package internal

import (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"time"
)

func (lc *LicenseChecker) Validate() error {
	url := fmt.Sprintf("%s/license/lookup?key=%s&format=json", lc.LicenseAPIURL, lc.APIKey)
	resp, err := http.Get(url)
	if err != nil {
		lc.setValid(false)

		return fmt.Errorf("license lookup failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		lc.setValid(false)

		return fmt.Errorf("license lookup error: %s", resp.Status)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		lc.setValid(false)

		return fmt.Errorf("reading response failed: %w", err)
	}

	var data struct {
		Revoked   bool      `json:"revoked"`
		ExpiresAt time.Time `json:"expires_at"`
	}
	if err := json.Unmarshal(body, &data); err != nil {
		lc.setValid(false)

		return fmt.Errorf("unmarshal error: %w", err)
	}

	if data.Revoked || time.Now().After(data.ExpiresAt) {
		lc.setValid(false)

		return fmt.Errorf("license expired or revoked")
	}

	lc.mu.Lock()
	lc.valid = true
	lc.lastGood = time.Now()
	lc.mu.Unlock()

	log.Printf("✅ License validated. Expires: %s", data.ExpiresAt)
	return nil
}

func (lc *LicenseChecker) StartBackgroundCheck() {
	go func() {
		for {
			time.Sleep(lc.PollInterval)
			err := lc.Validate()
			if err != nil {
				log.Printf("⚠️ License check failed: %v", err)
			}
		}
	}()
}

func (lc *LicenseChecker) IsValid() bool {
	lc.mu.RLock()
	defer lc.mu.RUnlock()
	return lc.valid
}