package jitsi

import (
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"time"

	"github.com/golang-jwt/jwt/v5"
)

type Config struct {
	Secret string
	AppID string
	AppName string
	Domain string
	SiteDomain string
}

type JitsiClaims struct {
	jwt.RegisteredClaims
	Room      string        `json:"room,omitempty"`
	Context   *JitsiContext `json:"context,omitempty"`
}

type JitsiContext struct {
	User *JitsiUser `json:"user,omitempty"`
}

type JitsiUser struct {
	ID        string `json:"id"`
	Name      string `json:"name"`
	Email     string `json:"email,omitempty"`
	Avatar    string `json:"avatar,omitempty"`
	Moderator bool   `json:"moderator"`
}

func GenerateSecret() string {
	b := make([]byte, 32)
	rand.Read(b)
	return hex.EncodeToString(b)
}

func (c *Config) MeetURL(room, jwtToken string) string {
	domain := c.Domain
	if domain == "" {
		domain = "meet.jit.si"
	}
	return fmt.Sprintf("https://%s/%s?jwt=%s", domain, room, jwtToken)
}

func (c *Config) GenerateToken(userID, userName, room string, moderator bool, avatar string) (string, error) {
	if c.Secret == "" {
		return "", fmt.Errorf("jitsi secret is not configured")
	}
	if c.AppID == "" {
		return "", fmt.Errorf("jitsi app id is not configured")
	}

	now := time.Now().UTC()
	claims := JitsiClaims{
		RegisteredClaims: jwt.RegisteredClaims{
			Issuer:    c.AppID,
			Subject:   userID,
			Audience:  jwt.ClaimStrings{c.AppID},
			IssuedAt:  jwt.NewNumericDate(now),
			NotBefore: jwt.NewNumericDate(now),
			ExpiresAt: jwt.NewNumericDate(now.Add(1 * time.Hour)),
			ID:        fmt.Sprintf("%s-%d", userID, now.Unix()),
		},
		Room:      room,
		Context: &JitsiContext{
			User: &JitsiUser{
				ID:     userID,
				Name:   userName,
				Avatar: avatar,
				Moderator: moderator,
			},
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(c.Secret))
}