import streamlit as st
from streamlit_agraph import agraph, Config
from qdrant_client import models
from ui_config import COLLECTION_PREFIX, GRAPH_COLORS
from ui_callbacks import switch_to_editor_callback

def render_graph_explorer(graph_service):
    st.header("🕸️ Graph Explorer")
    
    # Session State initialisieren
    if "graph_center_id" not in st.session_state: st.session_state.graph_center_id = None
    
    # Defaults speichern für Persistenz
    st.session_state.setdefault("graph_depth", 2)
    st.session_state.setdefault("graph_show_labels", True)
    # Defaults angepasst für BarnesHut (andere Skala!)
    st.session_state.setdefault("graph_spacing", 150) 
    st.session_state.setdefault("graph_gravity", -3000)

    col_ctrl, col_graph = st.columns([1, 4]) 
    
    with col_ctrl:
        st.subheader("Fokus")
        
        # Suche
        search_term = st.text_input("Suche Notiz", placeholder="Titel eingeben...")
        
        options = {}
        if search_term:
            hits, _ = graph_service.client.scroll(
                collection_name=f"{COLLECTION_PREFIX}_notes",
                scroll_filter=models.Filter(must=[models.FieldCondition(key="title", match=models.MatchText(text=search_term))]),
                limit=10
            )
            options = {h.payload['title']: h.payload['note_id'] for h in hits}
            
            if options:
                selected_title = st.selectbox("Ergebnisse:", list(options.keys()))
                if st.button("Laden", use_container_width=True):
                    st.session_state.graph_center_id = options[selected_title]
                    st.rerun()
        
        st.divider()
        
        # View Settings
        with st.expander("👁️ Ansicht & Layout", expanded=True):
            st.session_state.graph_depth = st.slider("Tiefe (Tier)", 1, 3, st.session_state.graph_depth)
            st.session_state.graph_show_labels = st.checkbox("Kanten-Beschriftung", st.session_state.graph_show_labels)
            
            st.markdown("**Physik (BarnesHut)**")
            # ACHTUNG: BarnesHut reagiert anders. Spring Length ist wichtig.
            st.session_state.graph_spacing = st.slider("Federlänge (Abstand)", 50, 500, st.session_state.graph_spacing, help="Wie lang sollen die Verbindungen sein?")
            st.session_state.graph_gravity = st.slider("Abstoßung (Gravity)", -20000, -1000, st.session_state.graph_gravity, help="Wie stark sollen sich Knoten abstoßen?")
            
            if st.button("Reset Layout"):
                st.session_state.graph_spacing = 150
                st.session_state.graph_gravity = -3000
                st.rerun()
                
        st.divider()
        st.caption("Legende (Top Typen)")
        for k, v in list(GRAPH_COLORS.items())[:8]:
            st.markdown(f"<span style='color:{v}'>●</span> {k}", unsafe_allow_html=True)

    with col_graph:
        center_id = st.session_state.graph_center_id
        
        if center_id:
            # Container für Action Bar OBERHALB des Graphen (Layout Fix)
            action_container = st.container()
            
            # Graph Laden
            with st.spinner(f"Lade Graph..."):
                # Daten laden (Cache wird genutzt)
                nodes, edges = graph_service.get_ego_graph(
                    center_id, 
                    depth=st.session_state.graph_depth,
                    show_labels=st.session_state.graph_show_labels
                )
                
                # Fetch Note Data für Button & Debug
                # Wir holen die Metadaten (inkl. path), was für den Editor-Callback reicht.
                note_data = graph_service._fetch_note_cached(center_id)

            # --- ACTION BAR RENDEREN ---
            with action_container:
                c_act1, c_act2 = st.columns([3, 1])
                with c_act1:
                    st.caption(f"Aktives Zentrum: **{center_id}**")
                with c_act2:
                    if note_data:
                        st.button("📝 Bearbeiten", 
                                  use_container_width=True, 
                                  on_click=switch_to_editor_callback, 
                                  args=(note_data,))
                    else:
                        st.error("Daten nicht verfügbar")
                
                # DATA INSPECTOR (Payload Debug)
                with st.expander("🕵️ Data Inspector (Payload Debug)", expanded=False):
                    if note_data:
                        st.json(note_data)
                        if 'path' not in note_data:
                            st.error("ACHTUNG: Feld 'path' fehlt im Qdrant-Payload! Update-Modus wird nicht funktionieren.")
                        else:
                            st.success(f"Pfad gefunden: {note_data['path']}")
                    else:
                        st.info("Keine Daten geladen.")

            if not nodes:
                st.warning("Keine Daten gefunden.")
            else:
                # --- CONFIGURATION (BarnesHut) ---
                # Height-Trick für Re-Render (da key-Parameter nicht funktioniert)
                # Ändere Height minimal basierend auf Gravity
                dyn_height = 800 + (abs(st.session_state.graph_gravity) % 5)

                config = Config(
                    width=1000,
                    height=dyn_height, 
                    directed=True, 
                    physics={
                        "enabled": True,
                        # BarnesHut ist der Standard und stabilste Solver für Agraph
                        "solver": "barnesHut",
                        "barnesHut": {
                            "gravitationalConstant": st.session_state.graph_gravity,
                            "centralGravity": 0.3,
                            "springLength": st.session_state.graph_spacing,
                            "springConstant": 0.04,
                            "damping": 0.09,
                            "avoidOverlap": 0.1
                        },
                        "stabilization": {"enabled": True, "iterations": 600}
                    },
                    hierarchical=False,
                    nodeHighlightBehavior=True,
                    highlightColor="#F7A7A6",
                    collapsible=False
                )
                
                return_value = agraph(nodes=nodes, edges=edges, config=config)
                
                # Interaktions-Logik
                if return_value:
                    if return_value != center_id:
                        # Navigation: Neues Zentrum setzen
                        st.session_state.graph_center_id = return_value
                        st.rerun()
                    else:
                        # Klick auf das Zentrum selbst
                        st.toast(f"Zentrum: {return_value}")
                            
        else:
            st.info("👈 Bitte wähle links eine Notiz aus.")