import time
import json
import tempfile

from huggingface_hub import HfApi, hf_hub_download
import os
import threading
from pathlib import Path

from src.config import DATASET_REPO_ID, DS_RESULTS_PATH
from src.user_eval import evaluate_submission


def run_evaluation(submission_path):
    print(f"Starting evaluation for: {submission_path}")
    main_eval(DATASET_REPO_ID, submission_path, DS_RESULTS_PATH)
    print(f"Evaluation process complete for: {submission_path}", flush=True)


def start_background_evaluation(submission_path):
    """Start evaluation in a background thread."""
    thread = threading.Thread(
        target=lambda: run_evaluation(submission_path),
        daemon=True
    )
    thread.start()
    return True


# --- Main Evaluation Logic ---
def main_eval(
        user_dataset_repo_id: str,
        submission_path_in_dataset: str,  # e.g., "submissions/uploaded_dir_name"
        results_base_path_in_dataset: str  # e.g., "results"
):
    start_time = time.time()
    # Infer submission name for logging and result path generation
    submission_name_for_files = Path(submission_path_in_dataset).name

    print(f"eval.py: Starting evaluation for submission: '{submission_name_for_files}'", flush=True)
    print(f"  User Data Repo: {user_dataset_repo_id}", flush=True)
    print(f"  Submission to download from: {submission_path_in_dataset}", flush=True)
    print(f"  Results to upload to: {results_base_path_in_dataset}/{submission_name_for_files}", flush=True)

    hf_api = HfApi()  # Will use HF_TOKEN from environment

    # Create a top-level temporary directory for all operations for this eval run
    with tempfile.TemporaryDirectory(prefix="eval_run_") as top_level_temp_dir_str:
        top_level_temp_dir = Path(top_level_temp_dir_str)
        local_submission_dir = top_level_temp_dir / "submissions"
        local_result_dir_for_upload = top_level_temp_dir / "results"

        os.makedirs(local_submission_dir, exist_ok=True)
        os.makedirs(local_result_dir_for_upload, exist_ok=True)

        # Path for the summary file within the local temporary result directory
        summary_file_path = local_result_dir_for_upload / "summary.txt"

        # Download submitted files from HF Dataset
        print(f"  Downloading submission files from '{submission_path_in_dataset}' to '{local_submission_dir}'...",
              flush=True)
        try:
            # Download the relevant submission file
            hf_hub_download(
                repo_id=user_dataset_repo_id,
                repo_type="dataset",
                local_dir=local_submission_dir,
                filename=f"{submission_path_in_dataset}/submission.jsonl",
            )
            print(f"  Downloaded submission file successfully.", flush=True)
            # Download the metadata file
            hf_hub_download(
                repo_id=user_dataset_repo_id,
                repo_type="dataset",
                local_dir=local_submission_dir,
                filename=f"{submission_path_in_dataset}/metadata.json",
            )
            print(f"  Downloaded metadata file successfully.", flush=True)

        except Exception as e_download:
            print(f"  CRITICAL ERROR - Failed to download submission files: {e_download}", flush=True)
            return 1

        # load generated models from jsonl to memory
        print(f"  Loading generated models from '{local_submission_dir}'...", flush=True)
        submitted_models = []
        with open(os.path.join(local_submission_dir, submission_path_in_dataset, "submission.jsonl"), "r",
                  encoding="utf-8") as f:
            for line in f:
                try:
                    json_obj = json.loads(line)
                    submitted_models.append(json_obj)
                except json.JSONDecodeError as e:
                    print(f"  ERROR: Failed to parse JSON object from line: {line}. Error: {e}", flush=True)

        # load metadata file
        with open(os.path.join(local_submission_dir, submission_path_in_dataset, "metadata.json"), "r",
                  encoding="utf-8") as f:
            metadata = json.load(f)

        print(f"  Loaded {len(submitted_models)} generated models.", flush=True)

        # Writes stats to the summary file
        evaluate_submission(submitted_models, summary_file_path, metadata["modelling_framework"], top_level_temp_dir)

        # Upload the entire local_result_dir_for_upload to HF Dataset
        result_path_on_hub = f"{results_base_path_in_dataset}/{submission_name_for_files}"
        print(f"  Uploading results from '{local_result_dir_for_upload}' to '{result_path_on_hub}' on dataset...",
              flush=True)
        try:
            hf_api.upload_folder(
                folder_path=str(local_result_dir_for_upload),
                path_in_repo=result_path_on_hub,
                repo_id=user_dataset_repo_id,
                repo_type="dataset",
                commit_message=f"Evaluation results for {submission_name_for_files}"
            )
            print("  Results uploaded successfully.", flush=True)
        except Exception as e_upload:
            print(f"  CRITICAL ERROR: Failed to upload results: {e_upload}", flush=True)
            # The summary.txt was written locally, but upload failed.

    elapsed_time = time.time() - start_time
    print(f"eval.py: Evaluation finished in {elapsed_time:.2f} seconds.", flush=True)