app.py

import os, json, re
from typing import List, Dict
from fastapi import FastAPI, Request
from fastapi.staticfiles import StaticFiles
from fastapi.responses import HTMLResponse, FileResponse
from pydantic import BaseModel

import faiss
import numpy as np
from sentence_transformers import SentenceTransformer
from groq import Groq
from gtts import gTTS

# ═══════════════════════════════════════════
# CONFIG
# ═══════════════════════════════════════════
GROQ_LLM_KEY     = os.environ.get("GROQ_LLM_KEY")
GROQ_WHISPER_KEY = os.environ.get("GROQ_WHISPER_KEY")

EMBED_MODEL   = "all-MiniLM-L6-v2"
LLM_MODEL     = "llama-3.3-70b-versatile"
TRANS_MODEL   = "llama-3.1-8b-instant"
WHISPER_MODEL = "whisper-large-v3"
DIM = 384

VALID_DOMAINS = {"islamic", "inheritance", "harassment", "general", "verify"}

DEPARTMENTS = {
    "muslim family laws ordinance": "Union Council / Family Court",
    "dowry": "Family Court or Police",
    "succession": "Family Court + Revenue Office",
    "harassment of women at workplace": "Ombudsperson",
    "domestic violence": "District Women Protection Committee",
    "penal code": "Local Police Station",
    "constitution": "High Court",
    "family courts": "Family Court",
}

# ═══════════════════════════════════════════
# LOAD EVERYTHING AT STARTUP
# ═══════════════════════════════════════════
print("⏳ Loading...")
embedder = SentenceTransformer(EMBED_MODEL)
index = faiss.read_index("faiss_index.bin")

with open("chunks_meta.json", "r") as f:
    chunk_metas = json.load(f)

chunk_texts = []
with open("all_chunks.jsonl", "r") as f:
    for line in f:
        chunk_texts.append(json.loads(line.strip())["text"])

llm_client = Groq(api_key=GROQ_LLM_KEY)
whisper_client = Groq(api_key=GROQ_WHISPER_KEY)

print(f"✅ Ready: {index.ntotal} vectors")

# ═══════════════════════════════════════════
# HELPERS
# ═══════════════════════════════════════════
def is_urdu_script(text: str) -> bool:
    for ch in text:
        if ('\u0600' <= ch <= '\u06FF' or '\u0750' <= ch <= '\u077F' or
            '\uFB50' <= ch <= '\uFDFF' or '\uFE70' <= ch <= '\uFEFF'):
            return True
    return False

def detect_language(text: str) -> str:
    if is_urdu_script(text): return "urdu"
    roman = {"kya","hai","mera","talaq","mehr","virasat","shohar","biwi",
             "case","police","court","ka","ki","ke","ko","se","mein",
             "karna","kaise","nahi","haan","batao","chahiye","hoga","apna"}
    words = text.lower().split()
    if not words: return "en"
    hits = sum(1 for w in words if w in roman)
    return "roman_urdu" if (hits/len(words)) > 0.12 else "en"

def translate(text: str, target: str) -> str:
    if target == "urdu":
        prompt = f"Translate to proper Urdu (Arabic script). Simple Pakistani Urdu:\n\n{text}"
    elif target == "roman":
        prompt = f"Translate to Roman Urdu (English alphabet):\n\n{text}"
    elif target == "en":
        src = "Urdu" if is_urdu_script(text) else "Roman Urdu"
        prompt = f"Translate this {src} to English:\n\n{text}"
    else: return text

    resp = llm_client.chat.completions.create(
        model=TRANS_MODEL,
        messages=[{"role": "user", "content": prompt}],
        temperature=0.2, max_tokens=1200
    )
    return resp.choices[0].message.content.strip()

def retrieve_chunks(query: str, top_k: int = 5, domain_filter: str = None):
    q_vec = embedder.encode([query], normalize_embeddings=True).astype("float32")
    scores, indices = index.search(q_vec, top_k * 3)
    results = []
    for score, idx in zip(scores[0], indices[0]):
        if idx == -1: continue
        meta = chunk_metas[idx]
        if domain_filter and domain_filter != "verify":
            if meta["domain"] != domain_filter and meta["domain"] != "general":
                continue
        results.append((score, chunk_texts[idx], meta))
        if len(results) >= top_k: break
    if not results: return [], []
    return [r[1] for r in results], [r[2] for r in results]

def infer_dept(meta_list):
    for meta in meta_list:
        act = meta.get("act_name","").lower()
        for k,v in DEPARTMENTS.items():
            if k in act: return v
    return "Relevant District Court"

def generate_answer(query: str, domain: str, mode: str, lang: str) -> dict:
    if domain not in VALID_DOMAINS:
        return {"error": "This is outside my domain.", "verdict": "OUT OF DOMAIN"}

    d_filter = None if domain == "verify" else domain
    texts, metas = retrieve_chunks(query, top_k=5, domain_filter=d_filter)

    if not texts:
        return {
            "plain_answer": "This specific point is not in my verified database.",
            "law_cited": "N/A",
            "verdict": "NOT IN DATABASE",
            "where_to_file": infer_dept([{"act_name": domain}]),
            "department": infer_dept([{"act_name": domain}])
        }

    context = "\n\n---\n\n".join([
        f"CHUNK {i+1} [Act: {m['act_name']}, Sec: {m['section']}, Year: {m['year']}]:\n{t}"
        for i,(t,m) in enumerate(zip(texts,metas))
    ])

    sys_msg = """You are a Pakistani legal educator. Rules:
1) ONLY use provided chunks. 2) No answer → NOT IN DATABASE + dept.
3) ALWAYS cite Act, Section, Year. 4) No paraphrasing beyond simplification.
5) NEVER combine laws. 6) Domain lock.

FORMAT:
PLAIN ANSWER: [1-3 sentences]
LAW CITED: [Act, Section, Year]
VERDICT: VERIFIED / NOT IN DATABASE
WHERE TO FILE: [Exact department + step]"""

    if mode == "verify":
        sys_msg = """Fact-checker. Use ONLY chunks.
VERDICT: VERIFIED / FARCE / NOT IN DATABASE
LAW CITED: [Act, Section, Year]
EVIDENCE: [Quote]"""

    dept_hint = f"\n\n[DIRECT TO]: {infer_dept(metas)}"
    messages = [
        {"role": "system", "content": sys_msg + dept_hint},
        {"role": "user", "content": f"[CHUNKS]\n{context}\n\n[QUERY]\n{query}"}
    ]

    resp = llm_client.chat.completions.create(
        model=LLM_MODEL, messages=messages, temperature=0.1, max_tokens=1200
    )
    raw = resp.choices[0].message.content.strip()

    # Parse structured response
    parsed = {"plain_answer": "", "law_cited": "", "verdict": "VERIFIED", 
              "where_to_file": "", "department": infer_dept(metas)}

    for line in raw.split('\n'):
        if line.startswith("PLAIN ANSWER:"):
            parsed["plain_answer"] = line.replace("PLAIN ANSWER:", "").strip()
        elif line.startswith("LAW CITED:"):
            parsed["law_cited"] = line.replace("LAW CITED:", "").strip()
        elif line.startswith("VERDICT:"):
            parsed["verdict"] = line.replace("VERDICT:", "").strip()
        elif line.startswith("WHERE TO FILE:"):
            parsed["where_to_file"] = line.replace("WHERE TO FILE:", "").strip()

    if not parsed["plain_answer"]:
        parsed["plain_answer"] = raw[:500]

    # Translate
    if lang == "urdu":
        parsed["plain_answer"] = translate(parsed["plain_answer"], "urdu")
        parsed["law_cited"] = translate(parsed["law_cited"], "urdu") if parsed["law_cited"] else ""
        parsed["where_to_file"] = translate(parsed["where_to_file"], "urdu") if parsed["where_to_file"] else ""
    elif lang == "roman":
        parsed["plain_answer"] = translate(parsed["plain_answer"], "roman")
        parsed["law_cited"] = translate(parsed["law_cited"], "roman") if parsed["law_cited"] else ""
        parsed["where_to_file"] = translate(parsed["where_to_file"], "roman") if parsed["where_to_file"] else ""

    return parsed

# ═══════════════════════════════════════════
# FASTAPI APP
# ═══════════════════════════════════════════
app = FastAPI(title="QaanoonSathi AI")

# Serve static files
app.mount("/static", StaticFiles(directory="static"), name="static")

class QueryRequest(BaseModel):
    query: str
    domain: str = "general"
    lang: str = "en"
    mode: str = "qa"

@app.get("/", response_class=HTMLResponse)
async def home():
    return FileResponse("static/index.html")

@app.post("/api/ask")
async def ask(req: QueryRequest):
    # Detect & translate input
    detected = detect_language(req.query)
    q = req.query
    if detected in ("urdu", "roman_urdu"):
        q = translate(req.query, "en")

    result = generate_answer(q, req.domain, req.mode, req.lang)
    result["detected_input_lang"] = detected
    result["original_query"] = req.query
    return result

@app.post("/api/voice")
async def voice_input(audio: bytes, domain: str = "general", lang: str = "en"):
    # Save temp audio
    with open("/tmp/input.wav", "wb") as f:
        f.write(audio)
    
    # Transcribe
    with open("/tmp/input.wav", "rb") as f:
        transcript = whisper_client.audio.transcriptions.create(
            model=WHISPER_MODEL, file=f, response_format="text"
        )
    
    # Process same as text
    detected = detect_language(transcript)
    q = translate(transcript, "en") if detected in ("urdu", "roman_urdu") else transcript
    
    result = generate_answer(q, domain, "qa", lang)
    result["transcript"] = transcript
    result["detected_input_lang"] = detected
    return result

@app.get("/api/tts")
async def text_to_speech_endpoint(text: str, lang: str = "en"):
    clean = re.sub(r'PLAIN ANSWER:|LAW CITED:|VERDICT:|WHERE TO FILE:', '', text)
    clean = re.sub(r'\n+', ' ', clean).strip()
    gl = "ur" if lang == "urdu" else "en"
    
    tts = gTTS(text=clean, lang=gl, slow=False)
    tts.save("/tmp/out.mp3")
    return FileResponse("/tmp/out.mp3", media_type="audio/mpeg")