"""Lambda generate-error-report function module."""

import json
import uuid
from typing import Any

import boto3
import pandas as pd
from mypy_boto3_s3.client import S3Client
from mypy_boto3_s3.paginator import ListObjectsV2Paginator
from owslogger.logger import OwsLoggingAdapter

from src.config import CSV_DELIMITER, S3_INPUT_BUCKET, S3_OUTPUT_BUCKET, app_logger

s3_client: S3Client = boto3.client("s3")


def handler(event: Any, context: Any) -> dict[str, str]:
    """Lambda Entrypoint."""
    logger = OwsLoggingAdapter(app_logger, {"correlation_id": uuid.uuid4()})
    export_id = event["export_id"]
    execution_name = event["execution_name"]
    prefix = f"{export_id}/{execution_name}"

    paginator: ListObjectsV2Paginator = s3_client.get_paginator("list_objects_v2")
    page_iterator = paginator.paginate(Bucket=S3_INPUT_BUCKET, Prefix=prefix)

    log_msg = f"Generating error reports in CSV for export: {export_id} - execution name: {execution_name}"
    logger.info(log_msg)

    errors: list[dict[str, str]] = []
    for page in page_iterator:
        for contents in page["Contents"]:
            file_key = contents.get("Key")
            if file_key is not None:
                if file_key.find("asset_copy_errors") != -1 and file_key.endswith(
                    ".json"
                ):
                    data = get_errors_from_s3(file_key)
                    errors.extend(data)

    if errors:
        write_csv_errors_to_s3(errors, export_id, logger)

    return {"export_id": export_id, "execution_name": execution_name}


def get_errors_from_s3(file_key: str) -> list[dict[str, str]]:
    file_obj = s3_client.get_object(Bucket=S3_INPUT_BUCKET, Key=file_key)
    file_content = file_obj["Body"].read().decode("utf-8")
    data = json.loads(file_content)
    # Remove source location (internal asset location) - not required in a user-facing error report
    filtered_data = [
        {key: val for key, val in d.items() if key != "source"} for d in data
    ]
    return filtered_data


def write_csv_errors_to_s3(
    errors: list[dict[str, str]], export_id: str, logger: OwsLoggingAdapter
) -> None:
    json_str = json.dumps(errors)
    json_data = pd.read_json(json_str)
    csv_data = json_data.to_csv(
        encoding="utf-8",
        sep=CSV_DELIMITER,
        index=False,
        header=["asset", "error_reason"],
    )
    filename = f"{export_id}/error_report.csv"
    try:
        s3_client.put_object(
            Bucket=S3_OUTPUT_BUCKET,
            Key=filename,
            Body=csv_data,
            ContentType="text/csv",
        )
    except Exception as e:
        error_class_name = e.__class__.__name__
        error_msg = f"Failed to upload CSV error report for export: {export_id} {error_class_name}: {str(e)}"
        logger.error(error_msg)