import os
from datetime import timedelta
import time

import pendulum
import requests
from airflow.decorators import dag
from airflow.decorators import task
from airflow.hooks.base import BaseHook
from opensearchpy import OpenSearch, helpers

S3_CONN_ID = os.getenv("S3_CONN_ID", "s3_conn")
EXECUTION_TIMEOUT = int(os.getenv("EXECUTION_TIMEOUT", 6))

default_args = {
    "execution_timeout": timedelta(hours=EXECUTION_TIMEOUT),
    "retries": int(os.getenv("DEFAULT_TASK_RETRIES", 1)),
    "retry_delay": timedelta(seconds=int(os.getenv("DEFAULT_RETRY_DELAY_SECONDS", 60))),
}


@dag(
    dag_id="open_data_portal_harvest",
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    schedule=None,
    dagrun_timeout=None,
    catchup=False,
    default_args=default_args,
    params={
        "S3_CONN_ID": "s3_conn",
        "OPENSEARCH_CONN_ID": "opensearch_default",
        "OS_INDEX_NAME": "euodp_raw"
    },
    tags=["aggregation"]
)
def harvest():
    @task
    def everything(**context):
        index_name = context["params"]["OS_INDEX_NAME"]
        conn = BaseHook.get_connection(context["params"]["OPENSEARCH_CONN_ID"])
        client = OpenSearch(
            hosts=[{'host': conn.host, 'port': conn.port}],
            http_auth=(conn.login, conn.password),
            use_ssl=True,
            verify_certs=False,
            ssl_show_warn=False,
            pool_maxsize=20
        )

        if not client.indices.exists(index_name):
            client.indices.create(index_name, {
                "settings": {
                    "index": {
                        "number_of_shards": 3,
                        "number_of_replicas": 0,
                        "codec": "zstd_no_dict",
                        "replication.type": "SEGMENT"
                    },
                },
                "mappings": {
                    "dynamic": False
                }
            })

        def store_results(hits):
            def _generate_data():
                for r in hits:
                    r['_index'] = index_name
                    r['_id'] = r['id']
                    yield r
            succeeded = 0
            failed = 0
            for success, item in helpers.parallel_bulk(client, actions=_generate_data(),
                                                       raise_on_exception=False,
                                                       raise_on_error=False,
                                                       chunk_size=5000,
                                                       max_chunk_bytes=50 * 1024 * 1024,
                                                       timeout=180):
                if success:
                    succeeded = succeeded + 1
                else:
                    print(item["index"]["error"])
                    failed = failed + 1
        headers = {'Accept': 'application/json'}
        r = requests.get('https://data.europa.eu/api/hub/search/search?filter=dataset&aggregation=false&limit=300&showScore=true&scroll=true', headers=headers).json()
        scroll_id = r['result']['scrollId']
        results = r['result']['results']
        store_results(results)
        max_retries = 10
        while scroll_id:
            try:
                r = requests.get('https://data.europa.eu/api/hub/search/scroll?scrollId=' + scroll_id, headers=headers)
                r.raise_for_status()
            except Exception as e:
                print(f"Error:" + str(e))
                time.sleep(0.1)
                max_retries = max_retries - 1
                if max_retries == 0:
                    raise Exception("Cannot fetch data")
                continue
            max_retries = 10
            r = r.json()
            scroll_id = r['result']['scrollId']
            results = r['result']['results']
            if len(results) <= 0:
                return
            store_results(results)

    everything()


harvest()