import asyncio
import logging
import uuid
from datetime import datetime, timedelta
from typing import Optional, List
from uuid import UUID, uuid4

from Tea.exceptions import TeaException

from iact3.config import TestConfig, IAC_NAME
from iact3.exceptions import Iact3Exception
from iact3.plugin.ros import StackPlugin
from iact3.util import generate_client_token_ex
from iact3.plugin.base_plugin import CredentialClient

LOG = logging.getLogger(__name__)


class Timer:
    def __init__(self, interval, callback, *args, **kwargs):
        self._interval = interval
        self._callback = callback
        self._args = args if args is not None else []
        self._kwargs = kwargs if kwargs is not None else {}
        self._task = asyncio.ensure_future(self._job())

    async def _job(self):
        while True:
            try:
                await self._callback(*self._args, **self._kwargs)
            except Exception as ex:
                LOG.error(f'an error occurred, {self._callback.__name__}, {ex}')
            await asyncio.sleep(self._interval)

    def cancel(self):
        self._task.cancel()


class FilterableList(list):
    def filter(self, kwargs: Optional[dict] = None):
        if not kwargs:
            return self
        f_list = FilterableList()
        for item in self:
            if criteria_matches(kwargs, item):
                f_list.append(item)
        return f_list


class Stacks(FilterableList):
    pass


class Resources(FilterableList):
    pass


class Events(FilterableList):
    pass


SYS_TAGS = {'CreatedBy': f'{IAC_NAME}'}


class Stacker:
    NULL_UUID = uuid.UUID(int=0)

    def __init__(self,
                 project_name: str = None,
                 tests: List[TestConfig] = None,
                 uid: uuid.UUID = NULL_UUID,
                 name_prefix: str = IAC_NAME,
                 tags: dict = None,
                 stacks: Stacks = None):
        self.tests = tests or []
        self.project_name = project_name
        self.stack_name_prefix = name_prefix
        self.uid = uuid.uuid4() if uid == Stacker.NULL_UUID else uid
        self.tags = tags if tags else {}
        self.stacks: Stacks = stacks or Stacks()
        self._sys_tags = {
            f'{IAC_NAME}-id': self.uid.hex,
            f'{IAC_NAME}-project-name': self.project_name,
        }
        self._sys_tags.update(SYS_TAGS)

    @classmethod
    def from_stacks(cls, stacks: Stacks):
        return cls(stacks=stacks)

    async def create_stacks(self):
        if self.stacks:
            raise Iact3Exception('Stacker already initialised with stack objects')
        self.tags.update(self._sys_tags)
        stack_tasks = [
            asyncio.create_task(Stack.create(test, self.tags, self.uid)) for test in self.tests
        ]
        self.stacks += await asyncio.gather(*stack_tasks)

    def status(self, **kwargs):
        stacks = self.stacks.filter(kwargs)
        result = {}
        for stack in stacks:
            status = stack.status
            result[StackStatus.curt(status)] = {stack.id: stack.status_reason}
        return result

    async def delete_stacks(self, **kwargs):
        stacks = self.stacks.filter(kwargs)
        stack_tasks = [
            asyncio.create_task(Stack.delete(stack)) for stack in stacks
        ]
        await asyncio.gather(*stack_tasks)
    
    async def get_stacks_price(self):
        if self.stacks:
            raise Iact3Exception('Stacker already initialised with stack objects')
        self.tags.update(self._sys_tags)
        stack_tasks = [
            asyncio.create_task(Stack.get_price(test, self.tags, self.uid)) for test in self.tests
        ]
        self.stacks += await asyncio.gather(*stack_tasks)

    async def preview_stacks_result(self):
        if self.stacks:
            raise Iact3Exception('Stacker already initialised with stack objects')
        self.tags.update(self._sys_tags)
        stack_tasks = [
            asyncio.create_task(Stack.preview_stack_result(test, self.tags, self.uid)) for test in self.tests
        ]
        self.stacks += await asyncio.gather(*stack_tasks)


def criteria_matches(kwargs: dict, instance):
    for k in kwargs:
        if not hasattr(instance, k):
            raise ValueError(f'{k} is not a valid property of {type(instance)}')
    for k, v in kwargs.items():
        ins_v = getattr(instance, k)
        if isinstance(v, list):
            return ins_v in v
        return ins_v == v
    return True


class StackStatus:
    COMPLETE = [
        'CREATE_COMPLETE',
        'UPDATE_COMPLETE',
        'DELETE_COMPLETE'
    ]
    IN_PROGRESS = [
        'CREATE_IN_PROGRESS',
        'UPDATE_IN_PROGRESS',
        'DELETE_IN_PROGRESS',
        'CREATE_ROLLBACK_IN_PROGRESS',
        'ROLLBACK_IN_PROGRESS'
    ]
    FAILED = [
        'CREATE_FAILED',
        'UPDATE_FAILED',
        'DELETE_FAILED',
        'CREATE_ROLLBACK_FAILED',
        'CREATE_ROLLBACK_COMPLETE',
        'ROLLBACK_FAILED',
        'ROLLBACK_COMPLETE'
    ]

    @classmethod
    def curt(cls, status):
        if status in cls.COMPLETE:
            return 'COMPLETE'
        elif status in cls.IN_PROGRESS:
            return 'IN_PROGRESS'
        elif status in cls.FAILED:
            return 'FAILED'
        else:
            return 'UNKNOWN'


class Event:
    def __init__(self, event_dict: dict):
        self.event_id: str = event_dict['EventId']
        self.stack_name: str = event_dict['StackName']
        self.logical_id: str = event_dict['LogicalResourceId']
        self.type: str = event_dict['ResourceType']
        self.status: str = event_dict['Status']
        self.timestamp: str = event_dict['CreateTime']
        self.physical_id: str = event_dict.get('PhysicalResourceId')
        self.status_reason: str = event_dict['StatusReason']

    def __str__(self):
        return '{} {} {}'.format(self.timestamp, self.logical_id, self.status)

    def __repr__(self):
        return '<Event object {} at {}>'.format(self.event_id, hex(id(self)))


class Resource:
    def __init__(
            self, stack_id: str, resource_dict: dict, test_name: str = '', uuid: UUID = None
    ):
        uuid = uuid if uuid else uuid4()
        self.stack_id: str = stack_id
        self.test_name: str = test_name
        self.uuid: UUID = uuid
        self.logical_id: str = resource_dict['LogicalResourceId']
        self.type: str = resource_dict['ResourceType']
        # self.status: str = resource_dict['ResourceStatus']
        self.status: str = resource_dict['Status']
        self.physical_id: str = ''
        self.last_updated_timestamp: datetime = datetime.fromtimestamp(0)
        self.status_reason: str = ''
        if 'PhysicalResourceId' in resource_dict.keys():
            self.physical_id = resource_dict['PhysicalResourceId']
        if 'UpdateTime' in resource_dict.keys():
            self.last_updated_timestamp = resource_dict['UpdateTime']
        if 'StatusReason' in resource_dict.keys():
            self.status_reason = resource_dict['StatusReason']

    def __str__(self):
        return '<Resource {} {}>'.format(self.logical_id, self.status)


class Stack:

    def __init__(self, region: str, stack_id: str, test_name: str = None,
                 uuid: UUID = None, status_reason: str = None, stack_name: str = None,
                 parameters: dict = None, credential: CredentialClient = None, 
                 template_price: dict = None, preview_result: dict = None):
        self.test_name: str = test_name
        self.uuid: UUID = uuid if uuid else uuid4()
        self.id: str = stack_id
        self.region = region
        self.plugin: StackPlugin = StackPlugin(region_id=region, credential=credential)
        self.name = stack_name
        self.parameters = parameters
        self.completion_time: timedelta = timedelta(0)

        self._status: str = ''
        self.status_reason: str = status_reason or ''
        self._launch_succeeded: bool = False
        self.auto_refresh_interval: timedelta = timedelta(seconds=60)
        self._last_event_refresh: datetime = datetime.fromtimestamp(0)
        self._last_resource_refresh: datetime = datetime.fromtimestamp(0)
        self.timer = Timer(self.auto_refresh_interval.total_seconds(), self.refresh)
        self.template_price = template_price
        self.preview_result = preview_result

    def __str__(self):
        return self.id

    def __repr__(self):
        return '<Stack object {} at {}>'.format(self.test_name, hex(id(self)))

    def _auto_refresh(self, last_refresh):
        if datetime.now() - last_refresh > self.auto_refresh_interval:
            return True
        return False

    @property
    def status(self):
        return self._status

    @status.setter
    def status(self, status):
        _complete = StackStatus.COMPLETE.copy()
        del _complete[_complete.index('DELETE_COMPLETE')]
        self._status = status
        if status in StackStatus.FAILED:
            self._launch_succeeded = False
            return
        if status in _complete:
            self._launch_succeeded = True
            return

    @property
    def launch_succeeded(self):
        return self._launch_succeeded

    @classmethod
    def from_stack_response(cls, stack: dict, credential: CredentialClient = None):
        return cls(
            region=stack['RegionId'],
            stack_id=stack['StackId'],
            test_name=stack.get('TestName'),
            uuid=stack.get('TestId'),
            stack_name=stack.get('StackName'),
            credential=credential
        )

    @classmethod
    async def create(cls, test: TestConfig, tags: dict = None, uuid: UUID = None) -> 'Stack':
        parameters = test.parameters
        template_args = test.template_config.to_dict()
        name = test.test_name
        if not tags:
            tags = {}
        tags.update({f'{IAC_NAME}-test-name': name})
        region = test.region
        credential = test.auth.credential
        plugin = StackPlugin(region_id=test.region, credential=credential)
        client_token = generate_client_token_ex(uuid.hex, name)
        stack_name = f'{IAC_NAME}-{name}-{region}-{uuid4().hex[:8]}'
        config_error = test.error
        if config_error:
            stack = cls(region, None, name, uuid,
                        status_reason=getattr(config_error, 'message', 'Unknown error'),
                        stack_name=stack_name, credential=credential)
            stack.status = getattr(config_error, 'code', 'Unknown error')
            stack._launch_succeeded = False
            stack.timer.cancel()
            return stack
        try:
            stack_id = await plugin.create_stack(
                stack_name=stack_name,
                parameters=parameters,
                timeout_in_minutes=60,
                client_token=client_token,
                tags=tags,
                **template_args,
                disable_rollback=True
            )
        except TeaException as ex:
            stack_id = None
            stack = cls(region, stack_id, name, uuid, status_reason=ex.message,
                        stack_name=stack_name, parameters=parameters, credential=credential)
            stack.status = ex.code
            stack._launch_succeeded = False
            stack.timer.cancel()
            return stack
        stack = cls(region, stack_id, name, uuid, stack_name=stack_name,
                    parameters=parameters, credential=credential)
        await stack.refresh()
        return stack

    @classmethod
    async def get_price(cls, test: TestConfig, tags: dict = None, uuid: UUID = None):
        parameters = test.parameters
        template_args = test.template_config.to_dict()
        name = test.test_name
        if not tags:
            tags = {}
        tags.update({f'{IAC_NAME}-test-name': name})
        region = test.region
        credential = test.auth.credential
        plugin = StackPlugin(region_id=test.region, credential=credential)
        stack_name = f'{IAC_NAME}-{name}-{region}-{uuid4().hex[:8]}'
        config_error = test.error
        if config_error:
            stack = cls(region, None, name, uuid,
                        status_reason=getattr(config_error, 'message', 'Unknown error'),
                        stack_name=stack_name, credential=credential)
            stack.status = getattr(config_error, 'code', 'Unknown error')
            stack._launch_succeeded = False
            stack.timer.cancel()
            return stack
        try:
            template_price = await plugin.get_template_estimate_cost(
                parameters=parameters,
                **template_args,
                region_id=region
            )
        except TeaException as ex:
            stack_id = None
            stack = cls(region, stack_id, name, uuid, status_reason=ex.message,
                        stack_name=stack_name, parameters=parameters, credential=credential)
            stack.status = ex.code
            stack._launch_succeeded = False
            stack.timer.cancel()
            return stack
        stack_id = None
        stack = cls(region, stack_id, name, uuid, stack_name=stack_name,
                    parameters=parameters, credential=credential, template_price=template_price)
        return stack
    
    @classmethod
    async def preview_stack_result(cls, test: TestConfig, tags: dict = None, uuid: UUID = None):
        parameters = test.parameters
        template_args = test.template_config.to_dict()
        name = test.test_name
        if not tags:
            tags = {}
        tags.update({f'{IAC_NAME}-test-name': name})
        region = test.region
        credential = test.auth.credential
        plugin = StackPlugin(region_id=test.region, credential=credential)
        stack_name = f'{IAC_NAME}-{name}-{region}-{uuid4().hex[:8]}'
        config_error = test.error
        if config_error:
            stack = cls(region, None, name, uuid,
                        status_reason=getattr(config_error, 'message', 'Unknown error'),
                        stack_name=stack_name, credential=credential)
            stack.status = getattr(config_error, 'code', 'Unknown error')
            stack._launch_succeeded = False
            stack.timer.cancel()
            return stack
        try:
            preview_result = await plugin.preview_stack(
                parameters=parameters,
                **template_args,
                region_id=region,
                stack_name=stack_name
            )
        except TeaException as ex:
            stack_id = None
            stack = cls(region, stack_id, name, uuid, status_reason=ex.message,
                        stack_name=stack_name, parameters=parameters, credential=credential)
            stack.status = ex.code
            stack._launch_succeeded = False
            stack.timer.cancel()
            return stack
        stack_id = None
        stack = cls(region, stack_id, name, uuid, stack_name=stack_name,
                    parameters=parameters, credential=credential, preview_result=preview_result)
        return stack

    async def refresh(self, properties: bool = True, events: bool = False, resources: bool = False) -> None:
        if properties:
            await self.set_stack_properties()
        if events:
            await self._fetch_stack_events()
            self._last_event_refresh = datetime.now()
        if resources:
            await self._fetch_stack_resources()
            self._last_resource_refresh = datetime.now()

    async def set_stack_properties(self, stack_properties: Optional[dict] = None) -> None:
        props: dict = stack_properties if stack_properties else {}
        if not props:
            if self.id:
                props = await self.plugin.get_stack(self.id) or {}
        self.status = props.get('Status')
        self.status_reason = props.get('StatusReason')
        if self.status not in StackStatus.IN_PROGRESS:
            self.timer.cancel()

    async def events(self, refresh: bool = False) -> Events:
        if refresh or not self._events or self._auto_refresh(self._last_event_refresh):
            await self._fetch_stack_events()
        return self._events

    async def _fetch_stack_events(self) -> None:
        self._last_event_refresh = datetime.now()
        events = Events()
        stack_events = await self.plugin.list_stack_events(self.id)
        for event in stack_events:
            events.append(Event(event))
        self._events = events

    async def resources(self, refresh: bool = False) -> Resources:
        if (
                refresh
                or not self._resources
                or self._auto_refresh(self._last_resource_refresh)
        ):
            await self._fetch_stack_resources()
        return self._resources

    async def _fetch_stack_resources(self) -> None:
        self._last_resource_refresh = datetime.now()
        resources = Resources()
        stack_resources = await self.plugin.list_stack_resources(self.id)
        for res in stack_resources:
            resources.append(Resource(self.id,res,self.test_name,self.uuid))
        self._resources = resources

    @staticmethod
    async def delete(stack) -> None:
        stack_id = stack.id
        if not stack_id:
            return
        await stack.plugin.delete_stack(stack_id=stack_id)
        LOG.info(f'Deleting stack: {stack_id}')
        await stack.refresh()
        stack.timer = Timer(stack.auto_refresh_interval.total_seconds(), stack.refresh)

    def error_events(self, refresh=False) -> Events:
        errors = Events()
        stacks = Stacks([self])
        for stack in stacks:
            for status in StackStatus.FAILED:
                errors += stack.events(refresh=refresh).filter({'status': status})
        return errors