"""
Auto-Updater
============
Checks Supabase for a newer version of screener_gui.py and stock_screener.py.
If found, silently downloads and replaces the files in the exe directory,
then restarts the application.

Called after a successful license check on every launch.
"""

import os
import sys
import tempfile
import shutil

import requests

# ---------------------------------------------------------------------------
# Current app version — bump this in lockstep with new Supabase version rows
# ---------------------------------------------------------------------------
APP_VERSION = "1.0.0"

# ---------------------------------------------------------------------------
# Supabase config (same anon key as license_check.py)
# ---------------------------------------------------------------------------
_SUPABASE_URL  = "https://yeispcpmepjelfbhfkwr.supabase.co"
_SUPABASE_ANON = (
    "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9."
    "eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6InllaXNwY3BtZXBqZWxmYmhma3dyIiwi"
    "cm9sZSI6ImFub24iLCJpYXQiOjE3NzM1MDkxOTAsImV4cCI6MjA4OTA4NTE5MH0."
    "8kq6HzpwF81_Sx36MXbx0wUqaT9Ul9POw1LzF5vxiOo"
)

_HEADERS = {
    "apikey":       _SUPABASE_ANON,
    "Content-Type": "application/json",
}

# Files that can be updated without rebuilding the exe
_UPDATABLE_FILES = ("screener_gui.py", "stock_screener.py")


def _exe_dir() -> str:
    if getattr(sys, "frozen", False):
        return os.path.dirname(sys.executable)
    return os.path.dirname(os.path.abspath(__file__))


def _parse_version(v: str) -> tuple:
    """Convert '1.2.3' → (1, 2, 3) for comparison."""
    try:
        return tuple(int(x) for x in v.strip().split("."))
    except Exception:
        return (0, 0, 0)


def _download_file(url: str, dest_path: str) -> None:
    """Download url → dest_path, using a temp file so the write is atomic."""
    tmp_dir  = tempfile.mkdtemp()
    tmp_path = os.path.join(tmp_dir, os.path.basename(dest_path))
    try:
        with requests.get(url, stream=True, timeout=30) as r:
            r.raise_for_status()
            with open(tmp_path, "wb") as f:
                for chunk in r.iter_content(chunk_size=65536):
                    f.write(chunk)
        shutil.move(tmp_path, dest_path)
    finally:
        shutil.rmtree(tmp_dir, ignore_errors=True)


def _restart() -> None:
    """Restart the current process cleanly."""
    if getattr(sys, "frozen", False):
        os.execv(sys.executable, [sys.executable] + sys.argv[1:])
    else:
        os.execv(sys.executable, [sys.executable] + sys.argv)


def check_and_apply_update() -> None:
    """
    Silently check for updates and apply them if available.
    Errors are swallowed — a failed update check never blocks the app.
    """
    try:
        resp = requests.post(
            f"{_SUPABASE_URL}/rest/v1/rpc/get_latest_version",
            headers=_HEADERS,
            json={},
            timeout=8,
        )
        resp.raise_for_status()
        data = resp.json()

        latest  = data.get("version", APP_VERSION)
        gui_url = data.get("gui_py_url")
        scr_url = data.get("screener_py_url")

        if _parse_version(latest) <= _parse_version(APP_VERSION):
            return  # already up to date

        exe_dir  = _exe_dir()
        updated  = False

        if gui_url:
            dest = os.path.join(exe_dir, "screener_gui.py")
            _download_file(gui_url, dest)
            updated = True

        if scr_url:
            dest = os.path.join(exe_dir, "stock_screener.py")
            _download_file(scr_url, dest)
            updated = True

        if updated:
            # Restart so the fresh .py files are loaded
            _restart()

    except Exception:
        # Never crash the app over a failed update check
        pass