#include <stdarg.h>
#include <stdio.h>
#include <string.h>

#include "ByteCodePrinter.h"

#define LINE_LENGTH 80

static ByteCode* code;
static int readIndex;
static int line;
static char buffer[LINE_LENGTH];
static int bIndex;

static void btPrintHeading() {
    puts("|  Index |  Line |            Operation | Argument 1 | Argument 2 |");
    puts("|--------|-------|----------------------|------------|------------|");
}

static void btAdd(const char* format, ...) {
    va_list args;
    va_start(args, format);
    bIndex += vsnprintf(buffer + bIndex, LINE_LENGTH - bIndex, format, args);
    va_end(args);
}

static void btFillBase() {
    buffer[0] = '\0';
    bIndex = 0;
    btAdd("| %6d | %5d |", readIndex - 1, line);
}

static void btRead(void* buffer, int length) {
    if(readIndex + length > code->length) {
        return;
    }
    memcpy(buffer, code->code + readIndex, length);
    readIndex += length;
}

static void btAddOperation(const char* s) {
    if(s[0] != '\0' && s[1] != '\0' && s[2] != '\0' && s[3] != '\0') {
        s += 3;
    }
    btAdd(" %20s |", s);
}

static void btAddInt() {
    int value = 0;
    btRead(&value, sizeof(int));
    btAdd(" %10d |", value);
}

static void btAddFloat() {
    float value = 0;
    btRead(&value, sizeof(float));
    btAdd(" %10.2f |", value);
}

static void btAddFiller() {
    btAdd("            |");
}

static void sPrintLine() {
    btRead(&line, 2);
    printf("| %6d |-------|----------------------|------------|------------|\n",
           readIndex - 3);
}

static void btPrintOp(const char* op) {
    btFillBase();
    btAddOperation(op);
    btAddFiller();
    btAddFiller();
    puts(buffer);
}

static void btPrintInt(const char* op) {
    btFillBase();
    btAddOperation(op);
    btAddInt();
    btAddFiller();
    puts(buffer);
}

static void btPrintInt2(const char* op) {
    btFillBase();
    btAddOperation(op);
    btAddInt();
    btAddInt();
    puts(buffer);
}

static void btPrintFloat(const char* op) {
    btFillBase();
    btAddOperation(op);
    btAddFloat();
    btAddFiller();
    puts(buffer);
}

static void btPrintString(const char* msg) {
    btFillBase();
    int length = 0;
    btRead(&length, sizeof(int));
    char* s = (char*)(code->code + readIndex);
    readIndex += length;
    btAddOperation(msg);
    btAdd(" %10s |", s);
    btAddFiller();
    puts(buffer);
}

#define PRINT_OP_BASE(op, name)                                                \
    case op:                                                                   \
        btPrint##name(#op);                                                    \
        break;
#define PRINT_OP(op) PRINT_OP_BASE(op, Op)
#define PRINT_OP_INT(op) PRINT_OP_BASE(op, Int)
#define PRINT_OP_INT2(op) PRINT_OP_BASE(op, Int2)

static void btConsumeOperation() {
    int op = code->code[readIndex++];
    switch(op) {
        PRINT_OP(OP_NOTHING);
        PRINT_OP_INT(OP_PUSH_INT);
        PRINT_OP_BASE(OP_PUSH_FLOAT, Float);
        PRINT_OP(OP_PUSH_NULL);
        PRINT_OP(OP_PUSH_TRUE);
        PRINT_OP(OP_PUSH_FALSE);
        PRINT_OP_INT2(OP_PUSH_VARS);
        PRINT_OP_INT(OP_POP_VARS);
        PRINT_OP(OP_POP);
        PRINT_OP(OP_SET);
        PRINT_OP(OP_PRE_INCREMENT);
        PRINT_OP(OP_POST_INCREMENT);
        PRINT_OP(OP_PRE_DECREMENT);
        PRINT_OP(OP_POST_DECREMENT);
        PRINT_OP(OP_ADD);
        PRINT_OP(OP_SUB);
        PRINT_OP(OP_MUL);
        PRINT_OP(OP_DIV);
        PRINT_OP(OP_MOD);
        PRINT_OP(OP_INVERT_SIGN);
        PRINT_OP(OP_LESS);
        PRINT_OP(OP_GREATER);
        PRINT_OP(OP_EQUAL);
        PRINT_OP(OP_NOT);
        PRINT_OP(OP_AND);
        PRINT_OP(OP_OR);
        PRINT_OP(OP_BIT_NOT);
        PRINT_OP(OP_BIT_AND);
        PRINT_OP(OP_BIT_OR);
        PRINT_OP(OP_BIT_XOR);
        PRINT_OP(OP_LEFT_SHIFT);
        PRINT_OP(OP_RIGHT_SHIFT);
        PRINT_OP(OP_PRINT);
        PRINT_OP_INT(OP_GOTO);
        PRINT_OP_INT2(OP_GOSUB);
        PRINT_OP_INT(OP_IF_GOTO);
        PRINT_OP(OP_SET_RETURN);
        PRINT_OP(OP_RETURN);
        PRINT_OP(OP_DUPLICATE);
        PRINT_OP(OP_ALLOCATE_ARRAY);
        PRINT_OP(OP_ARRAY_LENGTH);
        PRINT_OP_INT(OP_REFERENCE_FROM_VAR);
        PRINT_OP_INT(OP_REFERENCE_FROM_ARRAY);
        PRINT_OP(OP_DEREFERENCE);
        PRINT_OP_BASE(OP_PUSH_CONST_STRING, String);
        case OP_LINE: sPrintLine(); break;
        default: printf("Unknown: %d\n", op);
    }
}

void btPrint(ByteCode* bt) {
    code = bt;
    readIndex = 0;
    line = 0;
    btPrintHeading();
    while(readIndex < code->length) {
        btConsumeOperation();
    }
}