// config.rs — Unified configuration
//
// Single config file: ~/.config/poc-agent/config.json5
//   Memory settings in the "memory" section (Config)
//   Agent/backend settings at top level (AppConfig)
//
// Legacy fallback: ~/.config/poc-memory/config.jsonl
//   Env override: POC_MEMORY_CONFIG

use std::collections::HashMap;
use std::path::PathBuf;
use std::sync::{Arc, OnceLock, RwLock};

use anyhow::{Context as _, Result};
use figment::providers::Serialized;
use figment::{Figment, Provider};
use serde::{Deserialize, Serialize};

/// Config file path shared by all loaders.
pub fn config_path() -> PathBuf {
    dirs::home_dir()
        .unwrap_or_else(|| PathBuf::from("."))
        .join(".config/poc-agent/config.json5")
}

// ============================================================
// Memory config (the "memory" section)
// ============================================================

static CONFIG: OnceLock<RwLock<Arc<Config>>> = OnceLock::new();

#[derive(Debug, Clone, PartialEq, Deserialize)]
#[serde(rename_all = "lowercase")]
#[derive(Default)]
pub enum ContextSource {
    #[serde(alias = "")]
    #[default]
    Store,
    File,
    Journal,
}

#[derive(Debug, Clone, Deserialize)]
pub struct ContextGroup {
    pub label: String,
    #[serde(default)]
    pub keys: Vec<String>,
    #[serde(default)]
    pub source: ContextSource,
    /// Include this group in agent context (default true)
    #[serde(default = "default_true")]
    pub agent: bool,
}

fn default_true() -> bool { true }

#[derive(Debug, Clone, Deserialize)]
#[serde(default)]
pub struct Config {
    pub user_name: String,
    pub assistant_name: String,
    #[serde(deserialize_with = "deserialize_path")]
    pub data_dir: PathBuf,
    #[serde(deserialize_with = "deserialize_path")]
    pub projects_dir: PathBuf,
    pub core_nodes: Vec<String>,
    pub journal_days: u32,
    pub journal_max: usize,
    pub context_groups: Vec<ContextGroup>,
    pub llm_concurrency: usize,
    pub agent_budget: usize,
    #[serde(deserialize_with = "deserialize_path")]
    pub prompts_dir: PathBuf,
    #[serde(default, deserialize_with = "deserialize_path_opt")]
    pub agent_config_dir: Option<PathBuf>,
    /// Resolved from agent_model → models → backend (not in config directly)
    #[serde(skip)]
    pub api_base_url: Option<String>,
    #[serde(skip)]
    pub api_key: Option<String>,
    #[serde(skip)]
    pub api_model: Option<String>,
    /// Used to resolve API settings, not stored on Config
    #[serde(default)]
    agent_model: Option<String>,
    pub api_reasoning: String,
    pub agent_types: Vec<String>,
    /// Surface agent timeout in seconds.
    #[serde(default)]
    pub surface_timeout_secs: Option<u32>,
    /// Max conversation bytes to include in surface agent context.
    #[serde(default)]
    pub surface_conversation_bytes: Option<usize>,
    /// Hook events that trigger the surface agent.
    #[serde(default)]
    pub surface_hooks: Vec<String>,
}

impl Default for Config {
    fn default() -> Self {
        let home = PathBuf::from(std::env::var("HOME").expect("HOME not set"));
        Self {
            user_name: "User".to_string(),
            assistant_name: "Assistant".to_string(),
            data_dir: home.join(".consciousness"),
            projects_dir: home.join(".claude/projects"),
            core_nodes: vec!["identity".to_string(), "core-practices".to_string()],
            journal_days: 7,
            journal_max: 20,
            context_groups: vec![
                ContextGroup {
                    label: "identity".into(),
                    keys: vec!["identity".into()],
                    source: ContextSource::Store,
                    agent: true,
                },
                ContextGroup {
                    label: "core-practices".into(),
                    keys: vec!["core-practices".into()],
                    source: ContextSource::Store,
                    agent: true,
                },
            ],
            llm_concurrency: 1,
            agent_budget: 1000,
            prompts_dir: home.join("poc/consciousness/src/subconscious/prompts"),
            agent_config_dir: None,
            api_base_url: None,
            api_key: None,
            api_model: None,
            agent_model: None,
            api_reasoning: "high".to_string(),
            agent_types: vec![
                "linker".into(), "organize".into(), "distill".into(),
                "separator".into(), "split".into(),
            ],
            surface_timeout_secs: None,
            surface_conversation_bytes: None,
            surface_hooks: vec![],
        }
    }
}

impl Config {
    fn load_from_file() -> Self {
        if let Some(config) = Self::try_load_shared() {
            return config;
        }
        Self::load_legacy_jsonl()
    }

    /// Load from shared config. Memory settings in the "memory" section;
    /// API settings resolved from models + backend configuration.
    fn try_load_shared() -> Option<Self> {
        let content = std::fs::read_to_string(config_path()).ok()?;
        let root: serde_json::Value = json5::from_str(&content).ok()?;
        let mem_value = root.get("memory")?;

        let mut config: Config = serde_json::from_value(mem_value.clone()).ok()?;
        config.llm_concurrency = config.llm_concurrency.max(1);

        // Resolve API settings: agent_model → models → backend
        if let Some(model_name) = &config.agent_model
            && let Some(model_cfg) = root.get("models").and_then(|m| m.get(model_name.as_str())) {
                let backend_name = model_cfg.get("backend").and_then(|v| v.as_str()).unwrap_or("");
                let model_id = model_cfg.get("model_id").and_then(|v| v.as_str()).unwrap_or("");

                if let Some(backend) = root.get(backend_name) {
                    config.api_base_url = backend.get("base_url")
                        .and_then(|v| v.as_str()).map(String::from);
                    config.api_key = backend.get("api_key")
                        .and_then(|v| v.as_str()).map(String::from);
                }
                config.api_model = Some(model_id.to_string());
            }

        Some(config)
    }

    /// Load from legacy JSONL config (~/.config/poc-memory/config.jsonl).
    fn load_legacy_jsonl() -> Self {
        let path = std::env::var("POC_MEMORY_CONFIG")
            .map(PathBuf::from)
            .unwrap_or_else(|_| {
                PathBuf::from(std::env::var("HOME").expect("HOME not set"))
                    .join(".config/poc-memory/config.jsonl")
            });

        let mut config = Config::default();

        let Ok(content) = std::fs::read_to_string(&path) else {
            return config;
        };

        let mut context_groups: Vec<ContextGroup> = Vec::new();

        let stream = serde_json::Deserializer::from_str(&content)
            .into_iter::<serde_json::Value>();

        for result in stream {
            let Ok(obj) = result else { continue };

            if let Some(cfg) = obj.get("config") {
                if let Some(s) = cfg.get("user_name").and_then(|v| v.as_str()) {
                    config.user_name = s.to_string();
                }
                if let Some(s) = cfg.get("assistant_name").and_then(|v| v.as_str()) {
                    config.assistant_name = s.to_string();
                }
                if let Some(s) = cfg.get("data_dir").and_then(|v| v.as_str()) {
                    config.data_dir = expand_home(s);
                }
                if let Some(s) = cfg.get("projects_dir").and_then(|v| v.as_str()) {
                    config.projects_dir = expand_home(s);
                }
                if let Some(arr) = cfg.get("core_nodes").and_then(|v| v.as_array()) {
                    config.core_nodes = arr.iter()
                        .filter_map(|v| v.as_str().map(|s| s.to_string()))
                        .collect();
                }
                if let Some(d) = cfg.get("journal_days").and_then(|v| v.as_u64()) {
                    config.journal_days = d as u32;
                }
                if let Some(m) = cfg.get("journal_max").and_then(|v| v.as_u64()) {
                    config.journal_max = m as usize;
                }
                if let Some(n) = cfg.get("llm_concurrency").and_then(|v| v.as_u64()) {
                    config.llm_concurrency = n.max(1) as usize;
                }
                if let Some(n) = cfg.get("agent_budget").and_then(|v| v.as_u64()) {
                    config.agent_budget = n as usize;
                }
                if let Some(s) = cfg.get("prompts_dir").and_then(|v| v.as_str()) {
                    config.prompts_dir = expand_home(s);
                }
                if let Some(s) = cfg.get("agent_config_dir").and_then(|v| v.as_str()) {
                    config.agent_config_dir = Some(expand_home(s));
                }
                if let Some(s) = cfg.get("api_base_url").and_then(|v| v.as_str()) {
                    config.api_base_url = Some(s.to_string());
                }
                if let Some(s) = cfg.get("api_key").and_then(|v| v.as_str()) {
                    config.api_key = Some(s.to_string());
                }
                if let Some(s) = cfg.get("api_model").and_then(|v| v.as_str()) {
                    config.api_model = Some(s.to_string());
                }
                continue;
            }

            if let Some(label) = obj.get("group").and_then(|v| v.as_str()) {
                let keys = obj.get("keys")
                    .and_then(|v| v.as_array())
                    .map(|arr| arr.iter()
                        .filter_map(|v| v.as_str().map(|s| s.to_string()))
                        .collect())
                    .unwrap_or_default();

                let source = match obj.get("source").and_then(|v| v.as_str()) {
                    Some("file") => ContextSource::File,
                    Some("journal") => ContextSource::Journal,
                    _ => ContextSource::Store,
                };

                let agent = obj.get("agent").and_then(|v| v.as_bool()).unwrap_or(true);
                context_groups.push(ContextGroup { label: label.to_string(), keys, source, agent });
            }
        }

        if !context_groups.is_empty() {
            config.context_groups = context_groups;
        }

        config
    }
}

/// Get the global memory config (cheap Arc clone).
pub fn get() -> Arc<Config> {
    CONFIG
        .get_or_init(|| RwLock::new(Arc::new(Config::load_from_file())))
        .read()
        .unwrap()
        .clone()
}

/// Reload the config from disk. Returns true if changed.
pub fn reload() -> bool {
    let lock = CONFIG.get_or_init(|| RwLock::new(Arc::new(Config::load_from_file())));
    let new = Config::load_from_file();
    let mut current = lock.write().unwrap();
    let changed = format!("{:?}", **current) != format!("{:?}", new);
    if changed {
        *current = Arc::new(new);
    }
    changed
}

// ============================================================
// Agent config (top-level settings)
// ============================================================

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AppConfig {
    pub backend: String,
    pub anthropic: BackendConfig,
    pub openrouter: BackendConfig,
    #[serde(default)]
    pub deepinfra: BackendConfig,
    pub prompts: PromptConfig,
    pub debug: bool,
    pub compaction: CompactionConfig,
    pub dmn: DmnConfig,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub memory_project: Option<PathBuf>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub system_prompt_file: Option<PathBuf>,
    #[serde(default)]
    pub models: HashMap<String, ModelConfig>,
    #[serde(default = "default_model_name")]
    pub default_model: String,
}

#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct BackendConfig {
    #[serde(default)]
    pub api_key: String,
    #[serde(default)]
    pub model: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub base_url: Option<String>,
}

impl BackendConfig {
    fn resolve(&self, default_base: &str) -> Result<(String, String, String)> {
        if self.api_key.is_empty() {
            anyhow::bail!(
                "No API key. Set it in {} or use --api-key",
                config_path().display()
            );
        }
        let base = self.base_url.clone()
            .unwrap_or_else(|| default_base.to_string());
        Ok((base, self.api_key.clone(), self.model.clone()))
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PromptConfig {
    pub anthropic: String,
    pub other: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CompactionConfig {
    pub hard_threshold_pct: u32,
    pub soft_threshold_pct: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DmnConfig {
    pub max_turns: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ModelConfig {
    /// Backend name ("anthropic" or "openrouter")
    pub backend: String,
    /// Model identifier sent to the API
    pub model_id: String,
    /// Instruction file ("CLAUDE.md" or "POC.md").
    #[serde(default)]
    pub prompt_file: Option<String>,
    /// Context window size in tokens.
    #[serde(default)]
    pub context_window: Option<usize>,
}

impl Default for AppConfig {
    fn default() -> Self {
        Self {
            backend: "openrouter".to_string(),
            anthropic: BackendConfig {
                api_key: String::new(),
                model: "claude-opus-4-6-20250918".to_string(),
                base_url: None,
            },
            openrouter: BackendConfig {
                api_key: String::new(),
                model: "qwen/qwen3.5-397b-a17b".to_string(),
                base_url: Some("https://openrouter.ai/api/v1".to_string()),
            },
            deepinfra: BackendConfig {
                api_key: String::new(),
                model: String::new(),
                base_url: Some("https://api.deepinfra.com/v1/openai".to_string()),
            },
            prompts: PromptConfig {
                anthropic: "CLAUDE.md".to_string(),
                other: "POC.md".to_string(),
            },
            debug: false,
            compaction: CompactionConfig {
                hard_threshold_pct: 90,
                soft_threshold_pct: 80,
            },
            dmn: DmnConfig { max_turns: 20 },
            memory_project: None,
            system_prompt_file: None,
            models: HashMap::new(),
            default_model: String::new(),
        }
    }
}

fn default_model_name() -> String { String::new() }

/// Resolved, ready-to-use agent session config.
pub struct SessionConfig {
    pub api_base: String,
    pub api_key: String,
    pub model: String,
    pub prompt_file: String,
    pub system_prompt: String,
    /// Identity/personality files as (name, content) pairs.
    pub context_parts: Vec<(String, String)>,
    pub config_file_count: usize,
    pub memory_file_count: usize,
    pub session_dir: PathBuf,
    pub app: AppConfig,
}

impl SessionConfig {
    /// Join context parts into a single string for legacy interfaces.
    #[allow(dead_code)]
    pub fn context_message(&self) -> String {
        self.context_parts.iter()
            .map(|(name, content)| format!("## {}\n\n{}", name, content))
            .collect::<Vec<_>>()
            .join("\n\n---\n\n")
    }
}

/// A fully resolved model ready to construct an ApiClient.
#[allow(dead_code)]
pub struct ResolvedModel {
    pub name: String,
    pub api_base: String,
    pub api_key: String,
    pub model_id: String,
    pub prompt_file: String,
    pub context_window: Option<usize>,
}

impl AppConfig {
    /// Resolve the active backend and assemble prompts into a SessionConfig.
    pub fn resolve(&self, cli: &crate::agent::cli::CliArgs) -> Result<SessionConfig> {
        let cwd = std::env::current_dir().context("Failed to get current directory")?;

        let (api_base, api_key, model, prompt_file);

        if !self.models.is_empty() {
            let resolved = self.resolve_model(&self.default_model)?;
            api_base = resolved.api_base;
            api_key = resolved.api_key;
            model = resolved.model_id;
            prompt_file = resolved.prompt_file;
        } else {
            let (base, key, mdl) = match self.backend.as_str() {
                "anthropic" => self.anthropic.resolve("https://api.anthropic.com"),
                _ => self.openrouter.resolve("https://openrouter.ai/api/v1"),
            }?;
            api_base = base;
            api_key = key;
            model = mdl;
            prompt_file = if is_anthropic_model(&model) {
                self.prompts.anthropic.clone()
            } else {
                self.prompts.other.clone()
            };
        }

        let context_groups = get().context_groups.clone();

        let (system_prompt, context_parts, config_file_count, memory_file_count) =
            if let Some(ref path) = cli.system_prompt_file.as_ref().or(self.system_prompt_file.as_ref()) {
                let content = std::fs::read_to_string(path)
                    .with_context(|| format!("Failed to read {}", path.display()))?;
                (content, Vec::new(), 0, 0)
            } else {
                let system_prompt = crate::agent::identity::assemble_system_prompt();
                let (context_parts, cc, mc) = crate::agent::identity::assemble_context_message(&cwd, &prompt_file, self.memory_project.as_deref(), &context_groups)?;
                (system_prompt, context_parts, cc, mc)
            };

        let session_dir = dirs::home_dir()
            .unwrap_or_else(|| PathBuf::from("."))
            .join(".cache/poc-agent/sessions");
        std::fs::create_dir_all(&session_dir).ok();

        Ok(SessionConfig {
            api_base, api_key, model, prompt_file,
            system_prompt, context_parts,
            config_file_count, memory_file_count,
            session_dir,
            app: self.clone(),
        })
    }

    /// Look up a named model and resolve its credentials from the backend config.
    pub fn resolve_model(&self, name: &str) -> Result<ResolvedModel> {
        let model = self.models.get(name)
            .ok_or_else(|| anyhow::anyhow!(
                "Unknown model '{}'. Available: {}",
                name,
                self.model_names().join(", "),
            ))?;

        let (api_base, api_key) = match model.backend.as_str() {
            "anthropic" => (
                self.anthropic.base_url.clone()
                    .unwrap_or_else(|| "https://api.anthropic.com".to_string()),
                self.anthropic.api_key.clone(),
            ),
            "deepinfra" => (
                self.deepinfra.base_url.clone()
                    .unwrap_or_else(|| "https://api.deepinfra.com/v1/openai".to_string()),
                self.deepinfra.api_key.clone(),
            ),
            _ => (
                self.openrouter.base_url.clone()
                    .unwrap_or_else(|| "https://openrouter.ai/api/v1".to_string()),
                self.openrouter.api_key.clone(),
            ),
        };

        let prompt_file = model.prompt_file.clone()
            .unwrap_or_else(|| {
                if is_anthropic_model(&model.model_id) {
                    self.prompts.anthropic.clone()
                } else {
                    self.prompts.other.clone()
                }
            });

        Ok(ResolvedModel {
            name: name.to_string(),
            api_base,
            api_key,
            model_id: model.model_id.clone(),
            prompt_file,
            context_window: model.context_window,
        })
    }

    /// List available model names, sorted.
    pub fn model_names(&self) -> Vec<String> {
        let mut names: Vec<_> = self.models.keys().cloned().collect();
        names.sort();
        names
    }
}

// ============================================================
// Figment-based agent config loading
// ============================================================

struct Json5File(PathBuf);

impl Provider for Json5File {
    fn metadata(&self) -> figment::Metadata {
        figment::Metadata::named(format!("JSON5 file ({})", self.0.display()))
    }

    fn data(&self) -> figment::Result<figment::value::Map<figment::Profile, figment::value::Dict>> {
        match std::fs::read_to_string(&self.0) {
            Ok(content) => {
                let value: figment::value::Value = json5::from_str(&content)
                    .map_err(|e| figment::Error::from(format!("{}: {}", self.0.display(), e)))?;
                Serialized::defaults(value).data()
            }
            Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(figment::value::Map::new()),
            Err(e) => Err(figment::Error::from(format!("{}: {}", self.0.display(), e))),
        }
    }
}

macro_rules! merge_opt {
    ($fig:expr, $val:expr, $($key:expr),+) => {
        if let Some(ref v) = $val {
            $( $fig = $fig.merge(Serialized::default($key, v)); )+
        }
    };
}

fn build_figment(cli: &crate::agent::cli::CliArgs) -> Figment {
    let mut f = Figment::from(Serialized::defaults(AppConfig::default()))
        .merge(Json5File(config_path()));

    merge_opt!(f, cli.backend, "backend");
    merge_opt!(f, cli.model, "anthropic.model", "openrouter.model");
    merge_opt!(f, cli.api_key, "anthropic.api_key", "openrouter.api_key");
    merge_opt!(f, cli.api_base, "anthropic.base_url", "openrouter.base_url");
    merge_opt!(f, cli.system_prompt_file, "system_prompt_file");
    merge_opt!(f, cli.memory_project, "memory_project");
    merge_opt!(f, cli.dmn_max_turns, "dmn.max_turns");
    if cli.debug {
        f = f.merge(Serialized::default("debug", true));
    }

    f
}

/// Load just the AppConfig — no validation, no prompt assembly.
pub fn load_app(cli: &crate::agent::cli::CliArgs) -> Result<(AppConfig, Figment)> {
    let figment = build_figment(cli);
    let app: AppConfig = figment.extract().context("Failed to load configuration")?;
    Ok((app, figment))
}

/// Load the full config: figment → AppConfig → resolve backend → assemble prompts.
pub fn load_session(cli: &crate::agent::cli::CliArgs) -> Result<(SessionConfig, Figment)> {
    let (app, figment) = load_app(cli)?;
    let config = app.resolve(cli)?;
    Ok((config, figment))
}

/// Re-assemble prompts for a specific model's prompt file.
pub fn reload_for_model(app: &AppConfig, prompt_file: &str) -> Result<(String, Vec<(String, String)>)> {
    let cwd = std::env::current_dir().context("Failed to get current directory")?;

    if let Some(ref path) = app.system_prompt_file {
        let content = std::fs::read_to_string(path)
            .with_context(|| format!("Failed to read {}", path.display()))?;
        return Ok((content, Vec::new()));
    }

    let system_prompt = crate::agent::identity::assemble_system_prompt();
    let context_groups = get().context_groups.clone();
    let (context_parts, _, _) = crate::agent::identity::assemble_context_message(&cwd, prompt_file, app.memory_project.as_deref(), &context_groups)?;
    Ok((system_prompt, context_parts))
}

fn is_anthropic_model(model: &str) -> bool {
    let m = model.to_lowercase();
    m.contains("claude") || m.contains("opus") || m.contains("sonnet")
}

pub fn show_config(app: &AppConfig, figment: &Figment) {
    fn mask(key: &str) -> String {
        if key.is_empty() { "(not set)".into() }
        else if key.len() <= 8 { "****".into() }
        else { format!("{}...{}", &key[..4], &key[key.len() - 4..]) }
    }
    fn src(figment: &Figment, key: &str) -> String {
        figment.find_metadata(key).map_or("default".into(), |m| m.name.to_string())
    }

    println!("# Effective configuration\n");
    println!("backend: {:?}  ({})", app.backend, src(figment, "backend"));
    for (name, b) in [("anthropic", &app.anthropic), ("openrouter", &app.openrouter)] {
        println!("\n{}:", name);
        println!("  api_key: {}  ({})", mask(&b.api_key), src(figment, &format!("{name}.api_key")));
        println!("  model: {:?}  ({})", b.model, src(figment, &format!("{name}.model")));
        if let Some(ref url) = b.base_url {
            println!("  base_url: {:?}  ({})", url, src(figment, &format!("{name}.base_url")));
        }
    }
    println!("\nprompts:");
    println!("  anthropic: {:?}  ({})", app.prompts.anthropic, src(figment, "prompts.anthropic"));
    println!("  other: {:?}  ({})", app.prompts.other, src(figment, "prompts.other"));
    println!("\ndebug: {}  ({})", app.debug, src(figment, "debug"));
    println!("\ncompaction:");
    println!("  hard_threshold_pct: {}  ({})", app.compaction.hard_threshold_pct, src(figment, "compaction.hard_threshold_pct"));
    println!("  soft_threshold_pct: {}  ({})", app.compaction.soft_threshold_pct, src(figment, "compaction.soft_threshold_pct"));
    println!("\ndmn:");
    println!("  max_turns: {}  ({})", app.dmn.max_turns, src(figment, "dmn.max_turns"));
    if let Some(ref p) = app.system_prompt_file {
        println!("\nsystem_prompt_file: {:?}  ({})", p, src(figment, "system_prompt_file"));
    }
    if let Some(ref p) = app.memory_project {
        println!("\nmemory_project: {:?}  ({})", p, src(figment, "memory_project"));
    }
    println!("\ndefault_model: {:?}", app.default_model);
    if !app.models.is_empty() {
        println!("\nmodels:");
        for (name, m) in &app.models {
            println!("  {}:", name);
            println!("    backend: {:?}", m.backend);
            println!("    model_id: {:?}", m.model_id);
            if let Some(ref pf) = m.prompt_file {
                println!("    prompt_file: {:?}", pf);
            }
            if let Some(cw) = m.context_window {
                println!("    context_window: {}", cw);
            }
        }
    }
}

// ============================================================
// Helpers
// ============================================================

fn deserialize_path<'de, D: serde::Deserializer<'de>>(d: D) -> Result<PathBuf, D::Error> {
    let s: String = serde::Deserialize::deserialize(d)?;
    Ok(expand_home(&s))
}

fn deserialize_path_opt<'de, D: serde::Deserializer<'de>>(d: D) -> Result<Option<PathBuf>, D::Error> {
    let s: Option<String> = serde::Deserialize::deserialize(d)?;
    Ok(s.map(|s| expand_home(&s)))
}

pub fn expand_home(path: &str) -> PathBuf {
    if let Some(rest) = path.strip_prefix("~/") {
        PathBuf::from(std::env::var("HOME").expect("HOME not set")).join(rest)
    } else {
        PathBuf::from(path)
    }
}