package main

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

	"github.com/hamcha/tg"
)

type SearchResult struct {
	Name         string
	Description  *string
	Alternatives []string
	None         bool
}

type SearchResultData struct {
	ItemListElement []struct {
		Result struct {
			Name []struct {
				Value string `json:"@value"`
				Lang  string `json:"@language"`
			} `json:"name,omitempty"`
			Description []struct {
				Value string `json:"@value"`
				Lang  string `json:"@language"`
			} `json:"description,omitempty"`
			DetailedDescription []struct {
				Value string `json:"articleBody"`
				Lang  string `json:"inLanguage"`
			} `json:"detailedDescription,omitempty"`
		} `json:"result"`
	} `json:"itemListElement"`
	Error struct {
		Code    int    `json:"code"`
		Message string `json:"message"`
	} `json:"error,omitempty"`
}

const MAX_SEARCH_ALTS = 2

func search_init() {
	if strings.HasPrefix(*gapikey, "@") {
		data, err := ioutil.ReadFile((*gapikey)[1:])
		if err != nil {
			panic(err)
		}
		*gapikey = strings.TrimSpace(string(data))
	}
	if *gapikey == "" {
		panic(fmt.Errorf("Missing GAPI key for search module (provide it or --disable search)"))
	}
}

func search_message(broker *tg.Broker, update tg.APIMessage) {
	if isCommand(update, "search") {
		parts := strings.SplitN(*(update.Text), " ", 2)
		if len(parts) < 2 {
			broker.SendTextMessage(update.Chat, "Non mi hai dato niente da cercare!", &update.MessageID)
			return
		}
		broker.SendChatAction(update.Chat, tg.ActionTyping)

		result, err := searchAPI(parts[1])
		if err != nil {
			log.Printf("[search] %s\n", err.Error())
			broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
			return
		}

		if result.None {
			broker.SendTextMessage(update.Chat, "Non ho trovato nulla, mi spiace :(", &update.MessageID)
			return
		}

		resulttxt := fmt.Sprintf("Ecco la prima cosa che ho trovato:\n<b>%s</b>", result.Name)
		if result.Description != nil {
			resulttxt += "\n" + *(result.Description)
		}
		if len(result.Alternatives) > 0 {
			resulttxt += "\nAlternativamente:\n - " + strings.Join(result.Alternatives, "\n - ")
		}

		broker.SendTextMessage(update.Chat, resulttxt, &update.MessageID)
	}
}

func searchAPI(term string) (SearchResult, error) {
	resp, err := http.Get("https://kgsearch.googleapis.com/v1/entities:search?indent=true&languages=it&languages=en&query=" + url.QueryEscape(term) + "&key=" + *gapikey)
	if err != nil {
		return SearchResult{}, err
	}
	defer resp.Body.Close()

	var res SearchResultData
	err = json.NewDecoder(resp.Body).Decode(&res)
	if err != nil {
		return SearchResult{}, err
	}

	if res.Error.Message != "" {
		return SearchResult{}, fmt.Errorf("Request error: %d %s", res.Error.Code, res.Error.Message)
	}

	if len(res.ItemListElement) < 1 {
		return SearchResult{None: true}, nil
	}

	out := SearchResult{None: false}
	for _, item := range res.ItemListElement {
		// Skip elements without a name
		if item.Result.Name == nil || len(item.Result.Name) == 0 {
			continue
		}
		namestr := item.Result.Name[0].Value

		// Check if it has a small description
		if item.Result.Description != nil && len(item.Result.Description) > 0 {
			namestr += " (" + item.Result.Description[0].Value + ")"
		}

		// If we already had an item, add it to alternatives and find others
		if out.Name != "" {
			out.Alternatives = append(out.Alternatives, namestr)
			if len(out.Alternatives) > MAX_SEARCH_ALTS {
				break
			}
			continue
		}
		out.Name = namestr

		// Check for a description
		if item.Result.DetailedDescription != nil || len(item.Result.DetailedDescription) > 0 {
			out.Description = &(item.Result.DetailedDescription[0].Value)
		}
	}

	return out, nil
}