"""Users — profile + role assignment + organization management (v2.6, Casdoor-backed).

Organization panel endpoints (admin / procurement manager — same person):
- GET  /users                — list every user with role + assigned projects.
- POST /users                — define a new user (manual identity, casdoor_id optional).
- PATCH /users/{id}          — set/clear role; clearing (or switching away from
                               «pm») also unassigns the user from every project.
- POST /users/{id}/project   — assign/unassign ONE project (multi-project:
                               other assignments are kept; project_id=None
                               clears all; one PM per project).
- GET  /users/me/projects    — every project assigned to the caller (PM).

Role management is open to BOTH «admin» and «procurement_manager» (they are
the same person in this system), unlike the plain require_role("admin").
"""
import uuid

import httpx
from fastapi import APIRouter, Depends
from sqlalchemy import select, update, text
from sqlalchemy.ext.asyncio import AsyncSession

from app.auth import UserContext, get_current_user, require_role
from app.utils.audit import record as audit_record
from app.config import settings
from app.db.engine import get_db
from app.models.procurement import Project, User
from app.schemas.procurement import UserCreate, UserProjectUpdate, UserRoleUpdate
from app.utils.errors import (
    ConflictError,
    ForbiddenError,
    NotFoundError,
    ServiceUnavailableError,
    ValidationError,
)
from app.utils.serialization import to_iso

router = APIRouter(prefix="/users", tags=["users"])

USER_ROLE_LABELS = {
    "pm": "مدیر پروژه",
    "procurement_manager": "مدیر تدارکات",
    "admin": "ادمین",
    # کاربر فقطِ پنل مدیریت پروژه (PM) — به انبار/تدارکات دسترسی ندارد
    "supervisor": "سرپرست پروژه",
}


def user_to_dict(user: User, projects: list[Project] | None = None) -> dict:
    """Serialize a user. `projects` = every project the PM manages (1:N);
    project_id/project_name stay as the first (oldest) one for compatibility."""
    projects = projects or []
    first = projects[0] if projects else None
    return {
        "id": str(user.id),
        "casdoor_id": user.casdoor_id,
        "username": user.username,
        "first_name": user.first_name,
        "last_name": user.last_name,
        "phone": user.phone,
        "role": user.role,
        "role_label": USER_ROLE_LABELS.get(user.role) if user.role else None,
        "project_id": str(first.id) if first else None,
        "project_name": first.name if first else None,
        "projects": [{"id": str(p.id), "name": p.name} for p in projects],
        "created_at": to_iso(user.created_at),
    }


async def _org_manager(ctx: UserContext = Depends(get_current_user)) -> UserContext:
    """Admin, procurement manager, or project manager — organization management."""
    if ctx.role not in ("admin", "procurement_manager", "pm"):
        raise ForbiddenError("دسترسی به این بخش برای نقش شما مجاز نیست")
    return ctx


async def _user_projects(db: AsyncSession, user: User) -> list[Project]:
    """Every project assigned to the user (supervisor or PM) (oldest first)."""
    if user.role not in ("supervisor", "pm"):
        return []
    rows = (
        await db.execute(
            select(Project)
            .where(Project.pm_user_id == user.id)
            .order_by(Project.created_at, Project.id)
        )
    ).scalars().all()
    return list(rows)


async def _user_project(db: AsyncSession, user: User) -> Project | None:
    """First (oldest) project of a PM — legacy single-project view."""
    projects = await _user_projects(db, user)
    return projects[0] if projects else None


async def _unassign_projects(db: AsyncSession, user_id) -> None:
    """Clear the user's pm assignment on every project (role revocation)."""
    await db.execute(
        update(Project).where(Project.pm_user_id == user_id).values(pm_user_id=None)
    )


async def _casdoor_users() -> list[dict]:
    """Fetch the users of the Casdoor organization (org inventory) via the
    Casdoor management API, using the console admin session."""
    async with httpx.AsyncClient(timeout=15) as client:
        login = await client.post(
            f"{settings.CASDOOR_ENDPOINT}/api/login",
            json={
                "type": "login",
                "organization": "built-in",
                "username": settings.CASDOOR_ADMIN_USER,
                "password": settings.CASDOOR_ADMIN_PASSWORD,
                "application": "app-built-in",
            },
        )
        if login.status_code != 200 or (login.json() or {}).get("status") != "ok":
            raise ServiceUnavailableError("ورود به کنسول Casdoor برای همگام‌سازی ممکن نشد")
        resp = await client.get(
            f"{settings.CASDOOR_ENDPOINT}/api/get-users?owner={settings.CASDOOR_ORGANIZATION}"
        )
        resp.raise_for_status()
        body = resp.json()
        if body.get("status") != "ok":
            raise ServiceUnavailableError("دریافت کاربران Casdoor ناموفق بود")
        return body.get("data") or []


@router.get("/me")
async def me(ctx: UserContext = Depends(get_current_user), db: AsyncSession = Depends(get_db)):
    projects = await _user_projects(db, ctx.user)
    return {"data": user_to_dict(ctx.user, projects)}


@router.get("/me/projects")
async def my_projects(ctx: UserContext = Depends(get_current_user), db: AsyncSession = Depends(get_db)):
    """Every project assigned to the caller (empty list for non-PM roles).

    Drives the PM project switcher: the frontend validates its persisted
    active project against this list and falls back gracefully when a
    project is revoked."""
    projects = await _user_projects(db, ctx.user)
    return {"data": [{"id": str(p.id), "name": p.name} for p in projects]}


@router.get("")
async def list_users(
    _: UserContext = Depends(_org_manager),
    db: AsyncSession = Depends(get_db),
):
    """Every user (with role + assigned projects) — Organization panel."""
    users = (await db.execute(select(User).order_by(User.created_at))).scalars().all()
    supervisor_ids = {u.id for u in users if u.role in ("supervisor", "pm")}
    by_user: dict = {}
    if supervisor_ids:
        projs = (
            await db.execute(
                select(Project)
                .where(Project.pm_user_id.in_(supervisor_ids))
                .order_by(Project.created_at, Project.id)
            )
        ).scalars().all()
        for p in projs:
            by_user.setdefault(p.pm_user_id, []).append(p)
    return {
        "data": [user_to_dict(u, by_user.get(u.id, [])) for u in users],
        "meta": {"total": len(users)},
    }


@router.post("", status_code=201)
async def create_user(
    payload: UserCreate,
    ctx: UserContext = Depends(_org_manager),
    db: AsyncSession = Depends(get_db),
):
    """Define a new user (manual identity — casdoor_id optional)."""
    casdoor_id = (payload.casdoor_id or "").strip() or f"manual-{uuid.uuid4()}"
    duplicate = await db.scalar(select(User).where(User.casdoor_id == casdoor_id))
    if duplicate is not None:
        raise ConflictError("کاربری با این شناسه قبلاً ثبت شده است", field="casdoor_id")
    user = User(
        casdoor_id=casdoor_id,
        first_name=payload.first_name,
        last_name=payload.last_name or "",
        phone=payload.phone,
        role=payload.role,
    )
    db.add(user)
    await db.flush()
    await audit_record(db, actor=ctx.display_name, action="user.created", entity="user", entity_id=str(user.id), details={"role": payload.role})
    return {"data": user_to_dict(user)}


@router.patch("/{user_id}")
async def update_user_role(
    user_id,
    payload: UserRoleUpdate,
    ctx: UserContext = Depends(require_role("admin")),
    db: AsyncSession = Depends(get_db),
):
    """Set/clear a role — ADMIN ONLY (RBAC): procurement managers must not
    assign or elevate roles. Revoking (or switching away from «pm») also
    unassigns the user from their project."""
    user = await db.get(User, user_id)
    if user is None:
        raise NotFoundError("کاربر یافت نشد")
    previous_role = user.role
    if user.role in ("supervisor", "pm") and payload.role not in ("supervisor", "pm"):
        await _unassign_projects(db, user.id)
    user.role = payload.role
    await db.flush()
    await audit_record(db, actor=ctx.display_name, action="user.role_changed", entity="user", entity_id=str(user.id), details={"from": previous_role, "to": payload.role})
    projects = await _user_projects(db, user)
    return {"data": user_to_dict(user, projects)}


@router.post("/sync")
async def sync_casdoor_users(
    _: UserContext = Depends(_org_manager),
    db: AsyncSession = Depends(get_db),
):
    """Mirror the Casdoor organization users into the app's users table.

    Identity-only: roles are NOT touched here (role assignment stays in the
    app — PATCH /users/{id}, admin-only). Returns the merged user list.
    """
    cas_users = await _casdoor_users()
    created = 0
    for cu in cas_users:
        cid = str(cu.get("id") or "").strip()
        if not cid:
            continue
        existing = await db.scalar(select(User).where(User.casdoor_id == cid))
        if existing is None:
            uname = str(cu.get("name") or cu.get("preferred_username") or "") or None
            if uname:
                by_uname = await db.scalar(select(User).where(User.username == uname))
                if by_uname is not None:
                    by_uname.casdoor_id = cid
                    continue
            db.add(User(
                casdoor_id=cid,
                username=uname,
                first_name=str(
                    cu.get("firstName")
                    or cu.get("displayName")
                    or cu.get("name")
                    or "کاربر"
                ),
                last_name=str(cu.get("lastName") or ""),
                phone=str(cu.get("phone") or "") or None,
            ))
            created += 1
        elif not existing.username:
            uname = str(cu.get("name") or cu.get("preferred_username") or "") or None
            if uname:
                existing.username = uname
    await db.flush()

    users = (await db.execute(select(User).order_by(User.created_at))).scalars().all()
    supervisor_ids = {u.id for u in users if u.role in ("supervisor", "pm")}
    by_user: dict = {}
    if supervisor_ids:
        projs = (
            await db.execute(
                select(Project)
                .where(Project.pm_user_id.in_(supervisor_ids))
                .order_by(Project.created_at, Project.id)
            )
        ).scalars().all()
        for p in projs:
            by_user.setdefault(p.pm_user_id, []).append(p)
    return {
        "data": [user_to_dict(u, by_user.get(u.id, [])) for u in users],
        "meta": {"total": len(users), "created": created},
    }


@router.post("/{user_id}/project")
async def assign_user_project(
    user_id,
    payload: UserProjectUpdate,
    _: UserContext = Depends(_org_manager),
    db: AsyncSession = Depends(get_db),
):
    """Assign the user as PM of ONE project (multi-project aware).

    - project_id given: that project gets this PM (a previous PM there is
      replaced); the user's OTHER project assignments are kept.
    - project_id=None: clears ALL of the user's project assignments.

    Rules: the user must hold the «pm» role; a project has at most one PM.
    """
    user = await db.get(User, user_id)
    if user is None:
        raise NotFoundError("کاربر یافت نشد")
    if user.role not in ("supervisor", "pm"):
        raise ValidationError("ابتدا نقش این کاربر را «سرپرست پروژه» کنید", field="role")

    if payload.project_id is None:
        await _unassign_projects(db, user.id)
        if user.username:
            await db.execute(
                text("DELETE FROM project_assignments WHERE user_id IN (SELECT id FROM pm_users WHERE username = :uname)"),
                {"uname": user.username}
            )
        await db.flush()
        return {"data": user_to_dict(user)}

    project = await db.get(Project, payload.project_id)
    if project is None:
        raise NotFoundError("پروژه یافت نشد", field="project_id")
    project.pm_user_id = user.id
    if user.username:
        await db.execute(
            text("""
                INSERT INTO project_assignments (id, user_id, project_id)
                SELECT gen_random_uuid(), pu.id, :pid
                FROM pm_users pu
                WHERE pu.username = :uname
                AND NOT EXISTS (
                    SELECT 1 FROM project_assignments pa
                    WHERE pa.user_id = pu.id AND pa.project_id = :pid
                )
            """),
            {"pid": project.id, "uname": user.username}
        )
    await db.flush()
    return {"data": user_to_dict(user, await _user_projects(db, user))}