#!/usr/bin/env python3
"""Generate status.json from scraper JSON outputs and per-scraper stats files."""
from __future__ import annotations

import argparse
import json
import os
from datetime import datetime
from pathlib import Path

HERE = Path(__file__).parent
DATA_DIR = Path(os.environ.get("DATA_DIR", HERE))

SOURCE_FILES = {
    "Sreality":    "byty_sreality.json",
    "Realingo":    "byty_realingo.json",
    "Bezrealitky": "byty_bezrealitky.json",
    "iDNES":       "byty_idnes.json",
    "PSN":         "byty_psn.json",
    "CityHome":    "byty_cityhome.json",
}

STATS_FILES = {
    "Sreality":    "stats_sreality.json",
    "Realingo":    "stats_realingo.json",
    "Bezrealitky": "stats_bezrealitky.json",
    "iDNES":       "stats_idnes.json",
    "PSN":         "stats_psn.json",
    "CityHome":    "stats_cityhome.json",
}

MERGED_FILE = "byty_merged.json"
HISTORY_FILE = "scraper_history.json"


def count_source(path: Path) -> dict:
    """Read a scraper JSON and return accepted count + file mtime."""
    if not path.exists():
        return {"accepted": 0, "error": "soubor nenalezen"}
    try:
        data = json.loads(path.read_text(encoding="utf-8"))
        mtime = datetime.fromtimestamp(path.stat().st_mtime).isoformat(timespec="seconds")
        return {"accepted": len(data), "updated_at": mtime}
    except Exception as e:
        return {"accepted": 0, "error": str(e)}


def read_scraper_stats(path: Path) -> dict:
    """Load a per-scraper stats JSON. Returns {} on missing or corrupt file."""
    if not path.exists():
        return {}
    try:
        data = json.loads(path.read_text(encoding="utf-8"))
        return data if isinstance(data, dict) else {}
    except Exception:
        return {}


def append_to_history(status: dict, keep: int) -> None:
    """Append the current status entry to scraper_history.json, keeping only `keep` latest."""
    history_path = HERE / HISTORY_FILE
    history: list = []
    if history_path.exists():
        try:
            history = json.loads(history_path.read_text(encoding="utf-8"))
            if not isinstance(history, list):
                history = []
        except Exception:
            history = []

    history.append(status)

    # Keep only the N most recent entries
    if keep > 0 and len(history) > keep:
        history = history[-keep:]

    history_path.write_text(json.dumps(history, ensure_ascii=False, indent=2), encoding="utf-8")
    print(f"Historie uložena: {history_path} ({len(history)} záznamů)")


def main():
    parser = argparse.ArgumentParser(description="Generate status.json from scraper outputs.")
    parser.add_argument("--start-time", dest="start_time", default=None,
                        help="ISO timestamp of scrape start (default: now)")
    parser.add_argument("--duration", dest="duration", type=int, default=None,
                        help="Run duration in seconds")
    parser.add_argument("--keep", dest="keep", type=int, default=5,
                        help="Number of history entries to keep (default: 5, 0=unlimited)")
    args = parser.parse_args()

    start_time = args.start_time or datetime.now().isoformat(timespec="seconds")
    duration_sec = args.duration

    sources = []
    for name, filename in SOURCE_FILES.items():
        path = HERE / filename
        info = count_source(path)
        info["name"] = name

        # Merge in stats from the per-scraper stats file (authoritative for run data)
        stats = read_scraper_stats(HERE / STATS_FILES[name])
        for key in ("accepted", "fetched", "pages", "cache_hits", "excluded", "excluded_total",
                    "success", "duration_sec", "error"):
            if key in stats:
                info[key] = stats[key]

        sources.append(info)

    # Total accepted before dedup
    total_accepted = sum(s.get("accepted", 0) for s in sources)

    # Merged / deduplicated count
    merged_path = HERE / MERGED_FILE
    deduplicated = 0
    if merged_path.exists():
        try:
            merged = json.loads(merged_path.read_text(encoding="utf-8"))
            deduplicated = len(merged)
        except Exception:
            pass

    duplicates_removed = total_accepted - deduplicated if deduplicated else 0

    # Top-level success: True if no source has an error
    success = not any("error" in s for s in sources)

    status = {
        "status": "done",
        "timestamp": start_time,
        "duration_sec": duration_sec,
        "success": success,
        "total_accepted": total_accepted,
        "deduplicated": deduplicated,
        "duplicates_removed": duplicates_removed,
        "sources": sources,
    }

    out = DATA_DIR / "status.json"
    out.write_text(json.dumps(status, ensure_ascii=False, indent=2), encoding="utf-8")
    print(f"Status uložen: {out}")
    print(f"  Celkem bytů (před dedup): {total_accepted}")
    print(f"  Po deduplikaci:           {deduplicated}")
    if duplicates_removed:
        print(f"  Odstraněno duplikátů:     {duplicates_removed}")
    for s in sources:
        acc = s.get("accepted", 0)
        err = s.get("error", "")
        exc = s.get("excluded", {})
        exc_total = sum(exc.values()) if exc else s.get("excluded_total", 0)
        parts = [f"{s['name']:12s}: {acc} bytů"]
        if exc_total:
            parts.append(f"({exc_total} vyloučeno)")
        if err:
            parts.append(f"[CHYBA: {err}]")
        print("  " + "  ".join(parts))

    append_to_history(status, args.keep)


if __name__ == "__main__":
    main()