main.go

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"

	"github.com/google/go-github/v25/github"
	"golang.org/x/oauth2"
)

func main() {
	ctx := context.Background()
	ts := oauth2.StaticTokenSource(
		&oauth2.Token{AccessToken: "REPLACE_ME"},
	)
	tc := oauth2.NewClient(ctx, ts)

	client := github.NewClient(tc)

	// list all repositories for the authenticated user

	languages := []string{
		"c",
		"cpp",
		"css",
		"html",
		"php",
		"scala",
		"csharp",
		"swift",
		"go",
		"rust",
		"python",
		"ruby",
		"java",
		"javascript",
		"typescript",
		"shell",
		"ocaml",
		"clojure",
		"kotlin",
		"julia",
		"elixir",
		"erlang",
		"haskell",
		"r",
		"perl",
		"lua",
		"matlab",
	}

	repoMap := map[string][]string{}

	for _, language := range languages {
		rs, err := getRepos(ctx, client, language)
		if err != nil {
			log.Fatalf("error when fetching repos, err: %q", err)
		}

		names := []string{}
		for _, r := range rs {
			names = append(names, *r.FullName)
		}

		repoMap[language] = names

	}

	file, err := json.MarshalIndent(repoMap, "", " ")
	if err != nil {
		log.Fatalf("error when marshalling json, err: %q", err)
	}

	err = ioutil.WriteFile("repos.json", file, 0644)
	if err != nil {
		log.Fatalf("error when writing json file, err: %q", err)
	}

}

func writeRepos(fileName string, repoNames []string) {
	file, err := json.MarshalIndent(repoNames, "", " ")
	if err != nil {
		log.Fatalf("error when marshalling json, err: %q", err)
	}

	err = ioutil.WriteFile(fmt.Sprintf("%s.json", fileName), file, 0644)
	if err != nil {
		log.Fatalf("error when writing json file, err: %q", err)
	}
}

func getRepos(ctx context.Context, c *github.Client, language string) ([]github.Repository, error) {
	var allRepos []github.Repository
	opt := &github.SearchOptions{
		Sort:  "stars",
		Order: "desc",
		ListOptions: github.ListOptions{
			PerPage: 100,
		},
	}

	for {
		if len(allRepos) >= 1000 {
			return allRepos, nil
		}

		result, response, err := c.Search.Repositories(ctx, fmt.Sprintf("language:%s", language), opt)
		if err != nil {
			return nil, err
		}

		log.Printf("rate limit: %s", response.Rate)

		allRepos = append(allRepos, result.Repositories...)
		if response.NextPage == 0 {
			return allRepos, nil
		}

		opt.Page = response.NextPage
	}

}