from django.core.management.base import BaseCommand

import json

from ._spreadsheet_constants import *

# Template for the plant json to add as an entry for the fixtures
PLANT_JSON_TEMPLATE = {
    "model": "api.plant",
    "pk": None,
    "fields": {}
}


def check_field_value(field, field_value):
    """ Checks the validity of a feild value collected from the spreadsheet
    """
    expected_field_type = PLANT_COLS[field]['expected_type']
    model_field_name = PLANT_COLS[field].get('model_name', field)
    null_allowed = PLANT_COLS[field].get('null_allowed', False)
    max_length = PLANT_COLS[field].get('max_length', False)

    is_valid_type = isinstance(field_value, expected_field_type)
    is_int_when_float = expected_field_type == float and isinstance(
        field_value, int)
    is_valid_null = field_value is None and null_allowed
    is_over_max_length = max_length and isinstance(
        field_value, str) and len(field_value) > max_length

    if not(is_valid_type or is_int_when_float or is_valid_null):
        raise TypeError(
            f"Invalid json type for field {model_field_name} with value {field_value}. Expected '{expected_field_type}' but got '{type(field_value)}'.")
    elif is_over_max_length:
        raise TypeError(
            f"Invalid string length for {model_field_name} with value {field_value}. Expected length to be under {max_length} but was {len(field_value)}.")


def get_plant_json_from_row(row_data):
    """ Returns a json object representing a plant row from the spreadsheet.
    """
    plant_json_fields = {}
    for field, field_index in INFO_COL_INDEXES.items():
        if field not in PLANT_COLS:
            continue
        
        field_str = PLANT_COLS[field].get('str', field)
        model_field_name = PLANT_COLS[field].get('model_name', field_str)
        try:
            if field_str == "region":
                regions_list = get_pk_list_from_str(
                    row_data[field_index], ECO_REGION_PK_MAPPING, ECO_REGION_ADJUSTMENTS)
                plant_json_fields[model_field_name] = regions_list

            elif field_str == "soilorder":
                soil_orders_list = get_pk_list_from_str(
                    row_data[field_index], SOIL_ORDER_PK_MAPPING)
                plant_json_fields[model_field_name] = soil_orders_list

            elif field_str in {'wet', 'mesic', 'dry'}:
                if row_data[field_index] != None:
                    soil_variant_pk = SOIL_VARIANT_PK_MAPPING[field.capitalize()]
                    plant_json_fields[model_field_name] = plant_json_fields.get(
                        model_field_name, []) + [soil_variant_pk]
                else:
                    continue

            elif field_str in {'water', 'drought', 'frost', 'salinity'}:
                plant_json_fields[model_field_name] = TOLERANCE_PK_MAPPING[row_data[field_index]]

            elif field in PLANT_COLS:
                plant_json_fields[model_field_name] = row_data[field_index]
            
            check_field_value(field, plant_json_fields[model_field_name])

        except Exception as e:
            name_index = INFO_COL_INDEXES['SCIENTIFIC NAME']
            print(
                f"Error occured while adding the row for {row_data[name_index]}.")
            print(F"{type(e)}: {e}")
            print("SKIPPING ROW...")
            print("----------------------------------------------")

            return {}

    # Add zone spreadsheet data to the plant json fields.
    zone_list = []
    for zone, zone_index in ZONE_COL_INDEXES.items():
        if row_data[zone_index-DATA_START_COL] != None:
            zone_list.append(ZONE_PK_MAPPING[zone])
    plant_json_fields['zones'] = zone_list

    # Create a plant json object using the defined template
    plant_json = PLANT_JSON_TEMPLATE.copy()
    plant_json["fields"] = plant_json_fields

    return plant_json


def get_plant_json_fixture(sheet):
    """ Returns a django fixture json that represents the plant information extracted from the spreadsheet.
    """
    plant_json_fixture = []
    skipped_count = 0
    created_count = 0

    for row in sheet.iter_rows(min_col=DATA_START_COL, min_row=DATA_START_ROW, values_only=True):
        plant_json = get_plant_json_from_row(row)

        # If there is invalid data in a row, it will be skipped
        if plant_json != {}:
            plant_json_fixture.append(plant_json)
            created_count += 1
        else:
            skipped_count += 1

    # Print summary of data extraction from the spreadsheet
    print("Created plants fixture.")
    print(f"Rows Created: {created_count}")
    print(f"Rows Skipped: {skipped_count}")

    return plant_json_fixture


def save_plant_fixture(fixture):
    """ Saves the plant fixture to the django api fixtures directory.
    """
    fixture_filepath = DATA_DIR_PATH / 'fixtures' / 'plants.json'
    fixture_filepath.write_text(json.dumps(fixture))


class Command(BaseCommand):
    help = 'Ingests the plant spreadsheet data into the database'

    def handle(self, *args, **options):
        self.stdout.write('Creating plant fixtures...')
        plant_fixture = get_plant_json_fixture(SPREADSHEET)
        save_plant_fixture(plant_fixture)
        self.stdout.write(self.style.SUCCESS(
            'Plant fixtures created and saved successfully.'))