import streamlit as st
import requests
import json

st.title("PubChem Data Viewer")

if st.session_state.get('selected_cas', None) is None:
    st.warning("Nessun CAS Number selezionato. Torna alla pagina principale per effettuare una ricerca.")
    st.stop()
else:
    cas_number = st.session_state.selected_cas

# Make API request
with st.spinner("Fetching data from PubChem..."):
    try:
        response = requests.post(
            "https://api.cosmoguard.it/api/v1/common/pubchem",
            json={"cas": cas_number}
        )
        response.raise_for_status()
        result = response.json()
    except requests.exceptions.RequestException as e:
        st.error(f"Error fetching data: {e}")
        st.stop()

# Check if request was successful
if not result.get("success", False):
    st.error(f"API Error: {result.get('error', 'Unknown error')}")
    st.stop()

data = result.get("data", {})

# Display substance header
st.subheader(f"{data.get('first_pubchem_name', 'Unknown').title()}")

# Basic info container
with st.container(border=True):
    col1, col2, col3 = st.columns(3)
    with col1:
        st.caption("CAS Number")
        st.write(data.get("CAS", "—"))
    with col2:
        st.caption("PubChem CID")
        st.write(data.get("CID", "—"))
    with col3:
        if data.get("pubchem_link"):
            st.link_button("View on PubChem", data.get("pubchem_link"))

st.divider()

# Physical/Chemical Properties
st.subheader("Physical & Chemical Properties")

with st.container(border=True):
    prop_col1, prop_col2, prop_col3, prop_col4 = st.columns(4)

    with prop_col1:
        st.metric("Molecular Weight", f"{data.get('MolecularWeight', '—')} g/mol" if data.get('MolecularWeight') else "—")

    with prop_col2:
        st.metric("XLogP", data.get('XLogP', '—'))

    with prop_col3:
        st.metric("Exact Mass", data.get('ExactMass', '—'))

    with prop_col4:
        st.metric("TPSA", f"{data.get('TPSA', '—')} Ų" if data.get('TPSA') else "—")

st.divider()

# Melting Point
melting_points = data.get("Melting Point", [])
if melting_points:
    st.subheader("Melting Point")

    with st.expander(f"View {len(melting_points)} reference(s)", expanded=True):
        for idx, mp in enumerate(melting_points):
            with st.container(border=True):
                st.markdown(f"**Reference {idx + 1}**")

                if mp.get("Value"):
                    st.info(mp.get("Value"))

                if mp.get("Reference"):
                    st.caption(f"📚 {mp.get('Reference')}")

                if mp.get("Description"):
                    st.caption(f"ℹ️ {mp.get('Description')}")

                if mp.get("ReferenceNumber"):
                    st.caption(f"Ref #: {mp.get('ReferenceNumber')}")

# Dissociation Constants
dissociation_constants = data.get("Dissociation Constants", [])
if dissociation_constants:
    st.divider()
    st.subheader("Dissociation Constants (pKa)")

    with st.expander(f"View {len(dissociation_constants)} reference(s)", expanded=True):
        for idx, dc in enumerate(dissociation_constants):
            with st.container(border=True):
                st.markdown(f"**Reference {idx + 1}**")

                if dc.get("Value"):
                    # Check if it's a dictionary or string
                    value = dc.get("Value")
                    if isinstance(value, dict):
                        st.code(json.dumps(value, indent=2))
                    else:
                        st.info(value)

                if dc.get("Reference"):
                    st.caption(f"📚 {dc.get('Reference')}")

                if dc.get("ReferenceNumber"):
                    st.caption(f"Ref #: {dc.get('ReferenceNumber')}")

# Raw JSON viewer
st.divider()
with st.expander("View Raw JSON Response"):
    st.json(result)