class InstaUrlValidator:
    def __init__(self, input_url):
        self.protocol = 'https'
        self.host = 'www.instagram.com'
        self.path1 = 'p'

        self.input_user_key = ''
        self.input_url = input_url

    def preprocess_input_url(self):
        if type(self.input_url) != str:
            raise TypeError('input url error')

        self.preprocessed_input_url = self.input_url.strip()

    def check_protocol(self):
        start_index = 0
        end_index = self.preprocessed_input_url.find(':')
        if end_index == -1:
            return start_index

        if self.preprocessed_input_url[end_index+1] != '/' or self.preprocessed_input_url[end_index+2] != '/':
            raise ValueError('incorrect url format')

        return end_index + 3

    def check_host(self, start_index):
        end_index = self.preprocessed_input_url.find('/', start_index)
        if end_index == -1:
            raise ValueError('incorrect url format')

        input_host = self.preprocessed_input_url[start_index:end_index]
        if input_host not in self.host:
            raise ValueError('incorrect host')

        return end_index + 1

    def check_path1(self, start_index):
        end_index = self.preprocessed_input_url.find('/', start_index)
        if end_index == -1:
            raise ValueError('incorrect path')

        input_path1 = self.preprocessed_input_url[start_index:end_index]
        if input_path1 != self.path1:
            raise ValueError('incorrect path (/p/)')

        return end_index + 1

    def check_path2(self, start_index):
        end_index = self.preprocessed_input_url.find('/', start_index)
        # if end_index == -1:
        #     raise ValueError('incorrect path')
        #
        # self.input_user_key = self.preprocessed_input_url[start_index:end_index]

        if end_index != -1:
            self.input_user_key = self.preprocessed_input_url[start_index:end_index]
        else:
            self.input_user_key = self.preprocessed_input_url[start_index:]

    def make_instagram_url(self):
        if len(self.input_user_key) <= 0:
            raise ValueError('incorrect user key')

        url = self.protocol + '://' + self.host + '/' + self.path1 + '/' + self.input_user_key + '/'
        return url

    def validate_url(self):
        try:
            self.preprocess_input_url()
            start_index = self.check_protocol()
            start_index = self.check_host(start_index)
            start_index = self.check_path1(start_index)
            self.check_path2(start_index)

        except Exception as e:
            raise e

    def get_insta_url(self):
        try:
            self.validate_url()
            url = self.make_instagram_url()
        except Exception as e:
            raise e

        return url