"""
IOM Lager 6 — Observationer
FastAPI endpoints för CRUD.
"""

from __future__ import annotations

from datetime import datetime
from typing import Any

from fastapi import APIRouter, Depends, FastAPI, HTTPException, Query, status
from pydantic import BaseModel, Field

from observation_models import (
    AIAnalysis,
    ConditionGrade,
    Finding,
    GeoTag,
    Media,
    Observation,
    RiskAssessment,
    Weather,
)
from observation_store import ObservationStore, get_store


# ──────────────────────────────────────────────────────────────
# FastAPI app & router
# ──────────────────────────────────────────────────────────────

app = FastAPI(
    title="IOM Observation API",
    description="Lager 6 — Observationer för Infrastructure Object Model",
    version="1.0.0",
)

router = APIRouter(prefix="/observations", tags=["observations"])


# ──────────────────────────────────────────────────────────────
# Dependency injection
# ──────────────────────────────────────────────────────────────

async def get_observation_store() -> ObservationStore:
    store = get_store()
    try:
        yield store
    finally:
        await store.close()


# ──────────────────────────────────────────────────────────────
# Request / Response DTOs
# ──────────────────────────────────────────────────────────────

class ObservationCreate(BaseModel):
    id: str = Field(..., pattern=r"^OBS-[0-9]{4}-[0-9]{7}$")
    timestamp: datetime
    observer: str | None = None
    object_goid: str = Field(..., pattern=r"^[A-Z]{3}(-[A-Z]{3})+-[0-9]+$")
    findings: list[Finding] = Field(default_factory=list)
    media: list[Media] = Field(default_factory=list)
    weather: Weather | None = None
    ai_analysis: AIAnalysis | None = None
    risk_assessment: RiskAssessment | None = None
    condition: ConditionGrade | None = None
    notes: str | None = None
    extra: dict[str, Any] | None = None


class ObservationUpdate(BaseModel):
    timestamp: datetime | None = None
    observer: str | None = None
    findings: list[Finding] | None = None
    media: list[Media] | None = None
    weather: Weather | None = None
    ai_analysis: AIAnalysis | None = None
    risk_assessment: RiskAssessment | None = None
    condition: ConditionGrade | None = None
    notes: str | None = None
    extra: dict[str, Any] | None = None


class ObservationListResponse(BaseModel):
    items: list[Observation]
    total: int
    limit: int
    offset: int


class HealthResponse(BaseModel):
    status: str
    version: str
    timestamp: datetime


# ──────────────────────────────────────────────────────────────
# Endpoints
# ──────────────────────────────────────────────────────────────

@router.post(
    "",
    response_model=Observation,
    status_code=status.HTTP_201_CREATED,
    summary="Skapa en ny observation",
)
async def create_observation(
    payload: ObservationCreate,
    store: ObservationStore = Depends(get_observation_store),
) -> Observation:
    existing = await store.get(payload.id)
    if existing is not None:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail=f"Observation {payload.id!r} already exists",
        )
    observation = Observation(**payload.model_dump(exclude_none=True))
    return await store.create(observation)


@router.get(
    "/{observation_id}",
    response_model=Observation,
    summary="Hämta en observation med ID",
)
async def get_observation(
    observation_id: str,
    store: ObservationStore = Depends(get_observation_store),
) -> Observation:
    observation = await store.get(observation_id)
    if observation is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Observation {observation_id!r} not found",
        )
    return observation


@router.patch(
    "/{observation_id}",
    response_model=Observation,
    summary="Uppdatera en observation",
)
async def update_observation(
    observation_id: str,
    payload: ObservationUpdate,
    store: ObservationStore = Depends(get_observation_store),
) -> Observation:
    existing = await store.get(observation_id)
    if existing is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Observation {observation_id!r} not found",
        )
    update_data = payload.model_dump(exclude_unset=True, exclude_none=True)
    for key, value in update_data.items():
        setattr(existing, key, value)
    existing.updated_at = datetime.utcnow()
    return await store.update(existing)


@router.delete(
    "/{observation_id}",
    status_code=status.HTTP_204_NO_CONTENT,
    summary="Ta bort en observation",
)
async def delete_observation(
    observation_id: str,
    store: ObservationStore = Depends(get_observation_store),
) -> None:
    deleted = await store.delete(observation_id)
    if not deleted:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Observation {observation_id!r} not found",
        )


@router.get(
    "",
    response_model=ObservationListResponse,
    summary="Lista observationer med filtrering",
)
async def list_observations(
    object_goid: str | None = Query(None, description="Filtrera på GOID"),
    observer: str | None = Query(None, description="Filtrera på observer"),
    finding_code: str | None = Query(None, description="Filtrera på felkod"),
    start: datetime | None = Query(None, description="Startdatum (ISO 8601)"),
    end: datetime | None = Query(None, description="Slutdatum (ISO 8601)"),
    limit: int = Query(100, ge=1, le=1000),
    offset: int = Query(0, ge=0),
    store: ObservationStore = Depends(get_observation_store),
) -> ObservationListResponse:
    items: list[Observation]

    if object_goid:
        items = await store.list_by_object(object_goid, limit=limit, offset=offset)
    elif observer:
        items = await store.list_by_observer(observer, limit=limit, offset=offset)
    elif finding_code:
        items = await store.list_by_finding_code(
            finding_code, limit=limit, offset=offset
        )
    elif start and end:
        items = await store.list_by_date_range(start, end, limit=limit, offset=offset)
    else:
        # Fallback: hämta alla (sorterat efter senaste)
        now = datetime.utcnow()
        items = await store.list_by_date_range(
            datetime.min.replace(tzinfo=None),
            now,
            limit=limit,
            offset=offset,
        )

    return ObservationListResponse(
        items=items,
        total=len(items),
        limit=limit,
        offset=offset,
    )


# ──────────────────────────────────────────────────────────────
# Hälsocheck
# ──────────────────────────────────────────────────────────────

@app.get("/health", response_model=HealthResponse, tags=["health"])
async def health_check() -> HealthResponse:
    return HealthResponse(
        status="ok",
        version="1.0.0",
        timestamp=datetime.utcnow(),
    )


# ──────────────────────────────────────────────────────────────
# Registrera router
# ──────────────────────────────────────────────────────────────

app.include_router(router)


# ──────────────────────────────────────────────────────────────
# Entrypoint (uvicorn)
# ──────────────────────────────────────────────────────────────

if __name__ == "__main__":
    import uvicorn

    uvicorn.run("observation_api:app", host="0.0.0.0", port=8000, reload=True)