import re
import pexpect
ansi_escape = re.compile(r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
class ExpectationCollection:
    def __init__(self):
        self.expectations_lookup = {}

    def add_expectation(self, expectation):
        if expectation.get_pattern() in self.expectations_lookup:
            if expectation.context in [exp.context for exp in self.expectations_lookup[expectation.get_pattern()]]:
                print(f'Can not add {expectation} to collection')
                return False
        self.expectations_lookup[expectation.get_pattern()] = self.expectations_lookup.setdefault(expectation.get_pattern(), []) + [expectation]
        return True

    def add_expectation_from_descr(self, expectation, response=None, name=None):
        expectation = Expectation(expectation, response=response, name=name)
        self.add_expectation(expectation)

    def get_patterns(self):
        return [pexpect.EOF, pexpect.TIMEOUT] + list(self.expectations_lookup.keys())

    def get_expectations_by_pattern(self, pattern):
        return self.expectations_lookup.get(pattern, [])

    def get_expectations_by_name(self, name):
        return [expectation for expectation in self.get_expectations(recursive=True) if expectation.name == name]

    def get_exposed_expectation_names(self):
        return [expectation.name for expectation in self.get_expectations(recursive=True) if expectation.name]

    def set_expectation_response_by_name(self, name, response):
        for expectation in self.get_expectations_by_name(name):
            expectation.set_response(response)

    def get_expectations(self, recursive=False):
        expectations = [exp for exps in self.expectations_lookup.values() for exp in exps]
        if recursive:
            expectations.extend([exp for exps in expectations for exp in exps.get_following_expectations()])
        return list(set(expectations))

    def count_expectations(self):
        return len(self.get_expectations(recursive=True))

    def merge(self, collection):
        for expectation in collection.get_expectations():
            self.add_expectation(expectation)


class Expectation:
    def __init__(self, multiline_pattern, response=None, name=None):
        self.name = name
        self.context = [p.strip() for p in multiline_pattern.strip().split('\n') if p.strip()]
        self.pattern = self.context[-1]
        self.response = response
        self.next = {}

    def get_pattern(self, previous_answer=None):
        return re.compile(f'(.*){re.escape(self.pattern.format(variable=previous_answer))}(.*)')

    def set_next_expectation(self, expectation, triggers=None):
        if not isinstance(triggers, list):
            triggers = [triggers]
        for trigger in triggers:
            self.next[trigger] = expectation

    def set_response(self, response):
        print(f'Setting {response} for {self.pattern}')
        self.response = response

    def expect(self, spawned, previous_answer=None):
        print(f'-> expecting next "{self.pattern.format(variable=previous_answer)}"')
        p = spawned.expect([pexpect.EOF, pexpect.TIMEOUT, self.get_pattern(previous_answer=previous_answer)])
        if p not in [0, 1]:
            self.answer(spawned)
        else:
            print(f'-> before: {spawned.before}\n-> after: {spawned.after}\n-> {self.pattern}')

    def answer(self, spawned):
        print(f'-> answering "{self.response}" to "{spawned.after}"')
        if self.response is not None:
            spawned.sendline(self.response)
        if self.response in self.next:
            self.next[self.response].expect(spawned, previous_answer=self.response)
        elif None in self.next:
            self.next[None].expect(spawned, previous_answer=self.response)

    def is_the_one(self, context):
        #print(f'testing if it is the one {self.get_pattern()} for {context}')
        context = [l.strip() for l in context.strip().split('\r\n') if l.strip()]
        if not context:
            print('No context provided')
            return False
        context.reverse()
        for index, c in enumerate(self.context[len(self.context)-2::-1]):
            if c != ansi_escape.sub('', context[index]):
                return False
        return True

    def get_following_expectations(self):
        following = []
        for next_expectation in set(self.next.values()):
            following.append(next_expectation)
            following.extend(next_expectation.get_following_expectations())
        return following