from fastapi import APIRouter, Depends, Request, Form, HTTPException
from fastapi.responses import HTMLResponse, RedirectResponse, JSONResponse
import json

from deps import current_user, admin_required
from services.config_loader import ConfigService

router = APIRouter()

@router.get("/config", response_class=HTMLResponse)
async def config_editor(req: Request, user = Depends(admin_required)):
    """
    Show the JSON Config Editor.
    """
    raw_config = ConfigService.get_raw_config()
    
    return req.app.state.render(
        req,
        "admin/config_editor.html",
        config_json=raw_config,
        page_title="Config Editor"
    )

@router.post("/config/save")
async def save_config(
    req: Request,
    config_json: str = Form(...),
    user = Depends(admin_required)
):
    """
    Save the JSON Configuration.
    """
    try:
        # 1. Parse JSON to validate syntax
        new_config = json.loads(config_json)
        
        # 2. Logic Validation (basic)
        if "roles" not in new_config:
             raise ValueError("JSON must contain top-level 'roles' key.")
        
        # 3. Save via Service (handles atomic write & backup)
        success = ConfigService.save_config(new_config)
        
        if success:
            # Flash success via session if available, or return logic
            # Assuming flash() helper is available in main scope or we add it manually to session
            # We can reuse the flash helper logic if accessible, otherwise direct session append
            flashes = req.session.get("_flashes", [])
            flashes.append({"msg": "Configuration saved successfully. Backup created.", "cat": "success"})
            req.session["_flashes"] = flashes
            
            return RedirectResponse("/admin/config", status_code=302)
        else:
            raise Exception("Write operation failed.")

    except json.JSONDecodeError as e:
        error_msg = f"Invalid JSON: {e}"
        return req.app.state.render(
            req, 
            "admin/config_editor.html", 
            config_json=config_json, 
            error=error_msg
        )
    except Exception as e:
        error_msg = f"Error saving config: {e}"
        return req.app.state.render(
            req, 
            "admin/config_editor.html", 
            config_json=config_json, 
            error=error_msg
        )