use anyhow::{anyhow, Result};use jsonwebtoken::{DecodingKey, EncodingKey, Header, Validation};use serde::{Deserialize, Serialize};use std::{    borrow::Cow,    ops::Add,    time::{Duration, SystemTime, UNIX_EPOCH},}; const DEFAULT_TTL: Duration = Duration::from_secs(6 * 60 * 60); // 6 hours #[derive(Default, Serialize, Deserialize)]#[serde(rename_all = "camelCase")]pub struct ClaimGrants<'a> {    pub iss: Cow<'a, str>,    pub sub: Option<Cow<'a, str>>,    pub iat: u64,    pub exp: u64,    pub nbf: u64,    pub jwtid: Option<Cow<'a, str>>,    pub video: VideoGrant<'a>,} #[derive(Default, Serialize, Deserialize)]#[serde(rename_all = "camelCase")]pub struct VideoGrant<'a> {    pub room_create: Option<bool>,    pub room_join: Option<bool>,    pub room_list: Option<bool>,    pub room_record: Option<bool>,    pub room_admin: Option<bool>,    pub room: Option<Cow<'a, str>>,    pub can_publish: Option<bool>,    pub can_subscribe: Option<bool>,    pub can_publish_data: Option<bool>,    pub hidden: Option<bool>,    pub recorder: Option<bool>,} impl<'a> VideoGrant<'a> {    pub fn to_admin(room: &'a str) -> Self {        Self {            room_admin: Some(true),            room: Some(Cow::Borrowed(room)),            ..Default::default()        }    }     pub fn to_join(room: &'a str) -> Self {        Self {            room: Some(Cow::Borrowed(room)),            room_join: Some(true),            can_publish: Some(true),            can_subscribe: Some(true),            ..Default::default()        }    }     pub fn for_guest(room: &'a str) -> Self {        Self {            room: Some(Cow::Borrowed(room)),            room_join: Some(true),            can_publish: Some(false),            can_subscribe: Some(true),            ..Default::default()        }    }} pub fn create(    api_key: &str,    secret_key: &str,    identity: Option<&str>,    video_grant: VideoGrant,) -> Result<String> {    if video_grant.room_join.is_some() && identity.is_none() {        Err(anyhow!(            "identity is required for room_join grant, but it is none"        ))?;    }     let now = SystemTime::now();     let claims = ClaimGrants {        iss: Cow::Borrowed(api_key),        sub: identity.map(Cow::Borrowed),        iat: now.duration_since(UNIX_EPOCH).unwrap().as_secs(),        exp: now            .add(DEFAULT_TTL)            .duration_since(UNIX_EPOCH)            .unwrap()            .as_secs(),        nbf: 0,        jwtid: identity.map(Cow::Borrowed),        video: video_grant,    };    Ok(jsonwebtoken::encode(        &Header::default(),        &claims,        &EncodingKey::from_secret(secret_key.as_ref()),    )?)} pub fn validate<'a>(token: &'a str, secret_key: &str) -> Result<ClaimGrants<'a>> {    let token = jsonwebtoken::decode(        token,        &DecodingKey::from_secret(secret_key.as_ref()),        &Validation::default(),    )?;     Ok(token.claims)}