//! Theme loading commands — thin Tauri wrappers over `theme_common`.

use std::path::PathBuf;
use tauri::{AppHandle, Manager};
use tracing::instrument;

use super::ApiError;

pub use theme_common::{ThemeColors, ThemeMeta};

/// Returns theme directories in priority order (later overrides earlier by ID).
/// Each entry is `(path, is_custom)`.
fn theme_dirs(app: &AppHandle) -> Vec<(PathBuf, bool)> {
    let mut dirs = Vec::new();

    // 1. Bundled themes (production)
    if let Ok(resource_dir) = app.path().resource_dir() {
        let bundled = resource_dir.join("themes");
        if bundled.is_dir() {
            dirs.push((bundled, false));
        }
    }

    // 2. Dev fallback: CARGO_MANIFEST_DIR → 3 parents up → Git/themes/
    if let Some(dev_path) = theme_common::dev_themes_dir(env!("CARGO_MANIFEST_DIR").as_ref(), 3) {
        dirs.push((dev_path, false));
    }

    // 3. User custom themes (highest priority)
    if let Ok(config_dir) = app.path().app_config_dir() {
        let custom = config_dir.join("themes");
        if custom.is_dir() {
            dirs.push((custom, true));
        }
    }

    dirs
}

#[tauri::command]
#[instrument(skip_all)]
pub fn list_themes(app: AppHandle) -> Result<Vec<ThemeMeta>, ApiError> {
    let dirs = theme_dirs(&app);
    Ok(theme_common::list_themes_from_dirs(&dirs))
}

#[tauri::command]
#[instrument(skip_all)]
pub fn get_theme(app: AppHandle, id: String) -> Result<ThemeColors, ApiError> {
    let dirs = theme_dirs(&app);
    theme_common::load_theme(&dirs, &id).map_err(ApiError::internal)
}

#[tauri::command]
#[instrument(skip_all)]
pub fn get_custom_themes_dir(app: AppHandle) -> Result<String, ApiError> {
    let dir = app
        .path()
        .app_config_dir()
        .map_err(|e| ApiError::internal(e.to_string()))?
        .join("themes");
    std::fs::create_dir_all(&dir)
        .map_err(|e| ApiError::internal(format!("Failed to create themes dir: {}", e)))?;
    Ok(dir.to_string_lossy().to_string())
}

#[tauri::command]
#[instrument(skip_all)]
pub fn import_theme(app: AppHandle, path: String) -> Result<ThemeMeta, ApiError> {
    let custom_dir = app
        .path()
        .app_config_dir()
        .map_err(|e| ApiError::internal(e.to_string()))?
        .join("themes");
    theme_common::import_theme(std::path::Path::new(&path), &custom_dir)
        .map_err(ApiError::internal)
}

#[tauri::command]
#[instrument(skip_all)]
pub fn export_theme(app: AppHandle, id: String, path: String) -> Result<(), ApiError> {
    let dirs = theme_dirs(&app);
    theme_common::export_theme(&dirs, &id, std::path::Path::new(&path))
        .map_err(ApiError::internal)
}

#[cfg(test)]
mod tests {
    // Core theme logic tests live in theme-common crate.
    // App-specific tests here only if needed for theme_dirs behavior.
}