import io
import os
import re
import shutil
import pathlib
import subprocess
from typing import List, Union, Optional

import pandas as pd
from loguru import logger
from ruamel.yaml.comments import CommentedMap, CommentedSeq

import gradio as gr
from datasets import load_dataset
from yourbench_space import PATH


STAGES = [
    "ingestion",
    "upload_ingest_to_hub",
    "summarization",
    "chunking",
    "single_shot_question_generation",
    "multi_hop_question_generation",
    "lighteval",
    "citation_score_filtering",
]

STAGE_DISPLAY_MAP = {
    "ingestion": "Process Input Docs",
    "upload_ingest_to_hub": "Upload Dataset to Hub",
    "summarization": "Summarize Documents",
    "chunking": "Chunk Documents",
    "single_shot_question_generation": "Generate Single Shot Questions",
    "multi_hop_question_generation": "Generate Multi Hop Questions",
    "lighteval": "Generate Lighteval Subset",
    "citation_score_filtering": "Citation Score Filtering"
}


def to_commentable_yaml(obj):
    """
    Recursively converts standard Python dicts and lists into
    ruamel.yaml's CommentedMap and CommentedSeq so that comments
    can be attached when dumping YAML
    """
    # Convert dict to CommentedMap with recursively processed values
    if isinstance(obj, dict):
        return CommentedMap({k: to_commentable_yaml(v) for k, v in obj.items()})

    # Convert list to CommentedSeq with recursively processed elements
    elif isinstance(obj, list):
        return CommentedSeq([to_commentable_yaml(i) for i in obj])

    # Return non-container values as-is
    return obj


def map_stage_names(stages: list[str]) -> list[str]:
    return [STAGE_DISPLAY_MAP.get(stage, stage) for stage in stages]


def is_running_locally() -> bool:
    """
    Returns True if Gradio is running locally, False if it's running in a Hugging Face Space.
    """
    return os.getenv("SPACE_ID") is None  # SPACE_ID is set in Hugging Face Spaces


def save_files(oauth_token: gr.OAuthToken | None, session_state: gr.State, files: List[pathlib.Path]) -> str:
    """Save uploaded files to the UPLOAD_DIRECTORY/uuid safely"""
    if oauth_token is None and not is_running_locally():
        gr.Warning("You need to log in to use this Space")
        return

    saved_paths = []

    for file in [file.name for file in files]:
        try:
            source_path = pathlib.Path(file)
            upload_directory_uuid = pathlib.Path(f"{PATH}/{session_state.value}/uploaded_files")
            # Ensure the upload directory exists
            upload_directory_uuid.mkdir(parents=True, exist_ok=True)
            destination_path = upload_directory_uuid / source_path.name

            if not source_path.exists():
                print(f"File not found: {source_path}")
                continue  # Skip missing files

            shutil.move(str(source_path), str(destination_path))
            saved_paths.append(str(destination_path))

        except Exception as e:
            print(f"Error moving file {file}: {e}")

    return f"Files saved to: {', '.join(saved_paths)}" if saved_paths else "No files were saved"


def update_dataset(stages: list, hf_org: str, hf_prefix: str, oauth_token: gr.OAuthToken):
    """
    Updates the dataset based on the provided stages and dataset configuration.
    """
    ingestion_df = pd.DataFrame()
    summarization_df = pd.DataFrame()
    single_shot_df = pd.DataFrame()
    multi_hop_df = pd.DataFrame()
    lighteval_df = pd.DataFrame()

    # Construct dataset name from config
    dataset_name = f"{hf_org}/{hf_prefix}"

    if STAGE_DISPLAY_MAP["upload_ingest_to_hub"] in stages:
        ingestion_ds = load_dataset(
            dataset_name, name="ingested", split="train", streaming=True, token=oauth_token.token
        ).select_columns("document_text")
        ingestion_df = pd.DataFrame(ingestion_ds.take(1))

    if STAGE_DISPLAY_MAP["summarization"] in stages:
        summarization_ds = load_dataset(
            dataset_name, name="summarized", split="train", streaming=True, token=oauth_token.token
        ).select_columns(["document_summary", "summarization_model"])
        summarization_df = pd.DataFrame(summarization_ds.take(5))

    if STAGE_DISPLAY_MAP["single_shot_question_generation"] in stages:
        single_shot_ds = load_dataset(
            dataset_name,
            name="single_shot_questions",
            split="train",
            streaming=True,
            token=oauth_token.token,
        ).select_columns(["question", "self_answer", "estimated_difficulty"])
        single_shot_df = pd.DataFrame(single_shot_ds.take(5))

    if STAGE_DISPLAY_MAP["multi_hop_question_generation"] in stages:
        multi_hop_ds = load_dataset(
            dataset_name,
            name="multi_hop_questions",
            split="train",
            streaming=True,
            token=oauth_token.token,
        ).select_columns(["question", "self_answer", "estimated_difficulty"])
        multi_hop_df = pd.DataFrame(multi_hop_ds.take(5))

    if STAGE_DISPLAY_MAP["lighteval"] in stages:
        lighteval_ds = load_dataset(
            dataset_name, name="lighteval", split="train", streaming=True, token=oauth_token.token
        ).select_columns(["question", "ground_truth_answer", "question_category", "kind"])
        lighteval_df = pd.DataFrame(lighteval_ds.take(5))

    return (ingestion_df, summarization_df, single_shot_df, multi_hop_df, lighteval_df)


def should_enable_eval_tab(stages):
    logger.info(f"Stages received: {stages}")
    logger.info(f"Lighteval stage name: {STAGE_DISPLAY_MAP['lighteval']}")
    return STAGE_DISPLAY_MAP["lighteval"] in stages


def on_generation_succsess(stages):
    stages = stages or []
    if STAGE_DISPLAY_MAP["lighteval"] in stages:
        gr.Success("🌟 Your Dataset is ready for evaluation!")
        return gr.update(selected=2), gr.update(interactive=True, visible=True)
    return gr.update(), gr.update(interactive=False, visible=True)


class SubprocessManagerGroup:
    """Instanciates one manager per user (should be used as a singleton class)"""

    def __init__(self):
        self.managers: dict[str, SubprocessManager] = {}

    @staticmethod
    def grab_uuid(uid: Union[str, gr.State]):
        """If a gradio session state is provided, we pull the uuid from its value - else we assume the str is the uuid"""
        if isinstance(uid, gr.State):
            uid = uid.value
        return uid

    def create(self, uid: Union[str, gr.State]):
        uid = SubprocessManagerGroup.grab_uuid(uid)
        self.managers[uid] = SubprocessManager(uid)

    def get(self, uid: Union[str, "gr.State"]) -> Optional["SubprocessManager"]:
        uid = SubprocessManagerGroup.grab_uuid(uid)
        return self.managers.get(uid)

    def remove(self, uid: Union[str, gr.State]):
        uid = SubprocessManagerGroup.grab_uuid(uid)
        if manager := self.managers.get(uid):
            manager.stop_process()
            manager.clean_workdir()

        del self.managers[uid]

    def clean_workdir(self, uid: Union[str, gr.State]):
        uid = SubprocessManagerGroup.grab_uuid(uid)
        if manager := self.managers.get(uid):
            manager.clean_workdir()

    def start_process(self, uid: Union[str, gr.State], custom_env: dict | None):
        uid = SubprocessManagerGroup.grab_uuid(uid)
        self.managers[uid].start_process(custom_env=custom_env)

    def stop_process(self, uid: Union[str, gr.State]):
        uid = SubprocessManagerGroup.grab_uuid(uid)
        self.managers[uid].stop_process()

    def kill_process(self, uid: Union[str, gr.State]):
        uid = SubprocessManagerGroup.grab_uuid(uid)
        self.managers[uid].kill_process()

    def read_and_get_output(self, uid: Union[str, gr.State]):
        if uid is None:
            return "", []
        uid = SubprocessManagerGroup.grab_uuid(uid)
        return self.managers[uid].read_and_get_output()

    def is_running(self, uid: Union[str, gr.State]) -> bool:
        uid = SubprocessManagerGroup.grab_uuid(uid)
        if manager := self.managers.get(uid):
            return manager.is_running()
        return False


class SubprocessManager:
    def __init__(self, session_uid: str):
        self.session_uid = session_uid
        self.path = pathlib.Path(f"{PATH}/{session_uid}")
        self.path.mkdir(parents=True, exist_ok=True)
        self.config_path = pathlib.Path(f"{self.path}/config.yml")
        self.command = ["uv", "run", "yourbench", "run", "--config", str(self.config_path)]
        self.process = None
        self.output_stream = io.StringIO()
        self.exit_code = None

    def start_process(self, custom_env: dict | None):
        """Start the subprocess."""
        if self.is_running():
            logger.info("Process is already running")
            return

        self.output_stream = io.StringIO()
        self.exit_code = None

        try:
            logger.info(f"Starting process with command: {' '.join(self.command)}")
            self.process = subprocess.Popen(
                self.command,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,  # Combine stderr with stdout
                text=True,
                bufsize=1,
                start_new_session=True,
                env=custom_env,
            )
            os.set_blocking(self.process.stdout.fileno(), False)
            logger.info(f"Started process with PID: {self.process.pid}")
        except Exception as e:
            logger.error(f"Failed to start process: {str(e)}")
            return

    def read_and_get_output(self):
        """Read subprocess output, capture it, and return log and completed stages."""
        current_output = ""
        completed_stages = []

        if self.process and self.process.stdout:
            try:
                while True:
                    line = self.process.stdout.readline()
                    if line:
                        self.output_stream.write(line)
                    else:
                        break
            except BlockingIOError:
                pass

            current_output = self.output_stream.getvalue()
            completed_stages = list(set(re.findall(r"Completed stage: '([^']*)'", current_output)))

        return current_output, map_stage_names(completed_stages)

    def clean_workdir(self):
        shutil.rmtree(self.path, ignore_errors=True)

    def stop_process(self):
        """Terminate the subprocess."""
        if not self.is_running():
            logger.info("Process is not running")
            return
        logger.info("Sending SIGTERM to the Process")
        try:
            self.process.terminate()
            self.exit_code = self.process.wait(timeout=5)  # Wait up to 5 seconds for process to terminate
            logger.info(f"Process terminated by user with exit code {self.exit_code}")
        except subprocess.TimeoutExpired:
            logger.warning("Process did not terminate within timeout, sending SIGKILL")
            self.kill_process()

    def kill_process(self):
        """Forcefully kill the subprocess"""
        if not self.is_running():
            logger.info("Process is not running")
            return
        logger.info("Sending SIGKILL to the Process")
        try:
            self.process.kill()
            self.exit_code = self.process.wait(timeout=5)  # Wait up to 5 seconds for process to be killed
            logger.info(f"Process killed by user with exit code {self.exit_code}")
        except subprocess.TimeoutExpired:
            logger.error("Process could not be killed within timeout")

    def is_running(self):
        """Check if the subprocess is still running"""
        if self.process is None:
            return False

        return self.process.poll() is None

    def get_exit_details(self):
        """Return exit code and reason if process has terminated"""
        if self.process is None:
            return None, "Process was never started"

        if self.is_running():
            return None, "Process is still running"

        if self.exit_code is not None and self.exit_code != 0:
            return self.exit_code, "Process exited abnormaly"

        return self.exit_code, "Process exited normaly"

    def __del__(self):
        """Stop the process when object is deleted"""
        if self.process:
            self.process.kill()

        self.clean_workdir()