"""Project management service."""
import logging
from datetime import datetime, timezone

from sqlalchemy import func, select

from fabledassistant.models import async_session
from fabledassistant.models.note import Note
from fabledassistant.models.project import Project

logger = logging.getLogger(__name__)


async def create_project(
    user_id: int,
    title: str,
    description: str = "",
    goal: str = "",
    color: str | None = None,
) -> Project:
    async with async_session() as session:
        project = Project(
            user_id=user_id,
            title=title,
            description=description,
            goal=goal,
            color=color,
            status="active",
        )
        session.add(project)
        await session.commit()
        await session.refresh(project)
        return project


async def get_project(user_id: int, project_id: int) -> Project | None:
    async with async_session() as session:
        result = await session.execute(
            select(Project).where(Project.id == project_id, Project.user_id == user_id)
        )
        return result.scalars().first()


async def get_project_by_title(user_id: int, title: str) -> Project | None:
    async with async_session() as session:
        result = await session.execute(
            select(Project).where(
                Project.user_id == user_id,
                func.lower(Project.title) == func.lower(title.strip()),
            ).limit(1)
        )
        return result.scalars().first()


async def get_or_create_project(user_id: int, title: str) -> Project:
    project = await get_project_by_title(user_id, title)
    if project:
        return project
    return await create_project(user_id, title=title)


async def list_projects(user_id: int, status: str | None = None) -> list[Project]:
    async with async_session() as session:
        query = select(Project).where(Project.user_id == user_id)
        if status:
            query = query.where(Project.status == status)
        query = query.order_by(Project.updated_at.desc())
        result = await session.execute(query)
        return list(result.scalars().all())


async def update_project(user_id: int, project_id: int, **fields: object) -> Project | None:
    async with async_session() as session:
        result = await session.execute(
            select(Project).where(Project.id == project_id, Project.user_id == user_id)
        )
        project = result.scalars().first()
        if project is None:
            return None
        for key, value in fields.items():
            if hasattr(project, key):
                setattr(project, key, value)
        project.updated_at = datetime.now(timezone.utc)
        await session.commit()
        await session.refresh(project)
        return project


async def delete_project(user_id: int, project_id: int) -> bool:
    async with async_session() as session:
        result = await session.execute(
            select(Project).where(Project.id == project_id, Project.user_id == user_id)
        )
        project = result.scalars().first()
        if project is None:
            return False
        # Unlink notes (cascade handled by DB ON DELETE SET NULL, but we delete project here)
        await session.delete(project)
        await session.commit()
        return True


async def get_project_summary(user_id: int, project_id: int) -> dict:
    """Return task counts by status, note count, and last activity."""
    async with async_session() as session:
        # Task counts by status
        task_rows = await session.execute(
            select(Note.status, func.count(Note.id))
            .where(
                Note.user_id == user_id,
                Note.project_id == project_id,
                Note.status.isnot(None),
            )
            .group_by(Note.status)
        )
        task_counts: dict[str, int] = {}
        for status, count in task_rows.fetchall():
            task_counts[status] = count

        # Note count (non-tasks)
        note_count_result = await session.scalar(
            select(func.count(Note.id)).where(
                Note.user_id == user_id,
                Note.project_id == project_id,
                Note.status.is_(None),
            )
        )
        note_count = note_count_result or 0

        # Last activity
        last_activity_result = await session.scalar(
            select(func.max(Note.updated_at)).where(
                Note.user_id == user_id,
                Note.project_id == project_id,
            )
        )

        from fabledassistant.services.milestones import get_project_milestone_summary
        milestone_summary = await get_project_milestone_summary(user_id, project_id)

        return {
            "task_counts": task_counts,
            "note_count": note_count,
            "last_activity": last_activity_result.isoformat() if last_activity_result else None,
            "milestone_summary": milestone_summary,
        }