package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"time"
)

func mustAtoi(line string) int {
	i, _ := strconv.Atoi(line)
	return i
}

func main() {
	start := time.Now()
	partOne()
	duration := time.Since(start)
	partTwo()
	duration2 := time.Since(start)
	fmt.Printf("p1: %s, p2: %s\n", duration, duration2-duration)
}

func makeScanner(test bool) *bufio.Scanner {
	var f *os.File
	if test {
		f, _ = os.Open("inputs/testinput")
	} else {
		f, _ = os.Open("inputs/input")
	}
	reader := bufio.NewReader(f)
	return bufio.NewScanner(reader)
}

type intCodeProgram struct {
	program []int
}

func parseIntCodeInput(line string) intCodeProgram {
	program := intCodeProgram{
		program: make([]int, 0),
	}
	acc := []byte{}
	for _, v := range line {
		switch v {
		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
			acc = append(acc, byte(v))
		case ',':
			program.program = append(program.program, mustAtoi(string(acc)))
			acc = []byte{}
		}
	}
	program.program = append(program.program, mustAtoi(string(acc)))
	return program
}

func runIntCodeProgram(p intCodeProgram) intCodeProgram {
	pos := 0
	for {
		switch p.program[pos] {
		case 1:
			sum := p.program[p.program[pos+1]] + p.program[p.program[pos+2]]
			p.program[p.program[pos+3]] = sum
			pos += 4
		case 2:
			mul := p.program[p.program[pos+1]] * p.program[p.program[pos+2]]
			p.program[p.program[pos+3]] = mul
			pos += 4
		case 99:
			return p
		}
	}
}

func partOne() {
	scanner := makeScanner(false)

	scanner.Scan()
	prog := parseIntCodeInput(scanner.Text())
	prog.program[1] = 12
	prog.program[2] = 2
	fmt.Println(runIntCodeProgram(prog).program[0])
}

func partTwo() {
	scanner := makeScanner(false)

	scanner.Scan()
	prog := parseIntCodeInput(scanner.Text())
	possibleInputs := len(prog.program)
	for i := 0; i < possibleInputs; i++ {
		for j := 0; j < possibleInputs; j++ {
			thisRun := intCodeProgram{
				program: make([]int, len(prog.program)),
			}
			copy(thisRun.program, prog.program)
			thisRun.program[1] = i
			thisRun.program[2] = j
			if runIntCodeProgram(thisRun).program[0] == 19690720 {
				fmt.Println(100*i + j)
			}
		}
	}
}