app/chat.py

import streamlit as st
from streamlit_chat import message
from streamlit_mic_recorder import speech_to_text
import base64
import asyncio
import edge_tts
import gtts
from hashlib import md5
from io import BytesIO
from app.db import supabase
import os
import glob
import time
from dotenv import load_dotenv
from uuid import uuid4

load_dotenv()

# Bersihkan cache audio lama (opsional)
def clean_old_cache(tts_dir="cache_tts", max_age_hours=12):
    now = time.time()
    for f in glob.glob(os.path.join(tts_dir, "*.mp3")):
        if os.stat(f).st_mtime < now - max_age_hours * 3600:
            os.remove(f)

# Jalankan pembersihan saat startup
clean_old_cache()

def save_feedback_to_supabase(feedback_text):
    try:
        data = {"message": feedback_text}
        supabase.table("feedback").insert(data).execute()
        return True
    except Exception as e:
        st.error(f"Gagal menyimpan feedback: {e}")
        return False

def initialize_session_state():
    if 'history' not in st.session_state:
        st.session_state['history'] = []
    if 'generated' not in st.session_state:
        st.session_state['generated'] = ["Halo! Saya bisa membantu anda menjawab pertanyaan seputar Politeknik Negeri Padang!"]
    if 'past' not in st.session_state:
        st.session_state['past'] = ["Hai! 👋"]
    if 'data_len' not in st.session_state:
        st.session_state['data_len'] = 0
    if 'vector_store' not in st.session_state:
        st.session_state['vector_store'] = None
    if 'should_speak' not in st.session_state:
        st.session_state['should_speak'] = True
    if 'input_text' not in st.session_state:
        st.session_state['input_text'] = ""
    if 'tts_output' not in st.session_state:
        st.session_state['tts_output'] = ""
    if 'tts_played' not in st.session_state:
        st.session_state['tts_played'] = True  
    # Jangan auto-generate session_id di sini agar tidak membuat sesi baru tiap refresh.
    # Session akan dibuat/ditetapkan hanya oleh ensure_active_session() berdasarkan data di DB.

def _current_user():
    return st.session_state.get('user')

def save_message_to_supabase(user_id: str, session_id: str, role: str, content: str):
    try:
        supabase.table("chat_messages").insert({
            "user_id": user_id,
            "session_id": session_id,
            "role": role,
            "content": content,
        }).execute()
    except Exception as e:
        # Non-fatal in UI; log to console
        print(f"Gagal menyimpan pesan: {e}")

def load_history_from_supabase(user_id: str, session_id: str, limit: int = 100):
    try:
        res = (
            supabase
            .table("chat_messages")
            .select("role, content, created_at")
            .eq("user_id", user_id)
            .eq("session_id", session_id)
            .order("created_at", desc=False)
            .limit(limit)
            .execute()
        )
        rows = getattr(res, 'data', None) or []
        past, generated, history = [], [], []
        # Bootstrap greeting if empty
        if not rows:
            return past, generated, history
        for r in rows:
            if r["role"] == "user":
                past.append(r["content"])
            elif r["role"] == "assistant":
                generated.append(r["content"])
            # Build history pairs progressively when both sides exist
        # Reconstruct history as list of (user, assistant) tuples
        for i in range(min(len(past), len(generated))):
            history.append((past[i], generated[i]))
        return past, generated, history
    except Exception as e:
        print(f"Gagal memuat riwayat: {e}")
        return [], [], []

def create_chat_session(user_id: str, title: str = None) -> str:
    """Create a new chat session for user and return session_id."""
    try:
        payload = {"user_id": user_id}
        if title:
            payload["title"] = title
        res = (
            supabase
            .table("chat_sessions")
            .insert(payload)
            .execute()
        )
        data = getattr(res, 'data', None) or []
        if isinstance(data, list) and data:
            return data[0].get('id') or str(uuid4())
        if isinstance(data, dict) and data.get('id'):
            return data['id']
        return str(uuid4())
    except Exception as e:
        print(f"Gagal membuat sesi: {e}")
        return str(uuid4())

def list_chat_sessions(user_id: str, limit: int = 20):
    """List recent chat sessions for a user, newest first."""
    try:
        res = (
            supabase
            .table("chat_sessions")
            .select("id, title, created_at")
            .eq("user_id", user_id)
            .order("created_at", desc=True)
            .limit(limit)
            .execute()
        )
        data = getattr(res, 'data', None) or []
        return data
    except Exception as e:
        print(f"Gagal memuat daftar sesi: {e}")
        return []

def delete_chat_session(user_id: str, session_id: str) -> bool:
    """Delete a single chat session and its messages for a user."""
    try:
        # Delete messages first (FK safety)
        try:
            supabase.table("chat_messages").delete().eq("user_id", user_id).eq("session_id", session_id).execute()
        except Exception as e:
            # If messages table missing/empty, continue
            print(f"Info: hapus pesan sesi gagal/abaikan: {e}")
        # Delete the session row
        supabase.table("chat_sessions").delete().eq("user_id", user_id).eq("id", session_id).execute()
        return True
    except Exception as e:
        print(f"Gagal menghapus sesi: {e}")
        return False

def delete_all_chat_sessions(user_id: str) -> bool:
    """Delete all chat sessions and all messages for a user."""
    try:
        # Delete all messages for user
        try:
            supabase.table("chat_messages").delete().eq("user_id", user_id).execute()
        except Exception as e:
            print(f"Info: hapus semua pesan gagal/abaikan: {e}")
        # Delete all sessions for user
        supabase.table("chat_sessions").delete().eq("user_id", user_id).execute()
        return True
    except Exception as e:
        print(f"Gagal menghapus semua sesi: {e}")
        return False

def ensure_chat_session(user_id: str, session_id: str, title: str = None) -> str:
    """Ensure a chat session with given id exists; create if missing. Returns the session id."""
    try:
        # Check existence
        chk = (
            supabase
            .table("chat_sessions")
            .select("id")
            .eq("id", session_id)
            .limit(1)
            .execute()
        )
        data = getattr(chk, 'data', None) or []
        if (isinstance(data, list) and data) or (isinstance(data, dict) and data.get('id')):
            return session_id
    except Exception:
        pass
    # Create with explicit id
    try:
        payload = {"id": session_id, "user_id": user_id}
        if title:
            payload["title"] = title
        ins = (
            supabase
            .table("chat_sessions")
            .insert(payload)
            .execute()
        )
        data = getattr(ins, 'data', None) or []
        if isinstance(data, list) and data:
            return data[0].get('id', session_id)
        if isinstance(data, dict) and data.get('id'):
            return data.get('id', session_id)
        return session_id
    except Exception as e:
        print(f"Gagal memastikan sesi: {e}")
        return session_id

def _generate_session_title_from_text(text: str, max_len: int = 60) -> str:
    """Generate a concise session title from the first user message."""
    if not text:
        return "Percakapan Baru"
    # Normalize whitespace and strip
    t = " ".join(text.strip().split())
    # Remove surrounding quotes or trailing punctuation if too noisy
    t = t.strip('"\'\u201c\u201d')
    if len(t) > max_len:
        t = t[:max_len - 1].rstrip() + "…"
    return t or "Percakapan Baru"

def update_chat_session_title_if_empty(user_id: str, session_id: str, candidate_title: str) -> None:
    """If session has no title, set it to candidate_title."""
    try:
        chk = (
            supabase
            .table("chat_sessions")
            .select("id, title")
            .eq("id", session_id)
            .eq("user_id", user_id)
            .limit(1)
            .execute()
        )
        rows = getattr(chk, 'data', None) or []
        title_val = None
        if isinstance(rows, list) and rows:
            title_val = rows[0].get("title")
        elif isinstance(rows, dict):
            title_val = rows.get("title")
        if not title_val:
            safe_title = _generate_session_title_from_text(candidate_title)
            (
                supabase
                .table("chat_sessions")
                .update({"title": safe_title})
                .eq("id", session_id)
                .eq("user_id", user_id)
                .execute()
            )
    except Exception as e:
        # Non-fatal; just log
        print(f"Gagal mengatur judul sesi: {e}")

# edge-tts fallback (cadangan)
async def generate_audio_edge(text, path, voice="id-ID-GadisNeural"):
    communicate = edge_tts.Communicate(text, voice=voice)
    await communicate.save(path)

# fungsi utama TTS dengan fallback
def text_to_speech(text):
    cache_dir = "cache_tts"
    os.makedirs(cache_dir, exist_ok=True)
    filename = f"{md5(text.encode()).hexdigest()}.mp3"
    path = os.path.join(cache_dir, filename)

    if not os.path.exists(path):
        try:
            # ✅ Utama: gTTS
            tts = gtts.gTTS(text, lang="id")
            tts.save(path)
        except Exception as e:
            print(f"[gTTS gagal] {e}")
            try:
                # ✅ Cadangan: edge-tts
                asyncio.run(generate_audio_edge(text, path))
            except Exception as e2:
                print(f"[Edge-TTS juga gagal] {e2}")
                st.warning("🔇 Gagal membuat audio TTS.")
                return ""

    try:
        with open(path, "rb") as audio_file:
            audio_base64 = base64.b64encode(audio_file.read()).decode()

        return f"""
        <audio autoplay>
            <source src="data:audio/mp3;base64,{audio_base64}" type="audio/mp3">
        </audio>
        """
    except Exception as e:
        print(f"[Error saat membaca audio] {e}")
        return ""

def conversation_chat(query, chain, history):
    # Save user message first
    user = _current_user()
    if user:
        try:
            save_message_to_supabase(user_id=user["id"], session_id=st.session_state.get('session_id'), role="user", content=query)
        except Exception:
            pass
        # Try auto-name the session on first user message
        try:
            update_chat_session_title_if_empty(user_id=user["id"], session_id=st.session_state.get('session_id'), candidate_title=query)
        except Exception:
            pass
    result = chain({"question": query, "chat_history": history})
    answer = result["answer"]
    history.append((query, answer))
    # Save assistant reply
    if user:
        try:
            save_message_to_supabase(user_id=user["id"], session_id=st.session_state.get('session_id'), role="assistant", content=answer)
        except Exception:
            pass
    return answer

def display_chat_history(chain):
    reply_container = st.container()

    user_input_obj = st.chat_input("Masukkan pertanyaan", key="chat_input_field")

    col2, col3 = st.columns([1, 1])

    # Tombol TTS Aktif / Nonaktif
    with col2:
        if st.button("🔊 Text-to-Speech Aktif" if st.session_state['should_speak'] else "🔇 Text-to-Speech Nonaktif", 
                     key="toggle_tts", 
                     help="Aktifkan/Nonaktifkan Text-to-Speech", 
                     use_container_width=True):
            st.session_state['should_speak'] = not st.session_state['should_speak']
            st.rerun()

    # Tombol Input Suara
    with col3:
        stt_text = speech_to_text(
            start_prompt="🎤 Input Suara",
            stop_prompt="🛑 Stop",
            language='id',
            just_once=True,
            key='stt_input',
            use_container_width=True,
        )

    # Jika ada STT
    if stt_text:
        st.session_state.input_text = stt_text
        st.rerun()

    # Ambil input user
    user_input = user_input_obj or st.session_state.get("input_text", "")

    if user_input:
        with st.spinner('Sedang membuat jawaban...'):
            output = conversation_chat(user_input, chain, st.session_state['history'])

        st.session_state['past'].append(user_input)
        st.session_state['generated'].append(output)
        st.session_state.input_text = ""

        # Reset flag supaya TTS siap memutar lagi
        if st.session_state['should_speak'] and output:
            st.session_state['tts_output'] = output
            st.session_state['tts_played'] = False

    # If user just logged in and no local history, try loading from DB
    if not st.session_state['history']:
        user = _current_user()
        if user:
            past, generated, history = load_history_from_supabase(user_id=user['id'], session_id=st.session_state.get('session_id'))
            if past or generated:
                st.session_state['past'] = past or st.session_state['past']
                st.session_state['generated'] = generated or st.session_state['generated']
                st.session_state['history'] = history or st.session_state['history']

    # Tampilkan Riwayat Chat
    if st.session_state['generated']:
        with reply_container:
            for i in range(len(st.session_state['generated'])):
                message(st.session_state["past"][i], is_user=True, key=str(i) + '_user', avatar_style="no-avatar")
                message(st.session_state["generated"][i], key=str(i), avatar_style="no-avatar")

    # Pemutaran TTS
    if st.session_state.get('tts_output') and not st.session_state.get('tts_played'):
        st.markdown(text_to_speech(st.session_state['tts_output']), unsafe_allow_html=True)
        st.session_state['tts_played'] = True