package webhooks

import (
	"bytes"
	"encoding/json"
	"errors"
	"net/http"
	"time"

	"github.com/go-logr/logr"

	"edge-infra.dev/pkg/lib/logging"
)

type SlackMessage struct {
	Text string `json:"text"`
}

type Slack interface {
	// GetClient() *http.Client
	SendMsg(msg *SlackMessage) error
}

type slack struct {
	logger     logr.Logger
	client     *http.Client
	webhookURL string
}

// Assert that the SlackMessage interface is implemented
var _ Slack = (*slack)(nil)

type Options struct {
	Logger *logr.Logger
	Client *http.Client
}

type Option func(*Options)

func NewSlackWebhook(url string, opts ...Option) Slack {
	options := Options{}
	for _, opt := range opts {
		opt(&options)
	}
	options = setOptionsDefaults(options)

	return &slack{
		logger:     options.Logger.WithValues("webhook", "slack"), // todo - come up with consistency
		client:     options.Client,
		webhookURL: url,
	}
}

func (s *slack) SendMsg(msg *SlackMessage) error {
	slackBody, err := json.Marshal(msg)
	if err != nil {
		return err
	}

	req, err := http.NewRequest(http.MethodPost, s.webhookURL, bytes.NewBuffer(slackBody))
	if err != nil {
		return err
	}
	req.Header.Add("Content-Type", "application/json")

	// todo - need to figure out logging levels better and make it configurable
	// once running smoothly we likely won't need to log this every time

	// ideally want a way to identify the messages but don't want to interfere with the REST
	// call itself
	// s.logger.Info("sending message for incident", "incident", msg.ID)

	resp, err := s.client.Do(req)
	if err != nil {
		return err
	}

	buf := new(bytes.Buffer)
	if _, err = buf.ReadFrom(resp.Body); err != nil {
		return err
	}

	// todo - need to improve this. probably look at what the response string may contain
	// in testing this has been due to rate limiting. so something we may have to account
	// for via code
	if buf.String() != "ok" {
		return errors.New("INVALID RESPONSE RETURNED FROM THE SLACK API")
	}

	return nil
}

// setOptionsDefaults set default values for Options fields.
func setOptionsDefaults(options Options) Options {
	if options.Logger == nil {
		options.Logger = &logging.NewLogger().Logger
	}
	if options.Client == nil {
		options.Client = &http.Client{Timeout: 10 * time.Second}
	}
	return options
}