package main

import (
	"encoding/json"
	"net/http"
	"net/url"
	"os"
	"strings"
	"time"

	tgbotapi "git.zio.sh/astra/telegram-bot-api"
	"github.com/astravexton/logger"
	"github.com/google/uuid"
)

const openverseURL = "https://api.openverse.org/v1/images/"

var httpClient = &http.Client{Timeout: 5 * time.Second}

type openverseResponse struct {
	ResultCount int              `json:"result_count"`
	Results     []openverseImage `json:"results"`
}

type openverseImage struct {
	URL               string `json:"url"`
	Thumbnail         string `json:"thumbnail"`
	Title             string `json:"title"`
	Width             int    `json:"width"`
	Height            int    `json:"height"`
	ForeignLandingURL string `json:"foreign_landing_url"`
	Source            string `json:"source"`
	Filetype          string `json:"filetype"`
}

type Results struct {
	Height    int
	Image     string
	Source    string
	Thumbnail string
	Title     string
	URL       string
	Width     int
	Filetype  string
}

func main() {
	logger.Layout = time.Stamp
	logger.BitwiseLevel = logger.LogInfo | logger.LogWarning | logger.LogCritical
	bot, err := tgbotapi.NewBotAPI(os.Getenv("BOT_TOKEN"))
	if err != nil {
		logger.Critical(err.Error())
	}
	me, err := bot.GetMe()
	if err != nil {
		logger.Critical(err.Error())
	}
	logger.Info("Authorized as %s", me.UserName)

	u := tgbotapi.NewUpdate(0)
	u.Timeout = 60
	updates := bot.GetUpdatesChan(u)

	for update := range updates {
		if update.InlineQuery != nil {
			if update.InlineQuery.Query != "" {
				logger.Debug("Inline query %q from %s", update.InlineQuery.Query, update.InlineQuery.From)
				var results []interface{}

				images := getImageList(update.InlineQuery.Query)
				for c, image := range images {
					if c == 50 {
						break
					}
					var result interface{}
					if image.Filetype == "gif" || strings.HasSuffix(strings.ToLower(image.Image), ".gif") {
						result = &tgbotapi.InlineQueryResultGIF{
							Type:     "gif",
							ID:       uuid.New().String(),
							URL:      image.Image,
							ThumbURL: image.Thumbnail,
						}
					} else {
						result = &tgbotapi.InlineQueryResultPhoto{
							Type:     "photo",
							ID:       uuid.New().String(),
							URL:      image.Image,
							ThumbURL: image.Thumbnail,
						}
					}
					results = append(results, result)
				}
				inlineConf := tgbotapi.InlineConfig{
					InlineQueryID: update.InlineQuery.ID,
					IsPersonal:    false,
					CacheTime:     300,
					Results:       results,
				}
				bot.Request(inlineConf)
			}
		}
	}

}

func getImageList(query string) []Results {
	mature := "true"
	if strings.HasPrefix(query, "safe:on") {
		mature = "false"
		query = strings.TrimSpace(strings.TrimPrefix(query, "safe:on"))
	}
	if query == "" {
		return nil
	}

	// Anonymous requests are capped at 20; a registered token allows more.
	token := os.Getenv("OPENVERSE_TOKEN")
	pageSize := "20"
	if token != "" {
		pageSize = "50"
	}

	params := url.Values{}
	params.Set("q", query)
	params.Set("page_size", pageSize)
	params.Set("mature", mature)

	req, err := http.NewRequest(http.MethodGet, openverseURL+"?"+params.Encode(), nil)
	if err != nil {
		logger.Warning("building request: %s", err)
		return nil
	}
	req.Header.Set("User-Agent", "telegram-imagesearch-bot/1.0")
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}

	res, err := httpClient.Do(req)
	if err != nil {
		logger.Warning("openverse request failed: %s", err)
		return nil
	}
	defer res.Body.Close()

	if res.StatusCode != http.StatusOK {
		logger.Warning("openverse returned %s for %q", res.Status, query)
		return nil
	}

	var data openverseResponse
	if err := json.NewDecoder(res.Body).Decode(&data); err != nil {
		logger.Warning("decoding openverse response: %s", err)
		return nil
	}

	results := make([]Results, 0, len(data.Results))
	for _, img := range data.Results {
		results = append(results, Results{
			Height:    img.Height,
			Image:     img.URL,
			Source:    img.Source,
			Thumbnail: img.Thumbnail,
			Title:     img.Title,
			URL:       img.ForeignLandingURL,
			Width:     img.Width,
			Filetype:  img.Filetype,
		})
	}
	return results
}