use headless_chrome::Browser;
use headless_chrome::types::PrintToPdfOptions;
use nanobyte_opentelemetry::rocket::{TracingSpan, RequestId, OtelReqwestClient};
use nanobyte_tera::l18n::LanguageDescription;
use ovlach_data::cv::data::CV;
use reqwest::Client;
use rocket::fs::NamedFile;
use ::rocket::{State, http::Status};
use ::rocket::get;
use tempfile::NamedTempFile;
use tera::Context;
use tracing::{info_span, error, debug};
use crate::DefaultPerson;
use crate::{chromium::rocket::BrowserHolder, tools::{tera::NanoTera, pdf::PdfStream, rocket::RequestLanguage}, services::cv::fetch_cv_data_from_backend, CVBackendConfig};

// TODO: request-id
fn generate_pdf(browser: Browser, file: &NamedTempFile) -> Vec<u8> {
    let tab = browser.new_tab().unwrap();
    let path = format!("file://{}", file.path().to_str().unwrap());
    info_span!("open_pdf").in_scope(|| {
        debug!("Render pdf from {}", &path);
        tab.navigate_to(&path).unwrap().wait_until_navigated().unwrap();
    });

    let options = PrintToPdfOptions{
        margin_bottom: Some(0.0),
        margin_left: Some(0.0),
        margin_right: Some(0.0),
        margin_top: Some(0.0),
        print_background: Some(true),
        //paper_width: Some(29.7),
        //paper_height: Some(21.0),
        ..PrintToPdfOptions::default()
    };

    //thread::sleep(Duration::from_secs(10));

    let bytes = info_span!("print_pdf").in_scope(|| {
         tab.print_to_pdf(Some(options)).unwrap()
    });

    return bytes;
}

#[tracing::instrument]
fn render_template(template_name: &str, file: &NamedTempFile, tera: NanoTera, cv: CV, language: String) {
    // TODO: handle errors
    let mut tera_context = Context::new();
    tera_context.insert("cv", &cv);
    tera_context.insert("lang", &LanguageDescription::new(&language, "ovlach_pdf"));

    match tera.0.render_to("two_column.html.tera", &tera_context, file) {
        Ok(_) => {
            debug!("Rendered template to {}", file.path().to_str().unwrap());
        },
        Err(e) => {
            error!("Error rendering template {}: {}", &template_name, e);
        }
    }
}

#[get("/cv/<username>/<language>/output.pdf")]
pub async fn render_pdf_cv(username: &str, tera: NanoTera, tracing: TracingSpan, request_client: OtelReqwestClient,
    cv_config: &State<CVBackendConfig>, language: RequestLanguage, browser: BrowserHolder,
    default_person: &State<DefaultPerson>) -> Result<PdfStream, Status> {
    let entered_span = tracing.0.enter();
    match fetch_cv_data_from_backend(&cv_config.cv_backend_path, &default_person.inner().default_person_name, &request_client.0).await {
        Ok(cv_data) => {
            let file = tempfile::Builder::new().suffix(".html").tempfile().unwrap();
            render_template("two_column", &file, tera, cv_data, language.language);
            let span = info_span!("render_pdf", username = username);
            let pdf = span.in_scope(||{
                generate_pdf(browser.browser, &file)
            });
            drop(entered_span);
            Ok(PdfStream::new(pdf))
        },
        Err(e) => {
            error!("Error fetching cv data: {:?}", e);
            Err(Status::InternalServerError)
        }
    }
}

/// Route only for debuging
#[get("/cv/<username>/<language>/output.html")]
pub async fn render_html_cv(username: &str, tera: NanoTera, tracing: TracingSpan, request_client: OtelReqwestClient,
    cv_config: &State<CVBackendConfig>, language: RequestLanguage,
    default_person: &State<DefaultPerson>) -> Result<NamedFile, Status> {
    let _ = tracing.0.enter();
    match fetch_cv_data_from_backend(&cv_config.cv_backend_path, &default_person.inner().default_person_name, &request_client.0).await {
        Ok(cv_data) => {
            let file = tempfile::Builder::new().suffix(".html").tempfile().unwrap();
            render_template("two_column", &file, tera, cv_data, language.language);
            Ok(NamedFile::open(file.path()).await.unwrap())
        },
        Err(e) => {
            error!("Error fetching cv data: {:?}", e);
            Err(Status::InternalServerError)
        }
    }

}