package console

import (
	"errors"
)

var (
	commands = make(map[string]Commander)
)

// Console Command interface
type Commander interface {
	FromArgs(args []string) error // Load data from os arguments or flag.Args()
	Usage(string) string          // usage message
	RpcMethod() string            // Method which should be called remotely
	RpcParams() interface{}       // Parameters to send out on rpc
	RpcResult() interface{}       // Only requirement is to have a String method to print on console
	defaults() error              // set defaults wherever necessary
}

// Process args and return right command Value or error
func GetCommandValue(args []string) (Commander, error) {
	if len(args) < 2 {
		return nil, errors.New("\n\tUsage: cgr-console [cfg_opts...{-h}] <command>\n")
	}
	cmdVal, exists := commands[args[1]]
	if !exists {
		return nil, errors.New("\n\tUsage: cgr-console [cfg_opts...{-h}] <status|get_balance>\n")
	}
	if err := cmdVal.FromArgs(args); err != nil {
		return nil, err
	}
	return cmdVal, nil
}