import json
import traceback

from flask import request, flash, redirect, url_for, render_template, jsonify

from . import main
from .. import db
from ..models import Brand, Item, Area, RoomFunction, Room
from ..utils.load import eager_load_room_relationships

@main.route('/settings', methods=['GET', 'POST'])
def settings():
    if request.method == 'POST':
        form = request.form

        try:
            state = json.loads(form['formState'])
        except Exception:
            flash("Invalid form state submitted. JSON decode failed.", "danger")
            traceback.print_exc()
            return redirect(url_for('main.settings'))

        try:
            with db.session.begin():
                # Sync each table and grab temp ID maps
                brand_map = Brand.sync_from_state(state.get("brands", []))
                type_map = Item.sync_from_state(state.get("types", []))
                section_map = Area.sync_from_state(state.get("sections", []))
                function_map = RoomFunction.sync_from_state(state.get("functions", []))

                # Fix up room foreign keys based on real IDs
                submitted_rooms = []
                for room in state.get("rooms", []):
                    room = dict(room)  # shallow copy
                    sid = room.get("section_id")
                    fid = room.get("function_id")

                    if sid is not None:
                        sid_key = str(sid)
                        if sid_key in section_map:
                            room["section_id"] = section_map[sid_key]

                    if fid is not None:
                        fid_key = str(fid)
                        if fid_key in function_map:
                            room["function_id"] = function_map[fid_key]

                    submitted_rooms.append(room)

                Room.sync_from_state(
                    submitted_rooms=submitted_rooms,
                    section_map=section_map,
                    function_map=function_map
                )

            flash("Changes saved.", "success")

        except Exception as e:
            flash(f"Error saving changes: {e}", "danger")

        return redirect(url_for('main.settings'))

    # === GET ===
    brands = db.session.query(Brand).order_by(Brand.name).all()
    types = db.session.query(Item).order_by(Item.description).all()
    sections = db.session.query(Area).order_by(Area.name).all()
    functions = db.session.query(RoomFunction).order_by(RoomFunction.description).all()
    rooms = eager_load_room_relationships(db.session.query(Room).order_by(Room.name)).all()

    return render_template('settings.html',
        title="Settings",
        brands=[b.serialize() for b in brands],
        types=[{"id": t.id, "name": t.description} for t in types],
        sections=[s.serialize() for s in sections],
        functions=[f.serialize() for f in functions],
        rooms=[r.serialize() for r in rooms]
    )

@main.route("/api/settings", methods=["POST"])
def api_settings():
    try:
        payload = request.get_json(force=True)
    except Exception as e:
        return jsonify({"error": "Invalid JSON"}), 400

    errors = []
    errors += Brand.validate_state(payload.get("brands", []))
    errors += Item.validate_state(payload.get("types", []))
    errors += Area.validate_state(payload.get("sections", []))
    errors += RoomFunction.validate_state(payload.get("functions", []))
    errors += Room.validate_state(payload.get("rooms", []))

    if errors:
        return jsonify({"errors": errors}), 400

    try:
        with db.session.begin():
            section_map = Area.sync_from_state(payload["sections"])
            function_map = RoomFunction.sync_from_state(payload["functions"])
            Brand.sync_from_state(payload["brands"])
            Item.sync_from_state(payload["types"])
            Room.sync_from_state(payload["rooms"], section_map, function_map)
    except Exception as e:
        db.session.rollback()
        return jsonify({"errors": [str(e)]}), 500

    return jsonify({"message": "Settings updated successfully."}), 200