package lib

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
)

type WikiFetcher struct {
	Config Config
	Cache  *Cache
}

func (f WikiFetcher) Fetch() string {
	q := `{"query":"{ pages { list(orderBy: UPDATED, orderByDirection: DESC, limit: 1){ updatedAt title }}}"}`
	wikiURL := fmt.Sprintf("%s/graphql", f.Config.WikiBaseURL)
	req, _ := http.NewRequest("POST", wikiURL, bytes.NewBuffer([]byte(q)))
	req.Header.Set("Authorization", "Bearer "+f.Config.WikiToken)
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		return ""
	}
	defer res.Body.Close()

	var r struct {
		Data struct {
			Pages struct {
				List []struct {
					UpdatedAt string
					Title     string
					Path      string
				}
			}
		}
	}
	json.NewDecoder(res.Body).Decode(&r)
	if len(r.Data.Pages.List) == 0 {
		return ""
	}
	u := r.Data.Pages.List[0]
	if f.Cache.TryUpdate("wiki", u.UpdatedAt) {
		url := fmt.Sprintf("%s/%s", f.Config.WikiBaseURL, u.Path)
		return fmt.Sprintf("Wiki: %s <%s>", u.Title, url)
	}
	return ""
}