from __future__ import annotations

import logging
import os
import uuid
from datetime import datetime

import anthropic

from state import Artifact, Notebook

logger = logging.getLogger(__name__)

MODEL = "claude-haiku-4-5-20251001"
MAX_TOKENS = 1024


def _get_source_text(notebook: Notebook, max_chars: int = 8000, source_ids: list[str] | None = None) -> str:
    """Pull chunk text from vector store for this notebook."""
    try:
        from persistence.vector_store import VectorStore
        from ingestion_engine.embedding_generator import generate_query

        query_vector = generate_query("main ideas key concepts overview summary")
        filter_dict = None
        if source_ids:
            filter_dict = {"source_id": {"$in": source_ids}}
        matches = VectorStore().query(
            query_vector=query_vector,
            namespace=notebook.id,
            top_k=20,
            filter=filter_dict,
        )
        chunks = [m.get("text", "") for m in matches if m.get("text")]
        if chunks:
            return "\n\n".join(chunks)[:max_chars]
    except Exception as e:
        logger.warning("Could not retrieve chunks from vector store: %s", e)

    names = [s.filename for s in notebook.sources if s.status == "ready"]
    return "Sources: " + ", ".join(names) if names else "No sources available."


def _call_claude(system: str, prompt: str) -> str:
    client = anthropic.Anthropic(api_key=os.environ.get("ANTHROPIC_API_KEY"))
    response = client.messages.create(
        model=MODEL,
        max_tokens=MAX_TOKENS,
        system=system,
        messages=[{"role": "user", "content": prompt}],
    )
    return (response.content[0].text or "").strip()


def generate_conversation_summary(notebook: Notebook, style: str) -> Artifact:
    """Generate a conversation summary from notebook chat history."""
    style = style if style in ("brief", "detailed") else "detailed"

    if not notebook.messages:
        content = "_No conversation to summarize yet. Start chatting in the Chat tab first._"
    else:
        history = "\n\n".join(
            f"{m.role.capitalize()}: {m.content}" for m in notebook.messages
        )

        if style == "brief":
            instructions = (
                "Write a BRIEF summary (3-5 bullet points) covering:\n"
                "- The main topics discussed\n"
                "- Key questions asked and answers given\n"
                "- Any unresolved questions\n"
                "Keep it under 150 words."
            )
        else:
            instructions = (
                "Write a DETAILED summary covering:\n"
                "- The flow of the conversation\n"
                "- Each major topic explored with key insights\n"
                "- Important answers and explanations given\n"
                "- Any unresolved questions or follow-ups\n"
                "Use markdown headers and bullet points. Aim for 200-400 words."
            )

        prompt = (
            f"Summarize this study session conversation:\n\n"
            f"CONVERSATION:\n{history}\n\n"
            f"TASK:\n{instructions}\n\n"
            f"Begin with: ## Conversation Summary ({'Brief' if style == 'brief' else 'Detailed'})"
        )

        try:
            content = _call_claude(
                "You are an expert academic summarizer. Produce clear, well-structured summaries in markdown.",
                prompt,
            )
            if not content:
                raise ValueError("Empty response")
        except Exception as e:
            logger.error("Conversation summary failed: %s", e)
            content = f"_Summary generation failed: {e}. Please try again._"

    label = "Brief" if style == "brief" else "Detailed"
    return Artifact(
        id=str(uuid.uuid4()),
        type="conversation_summary",
        title=f"Conversation Summary ({label})",
        content=content,
        audio_path=None,
        created_at=datetime.now().isoformat(),
    )


def generate_document_summary(notebook: Notebook, style: str, source_ids: list[str] | None = None) -> Artifact:
    """Generate a document summary from notebook sources."""
    style = style if style in ("brief", "detailed") else "detailed"

    if style == "brief":
        instructions = (
            "Write a BRIEF summary (3-5 bullet points) covering:\n"
            "- The core theme or subject matter\n"
            "- The most important concepts or findings\n"
            "- The key takeaway\n"
            "Keep it under 150 words."
        )
    else:
        instructions = (
            "Write a DETAILED summary covering:\n"
            "- The main theme and purpose of the material\n"
            "- Each major concept or section with explanations\n"
            "- Key definitions, methods, or frameworks\n"
            "- Conclusions and practical implications\n"
            "Use markdown headers and bullet points. Aim for 300-500 words."
        )

    try:
        source_text = _get_source_text(notebook, source_ids=source_ids)
        prompt = (
            f"Summarize this study material:\n\n"
            f"SOURCE CONTENT:\n{source_text}\n\n"
            f"TASK:\n{instructions}\n\n"
            f"Begin with: ## Document Summary ({'Brief' if style == 'brief' else 'Detailed'})"
        )
        content = _call_claude(
            "You are an expert academic summarizer. Produce clear, well-structured summaries in markdown.",
            prompt,
        )
        if not content:
            raise ValueError("Empty response")
    except Exception as e:
        logger.error("Document summary failed: %s", e)
        content = f"_Summary generation failed: {e}. Please try again._"

    label = "Brief" if style == "brief" else "Detailed"
    return Artifact(
        id=str(uuid.uuid4()),
        type="document_summary",
        title=f"Document Summary ({label})",
        content=content,
        audio_path=None,
        created_at=datetime.now().isoformat(),
    )