package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/hamcha/tg"
)

type QRequest struct {
	SessionID string `json:"sessionId"`
	Query     string `json:"query"`
	Language  string `json:"lang"`
}

type QResponse struct {
	ID        string    `json:"id"`
	Timestamp time.Time `json:"timestamp"`
	Result    struct {
		Source           string            `json:"source"`
		ResolvedQuery    string            `json:"resolvedQuery"`
		Action           string            `json:"action"`
		ActionIncomplete bool              `json:"actionIncomplete"`
		Parameters       map[string]string `json:"parameters"`
		Contexts         []struct {
			Name       string `json:"name"`
			Parameters struct {
				Name string `json:"name"`
			} `json:"parameters"`
			Lifespan int `json:"lifespan"`
		} `json:"contexts"`
		Metadata struct {
			IntentID   string `json:"intentId"`
			IntentName string `json:"intentName"`
		} `json:"metadata"`
		Fulfillment struct {
			Speech string `json:"speech"`
		} `json:"fulfillment"`
	} `json:"result"`
	Status struct {
		Code      int    `json:"code"`
		ErrorType string `json:"errorType"`
	} `json:"status"`
}

const talkBaseURL = "https://api.api.ai/v1"

func talk_init() {
	if strings.HasPrefix(*talktoken, "@") {
		data, err := ioutil.ReadFile((*talktoken)[1:])
		if err != nil {
			panic(err)
		}
		*talktoken = strings.TrimSpace(string(data))
	}
	if *talktoken == "" {
		panic(fmt.Errorf("API token for api.ai must be provided! (provide it or --disable talk)"))
	}
}

func talk_message(broker *tg.Broker, update tg.APIMessage) {
	// Must be a text message
	if update.Text == nil {
		return
	}
	text := *(update.Text)

	// Must not be a command
	if text[0] == '/' {
		return
	}

	quoted := false

	// Make sure it's aimed at Clessy
	if strings.Index(text, "@"+*botname) >= 0 {
		// @maudbot <something>
		text = strings.Replace(text, "@"+*botname, "", 1)
	} else if idx := strings.Index(strings.ToLower(text), "clessy"); idx == 0 && len(text) > 7 {
		// Clessy, <something>
		text = strings.TrimLeft(text[len("clessy"):], ":,")
	} else if text[0] != '/' && update.ReplyTo != nil && update.ReplyTo.User.Username == *botname {
		// Reply to Clessy (previous prompt?) which is not a command (such as unsplash), pass
		quoted = true
	} else if update.Chat.Username != nil {
		// Private chat, pass
	} else {
		return
	}
	text = strings.TrimSpace(text)

	// Generate unique id for user
	id := strconv.FormatInt(update.User.UserID, 36)
	if len(id) > 36 {
		id = id[:36]
	}

	// Create POST body
	data, err := json.Marshal(QRequest{
		SessionID: id,
		Query:     text,
		Language:  "it",
	})
	if err != nil {
		log.Printf("[talk] Could not create JSON body: %s\n", err.Error())
		broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
		return
	}

	// Build the request
	req, err := http.NewRequest("POST", talkBaseURL+"/query?v=20150910", bytes.NewReader(data))
	if err != nil {
		log.Printf("[talk] Could not create POST request: %s\n", err.Error())
		broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
		return
	}

	if !quoted {
		broker.SendChatAction(update.Chat, tg.ActionTyping)
	}

	req.Header.Add("Authorization", "Bearer "+*talktoken)
	req.Header.Set("Content-Type", "application/json; charset=utf-8")

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		log.Printf("[talk] Request error: %s\n", err.Error())
		broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
		return
	}
	defer resp.Body.Close()

	var record QResponse
	if err := json.NewDecoder(resp.Body).Decode(&record); err != nil {
		log.Printf("[talk] Could not decode JSON response: %s\n", err.Error())
		broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
		return
	}

	if record.Status.ErrorType != "success" {
		body, _ := json.MarshalIndent(record, "", "  ")
		log.Printf("[talk] Non-success status, full response body follows:\n%s\n", body)
		broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
		return
	}

	reply := record.Result.Fulfillment.Speech

	// Replace tokens if found
	if strings.Index(reply, "$") >= 0 {
		reply = strings.Replace(reply, "$name", update.User.FirstName, -1)
	}

	// Call command if needed
	if reply[0] == '#' {
		//TODO Find a better way?
		if strings.HasPrefix(reply, "#metafora") {
			reply = metaforaAPI()
		}
		return
	}

	if record.Result.Action != "" && !record.Result.ActionIncomplete {
		switch record.Result.Action {
		case "viaggi":
			// Check that both parameters are given
			if record.Result.Parameters["from-city"] != "" && record.Result.Parameters["to-city"] != "" {
				data, err := viaggiAPI(record.Result.Parameters["from-city"], record.Result.Parameters["to-city"])
				if err != nil {
					log.Printf("[talk] viaggi failed:\n%s\n", record.Result.Action)
					broker.SendTextMessage(update.Chat, "<b>ERRORE!</b> @hamcha controlla la console!", &update.MessageID)
					return
				}
				reply += "\n" + data
			}
		case "search":
			result, err := searchAPI(record.Result.Parameters["search-item"])
			if err != nil {
				log.Printf("[talk] search failed:\n%s\n", record.Result.Action)
				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
			}

			reply = fmt.Sprintf("%s\n<b>%s</b>", reply, result.Name)
			if result.Description != nil {
				reply += "\n" + *(result.Description)
			}
			if len(result.Alternatives) > 0 {
				reply += "\nAlternativamente:\n - " + strings.Join(result.Alternatives, "\n - ")
			}
		case "input.unknown":
			// Don't reply if quoted (probably just a comment)
			if quoted {
				return
			}
		default:
			log.Printf("[talk] Unknown action called:\n%s\n", record.Result.Action)
		}
	}

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