package sms

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"
)

// HTTPClient sends SMS via the SMSGlobal HTTP API (api.smsglobal.com/http-api.php).
// This is the PROVEN path — validated live 2026-08-05 with real credentials
// (response: OK: 0; Sent queued message ID ...). Matches the 2014 WhereWoof
// integration pattern: action=sendsms, user/password, from, userfield, to, text.
type HTTPClient struct {
	user     string
	password string
	from     string // verified number or sender, international format without '+'
	http     *http.Client
}

// NewHTTP returns an HTTP-API client. from is required (verified number or
// registered sender, e.g. "61423274487").
func NewHTTP(user, password, from string) *HTTPClient {
	return &HTTPClient{
		user:     user,
		password: password,
		from:     from,
		http:     &http.Client{Timeout: 15 * time.Second},
	}
}

// Send posts a message to the destination (international format, no '+').
func (c *HTTPClient) Send(to, body string) error {
	form := url.Values{}
	form.Set("action", "sendsms")
	form.Set("user", c.user)
	form.Set("password", c.password)
	form.Set("from", c.from)
	form.Set("userfield", fmt.Sprintf("MID%sWSIDwherewoof", time.Now().UTC().Format("20060102150405")))
	form.Set("to", to)
	form.Set("text", body)
	form.Set("maxsplit", "5")

	resp, err := c.http.PostForm("https://api.smsglobal.com/http-api.php", form)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	b, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
	s := strings.TrimSpace(string(b))
	if !strings.HasPrefix(s, "OK:") {
		return fmt.Errorf("smsglobal http: %s", s)
	}
	return nil
}