import sqlite3
from typing import List

from src.common import *


class DataLoader:
    active_db = "02_baseline_products_dataset"
    db_dir = os.path.join(data_dir, 'sqlite')
    db_file = os.path.join(db_dir, f"{active_db}.db")
    loaded = False

    @classmethod
    def set_db_name(cls, name: str):
        if name != cls.active_db:
            new_file = os.path.join(data_dir, 'sqlite', f"{name}.db")
            cls.db_file = os.path.join(DataLoader.db_dir, f"{name}.db")
            DataLoader.load_data(reload=True)
            cls.active_db = name

    @staticmethod
    def current_db() -> str:
        return DataLoader.active_db[:-3]

    @staticmethod
    def available_dbs() -> List[str]:
        return [f[:-3] for f in os.listdir(DataLoader.db_dir) if ('products' in f) and f.endswith('.db')]

    @staticmethod
    def load_data(reload=False):
        if DataLoader.loaded and not reload:
            return

        # Wipe out any prior data
        Review.all = {}
        Feature.all = {}
        Product.all = {}
        Category.all = {}

        con = sqlite3.connect(DataLoader.db_file)
        cur = con.cursor()

        categories = cur.execute('SELECT * FROM categories').fetchall()
        for c in categories:
            Category.all[c[0]] = Category(c[0], c[1])

        features = cur.execute('SELECT * FROM features').fetchall()
        for f in features:
            feat = Feature(f[0], f[1], Category.all[f[2]])
            Feature.all[f[0]] = feat
            Category.all[f[2]].features.append(feat)

        products = cur.execute('SELECT * FROM products').fetchall()
        for p in products:
            prod = Product(p[0], p[1], p[2], p[3], Category.all[p[4]])
            Product.all[p[0]] = prod
            Category.all[p[4]].products.append(prod)

        prod_feats = cur.execute('SELECT * FROM product_features').fetchall()
        for pf in prod_feats:
            Product.all[pf[1]].features.append(Feature.all[pf[2]])
            Feature.all[pf[2]].products.append(Product.all[pf[1]])

        reviews = cur.execute('SELECT * FROM reviews').fetchall()
        for r in reviews:
            rev = Review(r[0], r[2], r[3], Product.all[r[1]])
            Review.all[r[0]] = rev
            Product.all[r[1]].reviews.append(rev)

        DataLoader.loaded = True


class Category:
    all = {}

    @staticmethod
    def all_sorted():
        all_cats = list(Category.all.values())
        all_cats.sort(key=lambda x: x.name)
        return all_cats

    @staticmethod
    def by_name(name: str):
        all_cats = list(Category.all.values())
        for c in all_cats:
            if c.name == name:
                return c

    def __init__(self, id, name):
        self.id = id
        self.name = name
        self.features = []
        self.products = []

    @property
    def feature_count(self):
        return len(self.features)

    @property
    def product_count(self):
        return len(self.products)

    @property
    def singular_name(self):
        if self.name[-1] == "s":
            return self.name[:-1]  # Clip the s
        return self.name

    @property
    def lower_singular_name(self):
        if self.name[-1] == "s":
            return self.name[:-1].lower()  # Clip the s
        return self.name.lower()


class Feature:
    all = {}

    def __init__(self, id, name, category):
        self.id = id
        self.name = name
        self.category = category
        self.products = []

    @property
    def product_count(self):
        return len(self.products)

    def __repr__(self):
        return self.name


class Product:
    all = {}

    def __init__(self, id, name, description, price, category):
        self.id = id
        self.name = name
        self.description = description
        self.price = round(price, 2)
        self.category = category
        self.features = []
        self.reviews = []

    @property
    def feature_count(self):
        return len(self.features)

    @property
    def review_count(self):
        return len(self.reviews)

    @property
    def average_rating(self, decimals=2):
        if self.review_count == 0:
            return 0.0
        return float(round(sum([r.rating for r in self.reviews]) / self.review_count, decimals))

    @staticmethod
    def for_ids(ids: List[str]):
        return[Product.all[i] for i in ids]

    @staticmethod
    def all_as_list():
        return list(Product.all.values())


class Review:
    all = {}

    def __init__(self, id, rating, review_text, product):
        self.id = id
        self.rating = rating
        self.review_text = review_text
        self.product = product