#!/usr/bin/env python
import argparse
import logging
import os
import sys
from itertools import islice
from requests.exceptions import HTTPError

import django
from rest_framework.exceptions import ValidationError
from slugify import slugify

from metagenedb.common.utils.api import MetageneDBCatalogGeneAPI
from metagenedb.common.utils.parsers import IGCLineParser

# Before model import, we need to called django.setup() to Load apps
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "metagenedb.settings")
django.setup()

from metagenedb.apps.catalog.models import Gene, Function, Taxonomy  # noqa
from metagenedb.apps.catalog.serializers import GeneSerializer  # noqa

logging.basicConfig(level=logging.INFO)
_LOGGER = logging.getLogger(__name__)

PHYLUM_COL = 'taxo_phylum'
GENUS_COL = 'taxo_genus'
SELECTED_KEYS = ['gene_id', 'length', 'kegg_ko', PHYLUM_COL, GENUS_COL]


def parse_gene(raw_line, selected_keys=SELECTED_KEYS):
    """
    Use IGCLineParser and return selected keys
    """
    gene_parser = IGCLineParser()
    all_dict = gene_parser.gene(raw_line)
    selected_dict = {k: v for k, v in all_dict.items() if k in selected_keys}
    return selected_dict


def select_taxonomy(gene_dict, unknown_val='unknown'):
    """
    Select the taxonomy to be assigned for the gene.
    genus has priority on phylum. If both unknow, remove the taxonomy key
    """
    phylum = gene_dict.pop(PHYLUM_COL)
    genus = gene_dict.pop(GENUS_COL)
    if genus != unknown_val:
        queryset = Taxonomy.objects.filter(name=genus, rank="genus")
        if queryset.count() > 1:
            _LOGGER.warning(f"More than 1 result found for genus {genus}. First result is kept.")
        gene_dict.update(
            {'taxonomy': queryset[0].tax_id}
        )
    elif phylum != unknown_val:
        queryset = Taxonomy.objects.filter(name=phylum, rank="phylum")
        if queryset.count() > 1:
            _LOGGER.warning(f"More than 1 result found for phylum {phylum}. First result is kept.")
        gene_dict.update(
            {'taxonomy': queryset[0].tax_id}
        )
    return gene_dict


class ImportIGCGenes(object):
    METAGENEDB_GENE_API = MetageneDBCatalogGeneAPI

    def __init__(self, annotation_file, url, skip_tax=False, skip_functions=False):
        self.annotation_file = annotation_file
        self.url = url
        self.metagenedb_gene_api = self.METAGENEDB_GENE_API(base_url=self.url)
        # Skip some insertion if specified in script options
        self.skip_tax = skip_tax
        self.skip_functions = skip_functions

    def _clean_gene(self, gene_dict):
        gene_dict['gene_id'] = slugify(gene_dict['gene_id'])
        if self.skip_tax:
            gene_dict.pop('taxonomy')
        if self.skip_functions:
            gene_dict.pop('functions')
        return gene_dict

    def _upsert_gene(self, gene_dict):
        clean_gene_dict = self._clean_gene(gene_dict)
        try:
            gene_id = clean_gene_dict['gene_id']
            self.metagenedb_gene_api.get(gene_id)  # Try to get obj to check if it exists
            self.metagenedb_gene_api.put(gene_id, clean_gene_dict)
        except HTTPError:
            self.metagenedb_gene_api.post(clean_gene_dict)

    def _insert_gene_list(self, chunk_genes):
        for gene_line in chunk_genes:
            gene_dict = parse_gene(gene_line)
            gene_dict_with_taxo = select_taxonomy(gene_dict)
            try:
                self._upsert_gene(gene_dict_with_taxo)
            except ValidationError as e:
                _LOGGER.warning(f"{e.__dict__} for gene_id: {gene_dict.get('gene_id')}. Insertion skipped.")

    def load_annotation_file_to_db_in_chunks(self, chunk_size=100000):
        processed_genes = 0
        with open(self.annotation_file, 'r') as file:
            while True:
                chunk_genes = list(islice(file, chunk_size))
                if not chunk_genes:
                    break
                processed_genes += len(chunk_genes)
                self._insert_gene_list(chunk_genes)
                _LOGGER.info(f"{processed_genes} genes processed so far...")
        _LOGGER.info(f"[DONE] {processed_genes} genes processed.")


def parse_arguments():
    """
    Defines parser.
    """
    parser = argparse.ArgumentParser(description='Populate database from a given IGC annotation file.')
    # Common arguments for analysis and annotations
    parser.add_argument('annotation', help='IGC annotation file')
    parser.add_argument('url', help='base URL of the instance.', default='http://localhost/')
    parser.add_argument('--skip_taxonomy', action='store_true', help='Skip taxonomy information from genes.')
    parser.add_argument('--skip_functions', action='store_true', help='Skip functions information from genes.')

    try:
        return parser.parse_args()
    except SystemExit:
        sys.exit(1)


def run():
    args = parse_arguments()
    load_annotation_file_to_db_in_chunks(args.annotation, args.url)


if __name__ == "__main__":
    run()