"""
student_login.py
----------------
學生登入元件。
用 clientside callback 直接讀 localStorage，避免 Python callback 時序問題。
"""
from __future__ import annotations
import dash
from dash import html, dcc, callback, Input, Output, State, no_update, clientside_callback
import dash_mantine_components as dmc
from dash_iconify import DashIconify


def create_student_store() -> dcc.Store:
    return dcc.Store(id="student-id-store", storage_type="local", data="")


def create_login_modal() -> html.Div:
    return html.Div([
        dmc.Modal(
            id="student-login-modal",
            opened=False,
            centered=True,
            closeOnClickOutside=False,
            closeOnEscape=False,
            withCloseButton=False,
            title=dmc.Group([
                DashIconify(icon="tabler:school", height=24),
                dmc.Text("歡迎使用數學學習平台", fw=700, size="lg"),
            ], gap="xs"),
            children=[
                dmc.Text(
                    "請輸入您的學號，系統將記錄您的學習進度。",
                    size="sm", c="dimmed", mb="md",
                ),
                dmc.TextInput(
                    id="student-id-input",
                    label="學號",
                    placeholder="例如：B11234567",
                    leftSection=DashIconify(icon="tabler:id-badge", height=16),
                    required=True,
                    mb="md",
                ),
                dmc.Alert(
                    id="student-login-error",
                    children="",
                    color="red",
                    variant="light",
                    style={"display": "none"},
                    mb="sm",
                ),
                dmc.Button(
                    "開始學習",
                    id="student-login-btn",
                    fullWidth=True,
                    leftSection=DashIconify(icon="tabler:arrow-right", height=16),
                ),
            ],
            size="sm",
        ),
    ])


def create_student_badge() -> html.Div:
    return html.Div(
        id="student-badge",
        style={"display": "none"},
        children=dmc.Group([
            dmc.Badge(
                id="student-badge-text",
                leftSection=DashIconify(icon="tabler:user", height=12),
                variant="light",
                color="teal",
                size="sm",
            ),
            dmc.ActionIcon(
                DashIconify(icon="tabler:logout", height=14),
                id="student-logout-btn",
                size="sm",
                variant="subtle",
                color="gray",
            ),
        ], gap=4),
    )


@callback(
    Output("student-id-store", "data", allow_duplicate=True),
    Input("student-logout-btn", "n_clicks"),
    prevent_initial_call=True,
)
def logout_student(n_clicks):
    if n_clicks:
        return ""
    return no_update


# ─── Clientside：頁面載入時直接從 localStorage 判斷是否開啟 modal ───────────
# 完全在瀏覽器端執行，不需要等 Python callback，沒有時序問題

clientside_callback(
    """
    function(storeData) {
        try {
            if (storeData && storeData !== "") {
                return false;
            }
            return true;
        } catch(e) {
            return true;
        }
    }
    """,
    Output("student-login-modal", "opened"),
    Input("student-id-store", "data"),
    prevent_initial_call=False,
)


# ─── Python callback：按下「開始學習」後儲存學號 ──────────────────────────

@callback(
    Output("student-id-store", "data"),
    Output("student-login-error", "children"),
    Output("student-login-error", "style"),
    Input("student-login-btn", "n_clicks"),
    State("student-id-input", "value"),
    prevent_initial_call=True,
)
def save_student_id(n_clicks, input_value):
    sid = (input_value or "").strip()
    if not sid:
        return no_update, "請輸入學號", {"display": "block"}

    # 寫入 Firebase
    try:
        from firebase_progress import upsert_student
        upsert_student(sid)
    except Exception as e:
        print(f"[Firebase] upsert_student 失敗：{e}")

    return sid, "", {"display": "none"}


# ─── 學生 badge 更新 ─────────────────────────────────────────────────────

@callback(
    Output("student-badge", "style"),
    Output("student-badge-text", "children"),
    Input("student-id-store", "data"),
)
def update_badge(student_id):
    if student_id:
        return {"display": "inline-flex", "alignItems": "center"}, f"學號：{student_id}"
    return {"display": "none"}, ""