regent-sdk 0.7.0

use crate::error::RegentError;
use crate::hosts::managed_host::InternalApiCallOutcome;
use crate::hosts::managed_host::{AssessCompliance, ReachCompliance};
use crate::hosts::properties::HostProperties;
use crate::secrets::SecretProvidersPool;
use crate::state::Check;
use crate::state::attribute::HostHandler;
use crate::state::attribute::Privilege;
use crate::state::attribute::Remediation;
use crate::state::compliance::AttributeComplianceAssessment;
use serde::{Deserialize, Serialize};

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "PascalCase")]
pub enum AptModuleInternalApiCall {
    Install(String),
    Remove(String),
    Upgrade,
}

impl std::fmt::Display for AptModuleInternalApiCall {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            AptModuleInternalApiCall::Install(package) => write!(f, "install {}", package),
            AptModuleInternalApiCall::Remove(package) => write!(f, "remove {}", package),
            AptModuleInternalApiCall::Upgrade => write!(f, "upgrade"),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "PascalCase")]
pub enum PackageExpectedState {
    Present,
    Absent,
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
#[serde(rename_all = "PascalCase")]
pub struct AptBlockExpectedState {
    state: Option<PackageExpectedState>,
    package: Option<String>,
    upgrade: Option<bool>,
}

// Chained methods to allow building an AptBlockExpectedState as follows :
// let apt_block = AptBlockExpectedState::builder()
//     .with_package_state("apache2", PackageExpectedState::Present)
//     .with_system_upgrade()
//     .build();
impl AptBlockExpectedState {
    pub fn builder() -> AptBlockExpectedState {
        AptBlockExpectedState {
            state: None,
            package: None,
            upgrade: None,
        }
    }

    pub fn with_system_upgrade(&mut self) -> &mut Self {
        self.upgrade = Some(true);
        self
    }

    pub fn with_package_state(
        &mut self,
        package_name: &str,
        package_state: PackageExpectedState,
    ) -> &mut Self {
        self.package = Some(package_name.to_string());
        self.state = Some(package_state);
        self
    }

    pub fn build(&self) -> Result<AptBlockExpectedState, RegentError> {
        if let Err(details) = self.check() {
            return Err(details);
        }
        Ok(self.clone())
    }
}

impl Check for AptBlockExpectedState {
    fn check(&self) -> Result<(), RegentError> {
        if let (None, None, None) = (&self.state, &self.package, self.upgrade) {
            return Err(RegentError::IncoherentExpectedState(format!(
                "All parameters are unset. Please describe the expected state."
            )));
        }
        if let (None, Some(package_name)) = (&self.state, &self.package) {
            return Err(RegentError::IncoherentExpectedState(format!(
                "Missing 'state' parameter. What is the expected state of the package ({}) ?",
                package_name
            )));
        }
        if let (Some(package_expected_state), None) = (&self.state, &self.package) {
            return Err(RegentError::IncoherentExpectedState(format!(
                "Missing 'package' parameter. Which package should be {:?} ?",
                package_expected_state
            )));
        }
        Ok(())
    }
}

impl<Handler: HostHandler> AssessCompliance<Handler> for AptBlockExpectedState {
    async fn assess_compliance(
        &self,
        host_handler: &mut Handler,
        _host_properties: &Option<HostProperties>,
        privilege: &Privilege,
        _optional_secret_provider: &Option<SecretProvidersPool>,
    ) -> Result<AttributeComplianceAssessment, RegentError> {
        let apt_available =
            match host_handler.is_this_command_available("apt-get", &Privilege::None) {
                Ok(availability) => availability,
                Err(details) => {
                    return Err(RegentError::FailedDryRunEvaluation(format!(
                        "{:?}",
                        details
                    )));
                }
            };
        let dpkg_available = match host_handler.is_this_command_available("dpkg", &Privilege::None)
        {
            Ok(availability) => availability,
            Err(details) => {
                return Err(RegentError::FailedDryRunEvaluation(format!(
                    "{:?}",
                    details
                )));
            }
        };

        if !apt_available || !dpkg_available {
            return Err(RegentError::FailedDryRunEvaluation(
                "APT not working on this host. Is this a debian-flavored linux distribution ?"
                    .to_string(),
            ));
        }

        let mut remediations: Vec<Remediation> = Vec::new();

        match &self.state {
            None => {}
            Some(state) => {
                match state {
                    PackageExpectedState::Present => {
                        // Check is package is already installed or needs to be
                        if is_package_installed(host_handler, self.package.clone().unwrap()) {
                            remediations.push(Remediation::None(format!(
                                "{} already present",
                                self.package.clone().unwrap()
                            )));
                        } else {
                            // Package is absent and needs to be installed
                            remediations.push(Remediation::Apt(AptApiCall::from(
                                AptModuleInternalApiCall::Install(self.package.clone().unwrap()),
                                privilege.clone(),
                            )));
                        }
                    }
                    PackageExpectedState::Absent => {
                        // Check is package is already absent or needs to be removed
                        if is_package_installed(host_handler, self.package.clone().unwrap()) {
                            // Package is present and needs to be removed
                            remediations.push(Remediation::Apt(AptApiCall::from(
                                AptModuleInternalApiCall::Remove(self.package.clone().unwrap()),
                                privilege.clone(),
                            )));
                        } else {
                            remediations.push(Remediation::None(format!(
                                "{} already absent",
                                self.package.clone().unwrap()
                            )));
                        }
                    }
                }
            }
        }

        // TODO: have this do an "apt update"
        // -> if no update available, state = Matched
        // -> if updates available, state = ApiCall -> action = "apt upgrade"
        if let Some(value) = self.upgrade {
            if value {
                remediations.push(Remediation::Apt(AptApiCall::from(
                    AptModuleInternalApiCall::Upgrade,
                    privilege.clone(),
                )));
            }
        }

        // If changes are only None, it means a Match. If only one change is not a None, return the whole list.
        for remediation in remediations.iter() {
            match remediation {
                Remediation::None(_) => {}
                _ => {
                    return Ok(AttributeComplianceAssessment::NonCompliant(remediations));
                }
            }
        }
        return Ok(AttributeComplianceAssessment::Compliant);
    }
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct AptApiCall {
    pub api_call: AptModuleInternalApiCall,
    privilege: Privilege,
}

impl AptApiCall {
    pub fn display(&self) -> String {
        match &self.api_call {
            AptModuleInternalApiCall::Install(package_name) => {
                return format!("Install - {}", package_name);
            }
            AptModuleInternalApiCall::Remove(package_name) => {
                return format!("Remove - {}", package_name);
            }
            AptModuleInternalApiCall::Upgrade => {
                return String::from("Upgrade");
            }
        }
    }
}

impl<Handler: HostHandler> ReachCompliance<Handler> for AptApiCall {
    async fn call(
        &self,
        host_handler: &mut Handler,
        _host_properties: &Option<HostProperties>,
        _optional_secret_provider: &Option<SecretProvidersPool>,
    ) -> Result<InternalApiCallOutcome, RegentError> {
        let (cmd, privilege) = match &self.api_call {
            AptModuleInternalApiCall::Install(package_name) => (
                format!(
                    "DEBIAN_FRONTEND=noninteractive apt-get install -y {}",
                    package_name
                ),
                &self.privilege,
            ),
            AptModuleInternalApiCall::Remove(package_name) => (
                format!(
                    "DEBIAN_FRONTEND=noninteractive apt-get remove --purge -y {}",
                    package_name
                ),
                &self.privilege,
            ),
            AptModuleInternalApiCall::Upgrade => (
                "apt-get update && DEBIAN_FRONTEND=noninteractive apt-get upgrade -y".to_string(),
                &self.privilege,
            ),
        };

        let cmd_result = host_handler.run_command(cmd.as_str(), privilege).unwrap();

        if cmd_result.return_code == 0 {
            Ok(InternalApiCallOutcome::Success(None))
        } else {
            Ok(InternalApiCallOutcome::Failure(format!(
                "RC : {}, STDOUT : {}, STDERR : {}",
                cmd_result.return_code, cmd_result.stdout, cmd_result.stderr
            )))
        }
    }
}

impl AptApiCall {
    fn from(api_call: AptModuleInternalApiCall, privilege: Privilege) -> AptApiCall {
        AptApiCall {
            api_call,
            privilege,
        }
    }
}

fn is_package_installed<Handler: HostHandler>(host_handler: &mut Handler, package: String) -> bool {
    let test = host_handler
        .run_command(format!("dpkg -s {}", package).as_str(), &Privilege::None)
        .unwrap();

    if test.return_code == 0 { true } else { false }
}

#[cfg(test)]
mod tests {

    use super::*;

    #[test]
    fn parsing_apt_module_block_from_yaml_str() {
        let raw_attributes = "---
- Package: apache2
  State: !Present

- Package: apache2
  State: !Absent

- Upgrade: true
    ";

        let attributes: Vec<AptBlockExpectedState> = yaml_serde::from_str(raw_attributes).unwrap();

        assert_eq!(attributes[0].package, Some("apache2".to_string()));
        assert_eq!(attributes[0].state, Some(PackageExpectedState::Present));
        assert_eq!(attributes[0].upgrade, None);

        assert_eq!(attributes[1].package, Some("apache2".to_string()));
        assert_eq!(attributes[1].state, Some(PackageExpectedState::Absent));
        assert_eq!(attributes[1].upgrade, None);

        assert_eq!(attributes[2].package, None);
        assert_eq!(attributes[2].state, None);
        assert_eq!(attributes[2].upgrade, Some(true));
    }

    #[test]
    fn rejecting_incorrect_apt_module_block_from_yaml_str() {
        let raw_attribute = "---
Package: apache2
    ";
        let yaml_part = yaml_serde::from_str::<AptBlockExpectedState>(raw_attribute);
        assert!(yaml_part.is_ok());
        assert!(yaml_part.unwrap().check().is_err());

        let raw_attribute = "---
Package:
State: !Absent
    ";
        let yaml_part = yaml_serde::from_str::<AptBlockExpectedState>(raw_attribute);
        assert!(yaml_part.is_ok());
        assert!(yaml_part.unwrap().check().is_err());

        let raw_attribute = "---
Package: apache2
State: !Absent
unknown_key: unknown_value
    ";
        assert!(yaml_serde::from_str::<AptBlockExpectedState>(raw_attribute).is_err());
    }
}