < (select before from vars))
            and ((select after from vars) is null or a.published_at > (select after from vars))
            and (a.published_at is not null)
            and ((select cve from vars) is null or exists (select cve from advisory_cves where advisory_id = a.id and cve ilike '%' || (select cve from vars) || '%'))
            and ((select synopsis from vars) is null or a.synopsis ilike '%' || (select synopsis from vars) || '%')
            and ((select severity from vars) is null or a.severity = (select severity from vars))
            and ((select kind from vars) is null or a.kind = (select kind from vars))
            and ((select search from vars) is null or
            ap.name like '%' || (select product from vars) || '%' or
            a.synopsis ilike '%' || (select search from vars) || '%' or
            a.description ilike '%' || (select search from vars) || '%' or
            exists (select cve from advisory_cves where advisory_id = a.id and cve ilike '%' || (select search from vars) || '%') or
            exists (select ticket_id from advisory_fixes where advisory_id = a.id and ticket_id ilike '%' || (select search from vars) || '%') or
            a.name ilike '%' || (select search from vars) || '%')
        group by a.id
        order by a.published_at desc
        limit (select size from vars) offset (select page_offset from vars)
        """

    connection = connections.get("default")
    results = await connection.execute_query(
        a, [
            keyword,
            params.get_size(),
            params.get_offset(),
            product,
            before,
            after,
            cve,
            synopsis,
            q_severity,
            q_kind,
        ]
    )

    count = 0
    if results:
        if results[1]:
            count = results[1][0]["total"]

    advisories = [Advisory(**x) for x in results[1]]
    return (
        count,
        advisories,
    )


@router.get(
    "",
    response_model=Pagination[Advisory_Pydantic_V2],
    dependencies=[
        Depends(pagination_ctx(Pagination[Advisory_Pydantic_V2], CompatParams))
    ]
)
async def list_advisories_compat_v2(
    params: CompatParams = Depends(),
    product: str = Query(default=None, alias="filters.product"),
    before_raw: str = Query(default=None, alias="filters.before"),
    after_raw: str = Query(default=None, alias="filters.after"),
    cve: str = Query(default=None, alias="filters.cve"),
    synopsis: str = Query(default=None, alias="filters.synopsis"),
    keyword: str = Query(default=None, alias="filters.keyword"),
    severity: str = Query(default=None, alias="filters.severity"),
    kind: str = Query(default=None, alias="filters.type"),
):
    state = await RedHatIndexState.first()

    fetch_adv = await fetch_advisories_compat(
        params,
        product,
        before_raw,
        after_raw,
        cve,
        synopsis,
        keyword,
        severity,
        kind,
    )
    count = fetch_adv[0]

    advisories = []
    for adv in fetch_adv[1]:
        await adv.fetch_related(
            "packages",
            "cves",
            "fixes",
            "affected_products",
            "packages",
            "packages__supported_product",
            "packages__supported_products_rh_mirror",
        )
        advisories.append(adv)

    v2_advisories: list[Advisory_Pydantic_V2] = []
    for advisory in advisories:
        v2_advisories.append(v3_advisory_to_v2(advisory))

    page = create_page(v2_advisories, count, params)
    page.lastUpdated = state.last_indexed_at.isoformat("T").replace(
        "+00:00",
        "",
    ) + "Z"

    return page


@router.get(":rss")
async def list_advisories_compat_v2_rss(
    params: CompatParams = Depends(),
    product: str = Query(default=None, alias="filters.product"),
    before_raw: str = Query(default=None, alias="filters.before"),
    after_raw: str = Query(default=None, alias="filters.after"),
    cve: str = Query(default=None, alias="filters.cve"),
    synopsis: str = Query(default=None, alias="filters.synopsis"),
    keyword: str = Query(default=None, alias="filters.keyword"),
    severity: str = Query(default=None, alias="filters.severity"),
    kind: str = Query(default=None, alias="filters.type"),
):
    fetch_adv = await fetch_advisories_compat(
        params,
        product,
        before_raw,
        after_raw,
        cve,
        synopsis,
        keyword,
        severity,
        kind,
    )
    count = fetch_adv[0]
    advisories = fetch_adv[1]
    advisories.reverse()

    ui_url = await get_setting(UI_URL)
    company_name = await get_setting(COMPANY_NAME)
    managing_editor = await get_setting(MANAGING_EDITOR)

    fg = RssGenerator()
    fg.title(f"{company_name} Errata Feed")
    fg.link(href=ui_url, rel="alternate")
    fg.language("en")
    fg.description(f"Advisories issued by {company_name}")
    fg.copyright(
        f"(C) {company_name} {datetime.datetime.now().year}. All rights reserved. CVE sources are copyright of their respective owners."
    )
    fg.managingEditor(f"{managing_editor} ({company_name})")

    if count != 0:
        fg.pubDate(advisories[0].published_at)
        fg.lastBuildDate(advisories[0].published_at)

    for advisory in advisories:
        fe = fg.add_entry()
        fe.title(f"{advisory.name}: {advisory.synopsis}")
        fe.link(href=f"{ui_url}/{advisory.name}", rel="alternate")
        fe.description(advisory.topic)
        fe.id(str(advisory.id))
        fe.pubDate(advisory.published_at)

    return Response(content=fg.rss_str(), media_type="application/xml")


@router.get(
    "/{advisory_name}",
    response_model=AdvisoryResponse,
)
async def get_advisory_compat_v2(advisory_name: str):
    advisory = await Advisory.filter(name=advisory_name).prefetch_related(
        "packages",
        "cves",
        "fixes",
        "affected_products",
        "packages",
        "packages__supported_product",
        "packages__supported_products_rh_mirror",
    ).get_or_none()

    if not advisory:
        raise HTTPException(404)

    return AdvisoryResponse(
        advisory=Advisory_Pydantic_V2.from_orm(v3_advisory_to_v2(advisory))
    )