"""
modules/clipboard_control.py — Phase 4 (System Control): Clipboard utilities + history.

No fake outputs: uses Win32 clipboard. History stored in data/clipboard_history.json.
"""

from __future__ import annotations

import json
import time
from dataclasses import dataclass
from pathlib import Path

import win32clipboard  # type: ignore
import win32con  # type: ignore


DATA_DIR = Path(__file__).resolve().parents[1] / "data"
HIST_PATH = DATA_DIR / "clipboard_history.json"


@dataclass(frozen=True, slots=True)
class ClipResult:
    ok: bool
    message: str


def _read_text() -> str | None:
    try:
        win32clipboard.OpenClipboard()
        if win32clipboard.IsClipboardFormatAvailable(win32con.CF_UNICODETEXT):
            data = win32clipboard.GetClipboardData(win32con.CF_UNICODETEXT)
            return str(data)
    except Exception:
        return None
    finally:
        try:
            win32clipboard.CloseClipboard()
        except Exception:
            pass
    return None


def snapshot() -> ClipResult:
    txt = _read_text()
    if not txt:
        return ClipResult(False, "Clipboard empty or non-text.")
    DATA_DIR.mkdir(parents=True, exist_ok=True)
    cur: list[dict] = []
    if HIST_PATH.exists():
        try:
            cur = json.loads(HIST_PATH.read_text(encoding="utf-8"))
        except Exception:
            cur = []
    cur.append({"ts": time.time(), "text": txt[:2000]})
    # Keep last 50
    cur = cur[-50:]
    HIST_PATH.write_text(json.dumps(cur, ensure_ascii=False), encoding="utf-8")
    return ClipResult(True, "Clipboard saved.")


def last(n: int = 5) -> ClipResult:
    if not HIST_PATH.exists():
        return ClipResult(False, "No clipboard history yet.")
    try:
        cur = json.loads(HIST_PATH.read_text(encoding="utf-8"))
        cur = list(cur)[-max(1, int(n)) :]
        texts = []
        for item in reversed(cur):
            t = str(item.get("text") or "").replace("\n", " ")
            texts.append(t[:120])
        return ClipResult(True, " | ".join(texts))
    except Exception:
        return ClipResult(False, "Clipboard history unreadable.")