import json
import os
from datetime import datetime, timezone
from pathlib import Path

AGENT_OS_DIR = Path(os.getenv("AGENT_OS_DIR", "/opt/agent-os"))
TOKEN_LOG = AGENT_OS_DIR / "logs" / "jon-snow" / "token-usage.jsonl"

# claude-sonnet-4-6 pricing (USD per token)
INPUT_COST_PER_TOKEN = 3.00 / 1_000_000
OUTPUT_COST_PER_TOKEN = 15.00 / 1_000_000


def log_usage(intent: str, prompt_tokens: int, completion_tokens: int) -> None:
    TOKEN_LOG.parent.mkdir(parents=True, exist_ok=True)
    cost = (prompt_tokens * INPUT_COST_PER_TOKEN) + (completion_tokens * OUTPUT_COST_PER_TOKEN)
    entry = {
        "ts": datetime.now(timezone.utc).isoformat(),
        "intent": intent,
        "in": prompt_tokens,
        "out": completion_tokens,
        "cost_usd": round(cost, 6),
    }
    with TOKEN_LOG.open("a") as f:
        f.write(json.dumps(entry) + "\n")


def get_summary() -> dict:
    if not TOKEN_LOG.exists():
        return _empty()

    entries = []
    for line in TOKEN_LOG.read_text().splitlines():
        line = line.strip()
        if line:
            try:
                entries.append(json.loads(line))
            except Exception:
                pass

    if not entries:
        return _empty()

    today = datetime.now(timezone.utc).date().isoformat()
    today_entries = [e for e in entries if e["ts"][:10] == today]

    by_intent: dict = {}
    for e in entries:
        b = by_intent.setdefault(e["intent"], {"calls": 0, "in": 0, "out": 0, "cost_usd": 0.0})
        b["calls"] += 1
        b["in"] += e["in"]
        b["out"] += e["out"]
        b["cost_usd"] = round(b["cost_usd"] + e["cost_usd"], 6)

    return {
        "all_time": {
            "calls": len(entries),
            "tokens_in": sum(e["in"] for e in entries),
            "tokens_out": sum(e["out"] for e in entries),
            "cost_usd": round(sum(e["cost_usd"] for e in entries), 6),
        },
        "today": {
            "calls": len(today_entries),
            "tokens_in": sum(e["in"] for e in today_entries),
            "tokens_out": sum(e["out"] for e in today_entries),
            "cost_usd": round(sum(e["cost_usd"] for e in today_entries), 6),
        },
        "by_intent": by_intent,
        "recent": entries[-20:],
    }


def _empty() -> dict:
    return {
        "all_time": {"calls": 0, "tokens_in": 0, "tokens_out": 0, "cost_usd": 0.0},
        "today": {"calls": 0, "tokens_in": 0, "tokens_out": 0, "cost_usd": 0.0},
        "by_intent": {},
        "recent": [],
    }