cargo-kconfig 0.0.1

/*
 Cargo KConfig - KConfig parser
 Copyright (C) 2022  Sjoerd van Leent

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Copyright Notice: Apache

Licensed under the Apache License, Version 2.0 (the "License"); you may not use
this file except in compliance with the License. You may obtain a copy of the
License at

   https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed
under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied. See the License for the
specific language governing permissions and limitations under the License.

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Copyright Notice: GPLv2

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

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Copyright Notice: MIT

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the “Software”), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

//! This module represents the main window of the ncurses interface of the
//! Kconfig menu.

use crate::cli_parser::dotconfig_file;
use crate::windowing::ll::mvwaddwch;

use super::input::CharPositions;
use super::input::CursorPos;
use super::ll::mvwaddwstr;
use super::result::HandleResult;
use super::traits::WindowLike;
use super::utils::create_window;
use super::utils::ColorPair;
use super::utils::StringExt;
use kconfig_represent::ConfigRegistry;
use kconfig_represent::DescriptorInfo;
use kconfig_represent::Error;
use kconfig_represent::InputMode;
use kconfig_represent::MenuItemDescriptor;
use ncurses::*;

pub(super) struct MainWindow {
    w: Option<WINDOW>,
    tree: Vec<String>,
    sw: Option<WINDOW>,
    registry: ConfigRegistry,
    menu_index: usize,
    first_visible_item: usize,
    config_under_edit: Option<String>,
    config_value_codepoints: Vec<char>,
    raw_cursor_offset: usize,
    input_mode: InputMode,
}

impl WindowLike for MainWindow {
    fn new() -> Self {
        Self {
            w: None,
            sw: None,
            tree: Vec::new(),
            registry: ConfigRegistry::default(),
            menu_index: 0,
            first_visible_item: 0,
            config_under_edit: None,
            config_value_codepoints: Vec::new(),
            raw_cursor_offset: 0,
            input_mode: InputMode::String,
        }
    }

    fn del(&self) {
        if let Some(w) = self.w {
            delwin(w);
        }
        if let Some(w) = self.sw {
            delwin(w);
        }
    }

    fn create(&mut self) {
        self.w = Some(create_window(
            LINES() - 2,
            COLS(),
            1,
            0,
            ColorPair::Default.raw(),
        ));

        self.sw = Some(create_window(
            LINES() - 6,
            COLS() - 4,
            3,
            2,
            ColorPair::Internal.raw(),
        ));
    }

    fn raw(&self) -> Option<WINDOW> {
        self.w
    }

    fn draw(&mut self) {
        if let Some(w) = self.w {
            wclear(w);
            wbkgd(w, COLOR_PAIR(ColorPair::Default.raw()));
            wrefresh(w);
            self.draw_subwindow();
        }
    }
}

impl MainWindow {
    pub(crate) fn set_registry(&mut self, registry: ConfigRegistry) {
        self.tree.push(registry.main_menu_name());
        self.registry = registry;
        self.reset_index();
    }

    pub(crate) fn handle_ch(&mut self, opt_wch: Option<WchResult>) -> HandleResult {
        match opt_wch {
            Some(wch) => match wch {
                WchResult::KeyCode(key_code) => match key_code {
                    KEY_F9 => HandleResult::Exit,
                    KEY_BACKSPACE => HandleResult::Backspace,
                    KEY_DC => HandleResult::Delete,
                    KEY_DOWN => HandleResult::NavDown,
                    KEY_UP => HandleResult::NavUp,
                    KEY_LEFT => HandleResult::MoveLeft,
                    KEY_RIGHT => HandleResult::MoveRight,
                    KEY_ENTER | KEY_SELECT => match self.config_under_edit {
                        None => HandleResult::Select,
                        Some(_) => HandleResult::Char('\n'),
                    },
                    _ => HandleResult::None,
                },
                WchResult::Char(utf32) => match char::from_u32(utf32) {
                    Some(c) => match self.config_under_edit {
                        Some(_) => HandleResult::Char(c),
                        None => match c {
                            '\n' | '\r' => HandleResult::Select,
                            'i' | 'I' => HandleResult::Info,
                            _ => HandleResult::None,
                        },
                    },
                    None => HandleResult::None,
                },
            },
            _ => HandleResult::None,
        }
    }

    pub fn increment_menu_index(&mut self) {
        if self.menu_index + 1 != self.menu_len_enabled() {
            self.menu_index += 1;
            self.draw_subwindow();
        }
    }

    pub fn decrement_menu_index(&mut self) {
        if self.menu_index != 0 {
            self.menu_index -= 1;
            self.draw_subwindow();
        }
    }

    /// This function is called when a selection is activated by
    /// pressing the enter or select keys on a keyboard.
    pub(crate) fn activate_selection(&mut self) -> Result<(), Error> {
        Ok(match self.active_descriptor() {
            Ok(descriptor) => match descriptor {
                MenuItemDescriptor::Menu(name) => self.push_menu(&name),
                MenuItemDescriptor::Config(name) => self.edit_config(&name)?,
            },
            Err(_) => (), // If not found, nothing happens
        })
    }

    fn save_config_value(&mut self) -> Result<(), Error> {
        if let Some(config_name) = &self.config_under_edit {
            self.registry.mutate_through_string(
                &config_name,
                &self.config_value_codepoints.iter().collect::<String>(),
            )?
        }
        Ok(())
    }

    /// Returns the descriptor of the current selected menu item
    pub(crate) fn active_descriptor(&self) -> Result<MenuItemDescriptor, Error> {
        let mut current_item = 0;
        let menu = self.active_menu_descriptor();
        if let Some(menu) = menu {
            for descriptor in self
                .registry
                .iter_enabled_sub_descriptors(&menu.to_string())
            {
                if current_item == self.menu_index {
                    return Ok(descriptor);
                }
                current_item += 1;
            }
        }
        Err(Error::from(
            "Current selected item descriptor not found".to_owned(),
        ))
    }

    /// Returns the information string belonging to the current selected menu item
    pub(crate) fn active_descriptor_info(&self) -> Result<DescriptorInfo, Error> {
        let descriptor = self.active_descriptor()?;
        Ok(self.registry.descriptor_info(&descriptor))
    }

    /// Pops menus, until the main menu has been reached by
    /// pressing the backspace key on the keyboard.
    pub(crate) fn pop_selection(&mut self) -> Result<bool, Error> {
        Ok(match self.config_under_edit {
            None => {
                if self.tree.len() > 1 {
                    self.tree.pop();
                    self.draw_subwindow();
                    true
                } else {
                    false
                }
            }
            Some(_) => {
                self.save_config_value()?;
                self.raw_cursor_offset = 0;
                self.config_under_edit = None;
                // Do not show the cursor any more
                curs_set(CURSOR_VISIBILITY::CURSOR_INVISIBLE);
                true
            }
        })
    }

    /// Activates a menu and pushes it onto the menu stack
    fn push_menu(&mut self, name: &str) {
        self.tree.push(name.to_string());
        self.reset_index();
        self.draw_subwindow();
    }

    /// Displays an edit window, aided with the help text, default values
    /// and other options.
    fn edit_config(&mut self, name: &str) -> Result<(), Error> {
        match self.registry.config_mutation_mode(name) {
            kconfig_represent::ConfigMutationMode::ThroughString(mode) => {
                self.config_value_codepoints = self.registry.config_value(name).chars().collect();
                self.raw_cursor_offset = self.config_value_codepoints.len();
                self.config_under_edit = Some(name.to_string());
                self.input_mode = mode;
            }
            kconfig_represent::ConfigMutationMode::ThroughStep => {
                self.registry.mutate_through_step(name)?
            }
            kconfig_represent::ConfigMutationMode::None => (),
        }

        // If a configuration is under edit, show the cursor
        if let Some(_) = self.config_under_edit {
            curs_set(CURSOR_VISIBILITY::CURSOR_VISIBLE);
        }

        Ok(())
    }

    fn determine_visible_item_range(&mut self) -> (usize, usize) {
        if let Some(w) = self.sw {
            // The border and a margin should be surrounding the text
            let height = (getmaxy(w) - 4) as usize;

            let mut last_visible_item = self.first_visible_item + height;
            if self.menu_index < self.first_visible_item {
                self.first_visible_item = self.menu_index;
            } else if self.menu_index > last_visible_item {
                self.first_visible_item = self.menu_index - height;
                last_visible_item = self.first_visible_item + height;
            }
            (self.first_visible_item, last_visible_item)
        } else {
            (0, 0)
        }
    }

    fn is_item_visible(&mut self, index: usize) -> bool {
        let (first_visible_item, last_visible_item) = self.determine_visible_item_range();
        index >= first_visible_item && index <= last_visible_item
    }

    pub fn refresh(&mut self) {
        super::refresh();
        if let Some(w) = self.sw {
            wrefresh(w);
        }
    }

    fn draw_subwindow(&mut self) {
        self.draw_backdrop();
        self.draw_menutext();
        self.draw_posstr();
        self.draw_inner();
        self.refresh();
    }

    fn draw_inner(&mut self) {
        match &self.config_under_edit {
            None => self.draw_inner_menu_mode(),
            Some(_) => self.draw_text_input(),
        }
    }

    /// If no configuration is under edit, show the regular menu entries
    /// and menu selection.
    fn draw_inner_menu_mode(&mut self) {
        let descriptor = match self.active_menu_descriptor() {
            Some(descriptor) => descriptor,
            None => return,
        };

        // The index is necessary, as this item must be visible
        let mut draw_index = 0;
        let mut current_item = 0;

        let sub_descriptors = self
            .registry
            .iter_enabled_sub_descriptors(&descriptor.to_string());

        for sub_descriptor in sub_descriptors {
            if {
                let ref this = self;
                let menu_item = &sub_descriptor;
                this.registry.menu_item_enabled(menu_item)
            } {
                // If there is a new line or other control character in the
                // formatted string, replace it with \<control-char>
                // trim the string to be smaller than the max. width of the
                // window.
                let formatted = self.render_submenu(&sub_descriptor);

                if self.is_item_visible(current_item) {
                    match current_item == self.menu_index {
                        true => self.draw_highlight(draw_index, &formatted),
                        false => self.draw_no_highlight(draw_index, &formatted),
                    };
                    draw_index += 1;
                }
                current_item += 1;
            }
        }
    }

    fn render_submenu(&self, sub_descriptor: &MenuItemDescriptor) -> String {
        let text = self
            .registry
            .menu_item_string(sub_descriptor)
            .chars()
            .map(|c| match c {
                '\n' => "\\n".to_owned(),
                '\r' => "\\r".to_owned(),
                '\t' => "\\t".to_owned(),
                '\x00'..='\x1F' => format!("\\{}", c as u8),
                ' '.. => c.to_string(),
            })
            .collect::<String>();

        if let Some(b) = self.registry.has_default_value_set(sub_descriptor) {
            if b {
                format!("[ ] {}", text)
            } else {
                format!("[*] {}", text)
            }
        } else {
            format!("{} ---->", text)
        }
    }

    fn draw_highlight(&self, index: usize, s: &str) {
        if let Some(w) = self.sw {
            wattron(w, COLOR_PAIR(ColorPair::Highlight.raw()));
            let s = self.chop_string(s);
            mvwaddstr(w, (index + 2) as i32, 2, s.as_str());
            wattron(w, COLOR_PAIR(ColorPair::Internal.raw()));
        }
    }

    fn draw_no_highlight(&self, index: usize, s: &str) {
        if let Some(w) = self.sw {
            let s = self.chop_string(s);
            mvwaddstr(w, (index + 2) as i32, 2, s.as_str());
        }
    }

    fn erase_text_input(&mut self) {
        if let Some(w) = self.sw {
            for y in 2..self.inner_height() - 4 {
                mvwaddstr(
                    w,
                    y,
                    2,
                    &format!("{:width$}", " ", width = (self.inner_width() - 4) as usize),
                );
            }
        }
    }

    /// Draws the edition of a configuration item
    fn draw_text_input(&mut self) {
        self.erase_text_input();
        let cursor_pos = CursorPos::new(
            2,
            2,
            (self.inner_width() - 2) as usize,
            (self.inner_height() - 2) as usize,
            &self.config_value_codepoints,
            self.raw_cursor_offset,
        );

        let char_positions = CharPositions::new(&cursor_pos);

        if let Some(w) = self.sw {
            for cp in char_positions.into_iter() {
                mvwaddwch(w, cp.y() as i32, cp.x() as i32, cp.c());
            }
            wmove(w, cursor_pos.y() as i32, cursor_pos.x() as i32);
        }
    }

    /// Edits a configuration value, if existing
    pub fn addchar(&mut self, c: char) {
        if self.input_mode == InputMode::Int && (c < '0' || c > '9') {
            return; // This is an illegal character entry
        }

        if self.input_mode == InputMode::Hex
            && (c < '0' || c > '9')
            && (c < 'A' || c > 'F')
            && (c < 'a' || c > 'f')
        {
            return; // This is an illegal character entry
        }

        if let Some(_) = self.config_under_edit {
            let v = if self.input_mode == InputMode::Hex {
                c.to_ascii_uppercase().to_string()
            } else {
                c.to_string()
            };

            let old_codepoints = self.config_value_codepoints.clone();

            self.config_value_codepoints.clear();
            let lhs = &old_codepoints[..self.raw_cursor_offset];
            let rhs = &old_codepoints[self.raw_cursor_offset..];
            self.config_value_codepoints.extend(lhs);
            self.config_value_codepoints.extend(v.chars());
            self.config_value_codepoints.extend(rhs);
            self.raw_cursor_offset += 1;
            self.draw_text_input();
            self.refresh();
        }
    }

    pub fn rmchar_left(&mut self) {
        if let Some(_) = self.config_under_edit {
            if !self.config_value_codepoints.is_empty()
                && ((self.input_mode == InputMode::Hex && self.raw_cursor_offset > 2)
                    || (self.input_mode != InputMode::Hex && self.raw_cursor_offset > 0))
            {
                let end = self.raw_cursor_offset - 1;
                let splitted = self.split_config_value();
                let lhs = splitted.0[..end].iter().cloned().collect::<Vec<char>>();
                let rhs = splitted.1.iter().cloned().collect::<Vec<char>>();
                self.replace_config_value_with_lhs_and_rhs(lhs, rhs);
                self.raw_cursor_offset = end;
                self.draw_text_input();
                self.refresh();
            }
        }
    }

    pub fn rmchar_right(&mut self) {
        if let Some(_) = self.config_under_edit {
            if self.raw_cursor_offset < self.config_value_codepoints.len() {
                let splitted = self.split_config_value();
                let lhs = splitted.0.iter().cloned().collect::<Vec<char>>();
                let rhs = splitted.1[1..].iter().cloned().collect::<Vec<char>>();
                self.replace_config_value_with_lhs_and_rhs(lhs, rhs);
                self.draw_text_input();
                self.refresh();
            }
        }
    }

    fn split_config_value(&mut self) -> (&[char], &[char]) {
        self.config_value_codepoints
            .split_at(self.raw_cursor_offset)
    }

    fn replace_config_value_with_lhs_and_rhs(&mut self, lhs: Vec<char>, rhs: Vec<char>) {
        self.config_value_codepoints.clear();
        self.config_value_codepoints.extend(&lhs);
        self.config_value_codepoints.extend(&rhs);
    }

    pub fn char_left(&mut self) {
        if self.raw_cursor_offset > 0 {
            self.raw_cursor_offset -= 1;
            self.draw_text_input();
            self.refresh();
        }
    }

    pub fn char_right(&mut self) {
        if self.raw_cursor_offset < self.config_value_codepoints.len() {
            self.raw_cursor_offset += 1;
            self.draw_text_input();
            self.refresh();
        }
    }

    pub fn changed(&self) -> bool {
        self.registry.changed()
    }

    pub fn save(&mut self) -> Result<(), Error> {
        self.registry.write_dotconfig_file(&dotconfig_file())
    }

    fn chop_string(&self, s: &str) -> String {
        if let Some(w) = self.sw {
            let width = (getmaxx(w) - 4) as usize;
            let mut max_string = if s.len() > width {
                s[..width].to_string()
            } else {
                s.to_string()
            };
            while max_string.len() < width {
                max_string.push(' ');
            }
            max_string
        } else {
            "".to_string()
        }
    }

    fn draw_menutext(&self) {
        if let Some(w) = self.sw {
            let width = getmaxx(w) - 4;
            let mut final_string = String::new();
            for item in self.tree.iter() {
                if final_string.len() == 0 {
                    final_string += &item;
                } else {
                    final_string += " > ";
                    final_string += &item;
                }
            }

            if let Some(config_name) = &self.config_under_edit {
                final_string += " ( ";
                final_string += config_name;
                final_string += " ) ";
            }

            wattron(w, A_BOLD());
            mvwaddwstr(w, 0, 2, &final_string.unicode_truncate(width));
            wattroff(w, A_BOLD());
        }
    }

    fn draw_posstr(&self) {
        if let None = self.config_under_edit {
            let index = self.menu_index + 1;
            let size = self.menu_len_enabled();
            if let Some(w) = self.sw {
                let pos_str = format!(
                    " Selected: {} of {} ({:.0}%) ",
                    index,
                    size,
                    (index as f32) * 100.0 / (size as f32)
                );

                wattron(w, A_BOLD());
                mvwaddstr(
                    w,
                    self.inner_height() - 1,
                    self.inner_width() - 2 - pos_str.len() as i32,
                    pos_str.as_str(),
                );
                wattroff(w, A_BOLD());
            }
        }
    }

    fn draw_backdrop(&self) {
        if let Some(w) = self.sw {
            wclear(w);
            wbkgd(w, COLOR_PAIR(ColorPair::Internal.raw()));
            wborder(
                w,
                ACS_VLINE(),
                ACS_VLINE(),
                ACS_HLINE(),
                ACS_HLINE(),
                ACS_ULCORNER(),
                ACS_URCORNER(),
                ACS_LLCORNER(),
                ACS_LRCORNER(),
            );
        }
    }

    fn menu_len_enabled(&self) -> usize {
        let descriptor = self.active_menu_descriptor();
        descriptor
            .map(|m| self.registry.menu_enabled_children_len(&m.to_string()))
            .unwrap_or_default()
    }

    /// Gets the active menu as determined by the navigation tree
    fn active_menu_descriptor(&self) -> Option<MenuItemDescriptor> {
        let name = self.tree.last()?;
        Some(MenuItemDescriptor::Menu(name.clone()))
    }

    fn reset_index(&mut self) {
        self.menu_index = 0;
        self.first_visible_item = 0;
    }

    fn inner_width(&self) -> i32 {
        match self.sw {
            Some(w) => getmaxx(w),
            None => 0,
        }
    }

    fn inner_height(&self) -> i32 {
        match self.sw {
            Some(w) => getmaxy(w),
            None => 0,
        }
    }
}