/*   SHS: Syntactically Homogeneous Shell
 *   Copyright (C) 2019  Aidan Hahn
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package shs

import (
    "strings"
    "fmt"
)

func FmtToken(arg *Token) string {
    suffix := "->"
    if arg.next == nil {
        suffix = ""
    }

    switch arg.tag {
    case LIST:
        return fmt.Sprintf("(%s, [List])%s", "LIST", suffix)

    default:
        return fmt.Sprintf("(%s, %s)%s", GetTagAsStr(arg.tag), arg._inner, suffix)
    }
}

func GetTagAsStr(tag token_t) string {
    switch tag {
    case LIST:
        return "LIST"
    case STRING:
        return "STRING"
    case NUMBER:
        return "NUMBER"
    case SYMBOL:
        return "SYMBOL"
    }
    return "UNKNOWN"
}

func PrintSExpression(arg *Token) {
    if arg == nil {
        return //TODO: Handle error here?
    }

    var lists TokenStack;
    lists.Push(arg)

loop:
    var constructor strings.Builder
    i := lists.Pop()
    if i == nil {
        return
    }

    for iter := i; iter != nil; iter = iter.next {
        if iter.tag == LIST {
            lists.Push(iter._inner.(*Token))
        }

        constructor.WriteString(FmtToken(iter))
    }

    println(constructor.String())
    goto loop
}