mod http_client;
mod models;

use anyhow::{Context, Result};
use clap::Parser;
use http_client::build_authenticated_client;
use models::{EpubResponse, SearchResponse};
use reqwest::Client;

/// Download and generate an EPUB from Safari Books Online.
#[derive(Parser, Debug)]
#[command(author, version, about, long_about = None)]
struct Args {
    /// The Book digits ID that you want to download.
    #[arg(required = true)]
    bookid: String,
    /// Path to the cookies.json file.
    #[arg(long, default_value = "cookies.json")]
    cookies: String,
    /// Do not delete the log file on success.
    #[arg(long = "preserve-log")]
    preserve_log: bool,
}

/// Fetches book metadata from the search endpoint.
async fn fetch_metadata(client: &Client, bookid: &str) -> Result<SearchResponse> {
    let url = format!("https://learning.oreilly.com/api/v2/search/?query={bookid}&limit=1");
    let response = client
        .get(&url)
        .send()
        .await?
        .error_for_status()?
        .json::<SearchResponse>()
        .await
        .context("Failed to deserialize Search API response.")?;
    Ok(response)
}

/// Fetches EPUB structural data (like the chapters URL)
async fn fetch_epub_data(client: &Client, bookid: &str) -> Result<EpubResponse> {
    let url = format!("https://learning.oreilly.com/api/v2/epubs/urn:orm:book:{bookid}/");
    let response = client
        .get(&url)
        .send()
        .await?
        .error_for_status()?
        .json::<EpubResponse>()
        .await
        .context("Failed to deserialize EPUB API response")?;
    Ok(response)
}

#[tokio::main]
async fn main() -> Result<()> {
    // Parse the command line arguments
    let args = Args::parse();

    println!("Welcome to SafariBooks Rust Port!");
    println!("Target Book ID: {}", args.bookid);

    // Initialise the HTTP client.
    println!("Loading cookies and initialising the HTTP client...");
    let client = build_authenticated_client(&args.cookies)?;

    println!("Fetching book metadata...");
    // Fetch from the search API.
    let search_data = fetch_metadata(&client, &args.bookid).await?;
    if let Some(book) = search_data.results.first() {
        println!("\n--- Book Found ---");
        println!("Title: {}", book.title);
        println!("Authors: {}", book.authors.join(", "));
        println!("Publisher: {}", book.publishers.join(", "));
        println!("Cover URL: {}", book.cover_url);
    } else {
        anyhow::bail!("Could not find book metadata for ID: {}", args.bookid);
    }
    // Fetch from the EPUB API.
    let epub_data = fetch_epub_data(&client, &args.bookid).await?;
    println!("Publication date: {}", epub_data.publication_date);
    println!("Chapters URL: {}", epub_data.chapters);
    println!("Resources URL: {}", epub_data.files);
    println!("------------------\n");

    Ok(())
}