from datetime import datetime

from sqlalchemy import select, update, func, delete
from sqlalchemy.orm import selectinload

from models import Project, Board
from schemas.project import *
from services.base import BaseService


class ProjectService(BaseService):
    async def get_projects(self) -> GetProjectsResponse:
        board_count_sub = (
            select(
                Board.project_id,
                func.count(Board.id).label('boards_count'),
            )
            .group_by(Board.project_id)
            .subquery()
        )
        stmt = (
            select(
                Project,
                func.coalesce(board_count_sub.c.boards_count, 0),
            )
            .outerjoin(board_count_sub, Project.id == board_count_sub.c.project_id)
            .options(
                selectinload(Project.attributes),
                selectinload(Project.modules),
            )
        )
        project_data = (await self.session.execute(stmt)).all()

        projects = []
        for project, boards_count in project_data:
            project_schema = FullProjectSchema(
                id=project.id,
                name=project.name,
                boards_count=boards_count,
                attributes=project.attributes,
                modules=project.modules,
            )
            projects.append(project_schema)

        return GetProjectsResponse(projects=projects)

    async def create_project(self, request: CreateProjectRequest) -> CreateProjectResponse:
        project = Project(
            name=request.project.name,
            created_at=datetime.now(),
        )
        self.session.add(project)
        await self.session.commit()
        return UpdateProjectResponse(ok=True, message="Проект успешно создан")

    async def update_project(self, request: UpdateProjectRequest) -> UpdateProjectResponse:
        stmt = (
            update(Project)
            .where(Project.id == request.project.id)
            .values(name=request.project.name)
        )
        await self.session.execute(stmt)
        await self.session.commit()

        return UpdateProjectResponse(ok=True, message="Проект успешно изменен")

    async def delete_project(self, project_id: int) -> DeleteProjectResponse:
        stmt_boards = select(Board).where(Board.project_id == project_id)
        boards = (await self.session.scalars(stmt_boards)).all()
        if len(boards) == 0:
            stmt = (
                delete(Project)
                .where(Project.id == project_id)
            )
        else:
            stmt = (
                update(Project)
                .where(Project.id == project_id)
                .values(is_deleted=True)
            )
        await self.session.execute(stmt)
        await self.session.commit()
        return DeleteProjectResponse(ok=True, message="Проект успешно удален")