# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import contextlib
import inspect
import os
import sys
import threading
import time
import uuid
from collections.abc import Sized
from functools import wraps
from timeit import default_timer as timer
from typing import Any, Callable, List, Optional, Set, TypeVar, Union, cast, overload

from typing_extensions import Final

from streamlit import config, util
from streamlit.logger import get_logger
from streamlit.proto.ForwardMsg_pb2 import ForwardMsg
from streamlit.proto.PageProfile_pb2 import Argument, Command

_LOGGER = get_logger(__name__)

# Limit the number of commands to keep the page profile message small
# since Segment allows only a maximum of 32kb per event.
_MAX_TRACKED_COMMANDS: Final = 200
# Only track a maximum of 25 uses per unique command since some apps use
# commands excessively (e.g. calling add_rows thousands of times in one rerun)
# making the page profile useless.
_MAX_TRACKED_PER_COMMAND: Final = 25

# A mapping to convert from the actual name to preferred/shorter representations
_OBJECT_NAME_MAPPING: Final = {
    "streamlit.delta_generator.DeltaGenerator": "DG",
    "pandas.core.frame.DataFrame": "DataFrame",
    "plotly.graph_objs._figure.Figure": "PlotlyFigure",
    "bokeh.plotting.figure.Figure": "BokehFigure",
    "matplotlib.figure.Figure": "MatplotlibFigure",
    "pandas.io.formats.style.Styler": "PandasStyler",
    "pandas.core.indexes.base.Index": "PandasIndex",
    "pandas.core.series.Series": "PandasSeries",
}

# A list of dependencies to check for attribution
_ATTRIBUTIONS_TO_CHECK: Final = [
    "snowflake",
    "torch",
    "tensorflow",
    "streamlit_extras",
    "streamlit_pydantic",
    "plost",
]

_ETC_MACHINE_ID_PATH = "/etc/machine-id"
_DBUS_MACHINE_ID_PATH = "/var/lib/dbus/machine-id"


def _get_machine_id_v3() -> str:
    """Get the machine ID

    This is a unique identifier for a user for tracking metrics in Segment,
    that is broken in different ways in some Linux distros and Docker images.
    - at times just a hash of '', which means many machines map to the same ID
    - at times a hash of the same string, when running in a Docker container
    """

    machine_id = str(uuid.getnode())
    if os.path.isfile(_ETC_MACHINE_ID_PATH):
        with open(_ETC_MACHINE_ID_PATH, "r") as f:
            machine_id = f.read()

    elif os.path.isfile(_DBUS_MACHINE_ID_PATH):
        with open(_DBUS_MACHINE_ID_PATH, "r") as f:
            machine_id = f.read()

    return machine_id


class Installation:
    _instance_lock = threading.Lock()
    _instance = None  # type: Optional[Installation]

    @classmethod
    def instance(cls) -> "Installation":
        """Returns the singleton Installation"""
        # We use a double-checked locking optimization to avoid the overhead
        # of acquiring the lock in the common case:
        # https://en.wikipedia.org/wiki/Double-checked_locking
        if cls._instance is None:
            with cls._instance_lock:
                if cls._instance is None:
                    cls._instance = Installation()
        return cls._instance

    def __init__(self):
        self.installation_id_v3 = str(
            uuid.uuid5(uuid.NAMESPACE_DNS, _get_machine_id_v3())
        )

    def __repr__(self) -> str:
        return util.repr_(self)

    @property
    def installation_id(self):
        return self.installation_id_v3


def _get_type_name(obj: object) -> str:
    """Get a simplified name for the type of the given object."""
    with contextlib.suppress(Exception):
        obj_type = type(obj)
        type_name = "unknown"
        if hasattr(obj_type, "__qualname__"):
            type_name = obj_type.__qualname__
        elif hasattr(obj_type, "__name__"):
            type_name = obj_type.__name__

        if obj_type.__module__ != "builtins":
            # Add the full module path
            type_name = f"{obj_type.__module__}.{type_name}"

        if type_name in _OBJECT_NAME_MAPPING:
            type_name = _OBJECT_NAME_MAPPING[type_name]
        return type_name
    return "failed"


def _get_top_level_module(func: Callable[..., Any]) -> str:
    """Get the top level module for the given function."""
    module = inspect.getmodule(func)
    if module is None or not module.__name__:
        return "unknown"
    return module.__name__.split(".")[0]


def _get_arg_metadata(arg: object) -> Optional[str]:
    """Get metadata information related to the value of the given object."""
    with contextlib.suppress(Exception):
        if isinstance(arg, (bool)):
            return f"val:{arg}"

        if isinstance(arg, Sized):
            return f"len:{len(arg)}"

    return None


def _get_command_telemetry(
    _command_func: Callable[..., Any], _command_name: str, *args, **kwargs
) -> Command:
    """Get telemetry information for the given callable and its arguments."""
    arg_keywords = inspect.getfullargspec(_command_func).args
    self_arg: Optional[Any] = None
    arguments: List[Argument] = []
    is_method = inspect.ismethod(_command_func)
    name = _command_name

    for i, arg in enumerate(args):
        pos = i
        if is_method:
            # If func is a method, ignore the first argument (self)
            i = i + 1

        keyword = arg_keywords[i] if len(arg_keywords) > i else f"{i}"
        if keyword == "self":
            self_arg = arg
            continue
        argument = Argument(k=keyword, t=_get_type_name(arg), p=pos)

        arg_metadata = _get_arg_metadata(arg)
        if arg_metadata:
            argument.m = arg_metadata
        arguments.append(argument)
    for kwarg, kwarg_value in kwargs.items():
        argument = Argument(k=kwarg, t=_get_type_name(kwarg_value))

        arg_metadata = _get_arg_metadata(kwarg_value)
        if arg_metadata:
            argument.m = arg_metadata
        arguments.append(argument)

    top_level_module = _get_top_level_module(_command_func)
    if top_level_module != "streamlit":
        # If the gather_metrics decorator is used outside of streamlit library
        # we enforce a prefix to be added to the tracked command:
        name = f"external:{top_level_module}:{name}"

    if (
        name == "create_instance"
        and self_arg
        and hasattr(self_arg, "name")
        and self_arg.name
    ):
        name = f"component:{self_arg.name}"

    return Command(name=name, args=arguments)


def to_microseconds(seconds: float) -> int:
    """Convert seconds into microseconds."""
    return int(seconds * 1_000_000)


F = TypeVar("F", bound=Callable[..., Any])


@overload
def gather_metrics(
    name: str,
    func: F,
) -> F:
    ...


@overload
def gather_metrics(
    name: str,
    func: None = None,
) -> Callable[[F], F]:
    ...


def gather_metrics(name: str, func: Optional[F] = None) -> Union[Callable[[F], F], F]:
    """Function decorator to add telemetry tracking to commands.

    Parameters
    ----------
    func : callable
    The function to track for telemetry.

    name : str or None
    Overwrite the function name with a custom name that is used for telemetry tracking.

    Example
    -------
    >>> @st.gather_metrics
    ... def my_command(url):
    ...     return url

    >>> @st.gather_metrics(name="custom_name")
    ... def my_command(url):
    ...     return url
    """

    if not name:
        _LOGGER.warning("gather_metrics: name is empty")
        name = "undefined"

    if func is None:
        # Support passing the params via function decorator
        def wrapper(f: F) -> F:
            return gather_metrics(
                name=name,
                func=f,
            )

        return wrapper
    else:
        # To make mypy type narrow Optional[F] -> F
        non_optional_func = func

    @wraps(non_optional_func)
    def wrapped_func(*args, **kwargs):
        exec_start = timer()
        # get_script_run_ctx gets imported here to prevent circular dependencies
        from streamlit.runtime.scriptrunner import get_script_run_ctx

        ctx = get_script_run_ctx()

        tracking_activated = (
            ctx is not None
            and ctx.gather_usage_stats
            and not ctx.command_tracking_deactivated
            and len(ctx.tracked_commands)
            < _MAX_TRACKED_COMMANDS  # Prevent too much memory usage
        )
        command_telemetry: Optional[Command] = None

        if ctx and tracking_activated:
            try:
                command_telemetry = _get_command_telemetry(
                    non_optional_func, name, *args, **kwargs
                )

                if (
                    command_telemetry.name not in ctx.tracked_commands_counter
                    or ctx.tracked_commands_counter[command_telemetry.name]
                    < _MAX_TRACKED_PER_COMMAND
                ):
                    ctx.tracked_commands.append(command_telemetry)
                ctx.tracked_commands_counter.update([command_telemetry.name])
                # Deactivate tracking to prevent calls inside already tracked commands
                ctx.command_tracking_deactivated = True
            except Exception as ex:
                # Always capture all exceptions since we want to make sure that
                # the telemetry never causes any issues.
                _LOGGER.debug("Failed to collect command telemetry", exc_info=ex)
        try:
            result = non_optional_func(*args, **kwargs)
        finally:
            # Activate tracking again if command executes without any exceptions
            if ctx:
                ctx.command_tracking_deactivated = False

        if tracking_activated and command_telemetry:
            # Set the execution time to the measured value
            command_telemetry.time = to_microseconds(timer() - exec_start)
        return result

    with contextlib.suppress(AttributeError):
        # Make this a well-behaved decorator by preserving important function
        # attributes.
        wrapped_func.__dict__.update(non_optional_func.__dict__)
        wrapped_func.__signature__ = inspect.signature(non_optional_func)  # type: ignore
    return cast(F, wrapped_func)


def create_page_profile_message(
    commands: List[Command],
    exec_time: int,
    prep_time: int,
    uncaught_exception: Optional[str] = None,
) -> ForwardMsg:
    """Create and return the full PageProfile ForwardMsg."""
    msg = ForwardMsg()
    msg.page_profile.commands.extend(commands)
    msg.page_profile.exec_time = exec_time
    msg.page_profile.prep_time = prep_time

    msg.page_profile.headless = config.get_option("server.headless")

    # Collect all config options that have been manually set
    config_options: Set[str] = set()
    if config._config_options:
        for option_name in config._config_options.keys():
            if not config.is_manually_set(option_name):
                # We only care about manually defined options
                continue

            config_option = config._config_options[option_name]
            if config_option.is_default:
                option_name = f"{option_name}:default"
            config_options.add(option_name)

    msg.page_profile.config.extend(config_options)

    # Check the predefined set of modules for attribution
    attributions: Set[str] = {
        attribution
        for attribution in _ATTRIBUTIONS_TO_CHECK
        if attribution in sys.modules
    }

    msg.page_profile.os = str(sys.platform)
    msg.page_profile.timezone = str(time.tzname)
    msg.page_profile.attributions.extend(attributions)

    if uncaught_exception:
        msg.page_profile.uncaught_exception = uncaught_exception

    return msg
