import logging
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, DateTime, Float
from sqlalchemy.orm import relationship
from sqlalchemy.sql.schema import ForeignKey, Sequence
from sqlalchemy.engine import create_engine
from sqlalchemy.orm.session import sessionmaker
import datetime
from contextlib import contextmanager
import uuid
import os

mainLogger = logging.getLogger("sorteerhoed")
logger = mainLogger.getChild("store")

Base = declarative_base()

"""
HIT lifetime:


created
accepted
(returned!)
working
awaiting amazon confirmation (submitted on page)
submitted

Actions:
creating Hit (creating hit with scanned image)

Scanning

"""

class HIT(Base):
    __tablename__ = 'hits'
    id = Column(Integer, Sequence('hit_id'), primary_key=True) # our sequential hit id
    hit_id = Column(String(255)) # amazon's hit id
    created_at = Column(DateTime, default=datetime.datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.datetime.utcnow)
    scanned_at = Column(DateTime, default=None)
    plotted_at = Column(DateTime, default=None)
    deleted_at = Column(DateTime, default=None)
    assignments = relationship("Assignment", back_populates="hit", order_by="Assignment.created_at")
    fee = Column(Float(precision=2), default=None)

    # previous hit so we can load the corrent image
    # previous_hit_id = Column(Integer, ForeignKey('hits.id'), default=None)
    # previous_hit = relationship("HIT")

    def getImagePath(self):
        return os.path.join('scanimation/interfaces/frames', f"{self.id:06d}.jpg")
    
    def getImageUrl(self):
        return os.path.join('/frames', f"{self.id:06d}.jpg")

    def getSvgImageUrl(self):
        return f"scans/{self.id:06d}.svg"

    def getSvgImagePath(self):
        return os.path.join('www', self.getSvgImageUrl())

    def getLastAssignment(self):
        if not len(self.assignments):
            return None
        return self.assignments[-1]

    def getAssignmentById(self, assignmentId):
        for a in self.assignments:
            if a.assignment_id == assignmentId:
                return a
        return None

    def getStatus(self):
        assignment = self.getLastAssignment()
        if self.deleted_at:
            return "deleted"
        if not self.hit_id:
            return "creating"
        if not assignment:
            return "awaiting worker"
        if self.scanned_at:
            return "scanned"
        return assignment.getStatus()
    
    def toDict(self) -> dict:
        values = {c.name: getattr(self, c.name) for c in self.__table__.columns}
        assignment = self.getLastAssignment()
        values['assignment'] = assignment.toDict() if assignment else None
        values['state'] = self.getStatus()
        values['scan_image'] = self.getImageUrl() if self.scanned_at else None
        values['svg_image'] = self.getSvgImageUrl() if self.isSubmitted() else None
        return values

    def delete(self):
        self.deleted_at = datetime.datetime.utcnow()
        
    def isSubmitted(self) -> bool:
        a = self.getLastAssignment()
        if not a:
            return False
        return bool(a.submit_page_at)
    
    def isConfirmed(self) -> bool:
        a = self.getLastAssignment()
        if not a:
            return False
        return bool(a.confirmed_at)

class Assignment(Base):
    __tablename__ = 'assignments'
    id = Column(Integer, Sequence('assignment_id'), primary_key=True) # our sequential hit id
    assignment_id = Column(String(255)) # amazon's assignment id
    hit_id = Column(Integer, ForeignKey('hits.id')) # our sequential hit id
    hit = relationship("HIT", back_populates="assignments")
    uuid = Column(String(32), default=lambda : uuid.uuid4().hex)

    created_at = Column(DateTime, default=datetime.datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.datetime.utcnow)

    assignment_id = Column(String(255), default = None)
    worker_id = Column(String(255), default = None)
    accept_at = Column(DateTime, default=None)  # accept time acccording to SQS
    # open_page_at = Column(DateTime, default=None)
    submit_page_at = Column(DateTime, default=None) # Submit the page
    confirmed_at = Column(DateTime, default=None) # validate with UUID when getting Message from Amazon
    abandoned_at = Column(DateTime, default=None)
    rejected_at = Column(DateTime, default=None)

    answer = Column(String(255), default=None)
    turk_ip = Column(String(255), default=None)
    turk_country = Column(String(255), default=None)
    turk_os = Column(String(255), default=None)
    turk_browser = Column(String(255), default=None)
    
    def getStatus(self):
        if self.rejected_at:
            return "rejected"
        if self.abandoned_at:
            return "abandoned"
        if not self.submit_page_at:
            return "working"
        if not self.confirmed_at:
            return "submitted"
        return "confirmed"
    
    def toDict(self) -> dict:
        values = {c.name: getattr(self, c.name) for c in self.__table__.columns}
        return values


class Store:
    def __init__(self, db_filename, logLevel=0):
        path = os.path.abspath(db_filename)
        if logLevel <= logging.DEBUG:
            logging.getLogger('sqlalchemy.engine').setLevel(logging.INFO)

        self.engine = create_engine('sqlite:///'+path, echo=False, connect_args={'check_same_thread': False})
        Base.metadata.create_all(self.engine)
        self.Session = sessionmaker(bind=self.engine)
        self.session = self.Session()

        self.currentHit = None # mirrors Centralmanagmenet, stored here so we can quickly access it from webserver classes
        self.updateHooks = []
    
    def registerUpdateHook(self, hook):
        if hook not in self.updateHooks:
            logger.info(f"Register update hook: {hook}")
            self.updateHooks.append(hook)
    
    def triggerUpdateHooks(self, hit = None):
        for hook in self.updateHooks:
            if callable(hook):  # it's a method
                hook(hit)
            else:  # assume it's an object
                hook.update(hit)

    @contextmanager
    def getSession(self):
        """Provide a transactional scope around a series of operations."""
        try:
            yield self.session
            self.session.commit()
        except:
            self.session.rollback()
            raise

    def getHits(self):
        return self.session.query(HIT).order_by(HIT.created_at.desc())

    def getHitById(self, hitId):
        return self.session.query(HIT).\
          filter(HIT.id==hitId).one()

    def getHitByRemoteId(self, amazonHitId):
        return self.session.query(HIT).\
          filter(HIT.hit_id==amazonHitId).one()


    def getLastSubmittedHit(self):
        return self.session.query(HIT).\
            join(Assignment).\
            filter(Assignment.submit_page_at!=None).\
            order_by(HIT.created_at.desc()).first()
    
    def getNewestHits(self, n = 2) -> list:
        hits = list(
            self.session.query(HIT).\
              filter(HIT.deleted_at==None).\
              order_by(HIT.created_at.desc()).limit(2)
        ) 
        # select DESC, because we want latest, then reverse list to get in right order
        hits.reverse()
        return hits

    def createHIT(self) -> HIT:
        with self.getSession() as s:
            hit = HIT()
            s.add(hit)
            s.flush()
            s.refresh(hit)
            logger.info(f"Created HIT {hit.id}")
        
        self.triggerUpdateHooks(hit)
        
        return hit

    def newAssignment(self, hit: HIT, assignmentId) -> Assignment:
        # TODO: reset() central management if has pending lastAssignment()
        
        with self.getSession() as s:
            assignment = Assignment()
            assignment.assignment_id = assignmentId
            hit.assignments.append(assignment)
            s.add(assignment)
            s.flush()
            s.refresh(hit)
            logger.info(f"Created Assignment {assignment.id}")
        
        self.triggerUpdateHooks(hit)
        
        return assignment

    def saveHIT(self, hit):
        with self.getSession() as s:
            logger.info(f"Updating hit! {hit.id}")
#             s.flush()
            self.triggerUpdateHooks(hit)

    def saveAssignment(self, assignment):
        with self.getSession() as s:
            logger.info(f"Updating assignment! {assignment.id}")
#             s.flush()
            self.triggerUpdateHooks(assignment.hit)

#     def addHIT(self, hit: HIT):
#         with self.getSession() as s:
#             s.add(hit)
#             s.flush()
#             s.refresh(hit)
#             logger.info(f"Added {hit.id}")

    def getAvgDurationOfPreviousNHits(self, n) -> int:
        latest_assignments = self.session.query(Assignment).\
          filter(Assignment.created_at!=None).\
          filter(Assignment.submit_page_at!=None).\
          order_by(Assignment.created_at.desc()).limit(n)
        durations = []

        for assignment in latest_assignments:
            durations.append((assignment.submit_page_at - assignment.created_at).total_seconds())
        if not len(durations):
            return int(2.5*60)  # default to 2.5 minutes
        return int(sum(durations) / len(durations))

    def getEstimatedHitDuration(self):
        return self.getAvgDurationOfPreviousNHits(5)

    def getHitTimeout(self):
        return 160 # max(160, self.getAvgDurationOfPreviousNHits(5)*2)

    def getHITs(self, n = 100):
        return self.session.query(HIT).\
                filter(HIT.submit_hit_at != None).\
                order_by(HIT.submit_hit_at.desc()).limit(n)