package twilio

import (
	"errors"
	"fmt"
	"log"
	"net/http"
	"net/url"
)

type Config struct {
	Contacts   []string `yaml:"contacts"`
	contacts   map[string]bool
	AccountSID string `yaml:"account_sid"`
	AuthToken  string `yaml:"auth_token"`
	Number     string `yaml:"telno"` // kas' telno
}

func (cfg *Config) postURL() string {
	return fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json",
		cfg.AccountSID)
}

func (cfg *Config) buildContacts() {
	cfg.contacts = map[string]bool{}
	for _, telno := range cfg.Contacts {
		cfg.contacts[telno] = true
	}
}

func (cfg *Config) NumberAuthorized(s string) bool {
	if cfg.contacts == nil || len(cfg.contacts) != len(cfg.Contacts) {
		cfg.buildContacts()
	}

	return cfg.contacts[s]
}

func validate(cfg *Config) error {
	if len(cfg.Contacts) == 0 {
		return errors.New("twilio: no authorized numbers (you won't be able to receive any messages)")
	}

	if cfg.AccountSID == "" {
		return errors.New("twilio: missing account SID")
	}

	if cfg.AuthToken == "" {
		return errors.New("twilio: missing auth token")
	}

	if cfg.Number == "" {
		return errors.New("twilio: no number configured")
	}

	return nil
}

var config *Config

func SetConfig(cfg *Config) error {
	if err := validate(cfg); err != nil {
		return err
	}
	config = cfg
	return nil
}

func Send(to string, message string) error {
	form := url.Values{
		"Body": {message},
		"From": {config.Number},
		"To":   {to},
	}

	resp, err := http.PostForm(config.postURL(), form)
	if err != nil {
		log.Printf("twilio send: %s", err)
	}

	resp.Body.Close()
	return nil
}