import enum

import marshmallow
from ldap3.core.exceptions import LDAPSocketOpenError
from marshmallow import INCLUDE
from sqlalchemy import func

from crc import db, ma
from crc.api.common import ApiError
from crc.models.file import FileDataModel
from crc.models.study import StudyModel
from crc.models.workflow import WorkflowModel
from crc.services.ldap_service import LdapService
from crc.services.file_service import FileService


class ApprovalStatus(enum.Enum):
    PENDING = "PENDING"   # no one has done jack.
    APPROVED = "APPROVED" # approved by the reviewer
    DECLINED = "DECLINED" # rejected by the reviewer
    CANCELED = "CANCELED" # The document was replaced with a new version and this review is no longer needed.


class ApprovalFile(db.Model):
    file_data_id = db.Column(db.Integer, db.ForeignKey(FileDataModel.id), primary_key=True)
    approval_id = db.Column(db.Integer, db.ForeignKey("approval.id"), primary_key=True)

    approval = db.relationship("ApprovalModel")
    file_data = db.relationship(FileDataModel)


class ApprovalModel(db.Model):
    __tablename__ = 'approval'
    id = db.Column(db.Integer, primary_key=True)
    study_id = db.Column(db.Integer, db.ForeignKey(StudyModel.id), nullable=False)
    study = db.relationship(StudyModel, backref='approval', cascade='all,delete')
    workflow_id = db.Column(db.Integer, db.ForeignKey(WorkflowModel.id), nullable=False)
    workflow = db.relationship(WorkflowModel)
    approver_uid = db.Column(db.String)  # Not linked to user model, as they may not have logged in yet.
    status = db.Column(db.String)
    message = db.Column(db.String, default='')
    date_created = db.Column(db.DateTime(timezone=True), default=func.now())
    version = db.Column(db.Integer) # Incremented integer, so 1,2,3 as requests are made.
    approval_files = db.relationship(ApprovalFile, back_populates="approval",
                                     cascade="all, delete, delete-orphan",
                                     order_by=ApprovalFile.file_data_id)


class Approval(object):

    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)

    @classmethod
    def from_model(cls, model: ApprovalModel):
        # TODO: Reduce the code by iterating over model's dict keys
        instance = cls()
        instance.id = model.id
        instance.study_id = model.study_id
        instance.workflow_id = model.workflow_id
        instance.version = model.version
        instance.approver_uid = model.approver_uid
        instance.status = model.status
        instance.message = model.message
        instance.date_created = model.date_created
        instance.version = model.version
        instance.title = ''
        if model.study:
            instance.title = model.study.title

        principal_investigator_id = model.study.primary_investigator_id
        instance.approver = {}
        try:
            ldap_service = LdapService()
            user_info = ldap_service.user_info(principal_investigator_id)
        except (ApiError, LDAPSocketOpenError) as exception:
            user_info = None
            instance.approver['display_name'] = 'Primary Investigator details'
            instance.approver['department'] = 'currently not available'

        if user_info:
            # TODO: Rename approver to primary investigator
            instance.approver['uid'] = model.approver_uid
            instance.approver['display_name'] = user_info.display_name
            instance.approver['title'] = user_info.title
            instance.approver['department'] = user_info.department

        # TODO: Organize it properly, move it to services
        doc_dictionary = FileService.get_reference_data(FileService.DOCUMENT_LIST, 'code', ['id'])

        instance.associated_files = []
        for approval_file in model.approval_files:
            try:
                extra_info = doc_dictionary[approval_file.file_data.file_model.irb_doc_code]
            except:
                extra_info = None
            associated_file = {}
            associated_file['id'] = approval_file.file_data.file_model.id
            if extra_info:
                irb_doc_code = approval_file.file_data.file_model.irb_doc_code
                associated_file['name'] = '_'.join((irb_doc_code, approval_file.file_data.file_model.name))
                associated_file['description'] = extra_info['description']
            else:
                associated_file['name'] = approval_file.file_data.file_model.name
                associated_file['description'] = 'No description available'
            associated_file['name'] = '(' + principal_investigator_id + ')' + associated_file['name']
            associated_file['content_type'] = approval_file.file_data.file_model.content_type
            instance.associated_files.append(associated_file)

        return instance

    def update_model(self, approval_model: ApprovalModel):
        approval_model.status = self.status
        approval_model.message = self.message


class ApprovalSchema(ma.Schema):
    class Meta:
        model = Approval
        fields = ["id", "study_id", "workflow_id", "version", "title",
            "version", "status", "message", "approver", "associated_files"]
        unknown = INCLUDE

    @marshmallow.post_load
    def make_approval(self, data, **kwargs):
        """Loads the basic approval data for updates to the database"""
        return Approval(**data)

# Carlos:  Here is the data structure I was trying to imagine.
# If I were to continue down my current traing of thought, I'd create
# another class called just "Approval" that can take an ApprovalModel from the
# database and construct a data structure like this one, that can
# be provided to the API at an /approvals endpoint with GET and PUT
# dat = { "approvals": [
#     {"id": 1,
#      "study_id": 20,
#      "workflow_id": 454,
#      "study_title": "Dan Funk (dhf8r)",  # Really it's just the name of the Principal Investigator
#      "workflow_version": "21",
#      "approver": {  # Pulled from ldap
#         "uid": "bgb22",
#         "display_name": "Billy Bob (bgb22)",
#         "title": "E42:He's a hoopy frood",
#         "department": "E0:EN-Eng Study of Parallel Universes",
#      },
#      "files": [
#          {
#              "id": 124,
#              "name": "ResearchRestart.docx",
#              "content_type": "docx-something-whatever"
#          }
#      ]
#      }
#     ...
# ]