gen.go

//go:build ignore
// +build ignore

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"
	"text/template"
	"time"

	"github.com/MarkusFreitag/advent-of-code/util"
)

var (
	year = time.Now().Year()
	day  = time.Now().Day()
)

func yearPkg() string { return fmt.Sprintf("year%d", year) }

func dayPkg() string { return fmt.Sprintf("day%d", day) }

func main() {
	if os.Args[1] != "" {
		num, err := strconv.Atoi(os.Args[1])
		if err != nil {
			fmt.Printf("YEAR must be a number: %s\n", err.Error())
			return
		}
		year = num
	}
	if os.Args[2] != "" {
		num, err := strconv.Atoi(os.Args[2])
		if err != nil {
			fmt.Printf("DAY must be a number: %s\n", err.Error())
			return
		}
		day = num
	}

	templates, err := template.ParseGlob("templates/*.tpl")
	if err != nil {
		fmt.Printf("error while loading templates: %s\n", err.Error())
		return
	}

	path := filepath.Join("puzzles", yearPkg(), dayPkg())
	// check whether this day has already been generated
	if _, err := os.Stat(path); !os.IsNotExist(err) {
		fmt.Printf("%d_%d already exists\n", year, day)
		return
	}

	/*
	   1. download the days puzzle input and save it at inputs/YEAR_DAY.txt
	   2. ensure the days package directory exists
	   3. generate the code and test files at puzzles/YEAR/DAY
	   4. regenerate the years code file
	   5. regenerate the puzzles code file
	*/

	input, err := util.InputFromURL(year, day, util.WithAoCUserAgent("github.com/MarkusFreitag/advent-of-code", "fmarkus@mailbox.org"))

	if err != nil {
		fmt.Printf("error while downloading puzzle input for %d:%d: %s\n", year, day, err.Error())
		return
	}
	if err := os.MkdirAll("inputs", os.ModePerm); err != nil {
		fmt.Printf("error while creating input directory: %s\n", err.Error())
		return
	}
	if err := util.InputToFile(year, day, input); err != nil {
		fmt.Printf("error while saving puzzle input into file: %s\n", err.Error())
		return
	}

	if err := os.MkdirAll(path, os.ModePerm); err != nil {
		fmt.Printf("error while creating package directories: %s\n", err.Error())
		return
	}

	dayData := struct {
		Package string
	}{
		Package: dayPkg(),
	}
	fd, err := os.OpenFile(filepath.Join(path, fmt.Sprintf("%s.go", dayPkg())), os.O_RDWR|os.O_CREATE, 0664)
	if err != nil {
		fmt.Printf("error while creating code file: %s\n", err.Error())
		return
	}
	if err := templates.ExecuteTemplate(fd, "day.tpl", dayData); err != nil {
		fmt.Printf("error while generating code: %s\n", err.Error())
		return
	}
	if err := fd.Close(); err != nil {
		fmt.Printf("error while saving code file: %s\n", err.Error())
		return
	}

	fd, err = os.OpenFile(filepath.Join(path, fmt.Sprintf("%s_test.go", dayPkg())), os.O_RDWR|os.O_CREATE, 0664)
	if err != nil {
		fmt.Printf("error while creating testcode file: %s\n", err.Error())
		return
	}
	if err := templates.ExecuteTemplate(fd, "day_test.tpl", dayData); err != nil {
		fmt.Printf("error while generating testcode: %s\n", err.Error())
		return
	}
	if err := fd.Close(); err != nil {
		fmt.Printf("error while saving testcode file: %s\n", err.Error())
		return
	}

	yearData := struct {
		Package string
		Imports []string
		Days    []string
	}{
		Package: yearPkg(),
		Imports: make([]string, 0),
		Days:    make([]string, 0),
	}
	entries, err := ioutil.ReadDir(filepath.Join("puzzles", yearPkg()))
	if err != nil {
		fmt.Print("err: %s\n", err.Error())
		return
	}
	for _, entry := range entries {
		if entry.IsDir() {
			yearData.Imports = append(
				yearData.Imports,
				fmt.Sprintf("github.com/MarkusFreitag/advent-of-code/puzzles/%s/%s", yearPkg(), entry.Name()),
			)
			yearData.Days = append(yearData.Days, entry.Name())
		}
	}
	fd, err = os.OpenFile(filepath.Join("puzzles", yearPkg(), fmt.Sprintf("%s.go", yearPkg())), os.O_RDWR|os.O_CREATE, 0664)
	if err != nil {
		fmt.Printf("error while creating code file: %s\n", err.Error())
		return
	}
	if err := templates.ExecuteTemplate(fd, "year.tpl", yearData); err != nil {
		fmt.Printf("error while generating code: %s\n", err.Error())
		return
	}
	if err := fd.Close(); err != nil {
		fmt.Printf("error while saving code file: %s\n", err.Error())
		return
	}

	puzzlesData := struct {
		Years []string
	}{
		Years: make([]string, 0),
	}
	entries, err = ioutil.ReadDir("puzzles")
	if err != nil {
		fmt.Print("err: %s\n", err.Error())
		return
	}
	for _, entry := range entries {
		if entry.IsDir() {
			puzzlesData.Years = append(puzzlesData.Years, entry.Name())
		}
	}
	fd, err = os.OpenFile(filepath.Join("puzzles", "puzzles.go"), os.O_RDWR|os.O_CREATE, 0664)
	if err != nil {
		fmt.Printf("error while creating code file: %s\n", err.Error())
		return
	}
	if err := templates.ExecuteTemplate(fd, "puzzles.tpl", puzzlesData); err != nil {
		fmt.Printf("error while generating code: %s\n", err.Error())
		return
	}
	if err := fd.Close(); err != nil {
		fmt.Printf("error while saving code file: %s\n", err.Error())
		return
	}
}