mod input;
mod update;
mod views;

use anyhow::{Result, anyhow};
use eframe::{NativeOptions, icon_data::from_png_bytes, run_native};
use egui::{Context, FontData, FontDefinitions, FontFamily, FontTweak, Vec2, ViewportBuilder};
use itertools::Itertools;
use pwsp_lib::{
    types::{
        audio_player::PlayerState,
        config::{GuiConfig, HotkeyConfig},
        gui::{AppState, AudioPlayerState},
        socket::Request,
    },
    utils::gui::{
        get_daemon_config, get_gui_config, make_request_async, make_request_sync,
        start_app_state_thread, update_daemon_config,
    },
};
use rfd::FileDialog;
use std::{
    cmp::Ordering,
    collections::{HashMap, HashSet},
    fs,
    hash::{DefaultHasher, Hash, Hasher},
    path::{Path, PathBuf},
    sync::{Arc, Mutex},
    thread,
};
use system_fonts::{FontStyle, FoundFontSource, find_for_locale};

const SUPPORTED_EXTENSIONS: [&str; 13] = [
    "mp3", "wav", "ogg", "flac", "mp4", "m4a", "aac", "mov", "mkv", "mka", "webm", "avi", "opus",
];

fn get_cache_file_for(path: &Path) -> PathBuf {
    let mut hasher = DefaultHasher::new();
    path.hash(&mut hasher);
    let hash = hasher.finish();
    dirs::cache_dir()
        .unwrap_or_else(|| PathBuf::from("/tmp"))
        .join("pwsp")
        .join(format!("{:x}.json", hash))
}

struct SoundpadGui {
    pub app_state: AppState,
    pub config: GuiConfig,
    pub audio_player_state: AudioPlayerState,
    pub audio_player_state_shared: Arc<Mutex<AudioPlayerState>>,
}

impl SoundpadGui {
    fn new(ctx: &Context) -> Self {
        let audio_player_state = Arc::new(Mutex::new(AudioPlayerState::default()));
        start_app_state_thread(audio_player_state.clone());

        let config = get_gui_config();

        ctx.set_zoom_factor(config.scale_factor);

        let mut soundpad_gui = SoundpadGui {
            app_state: AppState::default(),
            config: config.clone(),
            audio_player_state: AudioPlayerState::default(),
            audio_player_state_shared: audio_player_state.clone(),
        };

        soundpad_gui.app_state.dirs = config.dirs;
        soundpad_gui.app_state.hotkey_config = HotkeyConfig::load().unwrap_or_default();

        soundpad_gui
    }

    pub fn play_toggle(&mut self) {
        let (new_state, request) = {
            let guard = self
                .audio_player_state_shared
                .lock()
                .unwrap_or_else(|e| e.into_inner());
            match guard.state {
                PlayerState::Playing => (Some(PlayerState::Paused), Some(Request::pause(None))),
                PlayerState::Paused => (Some(PlayerState::Playing), Some(Request::resume(None))),
                PlayerState::Stopped => (None, None),
            }
        };

        if let Some(req) = request {
            make_request_async(req);
        }

        if let Some(state) = new_state {
            let mut guard = self
                .audio_player_state_shared
                .lock()
                .unwrap_or_else(|e| e.into_inner());
            guard.new_state = Some(state.clone());
            guard.state = state;
        }
    }

    pub fn open_file(&mut self) {
        let file_dialog = FileDialog::new().add_filter("Audio File", &SUPPORTED_EXTENSIONS);
        if let Some(path) = file_dialog.pick_file() {
            self.play_file(&path, false);
        }
    }

    pub fn add_dirs(&mut self) {
        let file_dialog = FileDialog::new();
        if let Some(paths) = file_dialog.pick_folders() {
            for path in paths {
                self.app_state.dirs.push(path);
            }
            self.app_state.dirs = self.app_state.dirs.iter().unique().cloned().collect();
            self.config.dirs = self.app_state.dirs.clone();
            self.config.save_to_file().ok();
        }
    }

    pub fn open_dir(&mut self, path: &PathBuf, ctx: Option<Context>, force_rescan: bool) {
        self.app_state.current_dir = Some(path.clone());

        if !self.app_state.dir_cache.contains_key(path) || force_rescan {
            match fs::read_dir(path) {
                Ok(read_dir) => {
                    let files = read_dir
                        .filter_map(|res| res.ok())
                        .map(|entry| entry.path())
                        .collect::<Vec<_>>();
                    self.app_state.listed_files = files.iter().cloned().collect();
                    self.app_state.dir_cache.insert(path.clone(), files);
                }
                Err(e) => {
                    eprintln!("Failed to read directory {:?}: {}", path, e);
                    self.app_state.listed_files.clear();
                }
            }
        } else {
            self.app_state.listed_files = self
                .app_state
                .dir_cache
                .get(path)
                .unwrap()
                .clone()
                .into_iter()
                .collect();
        }

        let is_scanning = self.app_state.scanning_dirs.lock().unwrap().contains(path);
        let is_cached = self.app_state.recursive_files_cache.contains_key(path);
        let has_scanned_this_session = self.app_state.scanned_this_session.contains(path);

        let needs_scan = force_rescan || !has_scanned_this_session || !is_cached;

        if !is_scanning && needs_scan {
            self.app_state
                .scanning_dirs
                .lock()
                .unwrap()
                .insert(path.clone());
            self.app_state.scanned_this_session.insert(path.clone());

            let finished_scans = self.app_state.finished_scans.clone();
            let scanning_dirs = self.app_state.scanning_dirs.clone();
            let path_clone = path.clone();

            thread::spawn(move || {
                let cache_file = get_cache_file_for(&path_clone);

                // 1. Try to load from disk cache if we don't have it in memory yet
                if !is_cached
                    && let Ok(data) = fs::read_to_string(&cache_file)
                    && let Ok((all_files, dir_updates)) = serde_json::from_str::<(
                        Vec<PathBuf>,
                        HashMap<PathBuf, Vec<PathBuf>>,
                    )>(&data)
                {
                    finished_scans.lock().unwrap().push((
                        path_clone.clone(),
                        all_files,
                        dir_updates,
                    ));
                    if let Some(ctx) = ctx.as_ref() {
                        ctx.request_repaint();
                    }
                }

                // 2. Scan recursively
                let mut all_files = Vec::new();
                let mut dir_updates = HashMap::new();
                let mut dirs_to_visit = vec![path_clone.clone()];

                while let Some(dir) = dirs_to_visit.pop() {
                    if let Ok(entries) = fs::read_dir(&dir) {
                        let mut children = Vec::new();
                        for entry in entries.filter_map(|e| e.ok()) {
                            let p = entry.path();
                            if p.is_dir() {
                                dirs_to_visit.push(p.clone());
                                children.push(p);
                            } else if crate::gui::SUPPORTED_EXTENSIONS.contains(
                                &p.extension()
                                    .unwrap_or_default()
                                    .to_str()
                                    .unwrap_or_default(),
                            ) {
                                all_files.push(p.clone());
                                children.push(p);
                            }
                        }
                        dir_updates.insert(dir, children);
                    }
                }

                // 3. Save to disk cache
                if let Some(parent) = cache_file.parent() {
                    fs::create_dir_all(parent).ok();
                }
                if let Ok(json) = serde_json::to_string(&(all_files.clone(), dir_updates.clone())) {
                    fs::write(&cache_file, json).ok();
                }

                // 4. Send to UI
                finished_scans
                    .lock()
                    .unwrap()
                    .push((path_clone.clone(), all_files, dir_updates));
                scanning_dirs.lock().unwrap().remove(&path_clone);
                if let Some(ctx) = ctx {
                    ctx.request_repaint();
                }
            });
        }
    }

    pub fn play_file(&mut self, path: &Path, concurrent: bool) {
        make_request_async(Request::play(&path.to_string_lossy(), concurrent));
    }

    pub fn set_input(&mut self, name: String) {
        make_request_async(Request::set_input(&name));

        if self.config.save_input
            && let Ok(mut daemon_config) = get_daemon_config()
        {
            daemon_config.default_input_name = Some(name);
            update_daemon_config(&daemon_config).ok();
        }
    }

    pub fn set_output(&mut self, name: String) {
        make_request_async(Request::set_output(&name));

        if self.config.save_input
            && let Ok(mut daemon_config) = get_daemon_config()
        {
            // Empty means "follow the system default", which is stored as no device.
            daemon_config.default_output_name = Some(name).filter(|n| !n.is_empty());
            update_daemon_config(&daemon_config).ok();
        }
    }

    pub fn toggle_loop(&mut self, id: Option<u32>) {
        make_request_async(Request::toggle_loop(id));
    }

    pub fn pause(&mut self, id: Option<u32>) {
        make_request_async(Request::pause(id));
    }

    pub fn resume(&mut self, id: Option<u32>) {
        make_request_async(Request::resume(id));
    }

    pub fn stop(&mut self, id: Option<u32>) {
        make_request_async(Request::stop(id));
    }

    pub fn play_hotkey_slot(&mut self, slot: &str) {
        make_request_async(Request::play_hotkey(slot));
    }

    pub fn get_filtered_files(
        &self,
        matching_dirs: &HashSet<PathBuf>,
        matching_files: &HashSet<PathBuf>,
    ) -> Vec<PathBuf> {
        let search_query = self.app_state.search_query.to_lowercase();
        let search_query = search_query.trim();

        let mut files: Vec<PathBuf> = self.app_state.listed_files.iter().cloned().collect();
        let sort_order = self
            .app_state
            .current_dir
            .as_ref()
            .map(|d| self.config.get_sort_order(d))
            .unwrap_or_default();

        files.sort_by(|a, b| {
            let a_is_dir = a.is_dir();
            let b_is_dir = b.is_dir();
            if a_is_dir && !b_is_dir {
                Ordering::Less
            } else if !a_is_dir && b_is_dir {
                Ordering::Greater
            } else {
                sort_order.compare(a, b)
            }
        });

        let is_cached = self
            .app_state
            .current_dir
            .as_ref()
            .is_some_and(|d| self.app_state.recursive_files_cache.contains_key(d));

        if !search_query.is_empty() && is_cached {
            files
                .into_iter()
                .filter(|p| {
                    if p.is_dir() {
                        matching_dirs.contains(p)
                    } else {
                        matching_files.contains(p)
                    }
                })
                .collect()
        } else {
            files
                .into_iter()
                .filter(|entry_path| {
                    if !entry_path.is_dir()
                        && !SUPPORTED_EXTENSIONS.contains(
                            &entry_path
                                .extension()
                                .unwrap_or_default()
                                .to_str()
                                .unwrap_or_default(),
                        )
                    {
                        return false;
                    }

                    if !search_query.is_empty() {
                        let file_name =
                            entry_path.file_name().unwrap_or_default().to_string_lossy();
                        if !file_name.to_lowercase().contains(search_query) {
                            return false;
                        }
                    }

                    true
                })
                .collect()
        }
    }
}

fn add_font(font_name: &str, font_bytes: &[u8], fonts: &mut FontDefinitions) -> Result<()> {
    let font_data = FontData::from_owned(font_bytes.to_vec()).tweak(FontTweak {
        scale: 1.0,
        hinting: Some(true),
        ..Default::default()
    });

    fonts
        .font_data
        .insert(font_name.to_owned(), font_data.into());

    fonts
        .families
        .entry(FontFamily::Proportional)
        .or_default()
        .insert(0, font_name.to_owned());
    fonts
        .families
        .entry(FontFamily::Monospace)
        .or_default()
        .insert(0, font_name.to_owned());

    Ok(())
}

fn load_system_fonts(fonts: &mut FontDefinitions) -> Result<()> {
    let (_, en_sans) = find_for_locale("en", FontStyle::Sans);
    let (_, en_serif) = find_for_locale("en", FontStyle::Serif);
    let (_, ja_sans) = find_for_locale("ja", FontStyle::Sans);
    let (_, ar_sans) = find_for_locale("ar", FontStyle::Sans);

    let system_fonts = [en_sans, en_serif, ja_sans, ar_sans].concat();

    for font in system_fonts.iter().rev() {
        let font_bytes = match &font.source {
            FoundFontSource::Path(path) => fs::read(path)?,
            FoundFontSource::Bytes(bytes) => bytes.to_vec(),
        };

        add_font(&font.key, &font_bytes, fonts)?;
    }

    Ok(())
}

pub async fn run() -> Result<()> {
    const ICON: &[u8] = include_bytes!("../../assets/icon.png");

    let options = NativeOptions {
        centered: true,

        viewport: ViewportBuilder::default()
            .with_app_id("ru.arabianq.pwsp")
            .with_inner_size(Vec2::new(1200.0, 800.0))
            .with_min_inner_size(Vec2::new(800.0, 600.0))
            .with_icon(from_png_bytes(ICON)?),

        ..Default::default()
    };

    match run_native(
        "Pipewire Soundpad",
        options,
        Box::new(|cc| {
            egui_material_icons::initialize(&cc.egui_ctx);

            let mut fonts = FontDefinitions::default();
            load_system_fonts(&mut fonts).ok();
            cc.egui_ctx.set_fonts(fonts);

            Ok(Box::new(SoundpadGui::new(&cc.egui_ctx)))
        }),
    ) {
        Ok(_) => {
            let config = get_gui_config();
            if config.pause_on_exit {
                make_request_sync(Request::pause(None)).ok();
            }
            Ok(())
        }
        Err(e) => Err(anyhow!(e.to_string())),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_get_filtered_files() {
        let mut gui = SoundpadGui {
            app_state: AppState::default(),
            config: GuiConfig::default(),
            audio_player_state: AudioPlayerState::default(),
            audio_player_state_shared: Arc::new(Mutex::new(AudioPlayerState::default())),
        };

        // Create some dummy paths
        // We will mock path properties using standard Rust PathBuf
        let dir_a = PathBuf::from("a_dir");
        let file_b = PathBuf::from("b_file.mp3");
        let file_c = PathBuf::from("c_file.wav");
        let file_txt = PathBuf::from("invalid.txt");

        gui.app_state.listed_files.insert(dir_a.clone());
        gui.app_state.listed_files.insert(file_b.clone());
        gui.app_state.listed_files.insert(file_c.clone());
        gui.app_state.listed_files.insert(file_txt.clone());

        // Note: is_dir() check in get_filtered_files relies on physical filesystem properties.
        // On the real OS filesystem, these paths don't exist, so they are treated as files.
        // Unsupported extensions (like .txt) will be filtered out.
        // So we expect only file_b and file_c, sorted alphabetically.
        let empty_dirs = HashSet::new();
        let empty_files = HashSet::new();
        let filtered = gui.get_filtered_files(&empty_dirs, &empty_files);
        assert_eq!(filtered.len(), 2);
        assert_eq!(filtered[0], file_b);
        assert_eq!(filtered[1], file_c);

        // Test search query
        gui.app_state.search_query = "c_fi".to_string();
        let filtered_search = gui.get_filtered_files(&empty_dirs, &empty_files);
        assert_eq!(filtered_search.len(), 1);
        assert_eq!(filtered_search[0], file_c);

        // Test sort order descending
        gui.app_state.current_dir = Some(PathBuf::from("dummy_dir"));
        gui.config.dirs_settings.insert(
            PathBuf::from("dummy_dir"),
            pwsp_lib::types::config::DirSettings {
                sort_order: pwsp_lib::types::config::SortOrder::AlphabeticalDesc,
            },
        );
        gui.app_state.search_query = String::new();
        let filtered_desc = gui.get_filtered_files(&empty_dirs, &empty_files);
        assert_eq!(filtered_desc.len(), 2);
        assert_eq!(filtered_desc[0], file_c);
        assert_eq!(filtered_desc[1], file_b);
    }
}