import streamlit as st
import re

st.set_page_config(
    page_title="Text Case Converter",
    layout="centered",
)

# ---------- Cool Tech Theme ----------
st.markdown("""
<style>
body {
    background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
}
.main { background: transparent; }

.card {
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(10px);
    border-radius: 22px;
    padding: 28px;
    box-shadow: 0 0 25px rgba(0,255,255,0.25);
    max-width: 720px;
    margin: auto;
}
h1, p, label, h3 {
    color: #e5f9ff !important;
    text-align: center;
}
textarea {
    border-radius: 14px !important;
    background: #020617 !important;
    color: #e5f9ff !important;
    border: 1px solid #0ea5e9 !important;
}
.stButton>button {
    width: 100%;
    height: 45px;
    border-radius: 12px;
    border: none;
    background: linear-gradient(90deg, #0ea5e9, #22d3ee);
    color: #020617;
    font-weight: bold;
    transition: 0.25s ease;
}
.stButton>button:hover {
    transform: scale(1.06);
    box-shadow: 0 0 15px #22d3ee;
}
.footer {
    text-align: center;
    color: #94a3b8;
    margin-top: 15px;
    font-size: 13px;
}
</style>
""", unsafe_allow_html=True)

# ---------- Helper Function ----------
def paragraph_style(text):
    sentences = re.split(r'(?<=[.!?])\s*', text.strip())
    fixed = []
    for s in sentences:
        s = s.strip()
        if not s:
            continue
        if not s.endswith(('.', '!', '?')):
            s += '.'
        fixed.append(s.capitalize())
    return " ".join(fixed)

# ---------- UI ----------
st.markdown("<div class='card'>", unsafe_allow_html=True)

st.markdown("<h1>Text Case Converter</h1>", unsafe_allow_html=True)
st.markdown("<p>Change your text instantly</p>", unsafe_allow_html=True)

text = st.text_area("", placeholder="Type or paste your text here...", height=180)

st.markdown("### Choose Conversion")

col1, col2, col3 = st.columns(3)

with col1:
    if st.button("UPPERCASE"):
        st.session_state["out"] = text.upper()
    if st.button("lowercase"):
        st.session_state["out"] = text.lower()

with col2:
    if st.button("Title Case"):
        st.session_state["out"] = text.title()
    if st.button("Sentence Case"):
        st.session_state["out"] = text.capitalize()

with col3:
    if st.button("Toggle Case"):
        st.session_state["out"] = text.swapcase()
    if st.button("Paragraph Style"):
        st.session_state["out"] = paragraph_style(text)

if "out" in st.session_state:
    st.markdown("### Output")
    st.text_area("", st.session_state["out"], height=150)

st.markdown("</div>", unsafe_allow_html=True)
st.markdown("<div class='footer'>Made with ❤️ using Streamlit</div>", unsafe_allow_html=True)