haste-jwt 0.1.1

use haste_fhir_model::r4::generated::{resources::ResourceType, terminology::IssueType};
use haste_fhir_operation_error::OperationOutcomeError;
use serde::{Deserialize, Serialize};

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum OIDCScope {
    OpenId,
    Profile,
    Email,
    OfflineAccess,
    OnlineAccess,
}

impl From<OIDCScope> for String {
    fn from(value: OIDCScope) -> Self {
        match value {
            OIDCScope::OpenId => "openid".to_string(),
            OIDCScope::Profile => "profile".to_string(),
            OIDCScope::Email => "email".to_string(),
            OIDCScope::OfflineAccess => "offline_access".to_string(),
            OIDCScope::OnlineAccess => "online_access".to_string(),
        }
    }
}

impl TryFrom<&str> for OIDCScope {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value {
            "openid" => Ok(Self::OpenId),
            "profile" => Ok(Self::Profile),
            "email" => Ok(Self::Email),
            "offline_access" => Ok(Self::OfflineAccess),
            "online_access" => Ok(Self::OnlineAccess),
            _ => Err(OperationOutcomeError::error(
                IssueType::NotSupported(None),
                format!("OIDC Scope '{}' not supported.", value),
            )),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub struct LaunchSystemScope;

impl From<LaunchSystemScope> for String {
    fn from(_: LaunchSystemScope) -> Self {
        "launch".to_string()
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum LaunchType {
    Encounter,
    Patient,
}

impl TryFrom<&str> for LaunchType {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value {
            "encounter" => Ok(LaunchType::Encounter),
            "patient" => Ok(LaunchType::Patient),
            _ => Err(OperationOutcomeError::error(
                IssueType::NotSupported(None),
                format!("Launch type '{}' not supported.", value),
            )),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub struct LaunchTypeScope {
    pub launch_type: LaunchType,
}

impl From<LaunchTypeScope> for String {
    fn from(value: LaunchTypeScope) -> Self {
        match value.launch_type {
            LaunchType::Encounter => "launch/encounter".to_string(),
            LaunchType::Patient => "launch/patient".to_string(),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum SmartResourceScopeUser {
    User,
    System,
    Patient,
}

impl TryFrom<&str> for SmartResourceScopeUser {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value {
            "user" => Ok(SmartResourceScopeUser::User),
            "system" => Ok(SmartResourceScopeUser::System),
            "patient" => Ok(SmartResourceScopeUser::Patient),
            _ => Err(OperationOutcomeError::error(
                IssueType::NotSupported(None),
                format!("Smart resource scope level '{}' not supported.", value),
            )),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum SmartResourceScopeLevel {
    ResourceType(ResourceType),
    AllResources,
}

impl TryFrom<&str> for SmartResourceScopeLevel {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value {
            "*" => Ok(SmartResourceScopeLevel::AllResources),
            resource_type => {
                let resource_type = ResourceType::try_from(value).map_err(|_e| {
                    OperationOutcomeError::error(
                        IssueType::NotSupported(None),
                        format!(
                            "Smart resource scope resource type '{}' not supported.",
                            resource_type,
                        ),
                    )
                })?;
                Ok(SmartResourceScopeLevel::ResourceType(resource_type))
            }
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum SmartResourceScopePermission {
    Create,
    Read,
    Update,
    Delete,
    Search,
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub struct SmartResourceScopePermissions(Vec<SmartResourceScopePermission>);

impl SmartResourceScopePermissions {
    pub fn new(permissions: Vec<SmartResourceScopePermission>) -> Self {
        Self(permissions)
    }

    pub fn has_permission(&self, permission: &SmartResourceScopePermission) -> bool {
        self.0.contains(permission)
    }

    pub fn add_permission(&mut self, permission: SmartResourceScopePermission) {
        if !self.has_permission(&permission) {
            self.0.push(permission);
        }
    }
}

static SMART_RESOURCE_SCOPE_PERMISSION_ORDER: &[char] = &['c', 'r', 'u', 'd', 's'];

impl TryFrom<&str> for SmartResourceScopePermissions {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value {
            "*" => Ok(SmartResourceScopePermissions::new(vec![
                SmartResourceScopePermission::Create,
                SmartResourceScopePermission::Read,
                SmartResourceScopePermission::Update,
                SmartResourceScopePermission::Delete,
                SmartResourceScopePermission::Search,
            ])),
            "write" => Ok(SmartResourceScopePermissions::new(vec![
                SmartResourceScopePermission::Create,
                SmartResourceScopePermission::Update,
                SmartResourceScopePermission::Delete,
            ])),
            "read" => Ok(SmartResourceScopePermissions::new(vec![
                SmartResourceScopePermission::Read,
                SmartResourceScopePermission::Search,
            ])),
            methods => {
                let mut methods_obj = SmartResourceScopePermissions::new(vec![]);

                // Scope requests with undefined or out of order interactions MAY be ignored, replaced with server default scopes, or rejected.
                // per [https://build.fhir.org/ig/HL7/smart-app-launch/scopes-and-launch-context.html#scopes-for-requesting-fhir-resources].
                let mut current_index: i8 = -1;
                for method in methods.chars() {
                    let found_index = SMART_RESOURCE_SCOPE_PERMISSION_ORDER
                        .iter()
                        .position(|o| *o == method)
                        .map(|p| p as i8);

                    if found_index <= Some(current_index) || found_index.is_none() {
                        return Err(OperationOutcomeError::error(
                            IssueType::NotSupported(None),
                            format!(
                                "Invalid scope access type methods: '{}' not supported or in wrong place must be in 'cruds' order.",
                                method
                            ),
                        ));
                    }

                    current_index = found_index.unwrap_or(0);

                    match method {
                        /*
                         * Type level create
                         */
                        'c' => {
                            methods_obj.add_permission(SmartResourceScopePermission::Create);
                        }
                        /*
                         * Instance level read
                         * Instance level vread
                         * Instance level history
                         */
                        'r' => {
                            methods_obj.add_permission(SmartResourceScopePermission::Read);
                        }
                        /*
                         * Instance level update Note that some servers allow for an update operation to create a new instance,
                         * and this is allowed by the update scope
                         * Instance level patch
                         */
                        'u' => {
                            methods_obj.add_permission(SmartResourceScopePermission::Update);
                        }
                        /*
                         * Instance level delete
                         */
                        'd' => {
                            methods_obj.add_permission(SmartResourceScopePermission::Delete);
                        }
                        /*
                         * Type level search
                         * Type level history
                         * System level search
                         * System level history
                         */
                        's' => {
                            methods_obj.add_permission(SmartResourceScopePermission::Search);
                        }
                        _ => {}
                    }
                }

                Ok(methods_obj)
            }
        }
    }
}
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct SMARTResourceScope {
    pub user: SmartResourceScopeUser,
    pub level: SmartResourceScopeLevel,
    pub permissions: SmartResourceScopePermissions,
}

impl From<SMARTResourceScope> for String {
    fn from(value: SMARTResourceScope) -> Self {
        let user_str = match value.user {
            SmartResourceScopeUser::User => "user",
            SmartResourceScopeUser::System => "system",
            SmartResourceScopeUser::Patient => "patient",
        };

        let level_str = match value.level {
            SmartResourceScopeLevel::AllResources => "*".to_string(),
            SmartResourceScopeLevel::ResourceType(resource_type) => {
                resource_type.as_ref().to_string()
            }
        };

        let mut permissions_str = String::new();
        if value
            .permissions
            .has_permission(&SmartResourceScopePermission::Create)
        {
            permissions_str.push('c');
        }
        if value
            .permissions
            .has_permission(&SmartResourceScopePermission::Read)
        {
            permissions_str.push('r');
        }
        if value
            .permissions
            .has_permission(&SmartResourceScopePermission::Update)
        {
            permissions_str.push('u');
        }
        if value
            .permissions
            .has_permission(&SmartResourceScopePermission::Delete)
        {
            permissions_str.push('d');
        }
        if value
            .permissions
            .has_permission(&SmartResourceScopePermission::Search)
        {
            permissions_str.push('s');
        }

        format!("{}/{}.{}", user_str, level_str, permissions_str)
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum SmartScope {
    LaunchSystem(LaunchSystemScope),
    LaunchType(LaunchTypeScope),
    Resource(SMARTResourceScope),
    FHIRUser,
}

impl From<SmartScope> for String {
    fn from(value: SmartScope) -> Self {
        match value {
            SmartScope::FHIRUser => "fhirUser".to_string(),
            SmartScope::LaunchSystem(launch_system) => String::from(launch_system),
            SmartScope::LaunchType(launch_type) => String::from(launch_type),
            SmartScope::Resource(resource) => String::from(resource),
        }
    }
}

impl TryFrom<&str> for SmartScope {
    type Error = OperationOutcomeError;
    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value {
            "fhirUser" => Ok(SmartScope::FHIRUser),
            "launch" => Ok(SmartScope::LaunchSystem(LaunchSystemScope)),
            _ if value.starts_with("launch/") => {
                let chunks: Vec<&str> = value.split('/').collect();
                if chunks.len() != 2 {
                    return Err(OperationOutcomeError::error(
                        IssueType::NotSupported(None),
                        format!("Invalid launch scope: '{}'.", value),
                    ));
                }

                let launch_type = LaunchType::try_from(chunks[1])?;

                Ok(SmartScope::LaunchType(LaunchTypeScope { launch_type }))
            }
            _ if value.starts_with("user/")
                || value.starts_with("system/")
                || value.starts_with("patient/") =>
            {
                let parts: Vec<&str> = value.split('/').collect();
                if parts.len() != 2 {
                    return Err(OperationOutcomeError::error(
                        IssueType::NotSupported(None),
                        format!("Invalid smart resource scope: '{}'.", value),
                    ));
                }

                let user = SmartResourceScopeUser::try_from(parts[0])?;
                let permissions_parts: Vec<&str> = parts[1].split('.').collect();
                if permissions_parts.len() != 2 {
                    return Err(OperationOutcomeError::error(
                        IssueType::NotSupported(None),
                        format!("Invalid smart resource scope: '{}'.", value),
                    ));
                }

                let level = SmartResourceScopeLevel::try_from(permissions_parts[0])?;
                let permissions = SmartResourceScopePermissions::try_from(permissions_parts[1])?;

                Ok(SmartScope::Resource(SMARTResourceScope {
                    user,
                    level,
                    permissions,
                }))
            }
            _ => Err(OperationOutcomeError::error(
                IssueType::NotSupported(None),
                format!("Smart Scope '{}' not supported.", value),
            )),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub enum Scope {
    OIDC(OIDCScope),
    SMART(SmartScope),
}

impl TryFrom<&str> for Scope {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        if let Ok(oidc_scope) = OIDCScope::try_from(value) {
            Ok(Self::OIDC(oidc_scope))
        } else {
            Ok(Self::SMART(SmartScope::try_from(value)?))
        }
    }
}

impl From<Scope> for String {
    fn from(value: Scope) -> Self {
        match value {
            Scope::OIDC(oidc_scope) => String::from(oidc_scope),
            Scope::SMART(smart_scope) => String::from(smart_scope),
        }
    }
}

#[derive(Debug, PartialEq, Eq, Clone)]
pub struct Scopes(pub Vec<Scope>);

impl Scopes {
    pub fn contains_scope(&self, scope: &Scope) -> bool {
        self.0.contains(scope)
    }
}

impl Default for Scopes {
    fn default() -> Self {
        Scopes(vec![])
    }
}

impl TryFrom<&str> for Scopes {
    type Error = OperationOutcomeError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        let scopes: Result<Vec<Scope>, OperationOutcomeError> = value
            .split_whitespace()
            .map(|s| Scope::try_from(s))
            .collect();

        Ok(Scopes(scopes?))
    }
}

// Used by sqlx binding this is not safe.
impl From<String> for Scopes {
    fn from(value: String) -> Self {
        let scopes = Self::try_from(value.as_str()).expect("Invalid scopes string");

        scopes
    }
}

impl<'de> Deserialize<'de> for Scopes {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let s = String::deserialize(deserializer)?;
        Scopes::try_from(s.as_str()).map_err(serde::de::Error::custom)
    }
}

impl From<Scopes> for String {
    fn from(value: Scopes) -> Self {
        value
            .0
            .into_iter()
            .map(|s| String::from(s))
            .collect::<Vec<_>>()
            .join(" ")
    }
}

impl Serialize for Scopes {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        serializer.serialize_str(&String::from(self.clone()))
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use haste_fhir_model::r4::generated::resources::ResourceType;

    #[test]
    fn test_multiple_correct() {
        assert_eq!(
            Scopes::try_from("openid profile email offline_access launch/patient user/*.*")
                .unwrap(),
            Scopes(vec![
                Scope::OIDC(OIDCScope::OpenId),
                Scope::OIDC(OIDCScope::Profile),
                Scope::OIDC(OIDCScope::Email),
                Scope::OIDC(OIDCScope::OfflineAccess),
                Scope::SMART(SmartScope::LaunchType(LaunchTypeScope {
                    launch_type: LaunchType::Patient,
                })),
                Scope::SMART(SmartScope::Resource(SMARTResourceScope {
                    user: SmartResourceScopeUser::User,
                    level: SmartResourceScopeLevel::AllResources,
                    permissions: SmartResourceScopePermissions::new(vec![
                        SmartResourceScopePermission::Create,
                        SmartResourceScopePermission::Read,
                        SmartResourceScopePermission::Update,
                        SmartResourceScopePermission::Delete,
                        SmartResourceScopePermission::Search,
                    ])
                })),
            ]),
        );

        assert_eq!(
            Scopes::try_from("launch/encounter   system/Patient.cud").unwrap(),
            Scopes(vec![
                Scope::SMART(SmartScope::LaunchType(LaunchTypeScope {
                    launch_type: LaunchType::Encounter,
                })),
                Scope::SMART(SmartScope::Resource(SMARTResourceScope {
                    user: SmartResourceScopeUser::System,
                    level: SmartResourceScopeLevel::ResourceType(ResourceType::Patient),
                    permissions: SmartResourceScopePermissions::new(vec![
                        SmartResourceScopePermission::Create,
                        SmartResourceScopePermission::Update,
                        SmartResourceScopePermission::Delete,
                    ])
                })),
            ]),
        );
    }

    #[test]
    fn invalid_order() {
        assert_eq!(
            Scopes::try_from("launch/encounter   system/Patient.duc").is_err(),
            true
        );
    }

    #[test]
    fn invalid_system() {
        assert_eq!(
            Scopes::try_from("launch/encounter   sytem/Patient.cud").is_err(),
            true
        );
    }

    #[test]
    fn unknown_scope() {
        assert_eq!(
            Scopes::try_from("badscope  sytem/Patient.cud").is_err(),
            true
        );
    }

    #[test]
    fn test_roundtrip() {
        assert_eq!(
            String::from(
                Scopes::try_from("openid profile email offline_access launch/patient user/*.*")
                    .unwrap()
            ),
            "openid profile email offline_access launch/patient user/*.cruds".to_string(),
        );

        assert_eq!(
            String::from(Scopes::try_from("launch/encounter system/Patient.cud").unwrap()),
            "launch/encounter system/Patient.cud".to_string()
        );
    }
}