package cli

import (
	"context"
	"os"
	"os/signal"
	"path/filepath"

	"github.com/FAU-CDI/wisski-distillery/internal/bootstrap"
	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
)

// Params are used to initialize the excutable.
type Params struct {
	ConfigPath string          // ConfigPath is the path to the configuration file for the distillery
	Context    context.Context // Context for the distillery
}

// ParamsFromEnv creates a new set of parameters from the environment.
// Uses [ReadBaseDirectory] or falls back to [BaseDirectoryDefault].
func ParamsFromEnv() (params Params, err error) {

	// try to read the base directory!
	value, err := ReadBaseDirectory(new(environment.Native)) // TODO: Are we sure about the native environment here?
	switch {
	case environment.IsNotExist(err):
		params.ConfigPath = bootstrap.BaseDirectoryDefault
	case err == nil:
		params.ConfigPath = value
	default:
		return params, err
	}

	// and add the configuration file name to it!
	params.ConfigPath = filepath.Join(params.ConfigPath, bootstrap.ConfigFile)

	// generate a new context
	ctx, cancel := context.WithCancel(context.Background())
	params.Context = ctx

	// cancel the context on an interrupt
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	go func() {
		<-c
		cancel()
	}()

	// and return the params!
	return params, nil
}