package main

import (
    "fmt"
    "os"    
    "regexp"
    "strings"
)


type ukaz struct {
    opcode int 
    st_operandov int
    format int // F1 - 1, F2 - 2, F3 - 3, F4 - 4, SIC - 5
    velikost int //v bajtih
}

var ukazna_tabela = map[string]int{
    "ADD": 0x18, 
    "ADDF": 0x58,
    "ADDR": 0x90, 
    "AND": 0x40, 
    "CLEAR": 0xB4,
    "COMP": 0x28,
    "COMPF": 0x88,
    "COMPR": 0xA0,
    "DIV": 0x24, 
    "DIVF": 0x64,
    "DIVR": 0x9C, 
    "FIX": 0xC4, 
    "FLOAT": 0xC0,
    "HIO": 0xF4, 
    "J": 0x3C, 
    "JEQ": 0x30, 
    "JGT": 0x34, 
    "JLT": 0x38,
    "JSUB": 0x48,
    "LDA": 0x00, 
    "LDB": 0x68, 
    "LDCH": 0x50,
    "LDF": 0x70,
    "LDL": 0x08, 
    "LDS": 0x6C,
    "LDT": 0x74,
    "LDX": 0x04,
    "LPS": 0xD0,
    "MUL": 0x20,
    "MULF": 0x60,
    "MULR": 0x98,
    "NORM": 0xC8, 
    "OR": 0x44,
    "RD": 0xD4,
    "RMO": 0xAC,
    "RSUB": 0x4C,
    "SHIFTL": 0xA4,
    "SHIFTR": 0xA8,
    "SIO": 0xF0,
    "SSK": 0xEC, 
    "STA": 0x0C,
    "STB": 0x78, 
    "STCH": 0x54,
    "STF": 0x80,
    "STI": 0xD4,
    "STL": 0x14,
    "STS": 0x74, 
    "STSW": 0xE8, 
    "STT": 0x84, 
    "STX": 0x10, 
    "SUB": 0x1C, 
    "SUBF": 0x5C, 
    "SUBR": 0x94, 
    "SVC": 0xB0, 
    "TD": 0xE0, 
    "TIO": 0xF8, 
    "TIX": 0x2C, 
    "TIXR": 0xB8,
    "WD": 0xDC
}

// Pregledovalnik bere vhodne vrstice in jih razgradi na posamezne enote.
// Razpoznane elemente okvalificira (oznaka / mnemonik / operand / komentar) 
// //<zbirniski stavek> ::== [<oznaka stavka>] <ločilo> <mnemonik> <ločilo> {<operand> <ločilo>} [<komentar>]



func main() {
    //register, _ := regexp.Compile("A|X|L|B|S|T|F")
    
    inputbyte, err := os.ReadFile("input_invalid.asm")
    if err != nil {
        fmt.Println("Error reading input file: ", err)
        return
    }
    input := string(inputbyte)
    pattern := regexp.MustCompile(`.*\n`)    
    matches := pattern.FindAllString(input, -1)
    //var AST []ukaz
    for _, el := range matches {
        match_pure_comment, err := regexp.MatchString(`(?m)^[\t ]*\..*$\n`, el)
        if err != nil {
            fmt.Println("Error while matching string.")
        }
        if match_pure_comment {
            continue
        }
        match_empty, err := regexp.MatchString(`(?m)^[\t ]*$\n`, el)
        if err != nil {
            fmt.Println("Error while matching string.")
        }
        if match_empty {
            continue
        }
        match_F1, err := regexp.MatchString(`(?m)^[A-Za-z_]*[\t ]+[A-Za-z]+[\t ]*(\..*)?$\n`, el)
        if err != nil {
            fmt.Println("Error while matching string.")
        }
        if match_F1 {
            var nov_ukaz ukaz
            nov_ukaz.format = 1
            nov_ukaz.st_operandov = 0
            nov_ukaz.velikost = 1
            pattern := regexp.MustCompile(`[\t ]+[A-Za-z]+`)
            mnemonik := strings.Trim(re.FindString(el), " \n")
            nov_ukaz.opcode = ukazna_tabela[mnemonik]; 
            fmt.Print(mnemonik)
        }  
    }
}