// SPDX-License-Identifier: GPL-3.0-only
/*
 * Copyright (c) 2024, Richard Acayan. All rights reserved.
 */

use std::convert::TryInto;
use std::fs::File;
use rgb::alt::BGR;
use rgb::alt::BGRA;
use rgb::RGB;
use yaml_rust2::yaml::Hash;
use yaml_rust2::yaml::LoadError;
use yaml_rust2::yaml::YamlDecoder;
use yaml_rust2::yaml::Yaml;

#[derive(Debug, Clone)]
pub struct KeyboardColors {
    pub background: BGRA<u8>,
    pub keycap: BGRA<u8>,
    pub keycap_pressed: BGRA<u8>,
    pub label: BGR<u8>,
    pub label_locked: BGR<u8>,
    pub label_pressed: BGR<u8>,
    pub sublabel: BGR<u8>,
}

impl Default for KeyboardColors {
    fn default() -> Self
    {
        Self {
            background: RGB::new(0, 0, 0).into(),
            keycap: RGB::new(0, 0, 0).into(),
            keycap_pressed: RGB::new(51, 51, 51).into(),
            label: RGB::new(255, 255, 255).into(),
            label_locked: RGB::new(0, 255, 25).into(),
            label_pressed: RGB::new(0, 153, 255).into(),
            sublabel: RGB::new(178, 178, 178).into(),
        }
    }
}

fn parse_color(yaml: &Yaml) -> Option<RGB<u8>>
{
    let mut color_bytes = yaml
        .as_vec()?
        .iter()
        .map_while(|b| b.as_i64())
        .map_while(|b| b.try_into().ok());

    Some(RGB::new(
        color_bytes.next()?,
        color_bytes.next()?,
        color_bytes.next()?
    ))
}

#[derive(Debug)]
pub struct Configuration {
    longpress: u64,
    repeat: u64,
    layout: String,
    extra_keys: Vec<String>,
    evfb_height: f64,
    wayland_height: i32,
    wayland_im_enable: bool,

    colors: KeyboardColors,
}

impl Configuration {
    fn get_configuration_file() -> Result<File, Box<dyn std::error::Error>> 
    {
        let xdg_dirs = xdg::BaseDirectories::new()?;
        let config_file = xdg_dirs.find_config_file("unfettered-keyboard.yaml")
            .ok_or(std::io::Error::new(std::io::ErrorKind::NotFound, "Config file not found"))?;
        println!("test{:?}",config_file);
        Ok(File::open(config_file)?)
    }

    fn load_evfb(&mut self, yaml: &Hash)
    {
        let height = yaml.get(&Yaml::String(String::from("height")));
        if let Some(height) = height {
            let height = match height.as_f64() {
                Some(h) => h.try_into().ok(),
                None => None,
            };
            let height = height.expect("Linux evdev-fbdev height should be a fraction from 0 to 1");
            self.evfb_height = height;
        }
    }

    fn load_wayland(&mut self, yaml: &Hash)
    {
        let height = yaml.get(&Yaml::String(String::from("height")));
        if let Some(height) = height {
            let height = match height.as_i64() {
                Some(h) => h.try_into().ok(),
                None => None,
            };
            let height = height.expect("Wayland height should be a 32-bit signed integer");
            self.wayland_height = height;
        }

        let im_enable = yaml.get(&Yaml::String(String::from("input-method")));
        if let Some(im_enable) = im_enable {
            let im_enable = im_enable.as_bool();
            let im_enable = im_enable.expect("Wayland height should be a 32-bit signed integer");
            self.wayland_im_enable = im_enable;
        }
    }

    fn load_colors(&mut self, yaml: &Hash)
    {
        if let Some(keycap) = yaml.get(&Yaml::String(String::from("keycap"))) {
            self.colors.keycap = parse_color(keycap)
                .expect("Keycap color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
        if let Some(keycap_pressed) = yaml.get(&Yaml::String(String::from("keycap_pressed"))) {
            self.colors.keycap_pressed = parse_color(keycap_pressed)
                .expect("Keycap pressed color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
        if let Some(label) = yaml.get(&Yaml::String(String::from("label"))) {
            self.colors.label = parse_color(label)
                .expect("Label color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
        if let Some(label_pressed) = yaml.get(&Yaml::String(String::from("label_pressed"))) {
            self.colors.label_pressed = parse_color(label_pressed)
                .expect("Label pressed color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
        if let Some(label_locked) = yaml.get(&Yaml::String(String::from("label_locked"))) {
            self.colors.label_locked = parse_color(label_locked)
                .expect("Label locked color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
        if let Some(sublabel) = yaml.get(&Yaml::String(String::from("sublabel"))) {
            self.colors.sublabel = parse_color(sublabel)
                .expect("Sublabel color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
        if let Some(background) = yaml.get(&Yaml::String(String::from("background"))) {
            self.colors.background = parse_color(background)
                .expect("Background color needs to be a list of 3 8-bit unsigned integers")
                .into();
        }
    }

    pub fn load() -> Result<Self, LoadError>
    {
        let mut cfg = Configuration {
            longpress: 600,
            repeat: 25,
            layout: String::from("latn_qwerty_us.xml"),
            extra_keys: vec![ String::from("alt"), String::from("meta") ],
            wayland_height: 185,
            wayland_im_enable: true,
            evfb_height: 0.25,

            colors: KeyboardColors::default(),
        };

        if let Ok(file) = Self::get_configuration_file() {
            let yaml = YamlDecoder::read(file).decode()?;
            let yaml = yaml[0].as_hash().expect("Top-level configuration should be a YAML mapping");

            let longpress = yaml.get(&Yaml::String(String::from("longpress_ms")));
            if let Some(longpress) = longpress {
                let longpress = match longpress.as_i64() {
                    Some(l) => l.try_into().ok(),
                    None => None,
                };
                let longpress = longpress.expect("Longpress time should be a 64-bit unsigned integer");
                cfg.longpress = longpress;
            }

            let repeat = yaml.get(&Yaml::String(String::from("repeat_ms")));
            if let Some(repeat) = repeat {
                let repeat = match repeat.as_i64() {
                    Some(l) => l.try_into().ok(),
                    None => None,
                };
                let repeat = repeat.expect("Repeat interval should be a 64-bit unsigned integer");
                cfg.repeat = repeat;
            }

            let layout = yaml.get(&Yaml::String(String::from("layout")));
            if let Some(layout) = layout {
                let layout = layout.as_str().expect("Layout should be a YAML string");
                cfg.layout = layout.to_string();
            }

            let keys = yaml.get(&Yaml::String(String::from("extra_keys")));
            if let Some(keys) = keys {
                let keys = keys.as_vec().expect("Extra keys should be a list");
                cfg.extra_keys = keys.iter().map(|y| String::from(y.as_str().unwrap())).collect();
                cfg.extra_keys.sort_unstable();
            }

            let wl = yaml.get(&Yaml::String(String::from("wayland")));
            if let Some(wl) = wl {
                let wl = wl.as_hash().expect("Wayland configuration should be a YAML mapping");
                cfg.load_wayland(wl);
            }

            let evfb = yaml.get(&Yaml::String(String::from("evfb")));
            if let Some(evfb) = evfb {
                let evfb = evfb.as_hash().expect("Linux evdev-fbdev configuration should be a YAML mapping");
                cfg.load_evfb(evfb);
            }

            let colors = yaml.get(&Yaml::String(String::from("colors")));
            if let Some(colors) = colors {
                let colors = colors.as_hash().expect("Color configuration should be a YAML mapping");
                cfg.load_colors(colors);
            }
        }

        Ok(cfg)
    }

    #[inline(always)]
    pub fn longpress_ms(&self) -> u64
    {
        self.longpress
    }

    #[inline(always)]
    pub fn repeat_ms(&self) -> u64
    {
        self.repeat
    }

    #[inline(always)]
    pub fn layout(&self) -> &str
    {
        &self.layout
    }

    #[inline(always)]
    pub fn extra_keys(&self) -> &Vec<String>
    {
        &self.extra_keys
    }

    #[inline(always)]
    pub fn wayland_height(&self) -> i32
    {
        self.wayland_height
    }

    #[inline(always)]
    pub fn wayland_im_enable(&self) -> bool
    {
        self.wayland_im_enable
    }

    #[inline(always)]
    pub fn evfb_height(&self) -> f64
    {
        self.evfb_height
    }

    #[inline(always)]
    pub fn colors(&self) -> &KeyboardColors
    {
        &self.colors
    }
}