use std::path::PathBuf;

use iced::{
    advanced::widget::Id,
    clipboard, highlighter, keyboard,
    widget::{
        button, column, container,
        pane_grid::{self, Pane, PaneGrid},
        row, text, text_editor, themer, tooltip, Column, Space,
    },
    Alignment, Element, Font, Length, Settings, Task, Theme,
};
use iced_builder::types::{
    element_name::ElementName, project::Project, rendered_element::ActionKind, DesignerPage,
};
use iced_builder::Message;
use iced_drop::droppable;

fn main() -> iced::Result {
    iced::application(App::title, App::update, App::view)
        .settings(Settings {
            fonts: vec![include_bytes!("../fonts/icons.ttf").as_slice().into()],
            ..Settings::default()
        })
        .theme(App::theme)
        .subscription(App::subscription)
        .run_with(App::new)
}

struct App {
    is_dirty: bool,
    is_loading: bool,
    project_path: Option<PathBuf>,
    project: Project,
    dark_theme: bool,
    pane_state: pane_grid::State<Panes>,
    focus: Option<Pane>,
    designer_page: DesignerPage,
    element_list: Vec<ElementName>,
    editor_content: text_editor::Content,
}

#[derive(Clone, Copy, Debug)]
enum Panes {
    Designer,
    ElementList,
}

impl App {
    fn new() -> (Self, Task<Message>) {
        let state = pane_grid::State::with_configuration(pane_grid::Configuration::Split {
            axis: pane_grid::Axis::Vertical,
            ratio: 0.8,
            a: Box::new(pane_grid::Configuration::Pane(Panes::Designer)),
            b: Box::new(pane_grid::Configuration::Pane(Panes::ElementList)),
        });
        (
            Self {
                is_dirty: false,
                is_loading: false,
                project_path: None,
                project: Project::new(),
                dark_theme: true,
                pane_state: state,
                focus: None,
                designer_page: DesignerPage::Designer,
                element_list: ElementName::ALL.to_vec(),
                editor_content: text_editor::Content::new(),
            },
            Task::none(),
        )
    }

    fn title(&self) -> String {
        let saved_state = if !self.is_dirty { "" } else { " *" };

        let project_name = match &self.project.title {
            Some(n) => {
                format!(
                    " - {}",
                    if n.len() > 60 {
                        format!("...{}", &n[n.len() - 40..])
                    } else {
                        n.to_owned()
                    }
                )
            }
            None => "".to_owned(),
        };

        format!("iced Builder{project_name}{saved_state}")
    }

    fn theme(&self) -> iced::Theme {
        if self.dark_theme {
            Theme::SolarizedDark
        } else {
            Theme::SolarizedLight
        }
    }

    fn update(&mut self, message: Message) -> Task<Message> {
        match message {
            Message::ToggleTheme => self.dark_theme = !self.dark_theme,
            Message::CopyCode => return clipboard::write(self.editor_content.text()),
            Message::SwitchPage(page) => self.designer_page = page,
            Message::EditorAction(action) => {
                if let text_editor::Action::Scroll { lines: _ } = action {
                    self.editor_content.perform(action);
                }
            }
            Message::DropNewElement(name, point, _) => {
                return iced_drop::zones_on_point(
                    move |zones| Message::HandleNew(name.clone(), zones),
                    point,
                    None,
                    None,
                )
                .into()
            }
            Message::HandleNew(name, zones) => {
                let ids: Vec<Id> = zones.into_iter().map(|z| z.0).collect();
                if ids.len() > 0 {
                    let action = ActionKind::new(ids, &mut self.project.content.clone(), None);
                    let result = name.handle_action(self.project.content.as_mut(), action);
                    if let Ok(Some(ref element)) = result {
                        self.project.content = Some(element.clone());
                    }
                    println!("{:?}", result);
                }
                let code = self
                    .project
                    .clone()
                    .app_code()
                    .unwrap_or_else(|err| err.to_string());
                self.editor_content = text_editor::Content::with_text(&code);
            }
            Message::MoveElement(element, point, _) => {
                return iced_drop::zones_on_point(
                    move |zones| Message::HandleMove(element.clone(), zones),
                    point,
                    None,
                    None,
                )
                .into()
            }
            Message::HandleMove(element, zones) => {
                let ids: Vec<Id> = zones.into_iter().map(|z| z.0).collect();
                if ids.len() > 0 {
                    println!(
                        "{:?}",
                        ActionKind::new(
                            ids,
                            &mut self.project.content.clone(),
                            Some(element.get_id())
                        )
                    );
                }
            }
            Message::PaneResized(pane_grid::ResizeEvent { split, ratio }) => {
                self.pane_state.resize(split, ratio);
            }
            Message::PaneClicked(pane) => {
                self.focus = Some(pane);
            }
            Message::PaneDragged(pane_grid::DragEvent::Dropped { pane, target }) => {
                self.pane_state.drop(pane, target);
            }
            Message::PaneDragged(_) => {}
            Message::NewFile => {
                if !self.is_loading {
                    self.project = Project::new();
                    self.project_path = None;
                    self.editor_content = text_editor::Content::new();
                }
            }
            Message::OpenFile => {
                if !self.is_loading {
                    self.is_loading = true;

                    return Task::perform(Project::from_file(), Message::FileOpened);
                }
            }
            Message::FileOpened(result) => {
                self.is_loading = false;
                self.is_dirty = false;

                if let Ok((path, project)) = result {
                    self.project = project.clone();
                    self.project_path = Some(path);
                    self.editor_content = text_editor::Content::with_text(
                        &project.app_code().unwrap_or_else(|err| err.to_string()),
                    );
                }
            }
            Message::SaveFile => {
                if !self.is_loading {
                    self.is_loading = true;

                    return Task::perform(
                        self.project
                            .clone()
                            .write_to_file(self.project_path.clone()),
                        Message::FileSaved,
                    );
                }
            }
            Message::FileSaved(result) => {
                self.is_loading = false;

                if let Ok(path) = result {
                    self.project_path = Some(path);
                    self.is_dirty = false;
                }
            }
        }

        Task::none()
    }

    fn subscription(&self) -> iced::Subscription<Message> {
        keyboard::on_key_press(|key, modifiers| match key.as_ref() {
            keyboard::Key::Character("o") if modifiers.command() => Some(Message::OpenFile),
            keyboard::Key::Character("s") if modifiers.command() => Some(Message::SaveFile),
            keyboard::Key::Character("n") if modifiers.command() => Some(Message::NewFile),
            _ => None,
        })
    }

    fn view(&self) -> Element<Message> {
        let header = row![button("Toggle Theme")
            .on_press(Message::ToggleTheme)
            .padding(5)]
        .width(200);
        let pane_grid = PaneGrid::new(&self.pane_state, |id, pane, _is_maximized| {
            let is_focused = Some(id) == self.focus;
            match pane {
                Panes::Designer => match &self.designer_page {
                    DesignerPage::Designer => {
                        let el_tree = match self.project.content.clone() {
                            Some(tree) => tree.as_element(),
                            None => text("Open a project or begin creating one").into(),
                        };
                        let content = container(themer(self.project.get_theme(), el_tree))
                            .id(iced::widget::container::Id::new("drop_zone"))
                            .height(Length::Fill)
                            .width(Length::Fill);
                        let title = row![
                            text("Designer"),
                            Space::with_width(Length::Fill),
                            button("Switch to Code view")
                                .on_press(Message::SwitchPage(DesignerPage::CodeView)),
                        ]
                        .align_y(Alignment::Center);
                        let title_bar = pane_grid::TitleBar::new(title)
                            .padding(10)
                            .style(style::title_bar);
                        pane_grid::Content::new(content)
                            .title_bar(title_bar)
                            .style(if is_focused {
                                style::pane_focused
                            } else {
                                style::pane_active
                            })
                    }
                    DesignerPage::CodeView => {
                        let title = row![
                            text("Generated Code"),
                            Space::with_width(Length::Fill),
                            tooltip(
                                button(
                                    container(
                                        text('\u{0e801}').font(Font::with_name("editor-icons"))
                                    )
                                    .center_x(30)
                                )
                                .on_press(Message::CopyCode),
                                "Copy code to clipboard",
                                tooltip::Position::FollowCursor
                            ),
                            Space::with_width(20),
                            button("Switch to Designer view")
                                .on_press(Message::SwitchPage(DesignerPage::Designer))
                        ]
                        .align_y(Alignment::Center);
                        let title_bar = pane_grid::TitleBar::new(title)
                            .padding(10)
                            .style(style::title_bar);
                        pane_grid::Content::new(
                            text_editor(&self.editor_content)
                                .on_action(Message::EditorAction)
                                .highlight(
                                    "rs",
                                    if self.dark_theme {
                                        highlighter::Theme::SolarizedDark
                                    } else {
                                        highlighter::Theme::InspiredGitHub
                                    },
                                )
                                .height(Length::Fill)
                                .padding(20),
                        )
                        .title_bar(title_bar)
                        .style(if is_focused {
                            style::pane_focused
                        } else {
                            style::pane_active
                        })
                    }
                },
                Panes::ElementList => {
                    let items_list = items_list_view(self.element_list.clone());
                    let content = column![items_list]
                        .align_x(Alignment::Center)
                        .height(Length::Fill)
                        .width(Length::Fill);
                    let title = text("Element List");
                    let title_bar = pane_grid::TitleBar::new(title)
                        .padding(10)
                        .style(style::title_bar);
                    pane_grid::Content::new(content)
                        .title_bar(title_bar)
                        .style(if is_focused {
                            style::pane_focused
                        } else {
                            style::pane_active
                        })
                }
            }
        })
        .width(Length::Fill)
        .height(Length::Fill)
        .spacing(10)
        .on_resize(10, Message::PaneResized)
        .on_click(Message::PaneClicked)
        .on_drag(Message::PaneDragged);

        let content = Column::new()
            .push(header)
            .push(pane_grid)
            .spacing(5)
            .align_x(Alignment::Center)
            .width(Length::Fill);

        container(content).height(Length::Fill).into()
    }
}

fn items_list_view<'a>(items: Vec<ElementName>) -> Element<'a, Message> {
    let mut column = Column::new()
        .spacing(20)
        .align_x(Alignment::Center)
        .width(Length::Fill);

    for item in items {
        column = column.push(
            droppable(text(item.clone().to_string()))
                .on_drop(move |point, rect| Message::DropNewElement(item.clone(), point, rect)),
        );
    }

    container(column)
        .width(Length::Fill)
        .height(Length::Fill)
        .into()
}

mod style {
    use iced::widget::container::Style;
    use iced::{Border, Theme};

    pub fn title_bar(theme: &Theme) -> Style {
        let palette = theme.extended_palette();

        Style {
            text_color: Some(palette.background.strong.text),
            background: Some(palette.background.strong.color.into()),
            ..Default::default()
        }
    }

    pub fn pane_active(theme: &Theme) -> Style {
        let palette = theme.extended_palette();

        Style {
            background: Some(palette.background.weak.color.into()),
            border: Border {
                width: 1.0,
                color: palette.background.strong.color,
                ..Border::default()
            },
            ..Default::default()
        }
    }

    pub fn pane_focused(theme: &Theme) -> Style {
        let palette = theme.extended_palette();

        Style {
            background: Some(palette.background.weak.color.into()),
            border: Border {
                width: 4.0,
                color: palette.background.strong.color,
                ..Border::default()
            },
            ..Default::default()
        }
    }
}