# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.

import errno
import logging
import os
import select
import signal
import subprocess
import sys

from termcolor import cprint

log = logging.getLogger(__name__)

import importlib
import json
from pathlib import Path

from llama_stack.distribution.utils.image_types import ImageType


def formulate_run_args(image_type, image_name, config, template_name) -> list:
    if image_type == ImageType.container.value or config.container_image:
        script = importlib.resources.files("llama_stack") / "distribution/start_container.sh"
        image_name = f"distribution-{template_name}" if template_name else config.container_image
        run_args = [script, image_name]
    elif image_type == ImageType.conda.value:
        current_conda_env = os.environ.get("CONDA_DEFAULT_ENV")
        image_name = image_name or current_conda_env
        if not image_name:
            cprint(
                "No current conda environment detected, please specify a conda environment name with --image-name",
                color="red",
            )
            return

        def get_conda_prefix(env_name):
            # Conda "base" environment does not end with "base" in the
            # prefix, so should be handled separately.
            if env_name == "base":
                return os.environ.get("CONDA_PREFIX")
            # Get conda environments info
            conda_env_info = json.loads(subprocess.check_output(["conda", "info", "--envs", "--json"]).decode())
            envs = conda_env_info["envs"]
            for envpath in envs:
                if envpath.endswith(env_name):
                    return envpath
            return None

        print(f"Using conda environment: {image_name}")
        conda_prefix = get_conda_prefix(image_name)
        if not conda_prefix:
            cprint(
                f"Conda environment {image_name} does not exist.",
                color="red",
            )
            return

        build_file = Path(conda_prefix) / "llamastack-build.yaml"
        if not build_file.exists():
            cprint(
                f"Build file {build_file} does not exist.\n\nPlease run `llama stack build` or specify the correct conda environment name with --image-name",
                color="red",
            )
            return

        script = importlib.resources.files("llama_stack") / "distribution/start_conda_env.sh"
        run_args = [
            script,
            image_name,
        ]
    else:
        # else must be venv since that is the only valid option left.
        current_venv = os.environ.get("VIRTUAL_ENV")
        venv = image_name or current_venv
        script = importlib.resources.files("llama_stack") / "distribution/start_venv.sh"
        run_args = [
            script,
            venv,
        ]
    return run_args


def run_with_pty(command):
    if sys.platform.startswith("win"):
        return _run_with_pty_win(command)
    else:
        return _run_with_pty_unix(command)


def in_notebook():
    try:
        from IPython import get_ipython

        if "IPKernelApp" not in get_ipython().config:  # pragma: no cover
            return False
    except ImportError:
        return False
    except AttributeError:
        return False
    return True


# run a command in a pseudo-terminal, with interrupt handling,
# useful when you want to run interactive things
def _run_with_pty_unix(command):
    import pty
    import termios

    master, slave = pty.openpty()

    old_settings = termios.tcgetattr(sys.stdin)
    original_sigint = signal.getsignal(signal.SIGINT)

    ctrl_c_pressed = False
    process = None

    def sigint_handler(signum, frame):
        nonlocal ctrl_c_pressed
        ctrl_c_pressed = True
        log.info("\nCtrl-C detected. Aborting...")

    try:
        # Set up the signal handler
        signal.signal(signal.SIGINT, sigint_handler)

        new_settings = termios.tcgetattr(sys.stdin)
        new_settings[3] = new_settings[3] & ~termios.ECHO  # Disable echo
        new_settings[3] = new_settings[3] & ~termios.ICANON  # Disable canonical mode
        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, new_settings)

        process = subprocess.Popen(
            command,
            stdin=slave,
            stdout=slave,
            stderr=slave,
            universal_newlines=True,
            preexec_fn=os.setsid,
        )

        # Close the slave file descriptor as it's now owned by the subprocess
        os.close(slave)

        def handle_io():
            while not ctrl_c_pressed:
                try:
                    rlist, _, _ = select.select([sys.stdin, master], [], [], 0.1)

                    if sys.stdin in rlist:
                        data = os.read(sys.stdin.fileno(), 1024)
                        if not data:
                            break
                        os.write(master, data)

                    if master in rlist:
                        data = os.read(master, 1024)
                        if not data:
                            break
                        sys.stdout.buffer.write(data)
                        sys.stdout.flush()

                except KeyboardInterrupt:
                    # This will be raised when Ctrl+C is pressed
                    break

                if process.poll() is not None:
                    break

        handle_io()
    except (EOFError, KeyboardInterrupt):
        pass
    except OSError as e:
        if e.errno != errno.EIO:
            raise
    finally:
        # Clean up
        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, old_settings)
        signal.signal(signal.SIGINT, original_sigint)

        os.close(master)
        if process and process.poll() is None:
            process.terminate()
            process.wait()

    return process.returncode


# run a command in a pseudo-terminal in windows, with interrupt handling,
def _run_with_pty_win(command):
    """
    Runs a command with interactive support using subprocess directly.
    """
    try:
        # For shell scripts on Windows, use appropriate shell
        if isinstance(command, (list, tuple)):
            if command[0].endswith(".sh"):
                if os.path.exists("/usr/bin/bash"):  # WSL
                    command = ["bash"] + command
                else:
                    # Use cmd.exe with bash while preserving all arguments
                    command = ["cmd.exe", "/c", "bash"] + command

        process = subprocess.Popen(
            command,
            shell=True,
            universal_newlines=True,
        )

        process.wait()

    except Exception as e:
        print(f"Error: {str(e)}")
        return 1
    finally:
        if process and process.poll() is None:
            process.terminate()
            process.wait()
    return process.returncode


def run_command(command):
    try:
        result = subprocess.run(command, capture_output=True, text=True, check=True)
        print("Script Output\n", result.stdout)
        return result.returncode
    except subprocess.CalledProcessError as e:
        print("Error running script:", e)
        print("Error output:", e.stderr)
        return e.returncode