changxi 0.2.0

TUI EPUB Reader
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use crate::config::Config;
use crate::core::{EpubReader, Reader};
use crate::progress::{BookProgress, Bookmark, ProgressStore};
use crate::ui::count_lines;
use ratatui::widgets::ListState;
use ratatui_image::FilterType;
use ratatui_image::picker::Picker;
use ratatui_image::protocol::StatefulProtocol;
use ratatui_image::sliced::SlicedProtocol;
use std::cmp::Reverse;
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::time::{SystemTime, UNIX_EPOCH};

#[derive(PartialEq, Clone, Copy)]
pub enum SortCriteria {
    Recent,
    Title,
    Author,
}

#[derive(PartialEq, Clone, Copy)]
pub enum ViewMode {
    Reading,
    Cover,
    ChapterBrowser,
    BookmarkBrowser,
    BookmarkRenaming,
    Library,
}

#[derive(PartialEq, Clone, Copy, Debug)]
pub enum SortOrder {
    Ascending,
    Descending,
}

pub struct App {
    pub reader: EpubReader,
    pub book_id: String,
    pub book_path: String,
    pub current_chapter: usize,
    pub scroll: usize,
    pub scroll_to_start: bool,
    pub scroll_to_end: bool,
    pub chapter_scrolls: HashMap<usize, usize>,
    pub image_protocols: HashMap<String, StatefulProtocol>,
    pub sliced_protocols: HashMap<String, SlicedProtocol>,
    pub mode: ViewMode,
    pub cover_protocol: Option<StatefulProtocol>,
    pub chapter_list_state: ListState,
    pub bookmark_list_state: ListState,
    pub bookmarks: Vec<Bookmark>,
    pub bookmark_rename_input: String,
    pub bookmark_rename_cursor_position: usize,
    pub chapter_titles: Vec<String>,
    pub chapter_levels: Vec<usize>,
    pub expanded_chapters: HashMap<usize, bool>,
    pub library_state: ListState,
    pub library_books: Vec<BookProgress>,
    pub library_cover_protocol: Option<StatefulProtocol>,
    pub sort_criteria: SortCriteria,
    pub sort_order: SortOrder,
    pub total_height: usize,
    pub viewport_height: usize,
    pub config: Config,
    pub chapter_heights: Vec<usize>,
    pub last_layout_width: usize,
    pub profile_dir: Option<PathBuf>,
}

impl App {
    pub fn new(
        reader: EpubReader,
        book_id: String,
        book_path: String,
        picker: &mut Picker,
        progress: BookProgress,
        config: Config,
        profile_dir: Option<PathBuf>,
    ) -> Self {
        let cover_protocol = if let Ok(Some(data)) = reader.cover_image() {
            if let Ok(img) = image::load_from_memory(&data) {
                Some(picker.new_resize_protocol(img))
            } else {
                None
            }
        } else {
            None
        };

        let current_chapter = progress.current_chapter;
        let scroll = progress
            .chapter_scrolls
            .get(&current_chapter)
            .cloned()
            .unwrap_or(0);

        let (scroll_to_end, scroll_to_start) = (false, false);

        // Build chapter titles and levels list from TOC
        let mut chapter_titles = Vec::new();
        let mut chapter_levels = Vec::new();
        let chapters_info = reader.get_chapters_info();
        let chapter_count = reader.chapter_count();

        if !chapters_info.is_empty() {
            for (i, info) in chapters_info.into_iter().enumerate() {
                let title = if !info.title.is_empty() {
                    info.title.clone()
                } else if let Ok(chapter) = reader.get_chapter(i) {
                    chapter.title.clone()
                } else {
                    format!("Chapter {}", i + 1)
                };
                chapter_titles.push(title);
                chapter_levels.push(info.level);
            }
        } else {
            // Fallback
            for i in 0..chapter_count {
                if let Ok(chapter) = reader.get_chapter(i) {
                    chapter_titles.push(chapter.title.to_string());
                } else {
                    chapter_titles.push(format!("Chapter {}", i + 1));
                }
                chapter_levels.push(0);
            }
        }

        let mut list_state = ListState::default();
        list_state.select(Some(current_chapter));

        let mut bookmark_list_state = ListState::default();
        if !progress.bookmarks.is_empty() {
            bookmark_list_state.select(Some(0));
        }

        let progress_path = profile_dir.as_ref().map(|p| {
            let mut p = p.clone();
            p.push("progress.json");
            p
        });
        let store = ProgressStore::load(progress_path);
        let mut library_books: Vec<BookProgress> = store.books.values().cloned().collect();
        library_books.sort_by_key(|b| Reverse(b.last_read));
        let library_state = ListState::default();

        App {
            reader,
            book_id,
            book_path,
            current_chapter,
            scroll,
            scroll_to_end,
            scroll_to_start,
            chapter_scrolls: progress.chapter_scrolls,
            image_protocols: HashMap::new(),
            sliced_protocols: HashMap::new(),
            mode: if cover_protocol.is_some() && current_chapter == 0 && scroll == 0 {
                ViewMode::Cover
            } else {
                ViewMode::Reading
            },
            cover_protocol,
            chapter_list_state: list_state,
            bookmark_list_state,
            bookmarks: progress.bookmarks,
            bookmark_rename_input: String::new(),
            bookmark_rename_cursor_position: 0,
            chapter_titles,
            chapter_levels,
            expanded_chapters: HashMap::new(),
            library_state,
            library_books,
            library_cover_protocol: None,
            sort_criteria: SortCriteria::Recent,
            sort_order: SortOrder::Ascending,
            total_height: 0,
            viewport_height: 0,
            config,
            chapter_heights: vec![0; chapter_count],
            last_layout_width: 0,
            profile_dir,
        }
    }

    fn get_progress_path(&self) -> Option<std::path::PathBuf> {
        self.profile_dir.as_ref().map(|p| {
            let mut p = p.clone();
            p.push("progress.json");
            p
        })
    }

    pub fn save_progress(&self) {
        let mut store = ProgressStore::load(self.get_progress_path());
        let mut chapter_scrolls = self.chapter_scrolls.clone();
        chapter_scrolls.insert(self.current_chapter, self.scroll);

        let last_read = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs();

        store.last_book_path = Some(self.book_path.clone());
        store.set_book(
            self.book_id.clone(),
            BookProgress {
                current_chapter: self.current_chapter,
                chapter_scrolls,
                title: self.reader.title().to_string(),
                author: self.reader.author().to_string(),
                path: self.book_path.clone(),
                last_read,
                view_type: self.config.view_type.clone(),
                bookmarks: self.bookmarks.clone(),
            },
        );
        let _ = store.save();
    }

    pub fn update_layout(&mut self, width: usize) {
        if self.last_layout_width == width {
            if self.current_chapter < self.chapter_heights.len() {
                self.total_height = self.chapter_heights[self.current_chapter];
            }
            return;
        }

        for i in 0..self.reader.chapter_count() {
            if let Ok(chapter) = self.reader.get_chapter(i) {
                let mut heights = Vec::new();
                for element in &chapter.elements {
                    heights.push(count_lines(element, width));
                }
                self.chapter_heights[i] = heights.iter().sum();
            }
        }
        self.last_layout_width = width;
        if self.current_chapter < self.chapter_heights.len() {
            self.total_height = self.chapter_heights[self.current_chapter];
        }
    }

    pub fn get_global_scroll(&self) -> usize {
        self.chapter_heights[..self.current_chapter]
            .iter()
            .sum::<usize>()
            + self.scroll
    }

    pub fn get_total_book_height(&self) -> usize {
        self.chapter_heights.iter().sum()
    }

    pub fn set_global_scroll(&mut self, global: usize) {
        let mut accumulated = 0;
        for (i, &h) in self.chapter_heights.iter().enumerate() {
            if global < accumulated + h {
                self.current_chapter = i;
                self.scroll = global - accumulated;
                self.save_progress();
                return;
            }
            accumulated += h;
        }
        // If we exceed total height, stay at the end
        self.current_chapter = self.chapter_heights.len().saturating_sub(1);
        self.scroll = self.chapter_heights.last().cloned().unwrap_or(0);
        self.save_progress();
    }

    pub fn jump_to_chapter(&mut self, index: usize) {
        if index < self.reader.chapter_count() {
            self.chapter_scrolls
                .insert(self.current_chapter, self.scroll);
            self.current_chapter = index;
            self.scroll = 0;
            self.mode = ViewMode::Reading;
            self.chapter_list_state.select(Some(self.current_chapter));
            self.save_progress();
        }
    }

    pub fn next_page(&mut self, i: usize) {
        if self.config.view_type == "continuous" {
            let jump = self.viewport_height;
            let current = self.get_global_scroll();
            self.set_global_scroll(current + jump);
            return;
        }
        let jump = if self.config.view_type == "book" && i == 2 {
            2 * self.viewport_height
        } else {
            self.viewport_height
        };

        if self.scroll + jump < self.total_height {
            self.scroll += jump;
            self.save_progress();
        } else {
            self.next_chapter();
        }
    }

    pub fn prev_page(&mut self, i: usize) {
        if self.config.view_type == "continuous" {
            let jump = self.viewport_height;
            let current = self.get_global_scroll();
            self.set_global_scroll(current.saturating_sub(jump));
            return;
        }
        let jump = if self.config.view_type == "book" && i == 2 {
            2 * self.viewport_height
        } else {
            self.viewport_height
        };

        if self.scroll >= jump {
            self.scroll -= jump;
            self.save_progress();
        } else if self.scroll > 0 {
            self.scroll = 0;
            self.save_progress();
        } else {
            self.previous_chapter_end();
        }
    }

    pub fn previous_chapter_end(&mut self) {
        if self.current_chapter > 0 {
            self.chapter_scrolls
                .insert(self.current_chapter, self.scroll);
            self.current_chapter -= 1;
            if self.config.view_type == "continuous" {
                if self.current_chapter < self.chapter_heights.len() {
                    self.scroll = self.chapter_heights[self.current_chapter]
                        .saturating_sub(self.viewport_height);
                } else {
                    self.scroll = 0;
                    self.scroll_to_end = true;
                }
            } else {
                self.scroll = 0;
                self.scroll_to_end = true;
            }
            self.mode = ViewMode::Reading;
            self.chapter_list_state.select(Some(self.current_chapter));
            self.save_progress();
        }
    }

    pub fn previous_chapter(&mut self) {
        if self.current_chapter > 0 {
            self.chapter_scrolls
                .insert(self.current_chapter, self.scroll);
            self.current_chapter -= 1;
            if self.config.view_type == "continuous" {
                self.scroll = 0;
            } else {
                self.scroll = self
                    .chapter_scrolls
                    .get(&self.current_chapter)
                    .cloned()
                    .unwrap_or(0);
            }
            self.mode = ViewMode::Reading;
            self.chapter_list_state.select(Some(self.current_chapter));
            self.save_progress();
        }
    }

    pub fn next_chapter(&mut self) {
        if self.current_chapter + 1 < self.reader.chapter_count() {
            self.chapter_scrolls
                .insert(self.current_chapter, self.scroll);
            self.current_chapter += 1;
            if self.config.view_type == "continuous" {
                self.scroll = 0;
            } else {
                self.scroll = self
                    .chapter_scrolls
                    .get(&self.current_chapter)
                    .cloned()
                    .unwrap_or(0);
            }
            self.mode = ViewMode::Reading;
            self.chapter_list_state.select(Some(self.current_chapter));
            self.save_progress();
        }
    }

    pub fn toggle_mode(&mut self) {
        self.mode = match self.mode {
            ViewMode::Reading => ViewMode::Cover,
            ViewMode::Cover => ViewMode::Reading,
            ViewMode::ChapterBrowser => ViewMode::Reading,
            ViewMode::BookmarkBrowser => ViewMode::Reading,
            ViewMode::BookmarkRenaming => ViewMode::Reading,
            ViewMode::Library => ViewMode::Reading,
        };
    }

    pub fn open_chapter_browser(&mut self) {
        self.chapter_list_state.select(Some(self.current_chapter));
        self.mode = ViewMode::ChapterBrowser;
    }

    pub fn add_bookmark(&mut self) {
        let chapter_title = self
            .chapter_titles
            .get(self.current_chapter)
            .cloned()
            .unwrap_or_default();

        let text_preview = if let Ok(chapter) = self.reader.get_chapter(self.current_chapter) {
            let full_text = chapter.content_as_text();
            full_text
                .chars()
                .take(100)
                .collect::<String>()
                .replace('\n', " ")
                + "..."
        } else {
            "No preview available".to_string()
        };

        let bookmark = Bookmark {
            name: chapter_title.clone(),
            chapter_index: self.current_chapter,
            scroll_position: self.scroll,
            chapter_title,
            text_preview,
            created_at: SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .unwrap_or_default()
                .as_secs(),
        };

        self.bookmarks.push(bookmark);
        self.save_progress();
    }

    pub fn remove_bookmark(&mut self) {
        if let Some(selected) = self.bookmark_list_state.selected()
            && selected < self.bookmarks.len()
        {
            self.bookmarks.remove(selected);
            if self.bookmarks.is_empty() {
                self.bookmark_list_state.select(None);
            } else {
                let new_selection = selected.min(self.bookmarks.len() - 1);
                self.bookmark_list_state.select(Some(new_selection));
            }
            self.save_progress();
        }
    }

    pub fn jump_to_bookmark(&mut self) {
        if let Some(selected) = self.bookmark_list_state.selected()
            && let Some(bookmark) = self.bookmarks.get(selected)
        {
            let chapter_index = bookmark.chapter_index;
            let scroll = bookmark.scroll_position;

            self.chapter_scrolls
                .insert(self.current_chapter, self.scroll);
            self.current_chapter = chapter_index;
            self.scroll = scroll;
            self.mode = ViewMode::Reading;
            self.chapter_list_state.select(Some(self.current_chapter));
            self.save_progress();
        }
    }

    pub fn open_bookmark_browser(&mut self) {
        if !self.bookmarks.is_empty() && self.bookmark_list_state.selected().is_none() {
            self.bookmark_list_state.select(Some(0));
        }
        self.mode = ViewMode::BookmarkBrowser;
    }

    pub fn start_renaming_bookmark(&mut self) {
        if let Some(selected) = self.bookmark_list_state.selected()
            && let Some(bookmark) = self.bookmarks.get(selected)
        {
            self.bookmark_rename_input = bookmark.name.clone();
            self.bookmark_rename_cursor_position = self.bookmark_rename_input.len();
            self.mode = ViewMode::BookmarkRenaming;
        }
    }

    pub fn finish_renaming_bookmark(&mut self) {
        if let Some(selected) = self.bookmark_list_state.selected()
            && selected < self.bookmarks.len()
        {
            self.bookmarks[selected].name = self.bookmark_rename_input.clone();
            self.save_progress();
        }
        self.mode = ViewMode::BookmarkBrowser;
    }

    pub fn expand_chapter(&mut self) {
        if let Some(selected) = self.chapter_list_state.selected() {
            // Map the visual selected index back to the real chapter index
            let visible_indices = self.get_visible_chapter_indices();
            if let Some(&real_index) = visible_indices.get(selected) {
                // Check if it has subchapters
                if real_index + 1 < self.chapter_levels.len()
                    && self.chapter_levels[real_index + 1] > self.chapter_levels[real_index]
                {
                    self.expanded_chapters.insert(real_index, true);
                }
            }
        }
    }

    pub fn collapse_chapter(&mut self) {
        if let Some(selected) = self.chapter_list_state.selected() {
            let visible_indices = self.get_visible_chapter_indices();
            if let Some(&real_index) = visible_indices.get(selected) {
                if self
                    .expanded_chapters
                    .get(&real_index)
                    .cloned()
                    .unwrap_or(false)
                {
                    self.expanded_chapters.insert(real_index, false);
                } else {
                    // If already collapsed or not a parent, try to collapse the parent
                    let current_level = self.chapter_levels[real_index];
                    if current_level > 0 {
                        for i in (0..real_index).rev() {
                            if self.chapter_levels[i] < current_level {
                                self.expanded_chapters.insert(i, false);
                                // Select the parent
                                let new_visible = self.get_visible_chapter_indices();
                                if let Some(new_pos) = new_visible.iter().position(|&idx| idx == i)
                                {
                                    self.chapter_list_state.select(Some(new_pos));
                                }
                                break;
                            }
                        }
                    }
                }
            }
        }
    }

    pub fn get_visible_chapter_indices(&self) -> Vec<usize> {
        let mut visible = Vec::new();
        let mut i = 0;
        while i < self.chapter_titles.len() {
            visible.push(i);
            let level = self.chapter_levels[i];
            let is_expanded = self.expanded_chapters.get(&i).cloned().unwrap_or(false);

            if !is_expanded {
                // Skip subchapters
                let mut j = i + 1;
                while j < self.chapter_titles.len() && self.chapter_levels[j] > level {
                    j += 1;
                }
                i = j;
            } else {
                i += 1;
            }
        }
        visible
    }

    pub fn open_library(&mut self, picker: &mut Picker) {
        let store = ProgressStore::load(self.get_progress_path());
        self.library_books = store
            .books
            .values()
            .filter(|b| Path::new(&b.path).exists())
            .cloned()
            .collect();
        if self.sort_order == SortOrder::Ascending {
            self.sort_library_asc();
        } else {
            self.sort_library_desc();
        }

        let current_index = self
            .library_books
            .iter()
            .position(|b| b.path == self.book_path);
        if self.library_state.selected().is_none() {
            self.library_state
                .select(current_index.or(if self.library_books.is_empty() {
                    None
                } else {
                    Some(0)
                }));
        }

        self.mode = ViewMode::Library;
        self.update_library_cover(picker);
    }

    pub fn sort_library_asc(&mut self) {
        match self.sort_criteria {
            SortCriteria::Recent => self.library_books.sort_by_key(|b| Reverse(b.last_read)),
            SortCriteria::Title => self.library_books.sort_by(|a, b| a.title.cmp(&b.title)),
            SortCriteria::Author => self.library_books.sort_by(|a, b| a.author.cmp(&b.author)),
        }
    }

    pub fn sort_library_desc(&mut self) {
        match self.sort_criteria {
            SortCriteria::Recent => self.library_books.sort_by_key(|b| b.last_read),
            SortCriteria::Title => self.library_books.sort_by(|b, a| a.title.cmp(&b.title)),
            SortCriteria::Author => self.library_books.sort_by(|b, a| a.author.cmp(&b.author)),
        }
    }

    pub fn toggle_sort(&mut self, picker: &mut Picker) {
        if self.sort_order == SortOrder::Ascending {
            self.sort_order = SortOrder::Descending;
            self.sort_library_desc();
        } else {
            self.sort_order = SortOrder::Ascending;
            self.sort_library_asc();
        }
        self.library_state.select(Some(0));
        self.update_library_cover(picker);
    }

    pub fn delete_book(&mut self, i: usize, store: &mut ProgressStore) {
        if i < self.library_books.len() {
            let book = &self.library_books[i];
            // Remove from store
            store.remove_book(&book.title, &book.author);

            // Remove from local list
            self.library_books.remove(i);

            // Save the updated store
            let _ = store.save();
        }
    }

    pub fn next_sort_criteria(&mut self, picker: &mut Picker) {
        self.sort_criteria = match self.sort_criteria {
            SortCriteria::Recent => SortCriteria::Title,
            SortCriteria::Title => SortCriteria::Author,
            SortCriteria::Author => SortCriteria::Recent,
        };
        if self.sort_order == SortOrder::Ascending {
            self.sort_library_asc();
        } else {
            self.sort_library_desc();
        }

        self.library_state.select(Some(0));
        self.update_library_cover(picker);
    }

    pub fn update_library_cover(&mut self, picker: &mut Picker) {
        if let Some(selected) = self.library_state.selected()
            && let Some(book) = self.library_books.get(selected)
            && let Ok(reader) = EpubReader::new(&book.path)
            && let Ok(Some(data)) = reader.cover_image()
            && let Ok(img) = image::load_from_memory(&data)
        {
            self.library_cover_protocol = Some(picker.new_resize_protocol(img));
            return;
        }
        self.library_cover_protocol = None;
    }

    pub fn select_book(&mut self) -> Option<String> {
        if let Some(selected) = self.library_state.selected()
            && let Some(book) = self.library_books.get(selected)
        {
            if book.path != self.book_path {
                return Some(book.path.clone());
            } else {
                self.mode = ViewMode::Reading;
            }
        }
        None
    }

    pub fn go_to_end(&mut self) {
        self.scroll_to_end = true;
    }

    pub fn go_to_start(&mut self) {
        self.scroll_to_start = true;
    }

    pub fn scroll_down(&mut self, i: usize) {
        if self.config.view_type == "continuous" {
            let current = self.get_global_scroll();
            self.set_global_scroll(current + i);
            return;
        }
        if self.scroll + i < self.total_height {
            self.scroll += i;
        } else if self.current_chapter + 1 < self.reader.chapter_count() {
            self.next_chapter();
            self.scroll = 0;
        } else {
            let max_scroll = self.total_height.saturating_sub(self.viewport_height);
            self.scroll = self.scroll.saturating_add(i).min(max_scroll);
        }
        self.save_progress();
    }

    pub fn scroll_up(&mut self, i: usize) {
        if self.config.view_type == "continuous" {
            let current = self.get_global_scroll();
            self.set_global_scroll(current.saturating_sub(i));
            return;
        }
        if self.scroll >= i {
            self.scroll -= i;
        } else if self.current_chapter > 0 {
            self.previous_chapter_end();
        } else {
            self.scroll = 0;
        }
        self.save_progress();
    }

    pub fn get_image_protocol(
        &mut self,
        path: &str,
        picker: &mut Picker,
    ) -> Option<&mut StatefulProtocol> {
        if !self.image_protocols.contains_key(path)
            && let Ok(data) = self.reader.get_image_by_path(path)
            && let Ok(img) = image::load_from_memory(&data)
        {
            self.image_protocols
                .insert(path.to_string(), picker.new_resize_protocol(img));
        }
        self.image_protocols.get_mut(path)
    }

    pub fn get_sliced_protocol(
        &mut self,
        path: &str,
        width: u16,
        height: u16,
        picker: &mut Picker,
    ) -> Option<&SlicedProtocol> {
        let key = format!("{}:{}:{}", path, width, height);
        if !self.sliced_protocols.contains_key(&key)
            && let Ok(data) = self.reader.get_image_by_path(path)
            && let Ok(img) = image::load_from_memory(&data)
        {
            // Resize image to fit the terminal width and height
            let font_size = picker.font_size();
            let font_width = if font_size.width == 0 {
                10
            } else {
                font_size.width
            };
            let font_height = if font_size.height == 0 {
                20
            } else {
                font_size.height
            };

            let target_px_width = width as u32 * font_width as u32;
            let target_px_height = height as u32 * font_height as u32;

            let img = if (img.width() > target_px_width || img.height() > target_px_height)
                && target_px_width > 0
                && target_px_height > 0
            {
                img.resize(target_px_width, target_px_height, FilterType::Lanczos3)
            } else {
                img
            };

            if let Ok(protocol) = SlicedProtocol::new(picker, img, None) {
                self.sliced_protocols.insert(key.clone(), protocol);
            }
        }
        self.sliced_protocols.get(&key)
    }
}