rebecca-core 0.2.0

use std::path::{Path, PathBuf};

use directories::BaseDirs;
use serde::{Deserialize, Serialize};

use crate::model::{DEFAULT_PROJECT_ARTIFACT_MAX_DEPTH, DEFAULT_PROJECT_ARTIFACT_MIN_AGE_DAYS};
use crate::scan_cache::{DEFAULT_DIRECTORY_SCAN_CACHE_MAX_AGE_SECONDS, ScanCachePolicy};
use crate::{RebeccaError, Result};

pub const CONFIG_SCHEMA_VERSION: u32 = 1;

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct AppPaths {
    pub config_dir: PathBuf,
    pub config_file: PathBuf,
    pub state_dir: PathBuf,
    pub cache_dir: PathBuf,
    pub history_file: PathBuf,
}

impl AppPaths {
    pub fn storage_entries(&self) -> Vec<AppStorageEntry> {
        vec![
            AppStorageEntry::new(
                AppStorageId::ConfigFile,
                self.config_file.clone(),
                AppStorageLifecycle::Configuration,
                AppStorageRetention::Preserve,
            ),
            AppStorageEntry::new(
                AppStorageId::ConfigDir,
                self.config_dir.clone(),
                AppStorageLifecycle::Configuration,
                AppStorageRetention::Preserve,
            ),
            AppStorageEntry::new(
                AppStorageId::StateDir,
                self.state_dir.clone(),
                AppStorageLifecycle::DurableState,
                AppStorageRetention::Preserve,
            ),
            AppStorageEntry::new(
                AppStorageId::CacheDir,
                self.cache_dir.clone(),
                AppStorageLifecycle::RebuildableCache,
                AppStorageRetention::Rebuildable,
            ),
            AppStorageEntry::new(
                AppStorageId::HistoryFile,
                self.history_file.clone(),
                AppStorageLifecycle::AppendOnlyHistory,
                AppStorageRetention::Preserve,
            ),
        ]
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct AppRuntimeConfig {
    pub app_paths: AppPaths,
    pub scan_cache_policy: ScanCachePolicy,
    pub protected_paths: Vec<PathBuf>,
    pub purge: PurgeRuntimeConfig,
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct PurgeRuntimeConfig {
    pub roots: Vec<PathBuf>,
    pub max_depth: usize,
    pub min_age_days: u64,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct AppStorageEntry {
    pub id: AppStorageId,
    pub path: PathBuf,
    pub lifecycle: AppStorageLifecycle,
    pub retention: AppStorageRetention,
}

impl AppStorageEntry {
    fn new(
        id: AppStorageId,
        path: PathBuf,
        lifecycle: AppStorageLifecycle,
        retention: AppStorageRetention,
    ) -> Self {
        Self {
            id,
            path,
            lifecycle,
            retention,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub enum AppStorageId {
    ConfigFile,
    ConfigDir,
    StateDir,
    CacheDir,
    HistoryFile,
}

impl AppStorageId {
    pub fn label(self) -> &'static str {
        match self {
            Self::ConfigFile => "Config file",
            Self::ConfigDir => "Config dir",
            Self::StateDir => "State dir",
            Self::CacheDir => "Cache dir",
            Self::HistoryFile => "History",
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub enum AppStorageLifecycle {
    Configuration,
    DurableState,
    RebuildableCache,
    AppendOnlyHistory,
}

impl AppStorageLifecycle {
    pub fn label(self) -> &'static str {
        match self {
            Self::Configuration => "configuration",
            Self::DurableState => "durable state",
            Self::RebuildableCache => "rebuildable cache",
            Self::AppendOnlyHistory => "append-only history",
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub enum AppStorageRetention {
    Preserve,
    Rebuildable,
}

impl AppStorageRetention {
    pub fn label(self) -> &'static str {
        match self {
            Self::Preserve => "preserve",
            Self::Rebuildable => "rebuildable",
        }
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(default, deny_unknown_fields)]
pub struct RebeccaConfig {
    pub version: u32,
    pub app_paths: RebeccaAppPathsConfig,
    pub scan_cache: RebeccaScanCacheConfig,
    pub protection: RebeccaProtectionConfig,
    pub purge: RebeccaPurgeConfig,
}

impl Default for RebeccaConfig {
    fn default() -> Self {
        Self {
            version: CONFIG_SCHEMA_VERSION,
            app_paths: RebeccaAppPathsConfig::default(),
            scan_cache: RebeccaScanCacheConfig::default(),
            protection: RebeccaProtectionConfig::default(),
            purge: RebeccaPurgeConfig::default(),
        }
    }
}

#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(default, deny_unknown_fields)]
pub struct RebeccaAppPathsConfig {
    pub state_dir: Option<PathBuf>,
    pub cache_dir: Option<PathBuf>,
    pub history_file: Option<PathBuf>,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(default, deny_unknown_fields)]
pub struct RebeccaScanCacheConfig {
    #[serde(default = "default_directory_record_max_age_seconds")]
    pub directory_record_max_age_seconds: u64,
}

#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(default, deny_unknown_fields)]
pub struct RebeccaProtectionConfig {
    pub protected_paths: Vec<PathBuf>,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(default, deny_unknown_fields)]
pub struct RebeccaPurgeConfig {
    pub roots: Vec<PathBuf>,
    #[serde(default = "default_project_artifact_max_depth")]
    pub max_depth: usize,
    #[serde(default = "default_project_artifact_min_age_days")]
    pub min_age_days: u64,
}

impl RebeccaScanCacheConfig {
    pub fn policy(&self) -> ScanCachePolicy {
        ScanCachePolicy::new(self.directory_record_max_age_seconds)
    }
}

impl Default for RebeccaScanCacheConfig {
    fn default() -> Self {
        Self {
            directory_record_max_age_seconds: default_directory_record_max_age_seconds(),
        }
    }
}

impl RebeccaPurgeConfig {
    pub fn runtime(&self) -> PurgeRuntimeConfig {
        PurgeRuntimeConfig {
            roots: self.roots.clone(),
            max_depth: self.max_depth,
            min_age_days: self.min_age_days,
        }
    }
}

impl Default for RebeccaPurgeConfig {
    fn default() -> Self {
        Self {
            roots: Vec::new(),
            max_depth: default_project_artifact_max_depth(),
            min_age_days: default_project_artifact_min_age_days(),
        }
    }
}

fn default_directory_record_max_age_seconds() -> u64 {
    DEFAULT_DIRECTORY_SCAN_CACHE_MAX_AGE_SECONDS
}

fn default_project_artifact_max_depth() -> usize {
    DEFAULT_PROJECT_ARTIFACT_MAX_DEPTH
}

fn default_project_artifact_min_age_days() -> u64 {
    DEFAULT_PROJECT_ARTIFACT_MIN_AGE_DAYS
}

pub fn default_app_paths() -> Result<AppPaths> {
    default_runtime_config().map(|config| config.app_paths)
}

pub fn load_app_paths() -> Result<AppPaths> {
    default_app_paths()
}

pub fn load_app_paths_from(config_file: &Path) -> Result<AppPaths> {
    load_runtime_config_from(config_file).map(|config| config.app_paths)
}

pub fn default_runtime_config() -> Result<AppRuntimeConfig> {
    let config_dir = default_config_dir()?;
    let config_file = config_dir.join("config.toml");
    let config = load_config(&config_file)?;
    resolve_runtime_config_with_config_dir(config_dir, config_file, &config)
}

pub fn load_runtime_config() -> Result<AppRuntimeConfig> {
    default_runtime_config()
}

pub fn load_runtime_config_from(config_file: &Path) -> Result<AppRuntimeConfig> {
    let config_dir = config_file
        .parent()
        .map(Path::to_path_buf)
        .unwrap_or_default();
    let config = load_config(config_file)?;
    resolve_runtime_config_with_config_dir(config_dir, config_file.to_path_buf(), &config)
}

pub fn load_config(config_file: &Path) -> Result<RebeccaConfig> {
    if !config_file.exists() {
        return Ok(RebeccaConfig::default());
    }

    let raw = std::fs::read_to_string(config_file).map_err(|err| RebeccaError::ConfigRead {
        path: config_file.to_path_buf(),
        message: err.to_string(),
    })?;
    if raw.trim().is_empty() {
        return Ok(RebeccaConfig::default());
    }

    let config = toml::from_str(&raw).map_err(|err| RebeccaError::ConfigParse {
        path: config_file.to_path_buf(),
        message: err.to_string(),
    })?;
    validate_config(config_file, &config)?;

    Ok(config)
}

pub fn resolve_app_paths(config: &RebeccaConfig) -> Result<AppPaths> {
    resolve_runtime_config(config).map(|config| config.app_paths)
}

pub fn resolve_runtime_config(config: &RebeccaConfig) -> Result<AppRuntimeConfig> {
    let config_dir = default_config_dir()?;
    let config_file = config_dir.join("config.toml");
    resolve_runtime_config_with_config_dir(config_dir, config_file, config)
}

fn resolve_runtime_config_with_config_dir(
    config_dir: PathBuf,
    config_file: PathBuf,
    config: &RebeccaConfig,
) -> Result<AppRuntimeConfig> {
    Ok(AppRuntimeConfig {
        app_paths: resolve_app_paths_with_config_dir(config_dir, config_file, config)?,
        scan_cache_policy: config.scan_cache.policy(),
        protected_paths: config.protection.protected_paths.clone(),
        purge: config.purge.runtime(),
    })
}

fn resolve_app_paths_with_config_dir(
    config_dir: PathBuf,
    config_file: PathBuf,
    config: &RebeccaConfig,
) -> Result<AppPaths> {
    let state_dir = resolve_or_default(
        env_path("REBECCA_STATE_DIR").or_else(|| config.app_paths.state_dir.clone()),
        default_state_dir,
    )?;
    let cache_dir = resolve_or_default(
        env_path("REBECCA_CACHE_DIR").or_else(|| config.app_paths.cache_dir.clone()),
        default_cache_dir,
    )?;
    let history_file = env_path("REBECCA_HISTORY_FILE")
        .or_else(|| config.app_paths.history_file.clone())
        .unwrap_or_else(|| state_dir.join("history.jsonl"));

    Ok(AppPaths {
        config_file,
        history_file,
        config_dir,
        state_dir,
        cache_dir,
    })
}

fn resolve_or_default(value: Option<PathBuf>, default: fn() -> Result<PathBuf>) -> Result<PathBuf> {
    match value {
        Some(path) => Ok(path),
        None => default(),
    }
}

fn validate_config(config_file: &Path, config: &RebeccaConfig) -> Result<()> {
    if config.version != CONFIG_SCHEMA_VERSION {
        return Err(RebeccaError::ConfigParse {
            path: config_file.to_path_buf(),
            message: format!(
                "unsupported config version {}; supported version is {}",
                config.version, CONFIG_SCHEMA_VERSION
            ),
        });
    }

    if config.scan_cache.directory_record_max_age_seconds == 0 {
        return Err(RebeccaError::ConfigParse {
            path: config_file.to_path_buf(),
            message: "scan_cache.directory_record_max_age_seconds must be at least 1".to_string(),
        });
    }

    for protected_path in &config.protection.protected_paths {
        validate_protected_path_config(config_file, protected_path)?;
    }

    for root in &config.purge.roots {
        validate_purge_root_config(config_file, root)?;
    }

    Ok(())
}

pub fn validate_user_protected_path(path: &Path) -> std::result::Result<(), String> {
    if path.as_os_str().is_empty() {
        return Err("path cannot be empty".to_string());
    }

    if !is_absolute_user_path(path) {
        return Err(format!("path must be absolute: {}", path.display()));
    }

    let contains_control_segment = path.components().any(|component| {
        matches!(
            component,
            std::path::Component::ParentDir | std::path::Component::CurDir
        )
    });
    if contains_control_segment {
        return Err(format!(
            "path cannot contain relative control segments: {}",
            path.display()
        ));
    }

    Ok(())
}

fn validate_protected_path_config(config_file: &Path, path: &Path) -> Result<()> {
    if let Err(message) = validate_user_protected_path(path) {
        return Err(RebeccaError::ConfigParse {
            path: config_file.to_path_buf(),
            message: format!("invalid protection.protected_paths entry: {message}"),
        });
    }

    Ok(())
}

fn validate_purge_root_config(config_file: &Path, path: &Path) -> Result<()> {
    if let Err(message) = validate_user_protected_path(path) {
        return Err(RebeccaError::ConfigParse {
            path: config_file.to_path_buf(),
            message: format!("invalid purge.roots entry: {message}"),
        });
    }

    Ok(())
}

fn is_absolute_user_path(path: &Path) -> bool {
    if path.is_absolute() {
        return true;
    }

    let normalized = path.as_os_str().to_string_lossy().replace('/', "\\");
    if normalized.starts_with("\\\\") {
        return true;
    }

    let bytes = normalized.as_bytes();
    bytes.len() >= 3 && bytes[0].is_ascii_alphabetic() && bytes[1] == b':' && bytes[2] == b'\\'
}

fn default_config_dir() -> Result<PathBuf> {
    if let Some(path) = env_path("REBECCA_CONFIG_DIR") {
        return Ok(path);
    }

    let base_dirs = BaseDirs::new().ok_or(RebeccaError::UserDirsUnavailable)?;
    Ok(base_dirs.config_dir().join("Rebecca"))
}

fn default_state_dir() -> Result<PathBuf> {
    if let Some(path) = env_path("REBECCA_STATE_DIR") {
        return Ok(path);
    }

    let base_dirs = BaseDirs::new().ok_or(RebeccaError::UserDirsUnavailable)?;
    Ok(base_dirs.data_local_dir().join("Rebecca").join("state"))
}

fn default_cache_dir() -> Result<PathBuf> {
    if let Some(path) = env_path("REBECCA_CACHE_DIR") {
        return Ok(path);
    }

    let base_dirs = BaseDirs::new().ok_or(RebeccaError::UserDirsUnavailable)?;
    Ok(base_dirs.cache_dir().join("Rebecca").join("cache"))
}

fn env_path(key: &str) -> Option<PathBuf> {
    let value = std::env::var_os(key)?;
    if value.is_empty() {
        return None;
    }

    Some(PathBuf::from(value))
}

#[cfg(test)]
mod tests {
    use super::{
        AppStorageId, AppStorageLifecycle, AppStorageRetention, CONFIG_SCHEMA_VERSION,
        RebeccaAppPathsConfig, RebeccaConfig, RebeccaPurgeConfig, RebeccaScanCacheConfig,
        default_app_paths, load_app_paths_from, load_config, load_runtime_config_from,
        resolve_app_paths, resolve_runtime_config,
    };
    use crate::model::{DEFAULT_PROJECT_ARTIFACT_MAX_DEPTH, DEFAULT_PROJECT_ARTIFACT_MIN_AGE_DAYS};
    use crate::scan_cache::DEFAULT_DIRECTORY_SCAN_CACHE_MAX_AGE_SECONDS;

    #[test]
    fn load_config_missing_file_returns_default() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");

        let config = load_config(&config_file).unwrap();

        assert_eq!(config, RebeccaConfig::default());
    }

    #[test]
    fn load_config_empty_file_returns_default() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(&config_file, "   \n").unwrap();

        let config = load_config(&config_file).unwrap();

        assert_eq!(config, RebeccaConfig::default());
    }

    #[test]
    fn load_config_comment_only_file_returns_default() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(&config_file, "# local Rebecca config\n").unwrap();

        let config = load_config(&config_file).unwrap();

        assert_eq!(config, RebeccaConfig::default());
    }

    #[test]
    fn load_config_defaults_to_current_schema_version() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[app_paths]
state_dir = "C:\\Rebecca\\State"
"#,
        )
        .unwrap();

        let config = load_config(&config_file).unwrap();

        assert_eq!(config.version, CONFIG_SCHEMA_VERSION);
        assert_eq!(
            config.scan_cache.directory_record_max_age_seconds,
            DEFAULT_DIRECTORY_SCAN_CACHE_MAX_AGE_SECONDS
        );
        assert!(config.purge.roots.is_empty());
        assert_eq!(config.purge.max_depth, DEFAULT_PROJECT_ARTIFACT_MAX_DEPTH);
        assert_eq!(
            config.purge.min_age_days,
            DEFAULT_PROJECT_ARTIFACT_MIN_AGE_DAYS
        );
    }

    #[test]
    fn load_config_accepts_current_schema_version() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
version = 1

[app_paths]
state_dir = "C:\\Rebecca\\State"

[scan_cache]
directory_record_max_age_seconds = 42

[purge]
roots = ['C:\Projects', 'D:\Work']
max_depth = 4
min_age_days = 0
"#,
        )
        .unwrap();

        let config = load_config(&config_file).unwrap();

        assert_eq!(config.version, CONFIG_SCHEMA_VERSION);
        assert_eq!(
            config.app_paths.state_dir,
            Some(std::path::PathBuf::from(r"C:\Rebecca\State"))
        );
        assert_eq!(config.scan_cache.directory_record_max_age_seconds, 42);
        assert_eq!(
            config.purge.roots,
            vec![
                std::path::PathBuf::from(r"C:\Projects"),
                std::path::PathBuf::from(r"D:\Work")
            ]
        );
        assert_eq!(config.purge.max_depth, 4);
        assert_eq!(config.purge.min_age_days, 0);
    }

    #[test]
    fn load_config_rejects_unsupported_schema_version() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(&config_file, "version = 2\n").unwrap();

        let err = load_config(&config_file).unwrap_err();

        let message = err.to_string();
        assert!(message.contains("unsupported config version 2"));
        assert!(message.contains("supported version is 1"));
        assert!(message.contains("config.toml"));
    }

    #[test]
    fn load_config_rejects_unknown_fields() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[app_paths]
unknown = "value"
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(err.to_string().contains("unknown field"));
        assert!(err.to_string().contains("config.toml"));
    }

    #[test]
    fn load_config_rejects_invalid_scan_cache_policy() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[scan_cache]
directory_record_max_age_seconds = 0
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(
            err.to_string()
                .contains("scan_cache.directory_record_max_age_seconds must be at least 1")
        );
        assert!(err.to_string().contains("config.toml"));
    }

    #[test]
    fn load_config_rejects_unknown_scan_cache_fields() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[scan_cache]
unknown = 1
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(err.to_string().contains("unknown field"));
        assert!(err.to_string().contains("config.toml"));
    }

    #[test]
    fn load_config_accepts_purge_settings() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        let root = temp.path().join("workspace");
        std::fs::write(
            &config_file,
            format!(
                r#"
[purge]
roots = ['{}']
max_depth = 3
min_age_days = 14
"#,
                root.display()
            ),
        )
        .unwrap();

        let config = load_config(&config_file).unwrap();

        assert_eq!(config.purge.roots, vec![root]);
        assert_eq!(config.purge.max_depth, 3);
        assert_eq!(config.purge.min_age_days, 14);
    }

    #[test]
    fn load_config_rejects_unknown_purge_fields() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[purge]
unknown = 1
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(err.to_string().contains("unknown field"));
        assert!(err.to_string().contains("config.toml"));
    }

    #[test]
    fn load_config_rejects_relative_purge_roots() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[purge]
roots = ['workspace']
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(err.to_string().contains("invalid purge.roots entry"));
        assert!(err.to_string().contains("path must be absolute"));
    }

    #[test]
    fn load_config_reports_read_errors() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::create_dir_all(&config_file).unwrap();

        let err = load_config(&config_file).unwrap_err();

        let message = err.to_string();
        assert!(message.contains("config read failed"));
        assert!(message.contains("config.toml"));
    }

    #[test]
    fn resolve_app_paths_honors_config_overrides() {
        let config = RebeccaConfig {
            version: CONFIG_SCHEMA_VERSION,
            app_paths: RebeccaAppPathsConfig {
                state_dir: Some(std::path::PathBuf::from(r"C:\Rebecca\State")),
                cache_dir: Some(std::path::PathBuf::from(r"C:\Rebecca\Cache")),
                history_file: Some(std::path::PathBuf::from(r"C:\Rebecca\State\audit.jsonl")),
            },
            scan_cache: RebeccaScanCacheConfig {
                directory_record_max_age_seconds: 42,
            },
            protection: super::RebeccaProtectionConfig::default(),
            purge: RebeccaPurgeConfig::default(),
        };

        let paths = resolve_app_paths(&config).unwrap();

        assert!(paths.config_dir.ends_with("Rebecca"));
        assert_eq!(
            paths.state_dir,
            std::path::PathBuf::from(r"C:\Rebecca\State")
        );
        assert_eq!(
            paths.cache_dir,
            std::path::PathBuf::from(r"C:\Rebecca\Cache")
        );
        assert_eq!(
            paths.history_file,
            std::path::PathBuf::from(r"C:\Rebecca\State\audit.jsonl")
        );
    }

    #[test]
    fn app_paths_storage_entries_pin_lifecycle_policy() {
        let config = RebeccaConfig {
            version: CONFIG_SCHEMA_VERSION,
            app_paths: RebeccaAppPathsConfig {
                state_dir: Some(std::path::PathBuf::from(r"C:\Rebecca\State")),
                cache_dir: Some(std::path::PathBuf::from(r"C:\Rebecca\Cache")),
                history_file: Some(std::path::PathBuf::from(r"C:\Rebecca\State\audit.jsonl")),
            },
            scan_cache: RebeccaScanCacheConfig::default(),
            protection: super::RebeccaProtectionConfig::default(),
            purge: RebeccaPurgeConfig::default(),
        };
        let paths = resolve_app_paths(&config).unwrap();

        let entries = paths.storage_entries();

        assert_eq!(
            entries.iter().map(|entry| entry.id).collect::<Vec<_>>(),
            vec![
                AppStorageId::ConfigFile,
                AppStorageId::ConfigDir,
                AppStorageId::StateDir,
                AppStorageId::CacheDir,
                AppStorageId::HistoryFile,
            ]
        );
        assert_eq!(
            entries
                .iter()
                .find(|entry| entry.id == AppStorageId::CacheDir)
                .map(|entry| (entry.lifecycle, entry.retention)),
            Some((
                AppStorageLifecycle::RebuildableCache,
                AppStorageRetention::Rebuildable,
            ))
        );
        assert_eq!(
            entries
                .iter()
                .find(|entry| entry.id == AppStorageId::HistoryFile)
                .map(|entry| (entry.lifecycle, entry.retention)),
            Some((
                AppStorageLifecycle::AppendOnlyHistory,
                AppStorageRetention::Preserve,
            ))
        );
    }

    #[test]
    fn resolve_runtime_config_derives_scan_cache_policy() {
        let purge_root = std::path::PathBuf::from(r"C:\Projects");
        let config = RebeccaConfig {
            version: CONFIG_SCHEMA_VERSION,
            app_paths: RebeccaAppPathsConfig::default(),
            scan_cache: RebeccaScanCacheConfig {
                directory_record_max_age_seconds: 17,
            },
            protection: super::RebeccaProtectionConfig::default(),
            purge: RebeccaPurgeConfig {
                roots: vec![purge_root.clone()],
                max_depth: 5,
                min_age_days: 0,
            },
        };

        let runtime_config = resolve_runtime_config(&config).unwrap();

        assert_eq!(
            runtime_config
                .scan_cache_policy
                .directory_record_max_age_seconds(),
            17
        );
        assert_eq!(runtime_config.purge.roots, vec![purge_root]);
        assert_eq!(runtime_config.purge.max_depth, 5);
        assert_eq!(runtime_config.purge.min_age_days, 0);
    }

    #[test]
    fn load_config_accepts_protected_paths() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        let protected_path = temp.path().join("AppData").join("Local").join("Keep");
        std::fs::write(
            &config_file,
            format!(
                r#"
[protection]
protected_paths = ['{}']
"#,
                protected_path.display()
            ),
        )
        .unwrap();

        let config = load_config(&config_file).unwrap();

        assert_eq!(config.protection.protected_paths, vec![protected_path]);
    }

    #[test]
    fn load_config_rejects_invalid_protected_path_entries() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[protection]
protected_paths = ['../Keep']
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(
            err.to_string()
                .contains("invalid protection.protected_paths entry")
        );
        assert!(err.to_string().contains("config.toml"));
    }

    #[test]
    fn load_config_rejects_relative_protected_paths() {
        let temp = tempfile::tempdir().unwrap();
        let config_file = temp.path().join("config.toml");
        std::fs::write(
            &config_file,
            r#"
[protection]
protected_paths = ['Keep/Cache']
"#,
        )
        .unwrap();

        let err = load_config(&config_file).unwrap_err();

        assert!(
            err.to_string()
                .contains("invalid protection.protected_paths entry")
        );
        assert!(err.to_string().contains("path must be absolute"));
    }

    #[test]
    fn load_app_paths_from_uses_config_file_when_present() {
        let temp = tempfile::tempdir().unwrap();
        let config_dir = temp.path().join("Rebecca");
        std::fs::create_dir_all(&config_dir).unwrap();
        std::fs::write(
            config_dir.join("config.toml"),
            r#"
[app_paths]
state_dir = "C:\\Rebecca\\State"
cache_dir = "C:\\Rebecca\\Cache"
history_file = "C:\\Rebecca\\State\\audit.jsonl"
"#,
        )
        .unwrap();

        let paths = load_app_paths_from(&config_dir.join("config.toml")).unwrap();

        assert_eq!(paths.config_file, config_dir.join("config.toml"));
        assert_eq!(paths.config_dir, config_dir);
        assert_eq!(
            paths.state_dir,
            std::path::PathBuf::from(r"C:\Rebecca\State")
        );
        assert_eq!(
            paths.cache_dir,
            std::path::PathBuf::from(r"C:\Rebecca\Cache")
        );
        assert_eq!(
            paths.history_file,
            std::path::PathBuf::from(r"C:\Rebecca\State\audit.jsonl")
        );
    }

    #[test]
    fn load_runtime_config_from_uses_config_file_scan_cache_policy() {
        let temp = tempfile::tempdir().unwrap();
        let config_dir = temp.path().join("Rebecca");
        std::fs::create_dir_all(&config_dir).unwrap();
        std::fs::write(
            config_dir.join("config.toml"),
            r#"
[scan_cache]
directory_record_max_age_seconds = 9
"#,
        )
        .unwrap();

        let config = load_runtime_config_from(&config_dir.join("config.toml")).unwrap();

        assert_eq!(
            config.scan_cache_policy.directory_record_max_age_seconds(),
            9
        );
    }

    #[test]
    fn default_app_paths_remain_available() {
        assert!(default_app_paths().is_ok());
    }
}