import json
import time
from datetime import datetime
from pathlib import Path

class KlingEventLogger:
    """Append-only JSONL event log for Kling AI operations."""

    def __init__(self, log_dir: str = "logs"):
        self.log_dir = Path(log_dir)
        self.log_dir.mkdir(exist_ok=True)

    def _write(self, event: dict):
        date = datetime.utcnow().strftime("%Y-%m-%d")
        filepath = self.log_dir / f"kling-{date}.jsonl"
        event["timestamp"] = datetime.utcnow().isoformat()
        with open(filepath, "a") as f:
            f.write(json.dumps(event) + "\n")

    def log_submission(self, task_id, prompt, model, duration, mode):
        self._write({
            "event": "task_submitted",
            "task_id": task_id,
            "model": model,
            "duration": int(duration),
            "mode": mode,
            "prompt_len": len(prompt),
        })

    def log_completion(self, task_id, status, elapsed_sec, credits_used):
        self._write({
            "event": "task_completed",
            "task_id": task_id,
            "status": status,
            "elapsed_sec": elapsed_sec,
            "credits_used": credits_used,
        })

    def log_error(self, task_id, error_type, message):
        self._write({
            "event": "task_error",
            "task_id": task_id,
            "error_type": error_type,
            "message": message[:200],
        })

from collections import defaultdict

class UsageAnalytics:
    """Aggregate metrics from JSONL event logs."""

    def __init__(self, log_dir: str = "logs"):
        self.log_dir = Path(log_dir)

    def _read_events(self, date: str = None):
        pattern = f"kling-{date}.jsonl" if date else "kling-*.jsonl"
        events = []
        for filepath in sorted(self.log_dir.glob(pattern)):
            with open(filepath) as f:
                for line in f:
                    events.append(json.loads(line))
        return events

    def daily_summary(self, date: str = None) -> dict:
        date = date or datetime.utcnow().strftime("%Y-%m-%d")
        events = self._read_events(date)

        submitted = [e for e in events if e["event"] == "task_submitted"]
        completed = [e for e in events if e["event"] == "task_completed"]
        errors = [e for e in events if e["event"] == "task_error"]

        succeeded = [e for e in completed if e["status"] == "succeed"]
        failed = [e for e in completed if e["status"] == "failed"]

        total_credits = sum(e.get("credits_used", 0) for e in completed)
        avg_elapsed = (sum(e["elapsed_sec"] for e in succeeded) / len(succeeded)
                      if succeeded else 0)

        by_model = defaultdict(int)
        for e in submitted:
            by_model[e["model"]] += 1

        return {
            "date": date,
            "total_submitted": len(submitted),
            "succeeded": len(succeeded),
            "failed": len(failed),
            "errors": len(errors),
            "success_rate": f"{len(succeeded) / max(len(completed), 1) * 100:.1f}%",
            "total_credits": total_credits,
            "avg_generation_sec": round(avg_elapsed),
            "by_model": dict(by_model),
        }

    def print_report(self, date: str = None):
        s = self.daily_summary(date)
        print(f"\n=== Kling AI Usage Report: {s['date']} ===")
        print(f"Submitted:    {s['total_submitted']}")
        print(f"Succeeded:    {s['succeeded']}")
        print(f"Failed:       {s['failed']}")
        print(f"Success rate: {s['success_rate']}")
        print(f"Credits used: {s['total_credits']}")
        print(f"Avg time:     {s['avg_generation_sec']}s")
        print(f"By model:")
        for model, count in s["by_model"].items():
            print(f"  {model}: {count}")

def cost_analysis(analytics: UsageAnalytics, days: int = 7):
    """Analyze cost trends over recent days."""
    from datetime import timedelta

    daily_costs = []
    for i in range(days):
        date = (datetime.utcnow() - timedelta(days=i)).strftime("%Y-%m-%d")
        summary = analytics.daily_summary(date)
        daily_costs.append({
            "date": date,
            "credits": summary["total_credits"],
            "videos": summary["total_submitted"],
            "estimated_usd": summary["total_credits"] * 0.14,
        })

    total_credits = sum(d["credits"] for d in daily_costs)
    total_videos = sum(d["videos"] for d in daily_costs)
    total_cost = sum(d["estimated_usd"] for d in daily_costs)

    print(f"\n=== {days}-Day Cost Summary ===")
    print(f"Total credits: {total_credits}")
    print(f"Total videos:  {total_videos}")
    print(f"Est. cost:     ${total_cost:.2f}")
    print(f"Avg/day:       ${total_cost / days:.2f}")

    for d in daily_costs:
        print(f"  {d['date']}: {d['credits']} credits, {d['videos']} videos, ${d['estimated_usd']:.2f}")

import csv

def export_usage_csv(analytics: UsageAnalytics, output: str = "kling_usage.csv"):
    events = analytics._read_events()
    with open(output, "w", newline="") as f:
        writer = csv.DictWriter(f, fieldnames=["timestamp", "event", "task_id",
                                                "model", "status", "credits_used",
                                                "elapsed_sec"])
        writer.writeheader()
        for e in events:
            writer.writerow({k: e.get(k, "") for k in writer.fieldnames})
    print(f"Exported {len(events)} events to {output}")