import std.stdio;
import std.string;
import std.conv;

import parser;

enum ObjType {
    FUNCTION,
    SCRIPT,
}

abstract class Obj {
    ObjType type;
}

class Function : Obj {
    Chunk chunk;
    int arity;
    string name;
    ObjType type;

    this(ObjType type, string name = "") {
        this.type = type;
        this.chunk = new Chunk();
        this.arity = 0;
        this.name = name;
    }

    override string toString() {
        if (type == ObjType.SCRIPT) {
            return "<neb>";
        } else {
            return format("<fn %s>", name);
        }
    }
}

enum OpCode {
    OP_ADD,
    OP_LESS,
    OP_NEGATE,
    OP_RETURN,
    OP_CONSTANT,
    OP_DEF_GLOBAL,
    OP_GET_GLOBAL,
    OP_SET_GLOBAL,
    OP_DEF_LOCAL,
    OP_GET_LOCAL,
    OP_SET_LOCAL,
    OP_POP,
    OP_POPB,
    OP_POP_SCOPE,
    OP_SUBTRACT,
    OP_NIL,

    OP_JUMP,
    OP_JUMP_IF_FALSE,
    OP_JUMP_IF_TRUE,

    OP_CALL,
}

class Chunk {
    int count = 0;
    ubyte[] code;
    int[] lines;
    Value[] constants;

    //int writeOp(OpCode opCode, int line) {
    int writeOp(ubyte opCode, int line) {
        this.code ~= opCode;
        this.lines ~= line;
        this.count++;
        assert(this.code.length == count);
        assert(this.lines.length == count);
        return count;
    }

    int addConstant(Value value) {
        this.constants ~= value;
        return to!int(this.constants.length - 1);
    }

}