package fr.celticinfo.lox

class AstPrinter : ExprVisitor<String> {
    fun print(expr: Expr): String {
        return expr.accept(this)
    }

    override fun visitCall(expr: Call): String {
        return parenthesize("call", expr.callee, *expr.arguments.toTypedArray())
    }

    override fun visitAssign(expr: Assign): String {
        return parenthesize("=", expr)
    }

    override fun visitBinary(expr: Binary): String {
        return parenthesize(expr.operator.lexeme, expr.left, expr.right)
    }

    override fun visitGrouping(expr: Grouping): String {
        return parenthesize("group", expr.expression)
    }

    override fun visitLiteral(expr: Literal): String {
        return expr.value?.toString() ?: "nil"
    }

    override fun visitLogical(expr: Logical): String {
        return parenthesize(expr.operator.lexeme, expr.left, expr.right)
    }

    override fun visitUnary(expr: Unary): String {
        return parenthesize(expr.operator.lexeme, expr.right)
    }

    override fun visitVariable(expr: Variable): String {
        return expr.name.lexeme
    }
    
    private fun parenthesize(name: String, vararg exprs: Expr): String {
        val builder = StringBuilder()
        builder.append("(").append(name)
        for (expr in exprs) {
            builder.append(" ")
            builder.append(expr.accept(this))
        }
        builder.append(")")
        return builder.toString()
    }
}