//! Pure domain entity for application settings.
//!
//! Defines `Settings` (top-level user configuration), `SettingsFlags`
//! (grouped boolean toggles), and `InternetMode` (network access level).
//! Serialised to `settings.json` by the infrastructure layer.
//!
//! # Architecture
//! This is a pure data structure with **no I/O logic**. Load/save
//! responsibilities live in `SettingsRepository` (domain::repository).
//!
//! ## Settings Fields
//! - `internet_mode` — network access policy (Off / ReadOnly / Full)
//! - `provider` / `model` — default LLM provider and model name
//! - `api_keys` — per-provider API key overrides (name → key)
//! - `max_tokens` / `temperature` — generation parameter defaults
//! - `review_max_lessons_per_run` — max lessons per auto-review pass
//! - `verify_command` — optional shell command to run for verification
//! - `workflow_max_concurrency` — max parallel hive-mind nodes
//! - `hive_mind_node_timeout_ms` — per-node timeout for hive-mind orchestration
//! - `flags` — grouped boolean feature toggles

use std::collections::HashMap;

use serde::{Deserialize, Serialize};

use super::app_config::AppConfig;

/// Controls how much network access the agent is permitted during a session.
///
/// ## Variants
/// - `Off` — no network access
/// - `ReadOnly` — HTTP GET / HEAD only
/// - `Full` — any HTTP method permitted
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
pub enum InternetMode {
    /// No network access permitted.
    #[default]
    Off,
    /// HTTP GET / HEAD requests only.
    ReadOnly,
    /// Any HTTP method permitted.
    Full,
}

/// Grouped boolean feature toggles for the application.
///
/// Kept as a separate struct to avoid clippy's
/// `default-too-many-fields` threshold on `Settings`.
///
/// ## Fields
/// - `review_enabled` — enable automatic inline review after edits
/// - `session_archive_enabled` — enable periodic session archiving
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SettingsFlags {
    pub review_enabled: bool,
    pub session_archive_enabled: bool,
}

impl Default for SettingsFlags {
    /// Returns the default flags with all features enabled.
    fn default() -> Self {
        Self {
            review_enabled: true,
            session_archive_enabled: true,
        }
    }
}

/// Returns the default hive-mind node timeout (600 seconds).
fn default_hive_mind_node_timeout_ms() -> u64 {
    600_000
}

/// Top-level application settings model.
///
/// Serialised to `settings.json` by the infrastructure persistence layer.
/// Holds LLM provider selection, generation parameters, feature flags,
/// and workflow configuration.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Settings {
    pub internet_mode: InternetMode,
    pub provider: String,
    pub model: String,
    pub api_keys: HashMap<String, String>,
    pub max_tokens: Option<u32>,
    pub temperature: Option<f32>,
    pub review_max_lessons_per_run: usize,
    pub adaptive_review_max_skip: u32,
    pub verify_command: Option<String>,
    pub verify_timeout_ms: u64,
    pub workflow_max_concurrency: usize,
    #[serde(flatten)]
    pub flags: SettingsFlags,
    #[serde(default = "default_hive_mind_node_timeout_ms")]
    pub hive_mind_node_timeout_ms: u64,
}

impl Default for Settings {
    fn default() -> Self {
        Self {
            internet_mode: InternetMode::Off,
            provider: "zen".to_string(),
            model: "deepseek-v4-flash-free".to_string(),
            api_keys: HashMap::new(),
            max_tokens: None,
            temperature: None,
            review_max_lessons_per_run: 5,
            adaptive_review_max_skip: 3,
            verify_command: None,
            verify_timeout_ms: 30_000,
            workflow_max_concurrency: 5,
            flags: SettingsFlags::default(),
            hive_mind_node_timeout_ms: 600_000,
        }
    }
}

/// Pick the effective model name for the main agent.
///
/// When `settings.provider` is `"claude"` (auto-detected from
/// `~/.claude/settings.json`), the provider's `default_model` (or the
/// app-level `default_model`) wins over a possibly-stale persisted
/// `settings.model`. Otherwise the user's explicit `settings.model` is used.
///
/// Why: the user's custom Claude endpoint (URL + API key from
/// `~/.claude/settings.json`) implies Opus as the model; a stale
/// `settings.json` (e.g. "deepseek-v4-flash-free") must not override it.
pub fn resolve_effective_model(settings: &Settings, app_config: &AppConfig) -> String {
    if settings.provider == "claude" {
        if let Some(m) = app_config
            .providers
            .get("claude")
            .and_then(|p| p.default_model.clone())
        {
            return m;
        }
        return app_config.default_model.clone();
    }
    settings.model.clone()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::cms::app_config::AppConfig;

    fn claude_app_config() -> AppConfig {
        let mut cfg = AppConfig::default();
        cfg.providers.insert(
            "claude".to_string(),
            crate::cms::ProviderConfig {
                api_base: "https://9router.example/v1".to_string(),
                api_key_env: Some("ANTHROPIC_API_KEY".to_string()),
                default_model: Some("claude-opus-5".to_string()),
                default_api_key: Some("sk-test".to_string()),
            },
        );
        cfg.default_provider = "claude".to_string();
        cfg.default_model = "claude-opus-5".to_string();
        cfg
    }

    #[test]
    fn claude_provider_uses_opus_model_over_stale_settings_model() {
        let settings = Settings {
            provider: "claude".to_string(),
            model: "deepseek-v4-flash-free".to_string(), // stale persisted
            ..Settings::default()
        };

        let model = resolve_effective_model(&settings, &claude_app_config());
        assert_eq!(model, "claude-opus-5");
    }

    #[test]
    fn non_claude_provider_uses_settings_model() {
        let settings = Settings {
            provider: "zen".to_string(),
            model: "my-model".to_string(),
            ..Settings::default()
        };

        let model = resolve_effective_model(&settings, &AppConfig::default());
        assert_eq!(model, "my-model");
    }

    #[test]
    fn claude_falls_back_to_app_default() {
        let settings = Settings {
            provider: "claude".to_string(),
            model: String::new(),
            ..Settings::default()
        };

        let cfg = AppConfig::default();
        let model = resolve_effective_model(&settings, &cfg);
        assert_eq!(model, cfg.default_model);
    }
}