Source code for streamlit_app.sections.sidebar

"""Sidebar, session state, and logo for the Streamlit app."""

from pathlib import Path
from typing import Optional

import streamlit as st

from config import SUPPORTED_LANGUAGE_CODES
from i18n import initialize_i18n, t
from streamlit_app.theme import get_streamlit_theme

# Key for "switch to X" button label per language code
_LANG_MENU_KEYS: dict[str, str] = {
    "es": "menu.language_spanish",
    "en": "menu.language_english",
    "de": "menu.language_german",
}

# Layout-only CSS (colors come from theme via get_main_css in app)
_SIDEBAR_LAYOUT_CSS = """
    <style>
    .sidebar-brand {
        text-align: center;
        padding: 0.5rem 0 1rem 0;
        border-bottom: 2px solid rgba(255,255,255,0.08);
        margin-bottom: 1rem;
    }
    .sidebar-brand h2 { font-size: 1.4rem; font-weight: 700; margin: 0; letter-spacing: -0.02em; }
    .sidebar-brand .version-badge {
        display: inline-block;
        font-size: 0.7rem;
        padding: 0.2rem 0.5rem;
        border-radius: 12px;
        margin-top: 0.35rem;
        font-weight: 600;
    }
    .sidebar-section {
        margin: 1.25rem 0 0.75rem 0;
        font-size: 0.8rem;
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 0.05em;
    }
    div[data-testid="stSidebar"] [data-testid="stRadio"] > label { font-size: 0.9rem; }
    </style>
"""


@st.cache_data
def _cached_logo_bytes(path: str) -> Optional[bytes]:
    """Load logo from disk once; cache for reruns."""
    p = Path(path)
    return p.read_bytes() if p.exists() else None




[docs]
def initialize_session_state() -> None:
    """Initialize Streamlit session state variables (language from config env)."""
    if "language" not in st.session_state:
        from config import get_env_from_schema

        st.session_state.language = get_env_from_schema("LANGUAGE")
    if "results" not in st.session_state:
        st.session_state.results = []
    if "plot_counter" not in st.session_state:
        st.session_state.plot_counter = 0






[docs]
def cycle_language() -> None:
    """Cycle to the next supported language (es -> en -> de -> es)."""
    codes = list(SUPPORTED_LANGUAGE_CODES)
    try:
        idx = codes.index(st.session_state.language)
    except ValueError:
        idx = 0
    next_idx = (idx + 1) % len(codes)
    st.session_state.language = codes[next_idx]
    initialize_i18n(st.session_state.language)






[docs]
def setup_sidebar(version: str) -> str:
    """
    Setup and render the sidebar with language selector and mode options.

    Args:
        version: Application version string to display in the sidebar.

    Returns:
        Selected operation mode (e.g. 'normal_fitting', 'watch_data').
    """
    with st.sidebar:
        st.markdown(_SIDEBAR_LAYOUT_CSS, unsafe_allow_html=True)
        st.markdown(
            f"""
            <div class="sidebar-brand">
                <h2>📊 RegressionLab</h2>
                <span class="version-badge">v{version}</span>
            </div>
        """,
            unsafe_allow_html=True,
        )

        codes = list(SUPPORTED_LANGUAGE_CODES)
        try:
            current_idx = codes.index(st.session_state.language)
        except ValueError:
            current_idx = 0
        next_idx = (current_idx + 1) % len(codes)
        next_code = codes[next_idx]
        next_lang_label = t(_LANG_MENU_KEYS[next_code])
        if st.button(next_lang_label, key="lang_toggle", width="stretch"):
            cycle_language()
            st.rerun()

        section_title = t("help.fitting_modes").replace("\n", "").strip()
        st.markdown(
            f'<p class="sidebar-section">{section_title}</p>', unsafe_allow_html=True
        )

        mode_options = [
            t("menu.normal_fitting"),
            t("menu.multiple_datasets"),
            t("menu.checker_fitting"),
            t("menu.total_fitting"),
            t("menu.view_data"),
        ]
        operation_mode = st.radio(
            t("help.fitting_modes"),
            mode_options,
            label_visibility="collapsed",
        )

        return operation_mode