from rest_framework import permissions
from rest_framework.permissions import IsAuthenticated

__all__ = [
    'IsAuthenticated',
    'CanCreateAndUpdateFeedbackLog',
    'GetOnly',
    'CanCreateAndUpdateGoal',
    'CanCreateAndUpdateNotification',
    'CanCreateAndUpdateCourseGoal',
]

class CanCreateAndUpdateFeedbackLog(permissions.BasePermission):

    def has_permission(self, request, view, obj=None):
        return True

    def has_object_permission(self, request, view, obj):
        if request.method in permissions.SAFE_METHODS:
            return True

        return obj.user == request.user

class GetOnly(permissions.BasePermission):

    def has_permission(self, request, view, obj=None):
        if request.method == 'GET':
            return True
        return False

    def has_object_permission(self, request, view, obj):
        if request.method == 'GET':
            return True
        return False

class CanCreateAndUpdateGoal(permissions.BasePermission):

    def has_permission(self, request, view, obj=None):
        return True

    def has_object_permission(self, request, view, obj):
        if request.method in permissions.SAFE_METHODS:
            return True

        # If there's a course, only the instructors can edit
        if obj.course:
            return obj.course in request.user.get_profile().instructorships
        # Otherwise, this is the user's personal goal.
        else:
            return obj.created_by == request.user
        return False

class CanCreateAndUpdateCourseGoal(permissions.BasePermission):

    def has_permission(self, request, view, obj=None):
        return True

    def has_object_permission(self, request, view, obj):
        if request.method in permissions.SAFE_METHODS:
            return True

        # If there's a course, only the instructors can edit
        if obj.course:
            return obj.course in request.user.get_profile().instructorships
        # Otherwise, this is the user's personal goal.
        else:
            return obj.created_by == request.user
        return False

class CanCreateAndUpdateNotification(permissions.BasePermission):

    def has_permission(self, request, view, obj=None):
        return True

    def has_object_permission(self, request, view, obj):
        if request.method in permissions.SAFE_METHODS:
            return True

        return obj.recipient == request.user