from enum import Enum
import subprocess

import click
from crewai_core.constants import CREWAI_TRAINED_AGENTS_FILE_ENV
from packaging import version

from crewai_cli.utils import build_env_with_all_tool_credentials, read_toml
from crewai_cli.version import get_crewai_version


class CrewType(Enum):
    STANDARD = "standard"
    FLOW = "flow"


def run_crew(trained_agents_file: str | None = None) -> None:
    """Run the crew or flow by running a command in the UV environment.

    Starting from version 0.103.0, this command can be used to run both
    standard crews and flows. For flows, it detects the type from pyproject.toml
    and automatically runs the appropriate command.

    Args:
        trained_agents_file: Optional path to a trained-agents pickle produced
            by ``crewai train -f``. When set, exported as
            ``CREWAI_TRAINED_AGENTS_FILE`` so agents load suggestions from this
            file instead of the default ``trained_agents_data.pkl``.
    """
    crewai_version = get_crewai_version()
    min_required_version = "0.71.0"
    pyproject_data = read_toml()

    # Check for legacy poetry configuration
    if pyproject_data.get("tool", {}).get("poetry") and (
        version.parse(crewai_version) < version.parse(min_required_version)
    ):
        click.secho(
            f"You are running an older version of crewAI ({crewai_version}) that uses poetry pyproject.toml. "
            f"Please run `crewai update` to update your pyproject.toml to use uv.",
            fg="red",
        )

    # Determine crew type
    is_flow = pyproject_data.get("tool", {}).get("crewai", {}).get("type") == "flow"
    crew_type = CrewType.FLOW if is_flow else CrewType.STANDARD

    # Display appropriate message
    click.echo(f"Running the {'Flow' if is_flow else 'Crew'}")

    # Execute the appropriate command
    execute_command(crew_type, trained_agents_file=trained_agents_file)


def execute_command(
    crew_type: CrewType, trained_agents_file: str | None = None
) -> None:
    """Execute the appropriate command based on crew type.

    Args:
        crew_type: The type of crew to run.
        trained_agents_file: Optional trained-agents pickle path forwarded to
            the subprocess via the ``CREWAI_TRAINED_AGENTS_FILE`` env var.
    """
    command = ["uv", "run", "kickoff" if crew_type == CrewType.FLOW else "run_crew"]

    env = build_env_with_all_tool_credentials()
    if trained_agents_file:
        env[CREWAI_TRAINED_AGENTS_FILE_ENV] = trained_agents_file

    try:
        subprocess.run(command, capture_output=False, text=True, check=True, env=env)  # noqa: S603

    except subprocess.CalledProcessError as e:
        handle_error(e, crew_type)

    except Exception as e:
        click.echo(f"An unexpected error occurred: {e}", err=True)


def handle_error(error: subprocess.CalledProcessError, crew_type: CrewType) -> None:
    """
    Handle subprocess errors with appropriate messaging.

    Args:
        error: The subprocess error that occurred
        crew_type: The type of crew that was being run
    """
    entity_type = "flow" if crew_type == CrewType.FLOW else "crew"
    click.echo(f"An error occurred while running the {entity_type}: {error}", err=True)

    if error.output:
        click.echo(error.output, err=True, nl=True)

    pyproject_data = read_toml()
    if pyproject_data.get("tool", {}).get("poetry"):
        click.secho(
            "It's possible that you are using an old version of crewAI that uses poetry, "
            "please run `crewai update` to update your pyproject.toml to use uv.",
            fg="yellow",
        )