launch.py

#!/usr/bin/env python3
"""
ViperCapture launcher
---------------------
Run this file directly with Python.
Handles venv setup, dependency install, browser install,
server startup, and opening your browser automatically.

On subsequent runs, dependency checks are skipped unless
requirements.txt has changed (hash-stamped in .venv/).
"""

from __future__ import annotations
import hashlib
from importlib.metadata import version
import os
import sys
import subprocess
import socket
import time
import webbrowser
from pathlib import Path

ROOT             = Path(__file__).parent.resolve()
VENV_PYTHON      = ROOT / ".venv" / ("Scripts/python.exe" if os.name == "nt" else "bin/python")
HOST             = "127.0.0.1"
PORT             = 8000
URL              = f"http://{HOST}:{PORT}/"
DEPS_STAMP       = ROOT / ".venv" / ".deps_stamp"
PLAYWRIGHT_STAMP = ROOT / ".venv" / ".playwright_stamp"


# ── Helpers ───────────────────────────────────────────────────

def port_open() -> bool:
    try:
        with socket.create_connection((HOST, PORT), timeout=1):
            return True
    except OSError:
        return False


def run(*cmd: str | Path, label: str = "") -> None:
    """Run a subprocess and exit hard if it fails."""
    result = subprocess.run([str(c) for c in cmd])
    if result.returncode != 0:
        tag = f" ({label})" if label else ""
        print(f"\n  ERROR{tag}: command exited with code {result.returncode}")
        print(f"  Command: {' '.join(str(c) for c in cmd)}")
        wait_and_exit(1)


def wait_and_exit(code: int = 0) -> None:
    if sys.stdin.isatty():
        input("\n  Press Enter to close...")
    sys.exit(code)


def _req_hash() -> str:
    """MD5 of requirements.txt — used to detect changes between runs."""
    req = ROOT / "requirements.txt"
    return hashlib.md5(req.read_bytes()).hexdigest() if req.exists() else ""


# ── Setup steps ───────────────────────────────────────────────

def ensure_venv() -> None:
    """
    If the venv doesn't exist yet, create it.
    If we're not running from the venv Python, re-launch with it so
    all subsequent imports and subprocess calls use the right Python.
    """
    if not VENV_PYTHON.exists():
        print("  [1/3] Creating Python environment (first run only)...")
        run(sys.executable, "-m", "venv", ROOT / ".venv", label="venv creation")

    this = Path(sys.executable).resolve()
    want = VENV_PYTHON.resolve()
    if this != want:
        # Hand off to the venv Python — this process becomes just a waiter.
        result = subprocess.run([str(VENV_PYTHON), __file__] + sys.argv[1:])
        sys.exit(result.returncode)


def ensure_deps() -> None:
    """
    Install packages from requirements.txt.
    Skipped on subsequent runs unless requirements.txt has changed.
    """
    current_hash = _req_hash()
    if DEPS_STAMP.exists() and DEPS_STAMP.read_text().strip() == current_hash:
        print("  [2/3] Python packages already up to date — skipping.")
        return

    print("  [2/3] Installing Python packages...")
    run(sys.executable, "-m", "pip", "install", "--upgrade", "pip", "-q",
        label="pip upgrade")
    run(sys.executable, "-m", "pip", "install", "-r", ROOT / "requirements.txt",
        label="pip install")
    DEPS_STAMP.write_text(current_hash)


def ensure_playwright() -> None:
    """
    Install Playwright's Chromium, Firefox, and WebKit browsers.
    Skipped when the installed browser matches the Playwright package version.
    """
    playwright_stamp = f"{version('playwright')}:chromium,firefox,webkit"
    if (
        PLAYWRIGHT_STAMP.exists()
        and PLAYWRIGHT_STAMP.read_text().strip() == playwright_stamp
    ):
        print("  [3/3] Playwright browsers already installed — skipping.")
        return

    print("  [3/3] Installing Playwright browsers...")
    command = [sys.executable, "-m", "playwright", "install", "--no-shell"]
    if sys.platform.startswith("linux"):
        command.append("--with-deps")
    run(*command, "chromium", "firefox", "webkit", label="playwright install")
    PLAYWRIGHT_STAMP.write_text(playwright_stamp)


# ── Main ──────────────────────────────────────────────────────

def main() -> None:
    print()
    print("  ViperCapture")
    print("  ------------")
    print()

    ensure_venv()    # may re-exec this script under the venv Python
    ensure_deps()
    ensure_playwright()

    # Server already running from a previous session?
    if port_open():
        print(f"\n  Server already running. Opening {URL}")
        webbrowser.open(URL)
        return

    # ── Start the server ────────────────────────────────────────
    print(f"\n  Starting server at {URL}")
    print("  Press Ctrl+C here to stop the server.\n")

    server = subprocess.Popen(
        [sys.executable, "-m", "uvicorn", "vipercapture.main:app",
         "--host", HOST, "--port", str(PORT)],
        cwd=str(ROOT),
    )

    # ── Wait for port (1 check/sec, 30s max) ────────────────────
    print("  Waiting for server to be ready...", end="", flush=True)
    ready = False
    for _ in range(30):
        if port_open():
            ready = True
            break
        if server.poll() is not None:
            # Server process already exited — don't wait the full 30s
            break
        time.sleep(1)
        print(".", end="", flush=True)
    print()

    if not ready:
        print("\n  ERROR: Server didn't start.")
        print("  Check the output above for details.")
        server.terminate()
        wait_and_exit(1)

    # ── Open browser ────────────────────────────────────────────
    webbrowser.open(URL)
    print(f"\n  Ready! Opened {URL} in your browser.")
    print("  Ctrl+C to stop the server.\n")

    # Keep this window alive — show server logs until Ctrl+C
    try:
        server.wait()
    except KeyboardInterrupt:
        print("\n  Stopping server...")
        server.terminate()
        try:
            server.wait(timeout=5)
        except subprocess.TimeoutExpired:
            server.kill()
        print("  Server stopped.")


if __name__ == "__main__":
    main()