"""Role-based access control helpers - using configurable permissions."""
from fastapi import HTTPException, status
from sqlalchemy.orm import Session
from app.models import models
from app.models.role_permission import Role, Permission, RolePermission
from app.models.milestone import Milestone
from app.models.task import Task


def get_user_role(db: Session, user_id: int, project_id: int) -> Role | None:
    """Get user's role in a project."""
    member = db.query(models.ProjectMember).filter(
        models.ProjectMember.user_id == user_id,
        models.ProjectMember.project_id == project_id,
    ).first()

    if member and member.role_id:
        return db.query(Role).filter(Role.id == member.role_id).first()

    # Check global admin
    user = db.query(models.User).filter(models.User.id == user_id).first()
    if user and user.is_admin:
        # Return global admin role
        return db.query(Role).filter(Role.is_global == True, Role.name == "superadmin").first()

    return None


def has_permission(db: Session, user_id: int, project_id: int, permission: str) -> bool:
    """Check if user has a specific permission in a project."""
    role = get_user_role(db, user_id, project_id)

    if not role:
        return False

    # Check if role has the permission
    perm = db.query(Permission).filter(Permission.name == permission).first()
    if not perm:
        return False

    role_perm = db.query(RolePermission).filter(
        RolePermission.role_id == role.id,
        RolePermission.permission_id == perm.id
    ).first()

    return role_perm is not None


def check_permission(db: Session, user_id: int, project_id: int, permission: str):
    """Raise 403 if user doesn't have the permission."""
    if not has_permission(db, user_id, project_id, permission):
        role = get_user_role(db, user_id, project_id)
        role_name = role.name if role else "none"
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail=f"Permission '{permission}' required. Your role: {role_name}"
        )


def check_project_role(db: Session, user_id: int, project_id: int, min_role: str = "member"):
    """Check if user has at least the specified role in a project."""
    user = db.query(models.User).filter(models.User.id == user_id).first()
    if user and user.is_admin:
        return True

    member = db.query(models.ProjectMember).filter(
        models.ProjectMember.user_id == user_id,
        models.ProjectMember.project_id == project_id,
    ).first()

    if not member or not member.role_id:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="You are not a member of this project"
        )

    role = db.query(Role).filter(Role.id == member.role_id).first()
    if not role:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Role not found"
        )

    # Legacy compatibility: most current routes use non-hierarchical names like dev/mgr.
    # For now, any valid membership passes those broad checks; strict edit rules are handled
    # by the explicit can_edit_* helpers below.
    if min_role in {"dev", "mgr", "viewer", "member", "guest", "admin"}:
        return True

    return True


def get_project_role_name(db: Session, user_id: int, project_id: int) -> str | None:
    if is_global_admin(db, user_id):
        return "admin"
    member = db.query(models.ProjectMember).filter(
        models.ProjectMember.user_id == user_id,
        models.ProjectMember.project_id == project_id,
    ).first()
    if not member or not member.role_id:
        return None
    role = db.query(Role).filter(Role.id == member.role_id).first()
    return role.name if role else None


def is_global_admin(db: Session, user_id: int) -> bool:
    user = db.query(models.User).filter(models.User.id == user_id).first()
    return bool(user and user.is_admin)


def has_project_admin_role(db: Session, user_id: int, project_id: int) -> bool:
    return get_project_role_name(db, user_id, project_id) == "admin"


def can_edit_project(db: Session, user_id: int, project: models.Project) -> bool:
    return (
        is_global_admin(db, user_id)
        or project.owner_id == user_id
        or has_project_admin_role(db, user_id, project.id)
    )


def ensure_can_edit_project(db: Session, user_id: int, project: models.Project):
    if not can_edit_project(db, user_id, project):
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Project edit permission denied")


def can_edit_milestone(db: Session, user_id: int, milestone: Milestone) -> bool:
    project = db.query(models.Project).filter(models.Project.id == milestone.project_id).first()
    if not project:
        return False
    return (
        is_global_admin(db, user_id)
        or project.owner_id == user_id
        or milestone.created_by_id == user_id
        or has_project_admin_role(db, user_id, milestone.project_id)
    )


def ensure_can_edit_milestone(db: Session, user_id: int, milestone: Milestone):
    if not can_edit_milestone(db, user_id, milestone):
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Milestone edit permission denied")


def can_edit_task(db: Session, user_id: int, task: Task) -> bool:
    project = db.query(models.Project).filter(models.Project.id == task.project_id).first()
    milestone = db.query(Milestone).filter(Milestone.id == task.milestone_id).first()
    if not project:
        return False
    return (
        is_global_admin(db, user_id)
        or project.owner_id == user_id
        or task.created_by_id == user_id
        or (milestone is not None and milestone.created_by_id == user_id)
        or has_project_admin_role(db, user_id, task.project_id)
    )


def ensure_can_edit_task(db: Session, user_id: int, task: Task):
    if not can_edit_task(db, user_id, task):
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Task edit permission denied")