package sim_8086

import "core:os"
import path "core:path/filepath"
import "core:fmt"
import "core:math"
import "core:strings"
import "core:reflect"

CPU := Cpu {
    memory = make([dynamic]u8, 65536),
}

main :: proc() {
    f,err := os.open(os.args[1])
    if err != os.ERROR_NONE {
        fmt.eprintln("ERROR:", err)
        os.exit(1)
    }
    defer os.close(f)

    what_to_print := len(os.args) >= 3 ? os.args[2] : ""

    data := make([]u8, 1024)
    bytes_read, err2 := os.read(f, data)
    if err2 != nil {
        // ...
        os.exit(1)
    }

    // asdf :u16 = 0b00000110_11011101
    // asdf2 :i16 = (i16)(asdf)
    // fmt.printfln("%d", asdf2)
    print_at_end := false
    line_count := 0
    instruction_list := make([dynamic]string, 0, 512)
    instructions_list := make([dynamic]Instruction, 0, 512)

    decode_data(&instructions_list, data[:], bytes_read)

    for inst in instructions_list {
        execute_instruction(inst)
    }

    if what_to_print == "registers" || what_to_print == "all" {
        fmt.println("Registers")
        for reg_val,name in CPU.registers {
            full := fmt.aprintf("%s: %d ", name, i16(reg_val.full))
            hex := fmt.aprintf("0x%04x ", u16(reg_val.full))
            fmt.printf("%s %*[1]s %s %*[4]s %08b %08b",
                       full, 18 - len(full), "|", hex, 10 - len(hex), "|", reg_val.high, reg_val.low)
            fmt.println()
        }
        fmt.println("\nFlags")
        for state,flag in CPU.flags {
            fmt.printf("%c:%d  ",reflect.enum_string(flag)[0], state ? 1 : 0)
        }
        fmt.println()

        failed_ref: bool
        path,ok := strings.replace(os.args[1], ".bin", ".txt", 1)
        ref_cpu,_ := extract_reference_cpu_state(path)
        for reg_val,name in ref_cpu.registers {
            if CPU.registers[name].full != reg_val.full {
                msg := "%s register does not match reference - Expected 0x%04x | Actual 0x%04x"
                fmt.printfln(msg, name, reg_val.full, CPU.registers[name].full)
                failed_ref = true
            }
        }
        for f in Flag {
            if ref_cpu.flags[f] != CPU.flags[f] {
                msg := "%s flag does not match reference - Expected %d | Actual %d"
                fmt.printfln(msg, f, ref_cpu.flags[f] ? 1 : 0, CPU.flags[f] ? 1 : 0)
                failed_ref = true
            }
        }
        if failed_ref {
            os.exit(1)
        }
    }
    if what_to_print == "instructions" || what_to_print == "all" {
        print_instructions_stdout(instructions_list[:])
    }
}