package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"net/url"
	"os"
	"strings"

	"github.com/AnthonyHewins/gotfy"
)

type authdTransport struct {
	underlyingTransport http.RoundTripper
}

func (t *authdTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	var ntfyToken string
	env := os.Environ()
	for _, keyVal := range env {
		keyValArr := strings.Split(keyVal, "=")
		if keyValArr[0] == "NTFY_TOKEN" {
			ntfyToken = keyValArr[1]
		}
	}

	req.Header.Add("Authorization", "Bearer "+ntfyToken)
	return t.underlyingTransport.RoundTrip(req)
}

type Ntfy struct {
	client *gotfy.Publisher
}

func SetupNtfyClient() *Ntfy {
	host := ""
	env := os.Environ()
	for _, keyVal := range env {
		keyValArr := strings.Split(keyVal, "=")
		if keyValArr[0] == "NTFY_HOST" {
			host = keyValArr[1]
		}
	}

	if host == "" {
		return nil
	}

	server, err := url.Parse(host)

	if err != nil {
		log.Fatal(err)
	}

	authdHttpClient := &http.Client{Transport: &authdTransport{underlyingTransport: http.DefaultTransport}}

	tp, err := gotfy.NewPublisher(server, authdHttpClient)

	if err != nil {
		log.Fatal(err)
	}

	if err != nil {
		log.Fatal(err)
	}

	return &Ntfy{client: tp}
}

func buildTitle(rsvp *Rsvp) string {
	builder := new(strings.Builder)
	if rsvp.Attending {
		peoplePerson := "people"
		if rsvp.PartySize == 1 {
			peoplePerson = "person"
		}
		fmt.Fprintf(builder, "%d %s confirmed!", rsvp.PartySize, peoplePerson)
	} else {
		fmt.Fprintf(builder, "Someone can't make it")
	}
	return builder.String()
}

func buildMessage(rsvp *Rsvp) string {
	builder := new(strings.Builder)
	if rsvp.Attending {
		builder.WriteString("Here's who is coming 👇")
		for _, mem := range rsvp.PartyMembers {
			age := "adult"
			if mem.Child {
				age = "👶"
			} else {
				age = "🧓"
			}
			dp := "n/a"
			if len(mem.DietaryPreferences) > 0 {
				dp = mem.DietaryPreferences
			}
			fmt.Fprintf(builder, "\n- %s %s, %s", age, mem.Name, dp)
		}
	} else {
		for _, mem := range rsvp.PartyMembers {
			fmt.Fprintf(builder, "%s\n", mem.Name)
		}
		builder.WriteString("can't make it")
	}
	return builder.String()
}

func numberToEmoji(num int64) string {
	switch num {
	case 0:
		return "zero"
	case 1:
		return "one"
	case 2:
		return "two"
	case 3:
		return "three"
	case 4:
		return "four"
	case 5:
		return "five"
	case 6:
		return "six"
	case 7:
		return "seven"
	case 8:
		return "eight"
	case 9:
		return "nine"
	default:
		return "question"
	}
}

func buildTags(rsvp *Rsvp) []string {
	if rsvp.Attending {
		return []string{"white_check_mark", numberToEmoji(rsvp.PartySize)}
	} else {
		return []string{"x"}
	}
}

func BuildNtfyMessage(topic string, rsvp *Rsvp) *gotfy.Message {
	return &gotfy.Message{
		Topic:    topic,
		Message:  buildMessage(rsvp),
		Title:    buildTitle(rsvp),
		Tags:     buildTags(rsvp),
		Priority: gotfy.Default,
	}
}

func (n *Ntfy) PublishNewRsvpNotification(rsvp *Rsvp) (string, error) {
	resp, err := n.client.SendMessage(context.Background(), BuildNtfyMessage("collinenlucy_nl", rsvp))

	if err != nil {
		return "", err
	}

	return resp.ID, nil
}