# server.py
import json
import random
import traceback
from typing import Optional
import uuid
from fastapi import APIRouter, Request
from fastapi.responses import JSONResponse
import pycountry
from pydantic import BaseModel
from chat_utils import chat
from config import SanatanConfig
from db import SanatanDatabase
from metadata import MetadataWhereClause
from modules.audio.model import AudioRequest
from modules.audio.service import svc_get_audio_urls
from modules.quiz.answer_validator import validate_answer
from modules.quiz.models import Question
from modules.quiz.quiz_helper import generate_question
import logging

from modules.video.model import VideoRequest
from modules.video.service import svc_get_video_urls

logging.basicConfig()
logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)

router = APIRouter()

# In-memory mapping from session_id -> thread_id
# For production, you may want Redis or a DB for persistence
thread_map = {}


class Message(BaseModel):
    language: str
    text: str
    session_id: str | None = None  # Optional session ID from client


class QuizGeneratePayload(BaseModel):
    language: Optional[str] = "English"
    scripture: Optional[str] = None
    complexity: Optional[str] = None
    mode: Optional[str] = None
    session_id: Optional[str] = None  # Optional session ID from client


class QuizEvalPayload(BaseModel):
    language: Optional[str] = "English"
    q: Question
    answer: str
    session_id: Optional[str] = None  # Optional session ID from client


LANG_NATIVE_NAMES = {
    "en": "English",
    "fr": "Français",
    "es": "Español",
    "hi": "हिन्दी",
    "bn": "বাংলা",
    "te": "తెలుగు",
    "mr": "मराठी",
    "ta": "தமிழ்",
    "ur": "اردو",
    "gu": "ગુજરાતી",
    "kn": "ಕನ್ನಡ",
    "ml": "മലയാളം",
    "pa": "ਪੰਜਾਬੀ",
    "as": "অসমীয়া",
    "mai": "मैथिली",
    "sd": "سنڌي",
    "sat": "ᱥᱟᱱᱛᱟᱲᱤ",
}


@router.get("/languages")
async def handle_fetch_languages():
    supported_lang_codes = [
        "en",
        "fr",
        "es",
        "hi",
        "bn",
        "te",
        "mr",
        "ta",
        "ur",
        "gu",
        "kn",
        "ml",
        "pa",
        "as",
        "mai",
        "sd",
        "sat",
    ]

    languages = []
    for code in supported_lang_codes:
        lang = pycountry.languages.get(alpha_2=code) or pycountry.languages.get(
            alpha_3=code
        )
        if lang is None:
            continue  # skip unknown codes
        english_name = lang.name
        native_name = LANG_NATIVE_NAMES.get(code, english_name)
        languages.append(
            {
                "code": code,
                "name": english_name,
                "native_name": native_name,
            }
        )

    languages.sort(key=lambda x: x["name"])
    return languages


@router.post("/greet")
async def handle_greet(msg: Message):
    markdown = "Namaskaram 🙏 I am **bhashyam.ai** and I can help you explore the following scriptures:\n---\n"
    for scripture in sorted(SanatanConfig().scriptures, key=lambda doc: doc["title"]):
        num_units = SanatanDatabase().count(
            collection_name=scripture["collection_name"]
        )
        markdown += f"- {scripture['title']} : `{num_units}` {scripture["unit"]}s\n"

    session_id = msg.session_id
    if not session_id:
        session_id = str(uuid.uuid4())
    return {"reply": markdown, "session_id": session_id}


@router.post("/chat")
async def handle_chat(msg: Message, request: Request):
    try:
        # Use existing session_id if provided, else generate new
        session_id = msg.session_id
        if not session_id:
            session_id = str(uuid.uuid4())
        print(session_id, ": user sent message : ", msg.text)
        # Get or create a persistent thread_id for this session
        if session_id not in thread_map:
            thread_map[session_id] = str(uuid.uuid4())
        thread_id = thread_map[session_id]

        # Call your graph/chat function
        reply_text = chat(
            debug_mode=False,
            message=msg.text,
            history=None,
            thread_id=thread_id,
            preferred_language=msg.language or "English",
        )

        # Return both reply and session_id to the client
        return {"reply": reply_text, "session_id": session_id}

    except Exception as e:
        traceback.print_exc()
        return JSONResponse(status_code=500, content={"reply": f"Error: {e}"})


@router.post("/quiz/generate")
async def handle_quiz_generate(payload: QuizGeneratePayload, request: Request):
    q = generate_question(
        collection=payload.scripture
        or random.choice(
            [
                s["collection_name"]
                for s in SanatanConfig.scriptures
                if s["collection_name"] != "yt_metadata"
            ]
        ),
        complexity=payload.complexity
        or random.choice(["beginner", "intermediate", "advanced"]),
        mode=payload.mode or random.choice(["mcq", "open"]),
        preferred_lamguage=payload.language or "English",
    )
    print(q.model_dump_json(indent=1))
    return q.model_dump()


@router.post("/quiz/eval")
async def handle_quiz_eval(payload: QuizEvalPayload, request: Request):
    result = validate_answer(
        payload.q, payload.answer, preferred_language=payload.language or "English"
    )
    print(result.model_dump_json(indent=1))
    return result


@router.get("/scriptures")
async def handle_get_scriptures():
    return_values = {}
    for scripture in SanatanConfig().scriptures:
        if scripture["collection_name"] != "yt_metadata":
            return_values[scripture["collection_name"]] = scripture["title"]
    return return_values


class ScriptureRequest(BaseModel):
    scripture_name: str
    unit_index: int


@router.post("/scripture")
async def get_scripture(req: ScriptureRequest):
    """
    Return a scripture unit (page or verse, based on config),
    including all metadata fields separately.
    used for page view to fetch by global index.
    """
    logger.info("get_scripture: received request to fetch scripture: %s", req)

    # find config entry for the scripture
    config = next(
        (s for s in SanatanConfig().scriptures if s["name"] == req.scripture_name), None
    )
    if not config:
        return {"error": f"Scripture '{req.scripture_name}' not found"}

    # fetch the raw document from DB
    raw_doc = SanatanDatabase().fetch_document_by_index(
        collection_name=config["collection_name"],
        index=req.unit_index,
        # unit_name=config.get("unit_field", config.get("unit")),
    )

    if not raw_doc or isinstance(raw_doc, str) or "error" in raw_doc:
        return {"error": f"No data available for unit {req.unit_index}"}

    # canonicalize it
    canonical_doc = SanatanConfig().canonicalize_document(
        scripture_name=req.scripture_name,
        document_text=raw_doc.get("document", ""),
        metadata_doc=raw_doc,
    )

    # add unit index & total units (so Flutter can paginate)
    canonical_doc["total"] = SanatanDatabase().count(config["collection_name"])

    print("canonical_doc = ", canonical_doc)
    return canonical_doc


@router.get("/scripture_configs")
async def get_scripture_configs():
    scriptures = []
    for s in SanatanConfig().scriptures:
        num_units = SanatanDatabase().count(collection_name=s["collection_name"])

        # Deep copy metadata_fields so we don’t mutate the original config
        metadata_fields = []
        for f in s.get("metadata_fields", []):
            f_copy = dict(f)
            lov = f_copy.get("lov")
            if callable(lov):  # evaluate the function
                try:
                    f_copy["lov"] = lov()
                except Exception as e:
                    f_copy["lov"] = []
            metadata_fields.append(f_copy)

        scriptures.append(
            {
                "name": s["name"],  # e.g. "bhagavad_gita"
                "title": s["title"],  # e.g. "Bhagavad Gita"
                "unit": s["unit"],  # e.g. "verse" or "page"
                "unit_field": s.get("unit_field", s.get("unit")),
                "total": num_units,
                "enabled": "field_mapping" in s,
                "source": s.get("source", ""),
                "credits": s.get("credits", f"{s.get('source','')}"),
                "metadata_fields": metadata_fields,
            }
        )

    return {"scriptures": sorted(scriptures, key=lambda s: s["title"])}


@router.post("/scripture/{scripture_name}/search")
async def search_scripture(
    scripture_name: str,
    filter_obj: Optional[MetadataWhereClause] = None,
):
    """
    Search scripture collection with optional filters.
    - `scripture_name`: Name of the collection
    - `filter_obj`: MetadataWhereClause (filters, groups, operator)
    - `n_results`: number of random results to return
    """
    try:
        db = SanatanDatabase()
        config = next(
            (s for s in SanatanConfig().scriptures if s["name"] == scripture_name), None
        )

        results = db.fetch_first_match(
            collection_name=config["collection_name"],
            metadata_where_clause=filter_obj,
        )

        print("results = ", results)
        # Flatten + canonicalize results
        formatted_results = []
        for i in range(len(results["metadatas"])):
            id = results["ids"][i]
            metadata_doc = results["metadatas"][i]
            metadata_doc["id"] = id
            print("metadata_doc = ", metadata_doc)
            document_text = (
                results["documents"][i] if results.get("documents") else None
            )

            canonical_doc = SanatanConfig().canonicalize_document(
                scripture_name, document_text, metadata_doc
            )
            formatted_results.append(canonical_doc)

        print("formatted_results = ", formatted_results)
        return {"results": formatted_results}

    except Exception as e:
        logger.error("Error while searching %s", e, exc_info=True)
        return {"error": str(e)}


@router.post("/audio")
async def generate_audio_urls(req: AudioRequest):
    logger.info("generate_audio_urls: %s", req)
    audio_urls = await svc_get_audio_urls(req)
    return audio_urls


@router.post("/video")
async def generate_audio_urls(req: VideoRequest):
    logger.info("generate_audio_urls: %s", req)
    video_urls = await svc_get_video_urls(req)
    return video_urls