import logging
import os
import queue
import threading
import time
from concurrent.futures import Future
from dataclasses import dataclass
from typing import Tuple

from PIL import Image

from surya.timing import (
    TimingCollector,
    log_timing_summary,
    reset_current_timing,
    set_current_timing,
    timing_span,
)
from vllm_tools import ocr_vllm_batch

logger = logging.getLogger(__name__)


@dataclass(frozen=True)
class OcrOptions:
    skip_text_detection: bool
    recognize_math: bool
    with_bboxes: bool


@dataclass
class OcrJob:
    image: Image.Image
    highres_image: Image.Image
    options: OcrOptions
    future: Future
    request_id: str


class VllmOcrBatcher:
    def __init__(self) -> None:
        self.max_batch_size = int(os.getenv("SUYA_MAX_BATCH_SIZE", "8"))
        self.batch_wait_ms = float(os.getenv("SUYA_BATCH_WAIT_MS", "25"))
        self.queue_timeout_seconds = float(os.getenv("SUYA_BATCH_QUEUE_TIMEOUT_SECONDS", "900"))
        self._queue: queue.Queue[OcrJob] = queue.Queue(
            maxsize=int(os.getenv("SUYA_MAX_QUEUE_SIZE", "128"))
        )
        self._thread = threading.Thread(target=self._run, name="vllm-ocr-batcher", daemon=True)
        self._thread.start()

    def submit(
        self,
        image: Image.Image,
        highres_image: Image.Image,
        *,
        skip_text_detection: bool,
        recognize_math: bool,
        with_bboxes: bool,
        request_id: str,
    ):
        future: Future = Future()
        job = OcrJob(
            image=image,
            highres_image=highres_image,
            options=OcrOptions(skip_text_detection, recognize_math, with_bboxes),
            future=future,
            request_id=request_id,
        )
        with timing_span("batcher_queue_put", request_id=request_id):
            self._queue.put(job, timeout=self.queue_timeout_seconds)
        with timing_span("batcher_wait_result", request_id=request_id):
            return future.result(timeout=self.queue_timeout_seconds)

    def _run(self) -> None:
        while True:
            first = self._queue.get()
            jobs = [first]
            deadline = time.perf_counter() + (self.batch_wait_ms / 1000.0)
            while len(jobs) < self.max_batch_size:
                remaining = deadline - time.perf_counter()
                if remaining <= 0:
                    break
                try:
                    jobs.append(self._queue.get(timeout=remaining))
                except queue.Empty:
                    break
            self._process_jobs(jobs)

    def _process_jobs(self, jobs: list[OcrJob]) -> None:
        groups: dict[OcrOptions, list[OcrJob]] = {}
        for job in jobs:
            groups.setdefault(job.options, []).append(job)

        for options, grouped_jobs in groups.items():
            start = time.perf_counter()
            collector = TimingCollector(
                request_id=",".join(job.request_id for job in grouped_jobs),
                batch_size=len(grouped_jobs),
            )
            token = set_current_timing(collector)
            try:
                with timing_span("batcher_process_jobs", batch_size=len(grouped_jobs)):
                    results = ocr_vllm_batch(
                        [job.image for job in grouped_jobs],
                        [job.highres_image for job in grouped_jobs],
                        skip_text_detection=options.skip_text_detection,
                        recognize_math=options.recognize_math,
                        with_bboxes=options.with_bboxes,
                    )
                for job, result in zip(grouped_jobs, results):
                    job.future.set_result(result)
                logger.info(
                    "vllm_batch_complete batch_size=%s option=%s duration_ms=%.2f request_ids=%s",
                    len(grouped_jobs),
                    options,
                    (time.perf_counter() - start) * 1000,
                    ",".join(job.request_id for job in grouped_jobs),
                )
                log_timing_summary(logger, collector)
            except Exception as exc:
                for job in grouped_jobs:
                    job.future.set_exception(exc)
                logger.exception(
                    "vllm_batch_failed batch_size=%s option=%s request_ids=%s",
                    len(grouped_jobs),
                    options,
                    ",".join(job.request_id for job in grouped_jobs),
                    exc_info=True,
                )
            finally:
                reset_current_timing(token)


vllm_ocr_batcher = VllmOcrBatcher()