# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
# or more contributor license agreements. Licensed under the Elastic License
# 2.0; you may not use this file except in compliance with the Elastic License
# 2.0.

import argparse
import json
import os
import re
import tarfile
import time
from getpass import getpass
from typing import Any, Dict, List, Optional

# Disable noisy warning about missing certificate verification
import urllib3
from elasticsearch import ApiError, Elasticsearch, TransportError, helpers
from loguru import logger

urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)


def sanitize_filename(name: str) -> str:
    """Sanitize filenames to prevent directory traversal and other security issues."""
    return re.sub(r"[^a-zA-Z0-9_-]", "_", name)


def is_within_directory(directory: str, target: str) -> bool:
    """Check if the target path is within the given directory."""
    abs_directory = os.path.abspath(directory)
    abs_target = os.path.abspath(target)
    return os.path.commonpath([abs_directory]) == os.path.commonpath(
        [abs_directory, abs_target]
    )


def safe_extract(tar: tarfile.TarFile, path: str = ".") -> None:
    """Safely extract tar files to prevent path traversal attacks."""
    for member in tar.getmembers():
        member_path = os.path.join(path, member.name)
        if not is_within_directory(path, member_path):
            raise Exception(f"Attempted Path Traversal in Tar File: {member.name}")
    tar.extractall(path=path)


def extract_archive(archive_path: str, output_dir: str) -> List[str]:
    """
    Extracts a tar.gz archive to the specified output directory.

    Args:
        archive_path (str): The path to the tar.gz archive.
        output_dir (str): The directory to extract files to.

    Returns:
        List[str]: A list of extracted file paths.
    """
    logger.info(f"Extracting archive {archive_path} to {output_dir}")
    try:
        with tarfile.open(archive_path, "r:gz") as tar:
            safe_extract(tar, path=output_dir)
            extracted_files = tar.getnames()
        return [os.path.join(output_dir, file) for file in extracted_files]
    except (tarfile.TarError, Exception) as e:
        logger.error(f"Error extracting archive: {e}")
        return []


def generate_actions(file_path: str, new_index: str):
    """
    Generator function that reads a .ndjson file and yields actions.
    It yields two lines at a time (action + document).

    Args:
        file_path (str): Path to the .ndjson file.
        new_index (str): The new index name to replace in actions.

    Yields:
        Dict[str, Any]: Action dictionaries for bulk upload.
    """
    try:
        with open(file_path, "r", encoding="utf-8") as f:
            while True:
                action_line = f.readline().strip()
                document_line = f.readline().strip()
                if not action_line or not document_line:
                    break
                # Replace the index name in the action
                action = json.loads(action_line)
                document = json.loads(document_line)

                yield {
                    "_op_type": "index",
                    "_index": new_index,
                    "_id": action["index"]["_id"],
                    "_source": document,
                }
    except IOError as e:
        logger.error(f"Error reading file {file_path}: {e}")


def upload_data(es_client: Elasticsearch, index: str, file_path: str) -> None:
    """
    Loads JSON data into the specified Elasticsearch index.

    Args:
        es_client (Elasticsearch): The Elasticsearch client.
        index (str): The index to load data into.
        file_path (str): Path to the data file.
    """
    try:
        response = helpers.bulk(
            es_client, generate_actions(file_path, index), index=index, chunk_size=1000
        )
        logger.info(f"{response[0]} documents uploaded to index {index}")
    except (ApiError, TransportError, Exception) as e:
        logger.error(f"Error uploading data: {e}")


def create_input_index(es_client: Elasticsearch, index: str) -> None:
    """
    Creates an Elasticsearch index for input data. If it exists, deletes and recreates it.

    Args:
        es_client (Elasticsearch): The Elasticsearch client.
        index (str): The index to create.
    """
    try:
        if es_client.indices.exists(index=index):
            logger.info(f"Deleting existing index {index}")
            es_client.indices.delete(index=index)
        logger.info(f"Creating index {index}")
        es_client.indices.create(index=index)
    except (ApiError, TransportError) as e:
        logger.error(f"Error creating index {index}: {e}")


def create_job_config(
    es_client: Elasticsearch,
    job_config: Dict[str, Any],
    new_index: Optional[str] = None,
) -> Optional[str]:
    """
    Uploads the job configuration using the put_job API.

    Args:
        es_client (Elasticsearch): The Elasticsearch client.
        job_config (Dict[str, Any]): The job configuration to upload.
        new_index (Optional[str]): New index name for the datafeed config.

    Returns:
        Optional[str]: The job ID if successful, None otherwise.
    """
    job_fields = [
        "job_id",
        "description",
        "analysis_config",
        "data_description",
        "model_snapshot_retention_days",
        "results_index_name",
        "analysis_limits",
        "custom_settings",
        "allow_lazy_open",
        "datafeed_config",
    ]
    filtered_config = {key: job_config[key] for key in job_fields if key in job_config}
    job_id = filtered_config.get("job_id")
    if not job_id:
        logger.error("Job ID not found in job configuration.")
        return None

    # Remove sensitive or irrelevant fields
    datafeed_config = filtered_config.get("datafeed_config", {})
    datafeed_config.pop("authorization", None)
    datafeed_config.pop("job_id", None)
    if new_index:
        datafeed_config["indices"] = [new_index]
    filtered_config["datafeed_config"] = datafeed_config

    # Check if the job already exists and delete it
    try:
        if es_client.ml.get_jobs(job_id=job_id):
            es_client.ml.delete_job(job_id=job_id, force=True)
            logger.info(f"Deleted existing job with ID: {job_id}")
    except (ApiError, TransportError):
        logger.info(f"Job with ID {job_id} does not exist, proceeding to create.")

    try:
        response = es_client.ml.put_job(job_id=job_id, body=filtered_config)
        logger.info(f"Job configuration uploaded with ID: {response['job_id']}")
        return job_id
    except (ApiError, TransportError) as e:
        logger.error(f"Error uploading job configuration: {e}")
        return None


def load_snapshot_stats(es_client: Elasticsearch, file_path: str) -> Optional[str]:
    """
    Loads snapshot statistics from the given file and indexes it in Elasticsearch.

    Args:
        es_client (Elasticsearch): The Elasticsearch client.
        file_path (str): The path to the snapshot statistics file.

    Returns:
        Optional[str]: The snapshot ID if successful, None otherwise.
    """
    logger.info(f"Loading snapshot statistics from {file_path}")
    try:
        with open(file_path, "r", encoding="utf-8") as f:
            snapshot_stats = json.load(f)
            snapshot_id = snapshot_stats.get("snapshot_id")
        if not snapshot_id:
            logger.error("Snapshot ID not found in snapshot statistics.")
            return None

        index_name = ".ml-anomalies-shared"
        # Extract ID from file name
        id_ = os.path.splitext(os.path.basename(file_path))[0].replace(
            "ml-anomalies-snapshot_doc_", ""
        )
        response = es_client.index(index=index_name, body=snapshot_stats, id=id_)
        logger.info(f"Snapshot statistics indexed with ID: {response['_id']}")
        return snapshot_id
    except (ApiError, TransportError, IOError, json.JSONDecodeError) as e:
        logger.error(f"Error indexing snapshot statistics: {e}")
        return None


def find_file(file_name: str, extracted_files: List[str]) -> Optional[str]:
    """Find a file in the extracted files list."""
    for file in extracted_files:
        if file_name in file:
            return file
    return None


def import_model_state(
    job_id: str, es_client: Elasticsearch, archive_path: str
) -> None:
    """
    Imports the model state, job configuration, annotations, and input data from an archive to Elasticsearch.

    Args:
        job_id (str): The ID of the job to import.
        es_client (Elasticsearch): The Elasticsearch client.
        archive_path (str): The path to the tar.gz archive.
    """
    safe_job_id = sanitize_filename(job_id)
    output_dir = f"extracted_{safe_job_id}"
    extracted_files = extract_archive(archive_path, output_dir)
    if not extracted_files:
        logger.error("No files extracted. Aborting import.")
        return

    input_index = None
    job_config_file = f"{safe_job_id}_config.json"
    snapshot_docs_file = f"{safe_job_id}_snapshot_docs.ndjson"
    input_file = f"{safe_job_id}_input.ndjson"
    snapshot_stats_file = None

    # Find snapshot statistics file
    for file in extracted_files:
        if "ml-anomalies-snapshot_doc" in file:
            snapshot_stats_file = file
            break

    # Load the input data if available
    file = find_file(input_file, extracted_files)
    if file:
        logger.info(f"Importing input data from {file}")
        input_index = f"{safe_job_id}-input"
        create_input_index(es_client, input_index)
        upload_data(es_client, input_index, file)
    else:
        logger.warning(f"Input data file {input_file} not found in the archive.")

    # Load the job configuration
    file = find_file(job_config_file, extracted_files)
    if file:
        logger.info(f"Importing job configuration from {file}")
        try:
            with open(file, "r", encoding="utf-8") as f:
                job_config = json.load(f)
            job_id = create_job_config(es_client, job_config, input_index)
            if not job_id:
                logger.error("Failed to create job configuration.")
                return
        except (IOError, json.JSONDecodeError) as e:
            logger.error(f"Error reading job configuration: {e}")
            return
    else:
        logger.error(
            f"Job configuration file {job_config_file} not found in the archive."
        )
        return

    # Load the job snapshot docs
    file = find_file(snapshot_docs_file, extracted_files)
    if file:
        logger.info(f"Importing snapshots from {file}")
        upload_data(es_client, ".ml-state-write", file)
    else:
        logger.error(
            f"Snapshot documents file {snapshot_docs_file} not found in the archive."
        )
        return

    # Load the snapshot stats
    if snapshot_stats_file:
        logger.info(f"Importing snapshot statistics from {snapshot_stats_file}")
        snapshot_id = load_snapshot_stats(es_client, snapshot_stats_file)
        if not snapshot_id:
            logger.error("Failed to load snapshot statistics.")
            return
    else:
        logger.error("Snapshot statistics file not found in the archive.")
        return

    # Revert the job to the snapshot
    time.sleep(2)  # Wait for the snapshot to be indexed
    try:
        es_client.ml.revert_model_snapshot(job_id=job_id, snapshot_id=snapshot_id)
        logger.info(f"Reverted job {job_id} to snapshot {snapshot_id}")
    except (ApiError, TransportError) as e:
        logger.error(f"Error reverting job to snapshot: {e}")
    finally:
        # Clean up extracted files and directory
        try:
            for file in extracted_files:
                os.remove(file)
            os.rmdir(output_dir)
        except OSError as e:
            logger.warning(f"Error cleaning up extracted files: {e}")

    logger.info(f"Import of job {job_id} completed successfully.")


def main() -> None:
    """Main function to import model state to Elasticsearch."""
    parser = argparse.ArgumentParser(description="Import model state to Elasticsearch.")
    parser.add_argument(
        "--url", type=str, default="https://localhost:9200", help="Elasticsearch URL"
    )
    parser.add_argument(
        "--username",
        type=str,
        required=True,
        help="Username for Elasticsearch authentication",
    )
    parser.add_argument(
        "--password", type=str, help="Password for Elasticsearch authentication"
    )
    parser.add_argument("--job_id", type=str, required=True, help="Job ID to import")
    parser.add_argument(
        "--archive_path", type=str, required=True, help="Path to the archive file"
    )
    parser.add_argument("--cloud_id", type=str, help="Cloud ID for Elasticsearch")
    parser.add_argument(
        "--ignore_certs",
        action="store_true",
        help="Ignore SSL certificate verification",
    )
    args = parser.parse_args()

    # Handle password securely
    if not args.password:
        args.password = getpass(prompt="Enter Elasticsearch password: ")

    # Validate archive_path
    if not os.path.isfile(args.archive_path):
        logger.error(f"Archive file {args.archive_path} does not exist.")
        return

    logger.info("Connecting to Elasticsearch")
    try:
        if args.cloud_id:
            logger.info("Connecting to Elasticsearch cloud using cloud_id")
            es_client = Elasticsearch(
                cloud_id=args.cloud_id,
                basic_auth=(args.username, args.password),
                verify_certs=(not args.ignore_certs),
            )
        else:
            logger.info("Connecting to Elasticsearch using URL")
            es_client = Elasticsearch(
                [args.url],
                basic_auth=(args.username, args.password),
                verify_certs=(not args.ignore_certs),
            )
    except (ApiError, TransportError) as e:
        logger.error(f"Failed to connect to Elasticsearch: {e}")
        return

    import_model_state(args.job_id, es_client, args.archive_path)


if __name__ == "__main__":
    main()