use axum::{extract::Extension, Json};
use tauri::Manager;

use crate::app_error::AppCommandError;
use crate::commands::system_settings as settings_commands;
use crate::db::service::app_metadata_service;
use crate::db::AppDatabase;
use crate::models::*;
use crate::network::proxy;

const SYSTEM_PROXY_SETTINGS_KEY: &str = "system_proxy_settings";
const SYSTEM_LANGUAGE_SETTINGS_KEY: &str = "system_language_settings";
const LANGUAGE_SETTINGS_UPDATED_EVENT: &str = "app://language-settings-updated";

// ---------------------------------------------------------------------------
// Read handlers
// ---------------------------------------------------------------------------

pub async fn get_system_proxy_settings(
    Extension(app): Extension<tauri::AppHandle>,
) -> Result<Json<SystemProxySettings>, AppCommandError> {
    let db = app.state::<AppDatabase>();
    let settings = settings_commands::load_system_proxy_settings(&db.conn).await?;
    Ok(Json(settings))
}

pub async fn get_system_language_settings(
    Extension(app): Extension<tauri::AppHandle>,
) -> Result<Json<SystemLanguageSettings>, AppCommandError> {
    let db = app.state::<AppDatabase>();
    let settings =
        settings_commands::load_system_language_settings(&db.conn).await?;
    Ok(Json(settings))
}

// ---------------------------------------------------------------------------
// Update handlers
// ---------------------------------------------------------------------------

pub async fn update_system_proxy_settings(
    Extension(app): Extension<tauri::AppHandle>,
    Json(settings): Json<SystemProxySettings>,
) -> Result<Json<SystemProxySettings>, AppCommandError> {
    let db = app.state::<AppDatabase>();

    // TODO: call normalize_proxy_settings once it is made pub(crate) in
    // commands/system_settings.rs. For now the frontend validates the URL.
    let serialized = serde_json::to_string(&settings).map_err(|e| {
        AppCommandError::invalid_input("Failed to serialize proxy settings")
            .with_detail(e.to_string())
    })?;

    app_metadata_service::upsert_value(
        &db.conn,
        SYSTEM_PROXY_SETTINGS_KEY,
        &serialized,
    )
    .await
    .map_err(AppCommandError::from)?;

    proxy::apply_system_proxy_settings(&settings)?;
    Ok(Json(settings))
}

pub async fn update_system_language_settings(
    Extension(app): Extension<tauri::AppHandle>,
    Json(settings): Json<SystemLanguageSettings>,
) -> Result<Json<SystemLanguageSettings>, AppCommandError> {
    let db = app.state::<AppDatabase>();

    let serialized = serde_json::to_string(&settings).map_err(|e| {
        AppCommandError::invalid_input("Failed to serialize language settings")
            .with_detail(e.to_string())
    })?;

    app_metadata_service::upsert_value(
        &db.conn,
        SYSTEM_LANGUAGE_SETTINGS_KEY,
        &serialized,
    )
    .await
    .map_err(AppCommandError::from)?;

    crate::web::event_bridge::emit_event(
        &app,
        LANGUAGE_SETTINGS_UPDATED_EVENT,
        settings.clone(),
    );

    Ok(Json(settings))
}