import os
import sys
from contextlib import contextmanager
from datetime import datetime
from pathlib import Path
from typing import Generator

from loguru import logger
from psutil import Process

from rdagent.core.utils import SingletonBaseClass, import_class

from .base import Storage
from .conf import LOG_SETTINGS
from .storage import FileStorage
from .utils import get_caller_info


class RDAgentLog(SingletonBaseClass):
    """
    The files are organized based on the tag & PID
    Here is an example tag

    .. code-block::

        a
        - b
        - c
            - 123
              - common_logs.log
            - 1322
              - common_logs.log
            - 1233
              - <timestamp>.pkl
            - d
                - 1233-673 ...
                - 1233-4563 ...
                - 1233-365 ...

    """

    # TODO: Simplify it to introduce less concepts ( We may merge RDAgentLog, Storage &)
    # Solution:  Storage => PipeLog, View => PipeLogView, RDAgentLog is an instance of PipeLogger
    # PipeLogger.info(...) ,  PipeLogger.get_resp() to get feedback from frontend.
    # def f():
    #   logger = PipeLog()
    #   logger.info("<code>")
    #   feedback = logger.get_reps()
    _tag: str = ""

    def __init__(self) -> None:
        self.storage = FileStorage(LOG_SETTINGS.trace_path)
        self.other_storages: list[Storage] = []
        for storage, args in LOG_SETTINGS.storages.items():
            storage_cls = import_class(storage)
            self.other_storages.append(storage_cls(*args))

        self.main_pid = os.getpid()

    @contextmanager
    def tag(self, tag: str) -> Generator[None, None, None]:
        if tag.strip() == "":
            raise ValueError("Tag cannot be empty.")
        if self._tag != "":
            tag = "." + tag

        # TODO: It may result in error in mutithreading or co-routine
        self._tag = self._tag + tag
        try:
            yield
        finally:
            self._tag = self._tag[: -len(tag)]

    def set_storages_path(self, path: str | Path) -> None:
        for storage in [self.storage] + self.other_storages:
            if hasattr(storage, "path"):
                storage.path = path

    def truncate_storages(self, time: datetime) -> None:
        for storage in [self.storage] + self.other_storages:
            storage.truncate(time=time)

    def get_pids(self) -> str:
        """
        Returns a string of pids from the current process to the main process.
        Split by '-'.
        """
        pid = os.getpid()
        process = Process(pid)
        pid_chain = f"{pid}"
        while process.pid != self.main_pid:
            parent_pid = process.ppid()
            parent_process = Process(parent_pid)
            pid_chain = f"{parent_pid}-{pid_chain}"
            process = parent_process
        return pid_chain

    def log_object(self, obj: object, *, tag: str = "") -> None:
        # TODO: I think we can merge the log_object function with other normal log methods to make the interface simpler.
        caller_info = get_caller_info()
        tag = f"{self._tag}.{tag}.{self.get_pids()}".strip(".")

        for storage in [self.storage] + self.other_storages:
            logp = storage.log(obj, tag=tag)
            logger.patch(lambda r: r.update(caller_info)).info(f"Log object to [{storage}], uri: {logp}")

    def _log(self, level: str, msg: str, *, tag: str = "", raw: bool = False) -> None:
        caller_info = get_caller_info()
        tag = f"{self._tag}.{tag}.{self.get_pids()}".strip(".")

        if raw:
            logger.remove()
            logger.add(sys.stderr, format=lambda r: "{message}")

        log_func = getattr(logger.patch(lambda r: r.update(caller_info)), level)
        log_func(msg)

        if raw:
            logger.remove()
            logger.add(sys.stderr)

    def info(self, msg: str, *, tag: str = "", raw: bool = False) -> None:
        self._log("info", msg, tag=tag, raw=raw)

    def warning(self, msg: str, *, tag: str = "", raw: bool = False) -> None:
        self._log("warning", msg, tag=tag, raw=raw)

    def error(self, msg: str, *, tag: str = "", raw: bool = False) -> None:
        self._log("error", msg, tag=tag, raw=raw)