use std::collections::HashMap;
use std::fs;
use std::io::Cursor;
use std::path::Path;

use base64_url as base64;
use image::ImageFormat;
use log::{debug, trace};
use ray_format::Ray;
use serde::{Deserialize, Serialize};
use tauri::api::dialog::blocking::FileDialogBuilder;
use tauri::api::path::{cache_dir, home_dir, picture_dir};

const OBJ_URL: &'static str = "data:image/png;base64,";

#[derive(Serialize, Deserialize, Clone, Debug)]
pub(crate) struct WebRay {
    frames: [String; 4],
    meta: HashMap<String, String>,
}

#[tauri::command]
pub(crate) async fn open_image() -> Option<String> {
    debug!("Opening iamge dialog...");
    let path = FileDialogBuilder::new()
        .add_filter("Images", &["png", "jpg"])
        .set_directory(picture_dir().unwrap_or_else(|| home_dir().unwrap()))
        .set_title("Select an image")
        .pick_file()?;
    if let Ok(b) = image::open(path) {
        let mut buf = Cursor::new(vec![]);
        b.write_to(&mut buf, ImageFormat::Png).unwrap();
        let encoded = base64::encode(buf.get_ref());
        trace!("Encoded: {:?}", encoded);

        Some(format!("{}{}", OBJ_URL, encoded))
    } else {
        None
    }
}

#[tauri::command]
pub(crate) async fn open_ray() -> Option<WebRay> {
    let path = FileDialogBuilder::new()
        .add_filter("Rays", &["ray"])
        .set_directory(home_dir()?)
        .pick_file()?;

    load_ray(path)
}

pub(crate) fn load_ray(path: impl AsRef<Path>) -> Option<WebRay> {
    let ray = Ray::load(path.as_ref()).ok()?;
    let mut frames = [String::new(), String::new(), String::new(), String::new()];
    let mut meta = HashMap::new();

    for i in 0..4 {
        debug!("Trying frame {}", i);
        if let Some(f) = ray.get_frame(i as usize) {
            debug!("Got frame {}", i);
            if f.is_empty() {
                debug!("Frame {} was empty", i);
                continue;
            }
            let encoded = base64::encode(&f);

            frames[i as usize] = format!("{}{}", OBJ_URL, encoded);
        }
    }

    for k in ray.get_meta_keys() {
        if let Some(v) = ray.get_meta_value(&k) {
            meta.insert(k.clone(), v.clone());
        }
    }

    fs::write(
        cache_dir().unwrap().join("cathode").join("last_selected"),
        path.as_ref()
            .canonicalize()
            .unwrap()
            .to_str()
            .unwrap()
            .as_bytes(),
    )
    .unwrap();
    Some(WebRay { frames, meta })
}

#[tauri::command]
pub(crate) async fn save_ray(ray: WebRay) -> Result<(), String> {
    if let Some(path) = FileDialogBuilder::new()
        .add_filter("Rays", &["ray"])
        .set_directory(home_dir().unwrap())
        .set_title("Save Ray")
        .set_file_name("new.ray")
        .save_file()
    {
        let mut res = Ray::default();

        for (i, f) in ray.frames.iter().enumerate() {
            let stripped = f.strip_prefix(OBJ_URL).unwrap_or(f);
            let decoded = base64::decode(stripped).unwrap();
            res.set_frame(i as usize, decoded);
        }

        for (k, v) in ray.meta {
            res.add_meta(k, v);
        }

        res.save(&path)
            .map_err(|e| format!("Failed to save ray file: {}", e))
    } else {
        Ok(())
    }
}