//! Fetch command implementation.
//!
//! Downloads car database, tracks database, and per-car timing data
//! from remote repositories.

use top_drives::{AppError, get_file};

use crate::parsing::fetch_times;

/// Base URL for the remote data repository on GitHub.
/// Single place to update if the repository path or branch changes.
const GITHUB_RAW_BASE: &str =
    "https://github.com/TiagoXavi/topdrives-records/raw/refs/heads/main/src/database";

/// Returns the full URL for the car database file.
fn cars_db_url() -> String {
    format!("{GITHUB_RAW_BASE}/cars_final.json")
}

/// Returns the full URL for the tracks database file.
fn tracks_db_url() -> String {
    format!("{GITHUB_RAW_BASE}/tracks_repo.json")
}

/// Downloads the tracks database file from the remote repository.
async fn get_tracks_file(tracks_db_path: &str) -> Result<(), AppError> {
    println!("Fetching tracks file...");
    get_file(&tracks_db_url(), tracks_db_path).await
}

/// Downloads the cars database file from the remote repository.
pub async fn get_cars_file(cars_db_path: &str) -> Result<(), AppError> {
    println!("Fetching cars file...");
    get_file(&cars_db_url(), cars_db_path).await
}

/// Executes the fetch command: downloads all data files.
///
/// Downloads the car database, tracks database, and per-car timing files.
/// Fails fast on critical dependency failures — the cars DB must be available
/// before per-car timing files can be fetched.
pub async fn run_fetch(cars_db_path: &str, tracks_db_path: &str, times_dir: &str) -> Result<(), AppError> {
    get_cars_file(cars_db_path).await?;
    get_tracks_file(tracks_db_path).await?;
    fetch_times(cars_db_path, times_dir).await?;
    println!("Fetch complete — all files downloaded successfully.");
    Ok(())
}