from datetime import datetime

from sqlalchemy import select, update, func, delete, and_

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


class ProjectService(BaseService):
    async def get_projects(self) -> GetProjectsResponse:
        boards_sub = (
            select(Board)
            .where(Board.is_deleted == False)
            .subquery()
        )
        stmt = (
            select(
                Project.id,
                Project.name,
                func.count(boards_sub.c.id)
            )
            .join(boards_sub, Project.id == boards_sub.c.project_id, isouter=True)
            .where(Project.is_deleted == False)
            .group_by(Project.id, Project.name)
            .order_by(Project.name)
        )
        project_data = (await self.session.execute(stmt)).all()

        projects = []
        for project_id, name, boards_count in project_data:
            project = ProjectSchemaWithCount(id=project_id, name=name, boards_count=boards_count)
            projects.append(project)

        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")