package main

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

	"git.nefrace.ru/nefrace/nechotron"
	"github.com/NicoNex/echotron/v3"
)

var docApiURL = "https://docs.godotengine.org/_/api/v2/search/?q=%s&project=godot&version=%s&language=en"
var docURL = "https://docs.godotengine.org/en/%s/search.html?q=%s"
var lastDocSearch = time.Now()

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, version string) (string, string, error) {
	since := time.Since(lastDocSearch)
	if since < 20*time.Second {
		return "Извините, запросы происходят слишком часто\\.", "", nil
	}
	lastDocSearch = time.Now()

	topic_escaped := nechotron.EscapeMd2(topic)
	not_found := fmt.Sprintf("Извините, по запросу *%s* ничего не найдено\\.", topic_escaped)
	exactUrl := fmt.Sprintf(docApiURL, url.QueryEscape(topic), version)
	looselyUrl := fmt.Sprintf(docApiURL, url.QueryEscape(topic+"*"), version)
	workedTopic := topic
	response, err := getAndDecode[DocResponse](exactUrl)
	if err != nil || len(response.Results) == 0 {
		workedTopic = topic + "*"
		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 := nechotron.EscapeMd2(r.Title)
		link, _ := url.JoinPath(r.Domain, r.Path)
		textResults += fmt.Sprintf("%d\\. [%s](%s)\n", i+1, text, link)
	}
	text := fmt.Sprintf("Вот что я нашла по запросу *%s* \\(для версии `%s`\\): \n\n%s", topic_escaped, version, textResults)
	return text, workedTopic, nil
}

var doc_variants []string = []string{"4.1", "3.5"}

func handleDocRequest(u *nechotron.Update) error {
	topic := u.Ctx.Value(nechotron.FilteredValue("docTopic")).(string)
	currentVersion := doc_variants[0]
	versionButtons := []echotron.InlineKeyboardButton{}
	for _, variant := range doc_variants {
		if variant == currentVersion {
			continue
		}
		versionButtons = append(versionButtons, nechotron.InButtonCallback("Для "+variant, fmt.Sprintf("docs:%s:%s", variant, topic)))
	}
	text, workedTopic, docerr := getDocs(topic, doc_variants[0])
	if docerr != nil {
		log.Println("Can't get docs: ", docerr)
	}
	kb := nechotron.NewInlineKeyboard().
		Row(versionButtons...).
		Row(nechotron.InButtonURL("Поискать самостоятельно", fmt.Sprintf(docURL, currentVersion, url.QueryEscape(workedTopic)))).
		Row(nechotron.InButtonCallback("Спасибо, не надо", "delete"))
	opts := nechotron.NewOptions().
		MarkdownV2().
		ReplyTo(u.MessageID()).
		ReplyMarkup(kb.Markup()).
		MessageOptions()

	_, err := u.AnswerText(text, opts)
	return err
}

func handleDocCallback(u *nechotron.Update) error {
	text := strings.TrimPrefix(u.Callback(), "docs:")
	items := strings.Split(text, ":")
	version := items[0]
	topic := items[1]
	versionButtons := []echotron.InlineKeyboardButton{}
	for _, variant := range doc_variants {
		if variant == version {
			continue
		}
		versionButtons = append(versionButtons, nechotron.InButtonCallback("Для "+variant, fmt.Sprintf("docs:%s:%s", variant, topic)))
	}
	text, workedTopic, docerr := getDocs(topic, version)
	if docerr != nil {
		log.Println("Can't get docs: ", docerr)
	}
	kb := nechotron.NewInlineKeyboard().
		Row(versionButtons...).
		Row(nechotron.InButtonURL("Поискать самостоятельно", fmt.Sprintf(docURL, version, url.QueryEscape(workedTopic)))).
		Row(nechotron.InButtonCallback("Спасибо, не надо", "delete"))
	opts := nechotron.NewOptions().
		MarkdownV2().
		ReplyMarkup(kb.Markup()).
		MessageTextOptions()

	_, err := u.EditText(text, opts)
	if err != nil {
		log.Println(err)
		log.Println(text)
	}
	return err
}