from datetime import datetime, timedelta, timezone

from fastapi import APIRouter, Query
from sqlalchemy import func, select
from sqlalchemy.orm import joinedload

from ..config import settings
from ..dependencies import Db
from ..models import (
    CatchReport,
    CommunityImportRun,
    DataSource,
    ExternalObservation,
    Fish,
    OfficialRecordImport,
    SourceType,
    Waterbody,
)
from ..schemas import (
    ImportRunPublicOut,
    OfficialRecordOut,
    PaginatedOfficialRecordOut,
    PublicObservationOut,
    SourceStatusOut,
)
from ..time_utils import aware

router = APIRouter()


@router.get("/api/v1/community-observations", response_model=list[PublicObservationOut])
def community_observations(
    db: Db,
    limit: int = Query(12, ge=1, le=50),
    offset: int = Query(0, ge=0),
    waterbody: str | None = None,
    fish: str | None = None,
) -> list[PublicObservationOut]:
    query = select(ExternalObservation).join(ExternalObservation.source).options(
        joinedload(ExternalObservation.source)
    ).where(
        ExternalObservation.catch_report_id.is_(None),
        ExternalObservation.status.not_in(["rejected", "withdrawn"]),
        DataSource.enabled.is_(True),
    )
    if waterbody:
        query = query.join(ExternalObservation.waterbody).where(Waterbody.slug == waterbody)
    if fish:
        query = query.join(ExternalObservation.fish).where(Fish.slug == fish)
    items = list(db.scalars(
        query.order_by(ExternalObservation.last_seen_at.desc(), ExternalObservation.id.desc())
        .offset(offset).limit(limit)
    ))
    result: list[PublicObservationOut] = []
    for item in items:
        missing = []
        if item.x is None or item.y is None:
            missing.append("координаты")
        if item.weight_g is None:
            missing.append("вес")
        result.append(PublicObservationOut(
            id=item.id,
            source_system=item.source_system,
            source_name=item.source.name,
            source_url=item.source_url,
            fish_name=item.fish_name,
            waterbody_name=item.waterbody_name,
            x=item.x,
            y=item.y,
            weight_g=item.weight_g,
            last_seen_at=item.last_seen_at,
            missing_fields=missing,
            quality="incomplete" if missing else "unverified",
        ))
    return result


@router.get("/api/v1/source-status", response_model=list[SourceStatusOut])
def source_status(db: Db) -> list[SourceStatusOut]:
    now = datetime.now(timezone.utc)
    result = []
    for source in db.scalars(select(DataSource).order_by(DataSource.name)):
        runs = list(db.scalars(
            select(CommunityImportRun)
            .where(CommunityImportRun.source_system == source.key)
            .order_by(CommunityImportRun.started_at.desc()).limit(20)
        ))
        latest = runs[0] if runs else None
        success = next((run for run in runs if run.status == "success"), None)
        if not source.enabled:
            state = "disabled"
        elif latest is None:
            state = "waiting"
        elif latest.status == "failed":
            state = "source_changed" if "CommunityParseError" in (latest.error_summary or "") else "temporarily_limited"
        elif aware(latest.started_at) < now - timedelta(seconds=settings.community_import_interval_seconds * 2):
            state = "stale"
        else:
            state = "healthy"
        result.append(SourceStatusOut(
            source_system=source.key,
            name=source.name,
            status=state,
            last_started_at=latest.started_at if latest else None,
            last_success_at=success.started_at if success else None,
            observations=db.scalar(
                select(func.count()).select_from(ExternalObservation)
                .where(ExternalObservation.source_system == source.key)
            ) or 0,
        ))
    return result


@router.get("/api/v1/records", response_model=PaginatedOfficialRecordOut)
def records(
    db: Db,
    fish: str | None = None,
    waterbody: str | None = None,
    category: str | None = None,
    limit: int = Query(50, ge=1, le=100),
    offset: int = Query(0, ge=0),
) -> PaginatedOfficialRecordOut:
    query = select(CatchReport).options(
        joinedload(CatchReport.fish),
        joinedload(CatchReport.waterbody),
        joinedload(CatchReport.bait),
    ).where(CatchReport.source_type == SourceType.official_record)
    if fish:
        query = query.join(CatchReport.fish).where(Fish.slug == fish)
    if waterbody:
        query = query.join(CatchReport.waterbody).where(Waterbody.slug == waterbody)
    if category:
        query = query.where(CatchReport.raw_payload["category"].as_string() == category)
    total = db.scalar(
        query.with_only_columns(func.count(CatchReport.id), maintain_column_froms=True).order_by(None)
    ) or 0
    items = list(db.scalars(
        query.order_by(CatchReport.caught_at.desc(), CatchReport.weight_g.desc(), CatchReport.id.desc())
        .offset(offset).limit(limit)
    ))
    return PaginatedOfficialRecordOut(
        items=[OfficialRecordOut(
            id=item.id,
            fish=item.fish.name_ru,
            weight_g=item.weight_g,
            waterbody=item.waterbody.name_ru,
            bait=item.bait.name if item.bait else None,
            player_name=item.player_name,
            record_date=item.caught_at,
            category=(item.raw_payload or {}).get("category"),
            region=(item.raw_payload or {}).get("region"),
            source_url=item.source_url,
        ) for item in items],
        total=total,
        limit=limit,
        offset=offset,
    )


@router.get("/api/v1/imports", response_model=list[ImportRunPublicOut])
def imports(
    db: Db,
    limit: int = Query(20, ge=1, le=100),
    offset: int = Query(0, ge=0),
) -> list[OfficialRecordImport]:
    return list(db.scalars(
        select(OfficialRecordImport)
        .order_by(OfficialRecordImport.started_at.desc(), OfficialRecordImport.id.desc())
        .offset(offset).limit(limit)
    ))