package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"net/url"
	"strings"
	"time"

	"github.com/go-telegram/bot"
)

var docApiURL = "https://docs.godotengine.org/_/api/v3/search/?q=project:godot %s"
var docURL = "https://docs.godotengine.org/en/stable/search.html?q=%s"
var docApiURL_ru = "https://docs.godotengine.org/_/api/v3/search/?q=project:godot-ru %s"
var docURL_ru = "https://docs.godotengine.org/ru/4.x/search.html?q=%s"
var lastDocSearch = time.Now().Add(-1 * time.Hour)

type DocResponse struct {
	Count    uint        `json:"count"`
	Next     string      `json:"next"`
	Previous string      `json:"previous"`
	Results  []DocResult `json:"results"`
}

type DocResult struct {
	Title      string        `json:"title"`
	Domain     string        `json:"domain"`
	Path       string        `json:"path"`
	Highlights DocHighlights `json:"highlights"`
}

type DocHighlights struct {
	Title []string `json:"title"`
}

func getAndDecode[T any](u string) (*T, error) {
	req, err := url.ParseRequestURI(u)
	if err != nil {
		log.Println("Can't parse url: ", err)
		return nil, err
	}
	result, err := http.Get(req.String())
	if err != nil {
		log.Println("Can't get http: ", err)
		return nil, err
	}
	defer result.Body.Close()
	var response T
	err = json.NewDecoder(result.Body).Decode(&response)
	if err != nil {
		return nil, err
	}
	return &response, nil
}

func getDocs(topic string, russian bool) (string, error) {
	apiURL := docApiURL
	pageURL := docURL
	if russian {
		apiURL = docApiURL_ru
		pageURL = docURL_ru
	}
	since := time.Since(lastDocSearch)
	GO_SEARCH_YOURSELF := fmt.Sprintf("\n\n[Попробуйте поискать самостоятельно\\!](%s)", fmt.Sprintf(pageURL, url.QueryEscape(topic)))
	if since < 5*time.Second {
		return "Извините, запросы происходят слишком часто" + GO_SEARCH_YOURSELF, nil
	}
	lastDocSearch = time.Now()

	topic_escaped := bot.EscapeMarkdown(topic)
	not_found := fmt.Sprintf("Извините, по запросу *%s* ничего не найдено\\."+GO_SEARCH_YOURSELF, topic_escaped)
	exactUrl := fmt.Sprintf(apiURL, url.QueryEscape(topic))
	looselyUrl := fmt.Sprintf(apiURL, url.QueryEscape(topic+"*"))
	response, err := getAndDecode[DocResponse](exactUrl)
	if err != nil || len(response.Results) == 0 {
		response, err = getAndDecode[DocResponse](looselyUrl)
		if err != nil || len(response.Results) == 0 {
			return not_found, nil
		}
	}
	textResults := ""
	for i, r := range response.Results {
		if i > 9 {
			break
		}
		text := bot.EscapeMarkdown(r.Title)
		link, _ := url.JoinPath(r.Domain, r.Path)
		textResults += fmt.Sprintf("%d\\. [%s](%s)\n", i+1, text, link)
	}
	textResults += fmt.Sprintf("\n\n Или вы можете попробовать [поискать самостоятельно](%s)\\!", fmt.Sprintf(pageURL, topic))
	text := fmt.Sprintf("Вот что я нашла по запросу *%s*: \n\n%s", topic_escaped, textResults)
	return text, nil
}

func HandleDocRequest(g Godette) {
	topic := strings.TrimPrefix(g.update.Message.Text, "/docs ")
	text, docerr := getDocs(topic, false)
	if docerr != nil {
		log.Println("Can't get docs: ", docerr)
	}

	_, err := g.ReplyWithMarkdown(text)
	if err != nil {
		log.Println(err)
	}
}

func HandleDocRequestRu(g Godette) {
	topic := strings.TrimPrefix(g.update.Message.Text, "/docs_ru ")
	text, docerr := getDocs(topic, true)
	if docerr != nil {
		log.Println("Can't get docs: ", docerr)
	}

	_, err := g.ReplyWithMarkdown(text)
	if err != nil {
		log.Println(err)
	}
}