"""
agent_trace.py
──────────────
Logs the 3-step GharScan agentic reasoning chain per inference call.
Traces are periodically pushed to HuggingFace Hub as a public dataset.

Qualifies for:  📡 Sharing is Caring badge
Dataset target: <hf_username>/gharscan-agent-traces
"""

import json
import uuid
import time
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional
from loguru import logger
from huggingface_hub import HfApi, login
import os


HF_TRACE_REPO   = os.getenv("HF_TRACE_REPO", "ritvik360/gharscan-agent-traces")
LOCAL_TRACE_DIR = Path("/tmp/gharscan_traces")
FLUSH_EVERY_N   = 20          # Push to Hub every N traces to avoid rate-limiting


class TraceSession:
    """Represents a single user inference session with 3 reasoning steps."""

    def __init__(self, session_id: Optional[str] = None):
        self.session_id   = session_id or str(uuid.uuid4())[:8]
        self.started_at   = datetime.now(timezone.utc).isoformat()
        self.steps: list  = []
        self.final_report: Optional[dict] = None
        self.duration_ms: Optional[int]   = None
        self._t0 = time.monotonic()

    def log_step(self, step_name: str, step_input: dict, step_output: dict) -> None:
        self.steps.append({
            "step":       step_name,                  # "classify" | "severity" | "cost"
            "input":      step_input,
            "output":     step_output,
            "elapsed_ms": int((time.monotonic() - self._t0) * 1000),
        })

    def finalize(self, final_report: dict) -> None:
        self.final_report = final_report
        self.duration_ms  = int((time.monotonic() - self._t0) * 1000)

    def to_dict(self) -> dict:
        return {
            "session_id":   self.session_id,
            "started_at":   self.started_at,
            "duration_ms":  self.duration_ms,
            "steps":        self.steps,
            "final_report": self.final_report,
        }


class AgentTraceLogger:
    """
    Manages trace collection and periodic HF Hub uploads.
    Keeps traces in local JSONL buffer; flushes to Hub every FLUSH_EVERY_N calls.
    """

    def __init__(self):
        LOCAL_TRACE_DIR.mkdir(parents=True, exist_ok=True)
        self._buffer_path = LOCAL_TRACE_DIR / "traces_buffer.jsonl"
        self._count       = 0
        self._api         = None
        self._hf_ready    = False
        self._init_hf()

    def _init_hf(self):
        """Try to authenticate with HF Hub. Silently skip if no token."""
        hf_token = os.getenv("HF_TOKEN")
        if hf_token:
            try:
                login(token=hf_token)
                self._api     = HfApi()
                self._hf_ready = True
                # Ensure dataset repo exists
                self._api.create_repo(
                    repo_id=HF_TRACE_REPO,
                    repo_type="dataset",
                    exist_ok=True,
                    private=False,
                )
                logger.info(f"AgentTraceLogger ready → {HF_TRACE_REPO}")
            except Exception as e:
                logger.warning(f"HF trace upload disabled: {e}")
        else:
            logger.warning("HF_TOKEN not set — traces saved locally only.")

    def start_trace(self) -> TraceSession:
        return TraceSession()

    def save_trace(self, session: TraceSession) -> None:
        """Append trace to local buffer; flush to HF Hub every N traces."""
        record = json.dumps(session.to_dict(), ensure_ascii=False)
        with open(self._buffer_path, "a", encoding="utf-8") as f:
            f.write(record + "\n")

        self._count += 1
        logger.debug(f"Trace saved [{self._count}]: session={session.session_id}")

        if self._count % FLUSH_EVERY_N == 0 and self._hf_ready:
            self._flush_to_hub()

    def _flush_to_hub(self) -> None:
        """Upload local JSONL buffer to HF Hub dataset repo."""
        try:
            timestamp = datetime.now(timezone.utc).strftime("%Y%m%d_%H%M%S")
            remote_filename = f"traces_{timestamp}.jsonl"

            self._api.upload_file(
                path_or_fileobj=str(self._buffer_path),
                path_in_repo=f"data/{remote_filename}",
                repo_id=HF_TRACE_REPO,
                repo_type="dataset",
                commit_message=f"Auto-flush: {self._count} traces",
            )

            # Reset local buffer after successful upload
            self._buffer_path.write_text("")
            logger.info(f"Traces flushed to Hub → {HF_TRACE_REPO}/data/{remote_filename}")

        except Exception as e:
            logger.error(f"Trace flush failed: {e}")

    def force_flush(self) -> None:
        """Call manually before Space shutdown to push remaining traces."""
        if self._hf_ready and self._buffer_path.exists():
            self._flush_to_hub()