import concurrent.futures
import logging
import os
import queue
import tempfile
import threading
import time
from typing import TYPE_CHECKING, Optional, Tuple

import wandb
import wandb.util
from wandb.filesync import stats, step_checksum, step_upload
from wandb.sdk.lib.paths import LogicalPath

if TYPE_CHECKING:
    from wandb.sdk.artifacts.artifact_manifest import ArtifactManifest
    from wandb.sdk.artifacts.artifact_saver import SaveFn
    from wandb.sdk.internal import file_stream, internal_api
    from wandb.sdk.internal.settings_static import SettingsStatic


logger = logging.getLogger(__name__)


class FilePusher:
    """Parallel file upload class.

    This manages uploading multiple files in parallel. It will restart a given file's
    upload job if it receives a notification that that file has been modified. The
    finish() method will block until all events have been processed and all uploads are
    complete.
    """

    MAX_UPLOAD_JOBS = 64

    def __init__(
        self,
        api: "internal_api.Api",
        file_stream: "file_stream.FileStreamApi",
        settings: Optional["SettingsStatic"] = None,
    ) -> None:
        self._api = api

        # Temporary directory for copies we make of some file types to
        # reduce the probability that the file gets changed while we're
        # uploading it.
        self._tempdir = tempfile.TemporaryDirectory("wandb")

        self._stats = stats.Stats()

        self._incoming_queue: queue.Queue[step_checksum.Event] = queue.Queue()
        self._event_queue: queue.Queue[step_upload.Event] = queue.Queue()

        self._step_checksum = step_checksum.StepChecksum(
            self._api,
            self._tempdir,
            self._incoming_queue,
            self._event_queue,
            self._stats,
        )
        self._step_checksum.start()

        self._step_upload = step_upload.StepUpload(
            self._api,
            self._stats,
            self._event_queue,
            self.MAX_UPLOAD_JOBS,
            file_stream=file_stream,
            settings=settings,
        )
        self._step_upload.start()

        self._stats_thread_stop = threading.Event()
        if os.environ.get("WANDB_DEBUG"):
            # debug thread to monitor and report file pusher stats
            self._stats_thread = threading.Thread(
                target=self._file_pusher_stats,
                daemon=True,
                name="FPStatsThread",
            )
            self._stats_thread.start()

    def _file_pusher_stats(self) -> None:
        while not self._stats_thread_stop.is_set():
            logger.info(f"FilePusher stats: {self._stats._stats}")
            time.sleep(1)

    def get_status(self) -> Tuple[bool, stats.Summary]:
        running = self.is_alive()
        summary = self._stats.summary()
        return running, summary

    def print_status(self, prefix: bool = True) -> None:
        step = 0
        spinner_states = ["-", "\\", "|", "/"]
        stop = False
        while True:
            if not self.is_alive():
                stop = True
            summary = self._stats.summary()
            line = f" {summary.uploaded_bytes / 1048576.0:.2f}MB of {summary.total_bytes / 1048576.0:.2f}MB uploaded ({summary.deduped_bytes / 1048576.0:.2f}MB deduped)\r"
            line = spinner_states[step % 4] + line
            step += 1
            wandb.termlog(line, newline=False, prefix=prefix)
            if stop:
                break
            time.sleep(0.25)
        dedupe_fraction = (
            summary.deduped_bytes / float(summary.total_bytes)
            if summary.total_bytes > 0
            else 0
        )
        if dedupe_fraction > 0.01:
            wandb.termlog(
                "W&B sync reduced upload amount by %.1f%%             "
                % (dedupe_fraction * 100),
                prefix=prefix,
            )
        # clear progress line.
        wandb.termlog(" " * 79, prefix=prefix)

    def file_counts_by_category(self) -> stats.FileCountsByCategory:
        return self._stats.file_counts_by_category()

    def file_changed(self, save_name: LogicalPath, path: str, copy: bool = True):
        """Tell the file pusher that a file's changed and should be uploaded.

        Args:
            save_name: string logical location of the file relative to the run
                directory.
            path: actual string path of the file to upload on the filesystem.
        """
        # Tests in linux were failing because wandb-events.jsonl didn't exist
        if not os.path.exists(path) or not os.path.isfile(path):
            return
        if os.path.getsize(path) == 0:
            return

        event = step_checksum.RequestUpload(path, save_name, copy)
        self._incoming_queue.put(event)

    def store_manifest_files(
        self,
        manifest: "ArtifactManifest",
        artifact_id: str,
        save_fn: "SaveFn",
    ) -> None:
        event = step_checksum.RequestStoreManifestFiles(manifest, artifact_id, save_fn)
        self._incoming_queue.put(event)

    def commit_artifact(
        self,
        artifact_id: str,
        *,
        finalize: bool = True,
        before_commit: step_upload.PreCommitFn,
        result_future: "concurrent.futures.Future[None]",
    ):
        event = step_checksum.RequestCommitArtifact(
            artifact_id, finalize, before_commit, result_future
        )
        self._incoming_queue.put(event)

    def finish(self, callback: Optional[step_upload.OnRequestFinishFn] = None):
        logger.info("shutting down file pusher")
        self._incoming_queue.put(step_checksum.RequestFinish(callback))
        self._stats_thread_stop.set()

    def join(self) -> None:
        # NOTE: must have called finish before join
        logger.info("waiting for file pusher")
        while self.is_alive():
            time.sleep(0.5)
        self._tempdir.cleanup()

    def is_alive(self) -> bool:
        return self._step_checksum.is_alive() or self._step_upload.is_alive()