//! Sharing a card's image: onto the clipboard on desktop, through the system
//! share sheet on Android.
//!
//! Android has no official Tauri share plugin, so this registers a small one
//! of our own whose Kotlin half (`SharePlugin.kt`, in the Android app module)
//! hands the image to `ACTION_SEND` via the app's FileProvider. The same
//! plugin looks up the display names of documents the file picker returns.

use tauri::AppHandle;

type Res<T> = Result<T, String>;

/// Scryfall serves each scan at several sizes under the same path; the
/// previews show "normal", but a shared or pasted image deserves "large".
fn large_variant(url: &str) -> String {
    if url.starts_with("https://cards.scryfall.io/normal/") {
        url.replacen("/normal/", "/large/", 1)
    } else {
        url.to_string()
    }
}

/// Copy (desktop) or share (Android) the card image at `url`. Returns what
/// happened — "copied" or "shared" — for the UI to confirm.
#[tauri::command]
pub async fn share_card_image(app: AppHandle, url: String, name: String) -> Res<&'static str> {
    crate::sync::blocking(move || {
        let bytes = mtgc_core::fetch_image(&large_variant(&url)).map_err(|e| e.to_string())?;
        deliver(&app, &bytes, &name)
    })
    .await
}

#[cfg(desktop)]
fn deliver(app: &AppHandle, bytes: &[u8], _name: &str) -> Res<&'static str> {
    use tauri_plugin_clipboard_manager::ClipboardExt;
    // The clipboard takes raw pixels, and Scryfall's scans are JPEGs.
    let rgba = image::load_from_memory(bytes).map_err(|e| e.to_string())?.to_rgba8();
    let (width, height) = rgba.dimensions();
    app.clipboard()
        .write_image(&tauri::image::Image::new(rgba.as_raw(), width, height))
        .map_err(|e| e.to_string())?;
    Ok("copied")
}

#[cfg(target_os = "android")]
fn deliver(app: &AppHandle, bytes: &[u8], name: &str) -> Res<&'static str> {
    use tauri::Manager;
    // The cache dir is what the FileProvider exposes (res/xml/file_paths.xml).
    // Named after the card, since that's what the receiving app shows.
    let dir = app.path().app_cache_dir().map_err(|e| e.to_string())?.join("shared");
    std::fs::create_dir_all(&dir).map_err(|e| e.to_string())?;
    let file_name: String = name
        .chars()
        .map(|c| if c.is_alphanumeric() || c == ' ' || c == '-' { c } else { '_' })
        .collect();
    let path = dir.join(format!("{}.jpg", file_name.trim()));
    std::fs::write(&path, bytes).map_err(|e| e.to_string())?;

    let plugin = app.state::<SharePlugin>();
    plugin
        .0
        .run_mobile_plugin::<()>(
            "shareImage",
            serde_json::json!({ "path": path.to_string_lossy(), "title": name }),
        )
        .map_err(|e| e.to_string())?;
    Ok("shared")
}

#[cfg(target_os = "ios")]
fn deliver(_app: &AppHandle, _bytes: &[u8], _name: &str) -> Res<&'static str> {
    Err("Sharing isn't available on iOS yet.".into())
}

/// The name the system file picker showed for a content:// URI, if the
/// document's provider reports one.
#[cfg(target_os = "android")]
pub fn display_name(app: &AppHandle, uri: &str) -> Option<String> {
    use tauri::Manager;

    #[derive(serde::Deserialize)]
    struct Named {
        name: Option<String>,
    }

    let plugin = app.state::<SharePlugin>();
    let named: Named = plugin
        .0
        .run_mobile_plugin("displayName", serde_json::json!({ "uri": uri }))
        .map_err(|e| crate::mlog!("display name for {uri}: {e}"))
        .ok()?;
    named.name
}

/// The Kotlin half's handle, for `run_mobile_plugin`.
#[cfg(target_os = "android")]
struct SharePlugin(tauri::plugin::PluginHandle<tauri::Wry>);

/// Registers the Android share plugin. A no-op plugin elsewhere.
pub fn init() -> tauri::plugin::TauriPlugin<tauri::Wry> {
    tauri::plugin::Builder::new("share")
        .setup(|_app, _api| {
            #[cfg(target_os = "android")]
            {
                use tauri::Manager;
                let handle = _api.register_android_plugin("com.garrettmills.mtgc", "SharePlugin")?;
                _app.manage(SharePlugin(handle));
            }
            Ok(())
        })
        .build()
}