package libmcpil
import (
	"strings"
	"os/exec"
	"os"
)

const Version = "1.0"

// Fetch the options from an executable_path as a map.
// executable_path must be a string with an executable
// that provides --print-available-feature-flags and its
// functionality.
func GetOptionsMap(executable_path string) map[string]bool {

	flags_unformatted, _ := exec.Command(executable_path, "--print-available-feature-flags").Output()
	flags_newline_split := strings.Split(string(flags_unformatted), "\n")
	//fmt.Println(flags_newline_split)
	flags_formatted := map[string]bool{}
	for i := 0; i <= len(flags_newline_split)-1; i++ {
		flag := flags_newline_split[i]
		if strings.HasPrefix(flag, "TRUE") {
			flags_formatted[string((flag[5:]))] = true
		} else if strings.HasPrefix(flag, "FALSE") {
			flags_formatted[string(flag[6:])] = false
	        }
		//fmt.Println(flags_formatted) // Debug
        }
	//fmt.Println(flags_formatted)

	return flags_formatted
}

// Same as GetOptionsMap but returns a slice of option
// names instead of options and their values.
func GetOptionsList (executable_path string) []string {
	flags_map := GetOptionsMap(executable_path)
	flags_slice := []string{}
	for key, _ := range flags_map {
		flags_slice = append(flags_slice, key)
	}
	return flags_slice
}


// Launch the game provided the executable path
// Features must be a slice with strings of enabled features.
//
func Launch (
	executable_path string,
	username string,
        render_distance string,
	debug bool,
	features []string,
	benchmark bool,
        ) *exec.Cmd {

	var executable_args []string // Arguments slice

	// Set the arguments
	if debug{
		executable_args = append(executable_args, "--debug")
	}
	if benchmark {
		executable_args = append(executable_args, "--benchmark")
	}

	cmd := exec.Command(executable_path, executable_args...) // Executable init

	cmd.Env = os.Environ() // This is required, without this Reborn won't work.

	features_string := strings.Join(features, "|") // Python equievelent of .join

	cmd.Env = append(cmd.Env, // Append the enviroment variables
	    "MCPI_USERNAME="+username,
	    "MCPI_RENDER_DISTANCE="+render_distance,
	    "MCPI_FEATURE_FLAGS="+features_string,
        )

	// Return the Cmd object to let the user do anything they want with it
	return cmd
}