monitord 0.22.0

use std::collections::HashSet;
use std::path::PathBuf;
use std::str::FromStr;

use configparser::ini::Ini;
use indexmap::map::IndexMap;
use int_enum::IntEnum;
use strum_macros::EnumString;
use thiserror::Error;
use tracing::error;

#[derive(Error, Debug)]
pub enum MonitordConfigError {
    #[error("Invalid value for '{key}' in '{section}': {reason}")]
    InvalidValue {
        section: String,
        key: String,
        reason: String,
    },
    #[error("Missing key '{key}' in '{section}'")]
    MissingKey { section: String, key: String },
}

#[derive(Clone, Debug, Default, EnumString, Eq, IntEnum, PartialEq, strum_macros::Display)]
#[repr(u8)]
pub enum MonitordOutputFormat {
    #[default]
    #[strum(serialize = "json", serialize = "JSON", serialize = "Json")]
    Json = 0,
    #[strum(
        serialize = "json-flat",
        serialize = "json_flat",
        serialize = "jsonflat"
    )]
    JsonFlat = 1,
    #[strum(
        serialize = "json-pretty",
        serialize = "json_pretty",
        serialize = "jsonpretty"
    )]
    JsonPretty = 2,
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct MonitordConfig {
    pub dbus_address: String,
    pub daemon: bool,
    pub daemon_stats_refresh_secs: u64,
    pub key_prefix: String,
    pub output_format: MonitordOutputFormat,
    pub dbus_timeout: u64,
}
impl Default for MonitordConfig {
    fn default() -> Self {
        MonitordConfig {
            dbus_address: crate::DEFAULT_DBUS_ADDRESS.into(),
            daemon: false,
            daemon_stats_refresh_secs: 30,
            key_prefix: "".to_string(),
            output_format: MonitordOutputFormat::default(),
            dbus_timeout: 30,
        }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct NetworkdConfig {
    pub enabled: bool,
    pub link_state_dir: PathBuf,
}
impl Default for NetworkdConfig {
    fn default() -> Self {
        NetworkdConfig {
            enabled: false,
            link_state_dir: crate::networkd::NETWORKD_STATE_FILES.into(),
        }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct Pid1Config {
    pub enabled: bool,
}
impl Default for Pid1Config {
    fn default() -> Self {
        Pid1Config { enabled: true }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct SystemStateConfig {
    pub enabled: bool,
}
impl Default for SystemStateConfig {
    fn default() -> Self {
        SystemStateConfig { enabled: true }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct TimersConfig {
    pub enabled: bool,
    pub allowlist: HashSet<String>,
    pub blocklist: HashSet<String>,
}
impl Default for TimersConfig {
    fn default() -> Self {
        TimersConfig {
            enabled: true,
            allowlist: HashSet::new(),
            blocklist: HashSet::new(),
        }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct UnitsConfig {
    pub enabled: bool,
    pub state_stats: bool,
    pub state_stats_allowlist: HashSet<String>,
    pub state_stats_blocklist: HashSet<String>,
    pub state_stats_time_in_state: bool,
}
impl Default for UnitsConfig {
    fn default() -> Self {
        UnitsConfig {
            enabled: true,
            state_stats: false,
            state_stats_allowlist: HashSet::new(),
            state_stats_blocklist: HashSet::new(),
            state_stats_time_in_state: true,
        }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct MachinesConfig {
    pub enabled: bool,
    pub allowlist: HashSet<String>,
    pub blocklist: HashSet<String>,
}
impl Default for MachinesConfig {
    fn default() -> Self {
        MachinesConfig {
            enabled: true,
            allowlist: HashSet::new(),
            blocklist: HashSet::new(),
        }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct DBusStatsConfig {
    pub enabled: bool,

    pub user_stats: bool,
    pub user_allowlist: HashSet<String>,
    pub user_blocklist: HashSet<String>,

    pub peer_stats: bool,
    pub peer_well_known_names_only: bool,
    pub peer_allowlist: HashSet<String>,
    pub peer_blocklist: HashSet<String>,

    pub cgroup_stats: bool,
    pub cgroup_allowlist: HashSet<String>,
    pub cgroup_blocklist: HashSet<String>,
}
impl Default for DBusStatsConfig {
    fn default() -> Self {
        DBusStatsConfig {
            enabled: true,

            user_stats: false,
            user_allowlist: HashSet::new(),
            user_blocklist: HashSet::new(),

            peer_stats: false,
            peer_well_known_names_only: false,
            peer_allowlist: HashSet::new(),
            peer_blocklist: HashSet::new(),

            cgroup_stats: false,
            cgroup_allowlist: HashSet::new(),
            cgroup_blocklist: HashSet::new(),
        }
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct BootBlameConfig {
    pub enabled: bool,
    pub cache_enabled: bool,
    pub num_slowest_units: u64,
    pub allowlist: HashSet<String>,
    pub blocklist: HashSet<String>,
}
impl Default for BootBlameConfig {
    fn default() -> Self {
        BootBlameConfig {
            enabled: false,
            cache_enabled: true,
            num_slowest_units: 5,
            allowlist: HashSet::new(),
            blocklist: HashSet::new(),
        }
    }
}

#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct VerifyConfig {
    pub enabled: bool,
    pub allowlist: HashSet<String>,
    pub blocklist: HashSet<String>,
}

#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct VarlinkConfig {
    pub enabled: bool,
}

/// Config struct
/// Each section represents an ini file section
#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct Config {
    pub machines: MachinesConfig,
    pub monitord: MonitordConfig,
    pub networkd: NetworkdConfig,
    pub pid1: Pid1Config,
    pub services: HashSet<String>,
    pub system_state: SystemStateConfig,
    pub timers: TimersConfig,
    pub units: UnitsConfig,
    pub dbus_stats: DBusStatsConfig,
    pub boot_blame: BootBlameConfig,
    pub verify: VerifyConfig,
    pub varlink: VarlinkConfig,
}

impl TryFrom<Ini> for Config {
    type Error = MonitordConfigError;

    fn try_from(ini_config: Ini) -> Result<Self, MonitordConfigError> {
        let mut config = Config::default();

        // [monitord] section
        if let Some(dbus_address) = ini_config.get("monitord", "dbus_address") {
            config.monitord.dbus_address = dbus_address;
        }
        if let Ok(Some(dbus_timeout)) = ini_config.getuint("monitord", "dbus_timeout") {
            config.monitord.dbus_timeout = dbus_timeout;
        }
        config.monitord.daemon = read_config_bool(&ini_config, "monitord", "daemon")?;
        if let Ok(Some(daemon_stats_refresh_secs)) =
            ini_config.getuint("monitord", "daemon_stats_refresh_secs")
        {
            config.monitord.daemon_stats_refresh_secs = daemon_stats_refresh_secs;
        }
        if let Some(key_prefix) = ini_config.get("monitord", "key_prefix") {
            config.monitord.key_prefix = key_prefix;
        }
        let output_format_str = ini_config.get("monitord", "output_format").ok_or_else(|| {
            MonitordConfigError::MissingKey {
                section: "monitord".into(),
                key: "output_format".into(),
            }
        })?;
        config.monitord.output_format = MonitordOutputFormat::from_str(&output_format_str)
            .map_err(|e| MonitordConfigError::InvalidValue {
                section: "monitord".into(),
                key: "output_format".into(),
                reason: e.to_string(),
            })?;

        // [networkd] section
        config.networkd.enabled = read_config_bool(&ini_config, "networkd", "enabled")?;
        if let Some(link_state_dir) = ini_config.get("networkd", "link_state_dir") {
            config.networkd.link_state_dir = link_state_dir.into();
        }

        // [pid1] section
        config.pid1.enabled = read_config_bool(&ini_config, "pid1", "enabled")?;

        // [services] section
        let config_map = ini_config.get_map().unwrap_or(IndexMap::from([]));
        if let Some(services) = config_map.get("services") {
            config.services = services.keys().map(|s| s.to_string()).collect();
        }

        // [system-state] section
        config.system_state.enabled = read_config_bool(&ini_config, "system-state", "enabled")?;

        // [timers] section
        config.timers.enabled = read_config_bool(&ini_config, "timers", "enabled")?;
        if let Some(timers_allowlist) = config_map.get("timers.allowlist") {
            config.timers.allowlist = timers_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(timers_blocklist) = config_map.get("timers.blocklist") {
            config.timers.blocklist = timers_blocklist.keys().map(|s| s.to_string()).collect();
        }

        // [units] section
        config.units.enabled = read_config_bool(&ini_config, "units", "enabled")?;
        config.units.state_stats = read_config_bool(&ini_config, "units", "state_stats")?;
        if let Some(state_stats_allowlist) = config_map.get("units.state_stats.allowlist") {
            config.units.state_stats_allowlist = state_stats_allowlist
                .keys()
                .map(|s| s.to_string())
                .collect();
        }
        if let Some(state_stats_blocklist) = config_map.get("units.state_stats.blocklist") {
            config.units.state_stats_blocklist = state_stats_blocklist
                .keys()
                .map(|s| s.to_string())
                .collect();
        }
        config.units.state_stats_time_in_state =
            read_config_bool(&ini_config, "units", "state_stats_time_in_state")?;

        // [machines] section
        config.machines.enabled = read_config_bool(&ini_config, "machines", "enabled")?;
        if let Some(machines_allowlist) = config_map.get("machines.allowlist") {
            config.machines.allowlist = machines_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(machines_blocklist) = config_map.get("machines.blocklist") {
            config.machines.blocklist = machines_blocklist.keys().map(|s| s.to_string()).collect();
        }

        // [dbus] section
        config.dbus_stats.enabled = read_config_bool(&ini_config, "dbus", "enabled")?;

        config.dbus_stats.user_stats = read_config_bool(&ini_config, "dbus", "user_stats")?;
        if let Some(user_allowlist) = config_map.get("dbus.user.allowlist") {
            config.dbus_stats.user_allowlist =
                user_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(user_blocklist) = config_map.get("dbus.user.blocklist") {
            config.dbus_stats.user_blocklist =
                user_blocklist.keys().map(|s| s.to_string()).collect();
        }

        config.dbus_stats.peer_stats = read_config_bool(&ini_config, "dbus", "peer_stats")?;
        config.dbus_stats.peer_well_known_names_only =
            read_config_bool(&ini_config, "dbus", "peer_well_known_names_only")?;
        if let Some(peer_allowlist) = config_map.get("dbus.peer.allowlist") {
            config.dbus_stats.peer_allowlist =
                peer_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(peer_blocklist) = config_map.get("dbus.peer.blocklist") {
            config.dbus_stats.peer_blocklist =
                peer_blocklist.keys().map(|s| s.to_string()).collect();
        }

        config.dbus_stats.cgroup_stats = read_config_bool(&ini_config, "dbus", "cgroup_stats")?;
        if let Some(cgroup_allowlist) = config_map.get("dbus.cgroup.allowlist") {
            config.dbus_stats.cgroup_allowlist =
                cgroup_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(cgroup_blocklist) = config_map.get("dbus.cgroup.blocklist") {
            config.dbus_stats.cgroup_blocklist =
                cgroup_blocklist.keys().map(|s| s.to_string()).collect();
        }

        // [boot] section
        config.boot_blame.enabled = read_config_bool(&ini_config, "boot", "enabled")?;
        if let Some(cache_enabled) =
            read_config_optional_bool(&ini_config, "boot", "cache_enabled")?
        {
            config.boot_blame.cache_enabled = cache_enabled;
        }
        if let Ok(Some(num_slowest_units)) = ini_config.getuint("boot", "num_slowest_units") {
            config.boot_blame.num_slowest_units = num_slowest_units;
        }
        if let Some(boot_allowlist) = config_map.get("boot.allowlist") {
            config.boot_blame.allowlist = boot_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(boot_blocklist) = config_map.get("boot.blocklist") {
            config.boot_blame.blocklist = boot_blocklist.keys().map(|s| s.to_string()).collect();
        }

        // [verify] section
        config.verify.enabled = read_config_bool(&ini_config, "verify", "enabled")?;
        if let Some(verify_allowlist) = config_map.get("verify.allowlist") {
            config.verify.allowlist = verify_allowlist.keys().map(|s| s.to_string()).collect();
        }
        if let Some(verify_blocklist) = config_map.get("verify.blocklist") {
            config.verify.blocklist = verify_blocklist.keys().map(|s| s.to_string()).collect();
        }

        // [varlink] section
        config.varlink.enabled = read_config_bool(&ini_config, "varlink", "enabled")?;

        Ok(config)
    }
}

/// Helper function to read "bool" config options
fn read_config_bool(config: &Ini, section: &str, key: &str) -> Result<bool, MonitordConfigError> {
    let option_bool =
        config
            .getbool(section, key)
            .map_err(|err| MonitordConfigError::InvalidValue {
                section: section.into(),
                key: key.into(),
                reason: err,
            })?;
    match option_bool {
        Some(bool_value) => Ok(bool_value),
        None => {
            error!(
                "No value for '{}' in '{}' section ... assuming false",
                key, section
            );
            Ok(false)
        }
    }
}

/// Helper function to read optional bool config options while preserving field defaults
fn read_config_optional_bool(
    config: &Ini,
    section: &str,
    key: &str,
) -> Result<Option<bool>, MonitordConfigError> {
    config
        .getbool(section, key)
        .map_err(|err| MonitordConfigError::InvalidValue {
            section: section.into(),
            key: key.into(),
            reason: err,
        })
}

#[cfg(test)]
mod tests {
    use std::io::Write;

    use tempfile::NamedTempFile;

    use super::*;

    const FULL_CONFIG: &str = r###"
[monitord]
dbus_address = unix:path=/system_bus_socket
dbus_timeout = 2
daemon = true
daemon_stats_refresh_secs = 0
key_prefix = unittest
output_format = json-pretty

[networkd]
enabled = true
link_state_dir = /links

[pid1]
enabled = true

[services]
foo.service
bar.service

[system-state]
enabled = true

[timers]
enabled = true

[timers.allowlist]
foo.timer

[timers.blocklist]
bar.timer

[units]
enabled = true
state_stats = true
state_stats_time_in_state = true

[units.state_stats.allowlist]
foo.service

[units.state_stats.blocklist]
bar.service

[machines]
enabled = true

[machines.allowlist]
foo
bar

[machines.blocklist]
foo2

[dbus]
enabled = true
user_stats = true
peer_stats = true
peer_well_known_names_only = true
cgroup_stats = true

[dbus.user.allowlist]
foo
bar

[dbus.user.blocklist]
foo2

[dbus.peer.allowlist]
foo
bar

[dbus.peer.blocklist]
foo2

[dbus.cgroup.allowlist]
foo
bar

[dbus.cgroup.blocklist]
foo2

[boot]
enabled = true
cache_enabled = false
num_slowest_units = 10

[boot.allowlist]
foo.service

[boot.blocklist]
bar.service

[varlink]
enabled = true
"###;

    const MINIMAL_CONFIG: &str = r###"
[monitord]
output_format = json-flat
"###;

    #[test]
    fn test_default_config() {
        assert!(Config::default().units.enabled)
    }

    #[test]
    fn test_minimal_config() {
        let mut monitord_config = NamedTempFile::new().expect("Unable to make named tempfile");
        monitord_config
            .write_all(MINIMAL_CONFIG.as_bytes())
            .expect("Unable to write out temp config file");

        let mut ini_config = Ini::new();
        let _config_map = ini_config
            .load(monitord_config.path())
            .expect("Unable to load ini config");

        let expected_config: Config = ini_config.try_into().expect("Failed to parse config");
        // See our one setting is not the default 'json' enum value
        assert_eq!(
            expected_config.monitord.output_format,
            MonitordOutputFormat::JsonFlat,
        );
        // See that one of the enabled bools are false
        assert!(!expected_config.networkd.enabled);
        // Boot cache defaults to enabled when not explicitly configured
        assert!(expected_config.boot_blame.cache_enabled);
    }

    #[test]
    fn test_full_config() {
        let expected_config = Config {
            monitord: MonitordConfig {
                dbus_address: String::from("unix:path=/system_bus_socket"),
                daemon: true,
                daemon_stats_refresh_secs: u64::MIN,
                key_prefix: String::from("unittest"),
                output_format: MonitordOutputFormat::JsonPretty,
                dbus_timeout: 2 as u64,
            },
            networkd: NetworkdConfig {
                enabled: true,
                link_state_dir: "/links".into(),
            },
            pid1: Pid1Config { enabled: true },
            services: HashSet::from([String::from("foo.service"), String::from("bar.service")]),
            system_state: SystemStateConfig { enabled: true },
            timers: TimersConfig {
                enabled: true,
                allowlist: HashSet::from([String::from("foo.timer")]),
                blocklist: HashSet::from([String::from("bar.timer")]),
            },
            units: UnitsConfig {
                enabled: true,
                state_stats: true,
                state_stats_allowlist: HashSet::from([String::from("foo.service")]),
                state_stats_blocklist: HashSet::from([String::from("bar.service")]),
                state_stats_time_in_state: true,
            },
            machines: MachinesConfig {
                enabled: true,
                allowlist: HashSet::from([String::from("foo"), String::from("bar")]),
                blocklist: HashSet::from([String::from("foo2")]),
            },
            dbus_stats: DBusStatsConfig {
                enabled: true,
                user_stats: true,
                user_allowlist: HashSet::from([String::from("foo"), String::from("bar")]),
                user_blocklist: HashSet::from([String::from("foo2")]),
                peer_stats: true,
                peer_well_known_names_only: true,
                peer_allowlist: HashSet::from([String::from("foo"), String::from("bar")]),
                peer_blocklist: HashSet::from([String::from("foo2")]),
                cgroup_stats: true,
                cgroup_allowlist: HashSet::from([String::from("foo"), String::from("bar")]),
                cgroup_blocklist: HashSet::from([String::from("foo2")]),
            },
            boot_blame: BootBlameConfig {
                enabled: true,
                cache_enabled: false,
                num_slowest_units: 10,
                allowlist: HashSet::from([String::from("foo.service")]),
                blocklist: HashSet::from([String::from("bar.service")]),
            },
            verify: VerifyConfig {
                enabled: false,
                allowlist: HashSet::new(),
                blocklist: HashSet::new(),
            },
            varlink: VarlinkConfig { enabled: true },
        };

        let mut monitord_config = NamedTempFile::new().expect("Unable to make named tempfile");
        monitord_config
            .write_all(FULL_CONFIG.as_bytes())
            .expect("Unable to write out temp config file");

        let mut ini_config = Ini::new();
        let _config_map = ini_config
            .load(monitord_config.path())
            .expect("Unable to load ini config");

        // See everything set / overloaded ...
        let actual_config: Config = ini_config.try_into().expect("Failed to parse config");
        assert_eq!(expected_config, actual_config);
    }

    #[test]
    fn test_invalid_config_returns_error() {
        let invalid_config = "[monitord]\ndaemon = notabool\noutput_format = json\n";
        let mut monitord_config = NamedTempFile::new().expect("Unable to make named tempfile");
        monitord_config
            .write_all(invalid_config.as_bytes())
            .expect("Unable to write out temp config file");

        let mut ini_config = Ini::new();
        let _config_map = ini_config
            .load(monitord_config.path())
            .expect("Unable to load ini config");

        let result: Result<Config, _> = ini_config.try_into();
        assert!(result.is_err());
    }
}