package utils

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
)

type Solver interface {
	ParseInput(input []string)
	SolvePart1() any
	SolvePart2() any
}

func ReadInput(inputFileName string) ([]string, error) {
	var input = make([]string, 0)

	reader, err := os.Open(inputFileName)
	if err != nil {
		return input, fmt.Errorf("failed to open input file: %w", err)
	}

	scanner := bufio.NewScanner(reader)
	for scanner.Scan() {
		input = append(input, scanner.Text())
	}
	return input, nil
}

func GetInputFileName(dayNumber int, testMode bool) string {
	var testString string
	if testMode {
		testString = "test"
	} else {
		testString = "prod"
	}

	return fmt.Sprintf("day%d/%s.in.txt", dayNumber, testString)
}

func DownloadInput(sessionCookie string, dayNumber int, inputFileName string) error {
	req, err := http.NewRequest("GET", fmt.Sprintf("https://adventofcode.com/2022/day/%d/input", dayNumber), nil)
	if err != nil {
		log.Fatalf("couldn't create reques: %s", err)
	}
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionCookie})

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	writer, err := os.Create(inputFileName)
	if err != nil {
		return err
	}

	if _, err := io.Copy(writer, resp.Body); err != nil {
		return err
	}

	return nil
}