"""
一场比赛的数据
"""
import json

class Match:
    """Match"""

    def __init__(self, raw, dtype='json'):
        """
        :param json_string: string represents data in json format
        """
        if dtype == 'json':
            self.raw_data = json.loads(raw)
            self.dtype = 'json'
        else:
            self.raw_data = raw
            self.dtype = 'mid'

    def query(self, cat, act):
        """
        start a query
        eg. match.query('game', 'created')
        :param cat: category
        "param act: action
        """
        if self.dtype == 'mid':
            raise RuntimeError("Query on intermediate result.")
        result = []
        for entry in self.raw_data:
            if entry['cat'] == cat and entry['act'] == act:
                result.append(entry)
        return Match(result, dtype='mid')

    def where(self, where_expr):
        """
        add some condition
        eg. match.query('player', 'join').where(lambda i: i['pid']==9527)
        """
        if self.dtype != 'mid':
            raise RuntimeError("Where query on raw data.")
        return Match([item for item in self.raw_data if where_expr(item)], dtype='mid')

    def orderby(self, key):
        """
        sort it!
        eg. match.query('player', 'join').where(lambda i: i['pid']<9527).orderby('created_at')
        """
        if self.dtype != 'mid':
            raise RuntimeError("Orderby query on raw data.")

        return Match(sorted(self.raw_data, key=lambda x: x[key]), dtype='mid')

    def select(self, key1, *args):
        """
        select some columns
        eg. match.query('player', 'join')
                 .select('pid', 'created_at')
                 .where(lambda i: i['pid']<9527)
                 .orderby('created_at')
        """
        if self.dtype != 'mid':
            raise RuntimeError("select query on raw data.")

        result = []

        keys = [key1]
        for k in args:
            keys.append(k)

        for entry in self.raw_data:
            dct = dict.fromkeys(keys)
            for k in keys:
                dct[k] = entry[k]
            result.append(dct)

        return Match(result, dtype='mid')

    def first(self):
        """
        return first result
        """
        if self.dtype != 'mid':
            raise RuntimeError("first query on raw data.")

        rawl = len(self.raw_data)
        return self.raw_data[0] if rawl > 0 else None

    @staticmethod
    def read_from_json(json_path):
        """
        从json_path读取json文件，并返回Match
        :param json_path: path to json file
        """
        json_string = ''
        with open(json_path, 'r', encoding='utf-8') as file:
            json_string = file.read()
        return Match(json_string)