"""Workspace API routes.

Workspaces are UI/navigation context only — they never affect permissions.
The X-Workspace-ID header is used for workspace context (per-tab, not session).
"""

from __future__ import annotations

import uuid
from typing import Any

from fastapi import APIRouter, Depends, HTTPException, Header, status
from pydantic import BaseModel
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.db import get_db
from app.deps import require_permission
from app.services import workspace_service

router = APIRouter(prefix="/api/v1/workspaces", tags=["Workspaces"])


class WorkspaceCreate(BaseModel):
    name: str
    icon: str = "LayoutGrid"
    description: str | None = None
    is_default: bool = False


class WorkspaceUpdate(BaseModel):
    name: str | None = None
    icon: str | None = None
    description: str | None = None
    is_default: bool | None = None
    is_active: bool | None = None


class ModuleAssignment(BaseModel):
    module_key: str
    is_visible: bool = True
    menu_order: int = 0
    config: dict[str, Any] = {}


class SetModules(BaseModel):
    modules: list[ModuleAssignment]


class UserAssignment(BaseModel):
    user_id: str
    role: str = "member"


@router.get("")
async def list_workspaces(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:read")),
):
    """List all workspaces for the tenant."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    return await workspace_service.list_workspaces(db, tenant_id)


@router.get("/my")
async def my_workspaces(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:read")),
):
    """Get workspaces assigned to the current user."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    user_id = uuid.UUID(current_user["user_id"])
    return await workspace_service.get_my_workspaces(db, tenant_id, user_id)


@router.get("/context")
async def workspace_context(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:read")),
    x_workspace_id: str | None = Header(None, alias="X-Workspace-ID"),
):
    """Get workspace context for the current user (modules, widgets).
    
    Uses X-Workspace-ID header for tab-local workspace selection.
    Falls back to user's default workspace if no header.
    """
    tenant_id = uuid.UUID(current_user["tenant_id"])
    user_id = uuid.UUID(current_user["user_id"])
    is_admin = current_user.get("is_system_admin", False)
    
    workspace_id = None
    if x_workspace_id:
        try:
            workspace_id = uuid.UUID(x_workspace_id)
        except ValueError:
            raise HTTPException(400, detail={"detail": "Invalid X-Workspace-ID", "code": "invalid_id"})
    else:
        # Find user's default workspace
        my = await workspace_service.get_my_workspaces(db, tenant_id, user_id)
        for ws in my["items"]:
            if ws.get("is_user_default"):
                workspace_id = uuid.UUID(ws["id"])
                break
        if workspace_id is None and my["items"]:
            workspace_id = uuid.UUID(my["items"][0]["id"])
    
    if workspace_id is None:
        return {"workspace_id": None, "modules": [], "widgets": []}
    
    ctx = await workspace_service.get_workspace_context(db, tenant_id, user_id, workspace_id)
    if ctx is None and not is_admin:
        # User not assigned — return empty context
        return {"workspace_id": str(workspace_id), "modules": [], "widgets": [], "error": "not_assigned"}
    elif ctx is None and is_admin:
        # Admin can see any workspace — get without user check
        ws_data = await workspace_service.get_workspace(db, tenant_id, workspace_id)
        if ws_data is None:
            return {"workspace_id": None, "modules": [], "widgets": []}
        return {
            "workspace_id": ws_data["id"],
            "name": ws_data["name"],
            "icon": ws_data["icon"],
            "role": "admin",
            "modules": ws_data.get("modules", []),
            "widgets": [],
        }
    return ctx


@router.post("", status_code=status.HTTP_201_CREATED)
async def create_workspace(
    body: WorkspaceCreate,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:create")),
):
    """Create a new workspace (Tenant Admin or System Admin)."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    user_id = uuid.UUID(current_user["user_id"])
    return await workspace_service.create_workspace(
        db, tenant_id, user_id, body.name, body.icon, body.description, body.is_default
    )


@router.get("/{workspace_id}")
async def get_workspace(
    workspace_id: str,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:read")),
):
    """Get a single workspace with modules and user count."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    try:
        wid = uuid.UUID(workspace_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid workspace_id", "code": "invalid_id"})
    result = await workspace_service.get_workspace(db, tenant_id, wid)
    if result is None:
        raise HTTPException(404, detail={"detail": "Workspace not found", "code": "not_found"})
    return result


@router.put("/{workspace_id}")
async def update_workspace(
    workspace_id: str,
    body: WorkspaceUpdate,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:update")),
):
    """Update a workspace."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    try:
        wid = uuid.UUID(workspace_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid workspace_id", "code": "invalid_id"})
    result = await workspace_service.update_workspace(
        db, tenant_id, wid, body.name, body.icon, body.description, body.is_default, body.is_active
    )
    if result is None:
        raise HTTPException(404, detail={"detail": "Workspace not found", "code": "not_found"})
    return result


@router.delete("/{workspace_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_workspace(
    workspace_id: str,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:delete")),
):
    """Delete a workspace (soft delete)."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    try:
        wid = uuid.UUID(workspace_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid workspace_id", "code": "invalid_id"})
    deleted = await workspace_service.delete_workspace(db, tenant_id, wid)
    if not deleted:
        raise HTTPException(404, detail={"detail": "Workspace not found", "code": "not_found"})


@router.post("/{workspace_id}/modules")
async def set_modules(
    workspace_id: str,
    body: SetModules,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:configure_modules")),
):
    """Set modules for a workspace (replaces all existing)."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    try:
        wid = uuid.UUID(workspace_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid workspace_id", "code": "invalid_id"})
    modules = [{"module_key": m.module_key, "is_visible": m.is_visible, "menu_order": m.menu_order, "config": m.config} for m in body.modules]
    return await workspace_service.set_workspace_modules(db, tenant_id, wid, modules)


@router.post("/{workspace_id}/users", status_code=status.HTTP_201_CREATED)
async def assign_user(
    workspace_id: str,
    body: UserAssignment,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:assign_users")),
):
    """Assign a user to a workspace."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    user_id = uuid.UUID(current_user["user_id"])
    try:
        wid = uuid.UUID(workspace_id)
        target_uid = uuid.UUID(body.user_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid ID", "code": "invalid_id"})
    return await workspace_service.assign_user(db, tenant_id, wid, target_uid, body.role, assigned_by=user_id)


@router.delete("/{workspace_id}/users/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
async def remove_user(
    workspace_id: str,
    user_id: str,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("workspaces:assign_users")),
):
    """Remove a user from a workspace."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    try:
        wid = uuid.UUID(workspace_id)
        uid = uuid.UUID(user_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid ID", "code": "invalid_id"})
    removed = await workspace_service.remove_user(db, tenant_id, wid, uid)
    if not removed:
        raise HTTPException(404, detail={"detail": "User not assigned to this workspace", "code": "not_found"})