import asyncio
import concurrent.futures
import logging
import pprint
import time
import traceback
from collections import defaultdict
from concurrent.futures import ThreadPoolExecutor
from copy import deepcopy
from dataclasses import dataclass, field
from typing import Callable, Dict, List, Optional, Tuple, Union

import numpy as np

import ray
import ray._common.test_utils as test_utils
from ray._private.gcs_utils import GcsChannel
from ray._raylet import GcsClient
from ray.actor import ActorHandle
from ray.dashboard.state_aggregator import (
    StateAPIManager,
)
from ray.util.state import list_tasks, list_workers
from ray.util.state.common import (
    DEFAULT_LIMIT,
    DEFAULT_RPC_TIMEOUT,
    ListApiOptions,
    PredicateType,
    SupportedFilterType,
)
from ray.util.state.state_manager import StateDataSourceClient

import psutil


@dataclass
class StateAPIMetric:
    latency_sec: float
    result_size: int


@dataclass
class StateAPICallSpec:
    api: Callable
    verify_cb: Callable
    kwargs: Dict = field(default_factory=dict)


@dataclass
class StateAPIStats:
    pending_calls: int = 0
    total_calls: int = 0
    calls: Dict = field(default_factory=lambda: defaultdict(list))


GLOBAL_STATE_STATS = StateAPIStats()

STATE_LIST_LIMIT = int(1e6)  # 1m
STATE_LIST_TIMEOUT = 600  # 10min


def invoke_state_api(
    verify_cb: Callable,
    state_api_fn: Callable,
    state_stats: StateAPIStats = GLOBAL_STATE_STATS,
    key_suffix: Optional[str] = None,
    print_result: Optional[bool] = False,
    err_msg: Optional[str] = None,
    **kwargs,
):
    """Invoke a State API

    Args:
        verify_cb: Callback that takes in the response from `state_api_fn` and
            returns a boolean, indicating the correctness of the results.
        state_api_fn: Function of the state API.
        state_stats: Stats container that tracks latency and call counts.
        key_suffix: Optional suffix appended to the stats key for this call.
        print_result: If True, pretty-print the API result.
        err_msg: Optional message included in the assertion error if the
            verify callback fails.
        **kwargs: Keyword arguments to be forwarded to the `state_api_fn`.

    Returns:
        The response from ``state_api_fn``.
    """
    if "timeout" not in kwargs:
        kwargs["timeout"] = STATE_LIST_TIMEOUT

    # Suppress missing output warning
    kwargs["raise_on_missing_output"] = False

    res = None
    try:
        state_stats.total_calls += 1
        state_stats.pending_calls += 1

        t_start = time.perf_counter()
        res = state_api_fn(**kwargs)
        t_end = time.perf_counter()

        if print_result:
            pprint.pprint(res)

        metric = StateAPIMetric(t_end - t_start, len(res))
        if key_suffix:
            key = f"{state_api_fn.__name__}_{key_suffix}"
        else:
            key = state_api_fn.__name__
        state_stats.calls[key].append(metric)
        assert verify_cb(
            res
        ), f"Calling State API failed. len(res)=({len(res)}): {err_msg}"
    except Exception as e:
        traceback.print_exc()
        assert (
            False
        ), f"Calling {state_api_fn.__name__}({kwargs}) failed with {repr(e)}."
    finally:
        state_stats.pending_calls -= 1

    return res


def invoke_state_api_n(*args, **kwargs):
    def verify():
        NUM_API_CALL_SAMPLES = 10
        for _ in range(NUM_API_CALL_SAMPLES):
            invoke_state_api(*args, **kwargs)
        return True

    test_utils.wait_for_condition(verify, retry_interval_ms=2000, timeout=30)


def aggregate_perf_results(state_stats: StateAPIStats = GLOBAL_STATE_STATS):
    """Aggregate stats of state API calls

    Return:
        This returns a dict of below fields:
            - max_{api_key_name}_latency_sec:
                Max latency of call to {api_key_name}
            - {api_key_name}_result_size_with_max_latency:
                The size of the result (or the number of bytes for get_log API)
                for the max latency invocation
            - avg/p99/p95/p50_{api_key_name}_latency_sec:
                The percentile latency stats
            - avg_state_api_latency_sec:
                The average latency of all the state apis tracked
    """
    # Prevent iteration when modifying error
    state_stats = deepcopy(state_stats)
    perf_result = {}
    for api_key_name, metrics in state_stats.calls.items():
        # Per api aggregation
        # Max latency
        latency_key = f"max_{api_key_name}_latency_sec"
        size_key = f"{api_key_name}_result_size_with_max_latency"
        metric = max(metrics, key=lambda metric: metric.latency_sec)

        perf_result[latency_key] = metric.latency_sec
        perf_result[size_key] = metric.result_size

        latency_list = np.array([metric.latency_sec for metric in metrics])
        # avg latency
        key = f"avg_{api_key_name}_latency_sec"
        perf_result[key] = np.average(latency_list)

        # p99 latency
        key = f"p99_{api_key_name}_latency_sec"
        perf_result[key] = np.percentile(latency_list, 99)

        # p95 latency
        key = f"p95_{api_key_name}_latency_sec"
        perf_result[key] = np.percentile(latency_list, 95)

        # p50 latency
        key = f"p50_{api_key_name}_latency_sec"
        perf_result[key] = np.percentile(latency_list, 50)

    all_state_api_latency = sum(
        metric.latency_sec
        for metric_samples in state_stats.calls.values()
        for metric in metric_samples
    )

    perf_result["avg_state_api_latency_sec"] = (
        (all_state_api_latency / state_stats.total_calls)
        if state_stats.total_calls != 0
        else -1
    )

    return perf_result


@ray.remote(num_cpus=0)
class StateAPIGeneratorActor:
    def __init__(
        self,
        apis: List[StateAPICallSpec],
        call_interval_s: float = 5.0,
        print_interval_s: float = 20.0,
        wait_after_stop: bool = True,
        print_result: bool = False,
    ) -> None:
        """An actor that periodically issues state API

        Args:
            apis: List of StateAPICallSpec.
            call_interval_s: State apis in the `apis` will be issued
                every `call_interval_s` seconds.
            print_interval_s: How frequent state api stats will be dumped.
            wait_after_stop: When true, call to `ray.get(actor.stop.remote())`
                will wait for all pending state APIs to return.
                Setting it to `False` might miss some long-running state apis calls.
            print_result: True if result of each API call is printed. Default False.
        """
        # Configs
        self._apis = apis
        self._call_interval_s = call_interval_s
        self._print_interval_s = print_interval_s
        self._wait_after_cancel = wait_after_stop
        self._logger = logging.getLogger(self.__class__.__name__)
        self._print_result = print_result

        # States
        self._tasks = None
        self._fut_queue = None
        self._executor = None
        self._loop = None
        self._stopping = False
        self._stopped = False
        self._stats = StateAPIStats()

    async def start(self):
        # Run the periodic api generator
        self._fut_queue = asyncio.Queue()
        self._executor = concurrent.futures.ThreadPoolExecutor()

        self._tasks = [
            asyncio.ensure_future(awt)
            for awt in [
                self._run_generator(),
                self._run_result_waiter(),
                self._run_stats_reporter(),
            ]
        ]
        await asyncio.gather(*self._tasks)

    def call(self, fn, verify_cb, **kwargs):
        def run_fn():
            try:
                self._logger.debug(f"calling {fn.__name__}({kwargs})")
                return invoke_state_api(
                    verify_cb,
                    fn,
                    state_stats=self._stats,
                    print_result=self._print_result,
                    **kwargs,
                )
            except Exception as e:
                self._logger.warning(f"{fn.__name__}({kwargs}) failed with: {repr(e)}")
                return None

        fut = asyncio.get_running_loop().run_in_executor(self._executor, run_fn)
        return fut

    async def _run_stats_reporter(self):
        while not self._stopped:
            # Keep the reporter running until all pending apis finish and the bool
            # `self._stopped` is then True
            self._logger.info(pprint.pprint(aggregate_perf_results(self._stats)))
            try:
                await asyncio.sleep(self._print_interval_s)
            except asyncio.CancelledError:
                self._logger.info(
                    "_run_stats_reporter cancelled, "
                    f"waiting for all api {self._stats.pending_calls}calls to return..."
                )

    async def _run_generator(self):
        try:
            while not self._stopping:
                # Run the state API in another thread
                for api_spec in self._apis:
                    fut = self.call(api_spec.api, api_spec.verify_cb, **api_spec.kwargs)
                    self._fut_queue.put_nowait(fut)

                await asyncio.sleep(self._call_interval_s)
        except asyncio.CancelledError:
            # Stop running
            self._logger.info("_run_generator cancelled, now stopping...")
            return

    async def _run_result_waiter(self):
        try:
            while not self._stopping:
                fut = await self._fut_queue.get()
                await fut
        except asyncio.CancelledError:
            self._logger.info(
                f"_run_result_waiter cancelled, cancelling {self._fut_queue.qsize()} "
                "pending futures..."
            )
            while not self._fut_queue.empty():
                fut = self._fut_queue.get_nowait()
                if self._wait_after_cancel:
                    await fut
                else:
                    # Ignore the queue futures if we are not
                    # waiting on them after stop() called
                    fut.cancel()
            return

    def get_stats(self):
        # deep copy to prevent race between reporting and modifying stats
        return aggregate_perf_results(self._stats)

    def ready(self):
        pass

    def stop(self):
        self._stopping = True
        self._logger.debug(f"calling stop, canceling {len(self._tasks)} tasks")
        for task in self._tasks:
            task.cancel()

        # This will block the stop() function until all futures are cancelled
        # if _wait_after_cancel=True. When _wait_after_cancel=False, it will still
        # wait for any in-progress futures.
        # See: https://docs.python.org/3.8/library/concurrent.futures.html
        self._executor.shutdown(wait=self._wait_after_cancel)
        self._stopped = True


def periodic_invoke_state_apis_with_actor(*args, **kwargs) -> ActorHandle:
    current_node_ip = ray._private.worker.global_worker.node_ip_address
    # Schedule the actor on the current node.
    actor = StateAPIGeneratorActor.options(
        resources={f"node:{current_node_ip}": 0.001}
    ).remote(*args, **kwargs)
    print("Waiting for state api actor to be ready...")
    ray.get(actor.ready.remote())
    print("State api actor is ready now.")
    actor.start.remote()
    return actor


def get_state_api_manager(gcs_address: str) -> StateAPIManager:
    gcs_client = GcsClient(address=gcs_address)
    gcs_channel = GcsChannel(gcs_address=gcs_address, aio=True)
    gcs_channel.connect()
    state_api_data_source_client = StateDataSourceClient(
        gcs_channel.channel(), gcs_client
    )
    return StateAPIManager(
        state_api_data_source_client,
        thread_pool_executor=ThreadPoolExecutor(
            thread_name_prefix="state_api_test_utils"
        ),
    )


def summarize_worker_startup_time():
    workers = list_workers(
        detail=True,
        filters=[("worker_type", "=", "WORKER")],
        limit=10000,
        raise_on_missing_output=False,
    )
    time_to_launch = []
    time_to_initialize = []
    for worker in workers:
        launch_time = worker.get("worker_launch_time_ms")
        launched_time = worker.get("worker_launched_time_ms")
        start_time = worker.get("start_time_ms")

        if launched_time > 0:
            time_to_launch.append(launched_time - launch_time)
        if start_time:
            time_to_initialize.append(start_time - launched_time)
    time_to_launch.sort()
    time_to_initialize.sort()

    def print_latencies(latencies):
        print(f"Avg: {round(sum(latencies) / len(latencies), 2)} ms")
        print(f"P25: {round(latencies[int(len(latencies) * 0.25)], 2)} ms")
        print(f"P50: {round(latencies[int(len(latencies) * 0.5)], 2)} ms")
        print(f"P95: {round(latencies[int(len(latencies) * 0.95)], 2)} ms")
        print(f"P99: {round(latencies[int(len(latencies) * 0.99)], 2)} ms")

    print("Time to launch workers")
    print_latencies(time_to_launch)
    print("=======================")
    print("Time to initialize workers")
    print_latencies(time_to_initialize)


def verify_failed_task(
    name: str, error_type: str, error_message: Union[str, List[str], None] = None
) -> bool:
    """
    Check if a task with 'name' has failed with the exact error type 'error_type'
    and 'error_message' in the error message.
    """
    tasks = list_tasks(filters=[("name", "=", name)], detail=True)
    assert len(tasks) == 1, tasks
    t = tasks[0]
    assert t["state"] == "FAILED", t
    assert t["error_type"] == error_type, t
    if error_message is not None:
        if isinstance(error_message, str):
            error_message = [error_message]
        for msg in error_message:
            assert msg in t.get("error_message", None), t
    return True


def wait_for_task_states(name_to_state: Dict[str, str], timeout: float = 30) -> None:
    """
    Block until every task in ``name_to_state`` is observed in its expected
    state via the State API, or raise if the timeout expires.
    """

    def _check():
        for name, state in name_to_state.items():
            tasks = list_tasks(filters=[("name", "=", name), ("state", "=", state)])
            assert len(tasks) == 1, f"{name} not in {state}"
        return True

    test_utils.wait_for_condition(_check, timeout=timeout)


def _is_actor_task_running(actor_pid: int, task_name: str):
    """
    Check whether the actor task `task_name` is running on the actor process
    with pid `actor_pid`.

    Args:
      actor_pid: The pid of the actor process.
      task_name: The name of the actor task.

    Returns:
      True if the actor task is running, False otherwise.

    Limitation:
        If the actor task name is set using options.name and is a substring of
        the actor name, this function may return true even if the task is not
        running on the actor process. To resolve this issue, we can possibly
        pass in the actor name.
    """
    if not psutil.pid_exists(actor_pid):
        return False

    """
    Why use both `psutil.Process.name()` and `psutil.Process.cmdline()`?

    1. Core worker processes call `setproctitle` to set the process title before
    and after executing tasks. However, the definition of "title" is a bit
    complex.

    [ref]: https://github.com/dvarrazzo/py-setproctitle

    > The process title is usually visible in files such as /proc/PID/cmdline,
    /proc/PID/status, /proc/PID/comm, depending on the operating system and
    kernel version. This information is used by user-space tools such as ps
    and top.

    Ideally, we would only need to check `psutil.Process.cmdline()`, but I decided
    to check both `psutil.Process.name()` and `psutil.Process.cmdline()` based on
    the definition of "title" stated above.

    2. Additionally, the definition of `psutil.Process.name()` is not consistent
    with the definition of "title" in `setproctitle`. The length of `/proc/PID/comm` and
    the prefix of `/proc/PID/cmdline` affect the return value of
    `psutil.Process.name()`.

    In addition, executing `setproctitle` in different threads within the same
    process may result in different outcomes.

    To learn more details, please refer to the source code of `psutil`:

    [ref]:
    https://github.com/giampaolo/psutil/blob/a17550784b0d3175da01cdb02cee1bc6b61637dc/psutil/__init__.py#L664-L693

    3. `/proc/PID/comm` will be truncated to TASK_COMM_LEN (16) characters
    (including the terminating null byte).

    [ref]:
    https://man7.org/linux/man-pages/man5/proc_pid_comm.5.html
    """
    name = psutil.Process(actor_pid).name()
    if task_name in name and name.startswith("ray::"):
        return True

    cmdline = psutil.Process(actor_pid).cmdline()
    # If `options.name` is set, the format is `ray::<task_name>`. If not,
    # the format is `ray::<actor_name>.<task_name>`.
    if cmdline and task_name in cmdline[0] and cmdline[0].startswith("ray::"):
        return True
    return False


def verify_schema(state, result_dict: dict, detail: bool = False):
    """
    Verify the schema of the result_dict is the same as the state.
    """
    state_fields_columns = set()
    if detail:
        state_fields_columns = state.columns()
    else:
        state_fields_columns = state.base_columns()

    for k in state_fields_columns:
        assert k in result_dict

    for k in result_dict:
        assert k in state_fields_columns

    # Make the field values can be converted without error as well
    state(**result_dict)


def create_api_options(
    timeout: int = DEFAULT_RPC_TIMEOUT,
    limit: int = DEFAULT_LIMIT,
    filters: List[Tuple[str, PredicateType, SupportedFilterType]] = None,
    detail: bool = False,
    exclude_driver: bool = True,
):
    if not filters:
        filters = []
    return ListApiOptions(
        limit=limit,
        timeout=timeout,
        filters=filters,
        server_timeout_multiplier=1.0,
        detail=detail,
        exclude_driver=exclude_driver,
    )