#![windows_subsystem = "windows"]

use anyhow::{anyhow, bail, Result};
use clap::{Arg, Command};
use fast_image_resize as fr;
use image::{io::Reader as ImageReader, DynamicImage};
use log::info;
use native_dialog::{FileDialog, MessageDialog};
use rexiv2::Metadata;
use rust_embed::RustEmbed;
use simplelog::{ColorChoice, ConfigBuilder, LevelFilter, TermLogger, TerminalMode};
use std::{fs::File, io::BufWriter, num::NonZeroU32, path::PathBuf, thread::JoinHandle};
use tempfile::tempdir;
use warp::Filter;
use wry::{
    application::{
        event::{Event, StartCause, WindowEvent},
        event_loop::{ControlFlow, EventLoop},
        window::WindowBuilder,
    },
    webview::WebViewBuilder,
};

#[derive(RustEmbed)]
#[folder = "embed/"]
struct Embed;

fn main() -> Result<()> {
    // Init log
    TermLogger::init(
        LevelFilter::Info,
        ConfigBuilder::new()
            .set_time_offset_to_local()
            .unwrap()
            .build(),
        TerminalMode::Mixed,
        ColorChoice::Auto,
    )?;

    let tmp_dir = tempdir()?;

    let cmd = Command::new("Simple panorama viewer")
        .arg(
            Arg::new("filename")
                .value_parser(clap::value_parser!(PathBuf))
                .help("Image path"),
        )
        .get_matches();

    let img_path = if let Some(img_path) = cmd.get_one::<PathBuf>("filename") {
        img_path.clone()
    } else {
        let user_dirs = directories::UserDirs::new().unwrap();
        let dir = if let Some(img_dir) = user_dirs.picture_dir() {
            img_dir
        } else {
            user_dirs.home_dir()
        };
        FileDialog::new()
            .add_filter(
                "Images",
                &[
                    "jpg", "JPG", "jpeg", "pjpeg", "pjpg", "PJPG", "webp", "avif",
                ],
            )
            .set_location(dir)
            .show_open_single_file()?
            .ok_or_else(|| anyhow!("No file"))?
    };

    if !img_path.exists() {
        MessageDialog::new()
            .set_title("Image error")
            .set_text(&format!("Image `{}` does not exist", img_path.display()))
            .set_type(native_dialog::MessageType::Error)
            .show_alert()?;
        bail!("File `{}` does not exist !", img_path.display());
    }

    info!("Open `{}`", img_path.display());
    let (width, height) = image::image_dimensions(&img_path)?;
    const MAX_IMG_SIZE: u32 = 20_000_000;
    info!("Image size {} * {}", width, height);
    let img_data_path = if height * width > MAX_IMG_SIZE {
        // @todo utilisation de rfd au lieu de message_dialog
        // @todo Option pas de resize / taille en ligne de commande
        // @todo Option pas de resize / taille dans une config (confy)
        // @todo Demande ensergistre l’action la première fois
        // @todo Option always en ligne de commnade
        // @todo Icon
        let ratio = (height * width) as f64 / MAX_IMG_SIZE as f64;
        let new_height = (height as f64 / ratio.sqrt()) as u32;
        let new_width = (width as f64 / ratio.sqrt()) as u32;

        if MessageDialog::new()
            .set_title("Resize")
            .set_text(&format!(
                "Resize the file to {} × {}",
                new_width, new_height
            ))
            .show_confirm()?
        {
            // Resize image
            let img = ImageReader::open(&img_path)?.decode()?;
            info!("Resize image to {} × {}", new_width, new_height);
            let image_resized = fast_image_resize(&img, new_width, new_height)?;

            // Save file and add metadata
            let tmp_img_path = tmp_dir.path().join("img.jpg");
            image_resized.write_to(
                &mut BufWriter::new(File::create(&tmp_img_path)?),
                image::ImageOutputFormat::Jpeg(95),
            )?;
            let metadata = Metadata::new_from_path(&img_path)?;
            metadata.save_to_file(&tmp_img_path)?;
            tmp_img_path
        } else {
            img_path
        }
    } else {
        img_path
    };

    info!("Run server");
    run_server(img_data_path);

    info!("Create webview");
    let event_loop = EventLoop::new();
    let window = WindowBuilder::new()
        .with_title("Simple panorama viewer")
        .with_maximized(true)
        .build(&event_loop)?;
    let _webview = WebViewBuilder::new(window)?
        .with_url("http://127.0.0.1:62371/index.html")?
        .build()?;

    info!("Event loop");
    event_loop.run(move |event, _, control_flow| {
        *control_flow = ControlFlow::Wait;

        match event {
            Event::NewEvents(StartCause::Init) => info!("Panorama open"),
            Event::WindowEvent {
                event: WindowEvent::CloseRequested,
                ..
            } => {
                info!("Close");
                *control_flow = ControlFlow::Exit
            }
            _ => (),
        }
    });
}

fn run_server(img_path: PathBuf) -> JoinHandle<()> {
    std::thread::spawn(|| {
        info!("Create runtime");
        let async_runtime = tokio::runtime::Builder::new_current_thread()
            .enable_all()
            .build()
            .unwrap();
        info!("Create response");
        let index = warp::path("index.html").map(|| {
            info!("Request `index.html`");
            let datas = get_file_data("index.html");
            warp::reply::html(datas)
        });
        let css = warp::path!("css" / String).map(move |val: String| {
            info!("Request css `{}`", &val);
            let datas = get_file_data(&format!("css/{}", val));
            warp::http::Response::builder().body(datas)
        });
        let js = warp::path!("js" / String).map(move |val: String| {
            info!("Request js `{}`", &val);
            let datas = get_file_data(&format!("js/{}", val));
            warp::http::Response::builder().body(datas)
        });
        let img = warp::path!("img").map(move || std::fs::read(&img_path).unwrap());
        info!("Launch webserver");
        async_runtime
            .block_on(warp::serve(img.or(index).or(css).or(js)).run(([127, 0, 0, 1], 62371)));
    })
}

fn get_file_data(filename: &str) -> String {
    if let Some(file) = Embed::get(filename) {
        std::str::from_utf8(file.data.as_ref())
            .unwrap_or("")
            .to_string()
    } else {
        "".to_string()
    }
}

/// Fast resize
pub fn fast_image_resize(
    img: &DynamicImage,
    max_width: u32,
    max_height: u32,
) -> Result<DynamicImage> {
    // Create source image
    let width = NonZeroU32::new(img.width()).unwrap();
    let height = NonZeroU32::new(img.height()).unwrap();
    let src_image =
        fr::Image::from_vec_u8(width, height, img.to_rgb8().into_raw(), fr::PixelType::U8x3)?;
    let mut src_view = src_image.view();

    // Create container for data of destination image
    let (dst_width, dst_height) = if width > height {
        (
            NonZeroU32::new(max_width).unwrap(),
            NonZeroU32::new((max_width * img.height()) / img.width()).unwrap(),
        )
    } else {
        (
            NonZeroU32::new((max_height * img.width()) / img.height()).unwrap(),
            NonZeroU32::new(max_height).unwrap(),
        )
    };
    src_view.set_crop_box_to_fit_dst_size(dst_width, dst_height, None);
    let mut dst_image = fr::Image::new(dst_width, dst_height, src_view.pixel_type());

    // Get mutable view of destination image data
    let mut dst_view = dst_image.view_mut();

    // Create Resizer instance and resize source image into buffer of destination image
    let mut resizer = fr::Resizer::new(fr::ResizeAlg::Convolution(fr::FilterType::Lanczos3));
    resizer.resize(&src_view, &mut dst_view)?;

    // Create Dynamic image
    let img_buffer = image::RgbImage::from_raw(
        dst_image.width().get(),
        dst_image.height().get(),
        dst_image.into_vec(),
    )
    .unwrap();

    Ok(img_buffer.into())
}