#![warn(unused_crate_dependencies)]

use clap::Parser;
use magick_rust::MagickWand;
use std::{fs, path::{Path, PathBuf}};
use rand::seq::IteratorRandom;
use xdg::BaseDirectories;

#[derive(Parser)]
#[command(version, about, long_about = None)]
struct Cli {
    /// Which folder to use to locate the images
    #[arg(short, long, value_name = "DIRECTORY")]
    directory: PathBuf,

    /// Size of the image to be output
    #[arg(short, long, value_name = "WIDTH")]
    size: usize,

    /// Search directory recursively
    #[arg(short = 'r', long = "recursive", action = clap::ArgAction::SetTrue)]
    recursive: Option<bool>,
}

pub struct ImgOps {
    width: usize,
    height: usize,
    x_offset: isize,
    y_offset: isize
}

pub fn get_random_image(directory: &Path,recursive: Option<bool>) -> Result<PathBuf,String> {
  match directory.canonicalize() {
    Ok(d) => match d.is_dir() {
        true => {
            let mut rng = rand::rng();
            let walker =
                globwalk::GlobWalkerBuilder::from_patterns(&d, &["*.{png,jpg,gif,webp,heic}"])
                .case_insensitive(true);
            let imgs = match recursive.is_some_and(|x|x) {
                true => {
                    walker.build().unwrap()
                },
                false => {
                    walker.max_depth(1).build().unwrap()
                },
            };
            match imgs.choose(&mut rng).unwrap() {
                Ok(o) => Ok(PathBuf::from(o.path())),
                Err(e) => Err(e.to_string()),
            }
        },
        false => Err(format!("{} is not a directory",d.to_str().unwrap_or_default())),
    },
    Err(e) => Err(e.to_string()),
  }
}

pub fn output_path(image_path: PathBuf) -> Result<PathBuf,String> {
    let xdg_dirs = BaseDirectories::with_prefix("random-image-scaler");
    //;
    match xdg_dirs.get_cache_home() {
        Some(cache) => match xdg_dirs.create_cache_directory(cache) {
            Ok(mut cache) => {
                cache.push(image_path.strip_prefix("/").unwrap());
                cache.add_extension("jpg");
                Ok(cache)
            },
            Err(e) => Err(e.to_string()),
        }
        None => Err("Could not resolve cache home?".to_string()),
    }
}

pub fn calc_img_ops(orig_height: usize, orig_width: usize, size: usize) -> ImgOps {
    let r = orig_width as f32 / orig_height as f32;
    //println!("r: {:#?}",r);
    let w = match r.gt(&1.0) {
        true => (r.abs() * size as f32) as usize,
        false => size,
    };
    //println!("w: {:#?}",w);
    let h = match r.lt(&1.0) {
        true => (size as f32 / r) as usize,
        false => size,
    };
    //println!("h: {:#?}",h);
    let x = match r.gt(&1.0) {
        true => (w - size) / 2,
        false => 0_usize,
    } as isize;
    //println!("x: {:#?}",x);
    let y = match r.lt(&1.0) {
        true => (h - size) / 2,
        false => 0_usize,
    } as isize;
    //println!("y: {:#?}",y);
    ImgOps{ width: w, height: h, x_offset: x, y_offset: y }
}

pub fn scale_image(image_path: PathBuf, cached_image_path: PathBuf, size: usize) -> Result<PathBuf,String> {
    let magick_image = MagickWand::new();
    match image_path.to_str() {
        Some(img_str) => {
            match magick_image.read_image(img_str) {
                Ok(_) => {
                    let ops = calc_img_ops(magick_image.get_image_height(), magick_image.get_image_width(), size);
                    match magick_image.resize_image(ops.width, ops.height, magick_rust::FilterType::Undefined) {
                        Ok(_) => match magick_image.crop_image(size, size, ops.x_offset, ops.y_offset) {
                            Ok(_) => {
                                let mut dir = fs::DirBuilder::new();
                                let _ = dir.recursive(true).create(cached_image_path.parent().unwrap());
                                match cached_image_path.to_str() {
                                    Some(cache_str) => match magick_image.write_image(cache_str) {
                                        Ok(_) => Ok(cached_image_path),
                                        Err(e) => Err(e.to_string()),
                                    },
                                    None => Err("Undefined filepath error".to_string()),
                                }
                            },
                            Err(_) => todo!(),
                        }
                        Err(e) => Err(e.to_string()),
                    }
                },
                Err(e) => Err(e.to_string()),
            }
        },
        None => Err("Undefined filepath error".to_string()),
    }
}

fn main() {
    let cli = Cli::parse();
    match get_random_image(&cli.directory, cli.recursive) {
        Ok(image_path) => {
            match output_path(image_path.clone()) {
                Ok(cached_image_path) => match cached_image_path.exists() {
                    true => println!("{}",cached_image_path.to_str().unwrap_or_default()),
                    false => match scale_image(image_path, cached_image_path, cli.size) {
                        Ok(final_path) => println!("{}",final_path.to_str().unwrap_or_default()),
                        Err(e) => eprintln!("{}",e),
                    },
                },
                Err(e) => eprintln!("{}",e),
            }
        },
        Err(e) => eprintln!("{}",e),
    }
}