"""
CV API routes.

Pola yang dipakai:
- Semua heavy endpoint pakai `def` (bukan `async def`) supaya FastAPI
  jalankan di threadpool, bukan event loop. Ini prevent blocking event loop
  yang menyebabkan health checks, readiness polling, dan semua request lain
  ikut hang.
- Endpoint /ready dipakai UI buat polling.
- _MODEL_WAIT_TIMEOUT dikurangi ke 30s (HF edge proxy timeout ~60s,
  jadi ada buffer 30s untuk compute aktual).
"""

from __future__ import annotations

import asyncio
import threading
from fastapi import APIRouter, HTTPException, UploadFile, File, status
from fastapi.responses import Response
from pydantic import BaseModel
from loguru import logger

from .schemas import (
    AnalyzeURLRequest, FullAnalysisResponse,
    ClassifyRequest, ClassificationResponse,
    SimilarityRequest, SimilarityResponse,
    VisualQARequest, VisualQAResponse,
    CaptionResponse, DetectionResponse, OCRResponse,
)
from .readiness import get_readiness
from ..cv_pipeline import CVPipeline

router = APIRouter()

_pipeline: CVPipeline = None
_pipeline_lock = threading.Lock()

_trigger_lock = threading.Lock()


def get_pipeline() -> CVPipeline:
    global _pipeline
    if _pipeline is None:
        with _pipeline_lock:
            if _pipeline is None:
                _pipeline = CVPipeline()
    return _pipeline


# Dikurangi dari 180s ke 30s.
# Semua model prewarmed dalam <2s. Kalau masih belum ready dalam 30s,
# ada masalah serius — lebih baik fail fast daripada block sampai HF proxy timeout.
_MODEL_WAIT_TIMEOUT = 90.0


def _trigger_and_wait(model_name: str):
    """
    Trigger lazy load model (akses pipeline property),
    lalu tunggu ReadinessTracker konfirmasi ready.
    Thread-safe: hanya satu thread yang load, sisanya tunggu.
    """
    readiness = get_readiness()

    with _trigger_lock:
        status_info = readiness.get_status(model_name)

        if status_info.state.value == "error":
            raise HTTPException(
                status_code=503,
                detail={
                    "error": "model_failed_to_load",
                    "model": model_name,
                    "message": status_info.error_message or "Model gagal dimuat.",
                    "hint": "Cek logs container untuk detail error.",
                },
            )

        need_spawn = status_info.state.value in ("not_loaded",)
        if need_spawn:
            readiness.mark_loading(model_name)

    if status_info.state.value == "ready":
        return

    if need_spawn:
        def _do_load():
            try:
                p = get_pipeline()
                if model_name == "captioner":
                    _ = p.captioner
                elif model_name == "yolo":
                    _ = p.yolo
                elif model_name == "clip":
                    _ = p.clip
                elif model_name == "ocr":
                    _ = p.ocr
                readiness.mark_ready(model_name)
                logger.info(f"Model '{model_name}' lazy-loaded dan ready.")
            except Exception as e:
                readiness.mark_error(model_name, str(e))
                logger.error(f"Lazy-load '{model_name}' failed: {e}")

        t = threading.Thread(target=_do_load, daemon=True, name=f"lazy-load-{model_name}")
        t.start()

    ok = readiness.wait_for(model_name, timeout=_MODEL_WAIT_TIMEOUT)
    if not ok:
        current = readiness.get_status(model_name).state.value
        if current == "error":
            err_msg = readiness.get_status(model_name).error_message
            raise HTTPException(
                status_code=503,
                detail={
                    "error": "model_failed_to_load",
                    "model": model_name,
                    "message": err_msg or f"Model '{model_name}' gagal dimuat.",
                    "hint": "Cek logs container untuk traceback lengkap.",
                },
            )
        raise HTTPException(
            status_code=503,
            detail={
                "error": "model_not_ready",
                "model": model_name,
                "current_state": current,
                "message": f"Model '{model_name}' belum siap setelah {_MODEL_WAIT_TIMEOUT}s.",
                "hint": "Cek GET /api/v1/ready. Coba request lagi dalam beberapa saat.",
            },
        )


def _ensure_models_ready(*model_names: str):
    """Pastikan semua model yang dibutuhkan endpoint sudah ready."""
    for name in model_names:
        _trigger_and_wait(name)


# === HEALTH & READINESS ===

@router.get("/health", tags=["meta"])
def health():
    return {"status": "ok"}


@router.get("/ready", tags=["meta"])
def ready():
    readiness = get_readiness()
    snap = readiness.snapshot()
    return snap


# === ANALYSIS ENDPOINTS ===
# PENTING: semua heavy endpoint pakai `def` bukan `async def`.
# FastAPI otomatis jalankan sync def di threadpool (anyio worker thread),
# sehingga blocking code (httpx, ONNX, Tesseract) tidak freeze event loop.

@router.post("/analyze/url", response_model=FullAnalysisResponse, tags=["analysis"])
def analyze_from_url(req: AnalyzeURLRequest):
    """Analisis gambar dari URL (caption + opsional detection/OCR/CLIP)."""
    import concurrent.futures as _cf
    needed = []
    if req.run_caption:
        needed.append("captioner")
    if req.run_detection:
        needed.append("yolo")
    if req.classification_labels:
        needed.append("clip")
    if req.run_ocr:
        needed.append("ocr")
    _ensure_models_ready(*needed)

    # Hard outer deadline — TOTAL_TIMEOUT (40s) di cv_pipeline sudah handle ini,
    # tapi kita tambah satu lapis lagi di route untuk jaga-jaga.
    ROUTE_TIMEOUT = 78.0  # sedikit lebih dari CVPipeline.TOTAL_TIMEOUT
    def _run_analyze():
        return get_pipeline().analyze(
            source=req.url,
            run_caption=req.run_caption,
            run_detection=req.run_detection,
            run_ocr=req.run_ocr,
            classification_labels=req.classification_labels,
        )

    with _cf.ThreadPoolExecutor(max_workers=1) as exc:
        fut = exc.submit(_run_analyze)
        try:
            result = fut.result(timeout=ROUTE_TIMEOUT)
        except _cf.TimeoutError:
            raise HTTPException(
                status_code=504,
                detail=(
                    "Analyze timeout setelah 42s. "
                    "Kemungkinan server gambar lambat atau memblok HF. "
                    "Coba URL gambar lain (imgur, ibb.co, raw GitHub, dll)."
                ),
            )
        except HTTPException:
            raise
        except Exception as e:
            logger.error(f"Analyze error: {e}")
            raise HTTPException(status_code=500, detail=str(e))

    return _to_response(result)


@router.post("/analyze/upload", response_model=FullAnalysisResponse, tags=["analysis"])
async def analyze_upload(
    file: UploadFile = File(...),
    run_caption: bool = True,
    run_detection: bool = False,
    run_ocr: bool = False,
):
    """Upload dan analisis gambar langsung (multipart)."""
    import concurrent.futures as _cf

    allowed = {"image/jpeg", "image/png", "image/webp", "image/gif"}
    if file.content_type not in allowed:
        raise HTTPException(400, detail=f"Tipe file tidak didukung: {file.content_type}")

    data = await file.read()
    if len(data) > 10 * 1024 * 1024:
        raise HTTPException(400, detail="Ukuran file maksimum 10MB")

    needed = []
    if run_caption:
        needed.append("captioner")
    if run_detection:
        needed.append("yolo")
    if run_ocr:
        needed.append("ocr")

    # Run blocking work in threadpool so we don't block event loop.
    # Pakai get_running_loop() (bukan get_event_loop() yang deprecated di Py3.10+).
    def _run():
        _ensure_models_ready(*needed)
        return get_pipeline().analyze(
            source=data,
            run_caption=run_caption,
            run_detection=run_detection,
            run_ocr=run_ocr,
        )

    UPLOAD_TIMEOUT = 78.0  # sama dengan analyze/url — hard deadline
    try:
        loop = asyncio.get_running_loop()
        with _cf.ThreadPoolExecutor(max_workers=1) as exc:
            fut = loop.run_in_executor(exc, _run)
            result = await asyncio.wait_for(fut, timeout=UPLOAD_TIMEOUT)
        return _to_response(result)
    except asyncio.TimeoutError:
        raise HTTPException(
            status_code=504,
            detail="Upload analyze timeout setelah 42s. Coba lagi atau kurangi ukuran gambar.",
        )
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Upload analyze error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


# === INDIVIDUAL TASKS ===

@router.post("/caption", response_model=CaptionResponse, tags=["tasks"])
def caption(url: str, prompt: str = None):
    """Generate deskripsi teks dari gambar."""
    _ensure_models_ready("captioner")
    try:
        from ..processors.image_preprocessor import ImagePreprocessor
        image = ImagePreprocessor.load(url)
        result = get_pipeline().captioner.caption(image, prompt=prompt)
        return CaptionResponse(caption=result.caption, model=result.model)
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Caption error: {e}")
        raise HTTPException(500, detail=f"Caption gagal: {e}")


@router.post("/detect", response_model=DetectionResponse, tags=["tasks"])
def detect(url: str, conf: float = None):
    """Deteksi objek dalam gambar dengan YOLOv8."""
    _ensure_models_ready("yolo")
    try:
        from ..processors.image_preprocessor import ImagePreprocessor
        image = ImagePreprocessor.load(url)
        result = get_pipeline().yolo.detect(image, conf_threshold=conf)
        return DetectionResponse(
            detections=[_det_to_schema(d) for d in result.detections],
            count=result.count,
            labels_summary=result.labels_summary,
            image_width=result.image_width,
            image_height=result.image_height,
            inference_time_ms=result.inference_time_ms,
        )
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Detect error: {e}")
        raise HTTPException(500, detail=f"Detection gagal: {e}")


@router.post("/classify", response_model=ClassificationResponse, tags=["tasks"])
def classify(req: ClassifyRequest):
    """Zero-shot classification dengan CLIP."""
    _ensure_models_ready("clip")
    try:
        from ..processors.image_preprocessor import ImagePreprocessor
        image = ImagePreprocessor.load(req.url)
        result = get_pipeline().clip.classify(image, req.labels)
        return ClassificationResponse(
            top_label=result.top_label,
            top_score=result.top_score,
            labels=result.labels,
            probabilities=result.probabilities,
        )
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Classify error: {e}")
        raise HTTPException(500, detail=f"Classify gagal: {e}")


@router.post("/ocr", response_model=OCRResponse, tags=["tasks"])
def ocr(url: str):
    """Ekstrak teks dari gambar dengan Tesseract OCR."""
    _ensure_models_ready("ocr")
    try:
        from ..processors.image_preprocessor import ImagePreprocessor
        image = ImagePreprocessor.load(url)
        result = get_pipeline().ocr.extract_text(image)
        return OCRResponse(
            full_text=result.full_text,
            boxes=[{"text": b.text, "confidence": b.confidence, "bbox": b.bbox}
                   for b in (result.boxes or [])],
            word_count=result.word_count,
            language=result.language,
            engine=result.engine,
        )
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"OCR error: {e}")
        raise HTTPException(500, detail=f"OCR gagal: {e}")


@router.post("/vqa", response_model=VisualQAResponse, tags=["tasks"])
def visual_qa(req: VisualQARequest):
    """Visual Question Answering."""
    _ensure_models_ready("captioner")
    try:
        from ..processors.image_preprocessor import ImagePreprocessor
        image = ImagePreprocessor.load(req.url)
        result = get_pipeline().captioner.visual_qa(image, req.question)
        return VisualQAResponse(question=req.question, answer=result.caption)
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"VQA error: {e}")
        raise HTTPException(500, detail=f"VQA gagal: {e}")


@router.post("/similarity", response_model=SimilarityResponse, tags=["tasks"])
def similarity(req: SimilarityRequest):
    """Hitung similarity antara gambar dan teks dengan CLIP."""
    _ensure_models_ready("clip")
    try:
        score = get_pipeline().image_text_similarity(req.url, req.text)
        if score > 0.3:
            interpretation = "Sangat relevan"
        elif score > 0.2:
            interpretation = "Cukup relevan"
        elif score > 0.1:
            interpretation = "Sedikit relevan"
        else:
            interpretation = "Tidak relevan"
        return SimilarityResponse(
            similarity_score=round(score, 4),
            text=req.text,
            interpretation=interpretation,
        )
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Similarity error: {e}")
        raise HTTPException(500, detail=f"Similarity gagal: {e}")


# === HELPERS ===

def _det_to_schema(d):
    from .schemas import DetectionSchema, BBoxSchema
    return DetectionSchema(
        label=d.label,
        confidence=d.confidence,
        bbox=BBoxSchema(
            x1=d.bbox.x1,
            y1=d.bbox.y1,
            x2=d.bbox.x2,
            y2=d.bbox.y2,
            width=d.bbox.width,
            height=d.bbox.height,
        ),
        class_id=d.class_id,
    )


def _to_response(result) -> FullAnalysisResponse:
    from .schemas import (
        FullAnalysisResponse, CaptionResponse, DetectionResponse,
        ClassificationResponse, OCRResponse, BBoxSchema, DetectionSchema, OCRBoxSchema,
    )
    cap = None
    if result.caption:
        cap = CaptionResponse(caption=result.caption.caption, model=result.caption.model)

    det = None
    if result.detections:
        det = DetectionResponse(
            detections=[_det_to_schema(d) for d in result.detections.detections],
            count=result.detections.count,
            labels_summary=result.detections.labels_summary,
            image_width=result.detections.image_width,
            image_height=result.detections.image_height,
            inference_time_ms=result.detections.inference_time_ms,
        )

    cls = None
    if result.classification:
        cls = ClassificationResponse(
            top_label=result.classification.top_label,
            top_score=result.classification.top_score,
            labels=result.classification.labels or [],
            probabilities=result.classification.probabilities or [],
        )

    ocr = None
    if result.ocr:
        ocr = OCRResponse(
            full_text=result.ocr.full_text,
            boxes=[
                OCRBoxSchema(text=b.text, confidence=b.confidence, bbox=b.bbox)
                for b in (result.ocr.boxes or [])
            ],
            word_count=result.ocr.word_count,
            language=result.ocr.language,
            engine=result.ocr.engine,
        )

    return FullAnalysisResponse(
        image_width=result.image_width,
        image_height=result.image_height,
        source=result.source,
        caption=cap,
        detections=det,
        classification=cls,
        ocr=ocr,
        summary_text=result.to_summary(),
        models_used=result.models_used,
        total_latency_ms=result.total_latency_ms,
    )