use std::sync::Arc;
use std::time::SystemTime;

use alacritty_terminal::index::Side;
use alacritty_terminal::selection::{Selection, SelectionType};
use alacritty_terminal::term::search::Match;
use alacritty_terminal::term::RenderableContent;
use alacritty_terminal::{
    grid::Dimensions,
    term::{cell::Flags, test::TermSize},
};
use floem::context::{EventCx, PaintCx};
use floem::event::Event;
use floem::peniko::Color;
use floem::pointer::PointerInputEvent;
use floem::views::editor::core::register::Clipboard;
use floem::views::editor::text::SystemClipboard;
use floem::{
    cosmic_text::{Attrs, AttrsList, FamilyOwned, TextLayout, Weight},
    id::Id,
    peniko::kurbo::{Point, Rect, Size},
    reactive::{create_effect, ReadSignal, RwSignal},
    view::{AnyWidget, View, ViewData, Widget},
    EventPropagation, Renderer,
};
use lapce_core::mode::Mode;
use lapce_rpc::{proxy::ProxyRpcHandler, terminal::TermId};
use lsp_types::Position;
use parking_lot::RwLock;
use unicode_width::UnicodeWidthChar;

use super::{panel::TerminalPanelData, raw::RawTerminal};
use crate::command::InternalCommand;
use crate::editor::location::{EditorLocation, EditorPosition};
use crate::listener::Listener;
use crate::workspace::LapceWorkspace;
use crate::{
    config::{color::LapceColor, LapceConfig},
    debug::RunDebugProcess,
    panel::kind::PanelKind,
    window_tab::Focus,
};

/// Threshold used for double_click/triple_click.
const CLICK_THRESHOLD: u128 = 400;

enum TerminalViewState {
    Config,
    Focus(bool),
    Raw(Arc<RwLock<RawTerminal>>),
}

struct TerminalLineContent<'a> {
    y: f64,
    bg: Vec<(usize, usize, Color)>,
    underline: Vec<(usize, usize, Color, f64)>,
    chars: Vec<(char, Attrs<'a>, f64, f64)>,
    cursor: Option<(char, f64)>,
}

pub struct TerminalView {
    data: ViewData,
    term_id: TermId,
    raw: Arc<RwLock<RawTerminal>>,
    mode: ReadSignal<Mode>,
    size: Size,
    is_focused: bool,
    config: ReadSignal<Arc<LapceConfig>>,
    run_config: ReadSignal<Option<RunDebugProcess>>,
    proxy: ProxyRpcHandler,
    launch_error: RwSignal<Option<String>>,
    internal_command: Listener<InternalCommand>,
    workspace: Arc<LapceWorkspace>,
    hyper_matches: Vec<Match>,
    previous_mouse_action: MouseAction,
    current_mouse_action: MouseAction,
}

#[allow(clippy::too_many_arguments)]
pub fn terminal_view(
    term_id: TermId,
    raw: ReadSignal<Arc<RwLock<RawTerminal>>>,
    mode: ReadSignal<Mode>,
    run_config: ReadSignal<Option<RunDebugProcess>>,
    terminal_panel_data: TerminalPanelData,
    launch_error: RwSignal<Option<String>>,
    internal_command: Listener<InternalCommand>,
    workspace: Arc<LapceWorkspace>,
) -> TerminalView {
    let id = Id::next();

    create_effect(move |_| {
        let raw = raw.get();
        id.update_state(TerminalViewState::Raw(raw));
    });

    create_effect(move |_| {
        launch_error.track();
        id.request_paint();
    });

    let config = terminal_panel_data.common.config;
    create_effect(move |_| {
        config.with(|_c| {});
        id.update_state(TerminalViewState::Config);
    });

    let proxy = terminal_panel_data.common.proxy.clone();

    create_effect(move |last| {
        let focus = terminal_panel_data.common.focus.get();

        let mut is_focused = false;
        if let Focus::Panel(PanelKind::Terminal) = focus {
            let tab = terminal_panel_data.active_tab(true);
            if let Some(tab) = tab {
                let terminal = tab.active_terminal(true);
                is_focused = terminal.map(|t| t.term_id) == Some(term_id);
            }
        }

        if last != Some(is_focused) {
            id.update_state(TerminalViewState::Focus(is_focused));
        }

        is_focused
    });

    TerminalView {
        data: ViewData::new(id),
        term_id,
        raw: raw.get_untracked(),
        mode,
        config,
        proxy,
        run_config,
        size: Size::ZERO,
        is_focused: false,
        launch_error,
        internal_command,
        workspace,
        hyper_matches: vec![],
        previous_mouse_action: Default::default(),
        current_mouse_action: Default::default(),
    }
}

impl TerminalView {
    fn char_size(&self) -> Size {
        let config = self.config.get_untracked();
        let font_family = config.terminal_font_family();
        let font_size = config.terminal_font_size();
        let family: Vec<FamilyOwned> =
            FamilyOwned::parse_list(font_family).collect();
        let attrs = Attrs::new().family(&family).font_size(font_size as f32);
        let attrs_list = AttrsList::new(attrs);
        let mut text_layout = TextLayout::new();
        text_layout.set_text("W", attrs_list);
        text_layout.size()
    }

    fn terminal_size(&self) -> (usize, usize) {
        let config = self.config.get_untracked();
        let line_height = config.terminal_line_height() as f64;
        let char_width = self.char_size().width;
        let width = (self.size.width / char_width).floor() as usize;
        let height = (self.size.height / line_height).floor() as usize;
        (width.max(1), height.max(1))
    }

    fn click(&self, pos: Point) -> Option<()> {
        let raw_origin = self.raw.read();
        let position = self.get_terminal_point(pos);
        let hy = self.hyper_matches.iter().find(|x| x.contains(&position))?;
        let hyperlink = raw_origin.term.bounds_to_string(*hy.start(), *hy.end());
        let content: Vec<&str> = hyperlink.split(':').collect();
        let (file, line_str, col_str) =
            (content.first()?, content.get(1)?, content.get(2)?);
        let (line, col) =
            (line_str.parse::<u32>().ok()?, col_str.parse::<u32>().ok()?);
        let parent_path = self.workspace.path.as_ref()?;
        self.internal_command.send(InternalCommand::JumpToLocation {
            location: EditorLocation {
                path: parent_path.join(file),
                position: Some(EditorPosition::Position(Position::new(line, col))),
                scroll_offset: None,
                ignore_unconfirmed: false,
                same_editor_tab: false,
            },
        });
        None
    }

    fn update_mouse_action_by_down(&mut self, mouse: PointerInputEvent) {
        let mut next_action = MouseAction::None;
        match self.current_mouse_action {
            MouseAction::None
            | MouseAction::LeftDouble { .. }
            | MouseAction::LeftSelect { .. }
            | MouseAction::RightOnce { .. } => {
                if mouse.button.is_primary() {
                    next_action = MouseAction::LeftDown { pos: mouse.pos };
                } else if mouse.button.is_secondary() {
                    next_action = MouseAction::RightDown { pos: mouse.pos };
                }
            }
            MouseAction::LeftOnce { pos, time } => {
                let during_mills =
                    time.elapsed().map(|x| x.as_millis()).unwrap_or(u128::MAX);
                match (
                    mouse.button.is_primary(),
                    mouse.pos == pos,
                    during_mills < CLICK_THRESHOLD,
                ) {
                    (true, true, true) => {
                        next_action = MouseAction::LeftOnceAndDown { pos, time };
                    }
                    (true, _, _) => {
                        next_action = MouseAction::LeftDown { pos: mouse.pos };
                    }
                    _ => {}
                }
            }
            MouseAction::LeftOnceAndDown { .. }
            | MouseAction::LeftDown { .. }
            | MouseAction::RightDown { .. } => {}
        }
        self.current_mouse_action = next_action;
    }
    fn update_mouse_action_by_up(&mut self, mouse: PointerInputEvent) {
        let mut next_action = MouseAction::None;
        match self.current_mouse_action {
            MouseAction::None => {}
            MouseAction::LeftDown { pos } => {
                match (mouse.button.is_primary(), mouse.pos == pos) {
                    (true, true) => {
                        next_action = MouseAction::LeftOnce {
                            pos,
                            time: SystemTime::now(),
                        }
                    }
                    (true, false) => {
                        next_action = MouseAction::LeftSelect {
                            start_pos: pos,
                            end_pos: mouse.pos,
                        };
                    }
                    _ => {}
                }
            }
            MouseAction::LeftOnce { .. } => {}
            MouseAction::LeftSelect { .. } => {}
            MouseAction::LeftOnceAndDown { pos, time } => {
                let during_mills =
                    time.elapsed().map(|x| x.as_millis()).unwrap_or(u128::MAX);
                match (
                    mouse.button.is_primary(),
                    mouse.pos == pos,
                    during_mills < CLICK_THRESHOLD,
                ) {
                    (true, true, true) => {
                        next_action = MouseAction::LeftDouble { pos };
                    }
                    (true, true, false) => {
                        next_action = MouseAction::LeftOnce {
                            pos: mouse.pos,
                            time: SystemTime::now(),
                        };
                    }
                    (true, false, _) => {
                        next_action = MouseAction::LeftSelect {
                            start_pos: pos,
                            end_pos: mouse.pos,
                        };
                    }
                    _ => {}
                }
            }
            MouseAction::LeftDouble { .. } => {}
            MouseAction::RightDown { pos } => {
                if mouse.button.is_secondary() && mouse.pos == pos {
                    next_action = MouseAction::RightOnce { pos };
                }
            }
            MouseAction::RightOnce { .. } => {}
        }
        self.previous_mouse_action = self.current_mouse_action;
        self.current_mouse_action = next_action;
    }

    fn get_terminal_point(&self, pos: Point) -> alacritty_terminal::index::Point {
        let col = (pos.x / self.char_size().width) as usize;
        let line_no =
            pos.y as i32 / (self.config.get().terminal_line_height() as i32);
        alacritty_terminal::index::Point::new(
            alacritty_terminal::index::Line(line_no),
            alacritty_terminal::index::Column(col),
        )
    }

    fn paint_content(
        &self,
        cx: &mut PaintCx,
        content: RenderableContent,
        line_height: f64,
        char_size: Size,
        config: &LapceConfig,
    ) {
        let term_bg = config.color(LapceColor::TERMINAL_BACKGROUND);
        let term_fg = config.color(LapceColor::TERMINAL_FOREGROUND);

        let font_size = config.terminal_font_size();
        let font_family = config.terminal_font_family();
        let family: Vec<FamilyOwned> =
            FamilyOwned::parse_list(font_family).collect();
        let attrs = Attrs::new().family(&family).font_size(font_size as f32);

        let char_width = char_size.width;

        let cursor_point = &content.cursor.point;

        let mut line_content = TerminalLineContent {
            y: 0.0,
            bg: Vec::new(),
            underline: Vec::new(),
            chars: Vec::new(),
            cursor: None,
        };
        for item in content.display_iter {
            let point = item.point;
            let cell = item.cell;
            let inverse = cell.flags.contains(Flags::INVERSE);

            let x = point.column.0 as f64 * char_width;
            let y =
                (point.line.0 as f64 + content.display_offset as f64) * line_height;
            let char_y = y + (line_height - char_size.height) / 2.0;
            let underline_y = (point.line.0 as f64 + content.display_offset as f64)
                * line_height
                + line_height;
            if y != line_content.y {
                self.paint_line_content(
                    cx,
                    &line_content,
                    line_height,
                    char_width,
                    config,
                );
                line_content.y = y;
                line_content.bg.clear();
                line_content.underline.clear();
                line_content.chars.clear();
                line_content.cursor = None;
            }

            let mut bg = config.terminal_get_color(&cell.bg, content.colors);
            let mut fg = config.terminal_get_color(&cell.fg, content.colors);
            if cell.flags.contains(Flags::DIM)
                || cell.flags.contains(Flags::DIM_BOLD)
            {
                fg = fg.with_alpha_factor(0.66);
            }

            if inverse {
                std::mem::swap(&mut fg, &mut bg);
            }

            if term_bg != bg {
                let mut extend = false;
                if let Some((_, end, color)) = line_content.bg.last_mut() {
                    if color == &bg && *end == point.column.0 {
                        *end += 1;
                        extend = true;
                    }
                }
                if !extend {
                    line_content
                        .bg
                        .push((point.column.0, point.column.0 + 1, bg));
                }
            }

            if self.hyper_matches.iter().any(|x| x.contains(&point)) {
                let mut extend = false;
                if let Some((_, end, _, _)) = line_content.underline.last_mut() {
                    if *end == point.column.0 {
                        *end += 1;
                        extend = true;
                    }
                }
                if !extend {
                    line_content.underline.push((
                        point.column.0,
                        point.column.0 + 1,
                        term_fg,
                        underline_y,
                    ));
                }
            }

            if cursor_point == &point {
                line_content.cursor = Some((cell.c, x));
            }

            let bold = cell.flags.contains(Flags::BOLD)
                || cell.flags.contains(Flags::DIM_BOLD);

            if &point == cursor_point && self.is_focused {
                fg = term_bg;
            }

            if cell.c != ' ' && cell.c != '\t' {
                let mut attrs = attrs.color(fg);
                if bold {
                    attrs = attrs.weight(Weight::BOLD);
                }
                line_content.chars.push((cell.c, attrs, x, char_y));
            }
        }
        self.paint_line_content(cx, &line_content, line_height, char_width, config);
    }

    fn paint_line_content(
        &self,
        cx: &mut PaintCx,
        line_content: &TerminalLineContent,
        line_height: f64,
        char_width: f64,
        config: &LapceConfig,
    ) {
        for (start, end, bg) in &line_content.bg {
            let rect = Size::new(
                char_width * (end.saturating_sub(*start) as f64),
                line_height,
            )
            .to_rect()
            .with_origin(Point::new(*start as f64 * char_width, line_content.y));
            cx.fill(&rect, bg, 0.0);
        }

        for (start, end, fg, y) in &line_content.underline {
            let rect =
                Size::new(char_width * (end.saturating_sub(*start) as f64), 1.0)
                    .to_rect()
                    .with_origin(Point::new(*start as f64 * char_width, y - 1.0));
            cx.fill(&rect, fg, 0.0);
        }

        if let Some((c, x)) = line_content.cursor {
            let rect =
                Size::new(char_width * c.width().unwrap_or(1) as f64, line_height)
                    .to_rect()
                    .with_origin(Point::new(x, line_content.y));
            let mode = self.mode.get_untracked();
            let cursor_color = if mode == Mode::Terminal {
                if self.run_config.with_untracked(|run_config| {
                    run_config.as_ref().map(|r| r.stopped).unwrap_or(false)
                }) {
                    config.color(LapceColor::LAPCE_ERROR)
                } else {
                    config.color(LapceColor::TERMINAL_CURSOR)
                }
            } else {
                config.color(LapceColor::EDITOR_CARET)
            };
            if self.is_focused {
                cx.fill(&rect, cursor_color, 0.0);
            } else {
                cx.stroke(&rect, cursor_color, 1.0);
            }
        }

        for (char, attr, x, y) in &line_content.chars {
            let mut text_layout = TextLayout::new();
            text_layout.set_text(&char.to_string(), AttrsList::new(*attr));
            cx.draw_text(&text_layout, Point::new(*x, *y));
        }
    }
}

impl Drop for TerminalView {
    fn drop(&mut self) {
        self.proxy.terminal_close(self.term_id);
    }
}

impl View for TerminalView {
    fn view_data(&self) -> &ViewData {
        &self.data
    }

    fn view_data_mut(&mut self) -> &mut ViewData {
        &mut self.data
    }

    fn build(self) -> AnyWidget {
        Box::new(self)
    }
}

impl Widget for TerminalView {
    fn view_data(&self) -> &ViewData {
        &self.data
    }

    fn view_data_mut(&mut self) -> &mut ViewData {
        &mut self.data
    }

    fn event(
        &mut self,
        _cx: &mut EventCx,
        _id_path: Option<&[Id]>,
        event: Event,
    ) -> EventPropagation {
        match event {
            Event::PointerDown(e) => {
                self.update_mouse_action_by_down(e);
            }
            Event::PointerUp(e) => {
                self.update_mouse_action_by_up(e);
                let mut clear_selection = false;
                match self.current_mouse_action {
                    MouseAction::LeftOnce { pos, .. } => {
                        clear_selection = true;
                        if self.click(pos).is_some() {
                            return EventPropagation::Stop;
                        }
                    }
                    MouseAction::LeftSelect { start_pos, end_pos } => {
                        let mut selection = Selection::new(
                            SelectionType::Simple,
                            self.get_terminal_point(start_pos),
                            Side::Left,
                        );
                        selection
                            .update(self.get_terminal_point(end_pos), Side::Right);
                        selection.include_all();
                        self.raw.write().term.selection = Some(selection);
                        _cx.app_state_mut().request_paint(self.data.id());
                    }
                    MouseAction::LeftDouble { pos } => {
                        let position = self.get_terminal_point(pos);
                        let mut raw = self.raw.write();
                        let start_point = raw.term.semantic_search_left(position);
                        let end_point = raw.term.semantic_search_right(position);

                        let mut selection = Selection::new(
                            SelectionType::Simple,
                            start_point,
                            Side::Left,
                        );
                        selection.update(end_point, Side::Right);
                        selection.include_all();
                        raw.term.selection = Some(selection);
                        _cx.app_state_mut().request_paint(self.data.id());
                    }
                    MouseAction::RightOnce { pos } => {
                        let position = self.get_terminal_point(pos);
                        let raw = self.raw.read();
                        if let Some(selection) = &raw
                            .term
                            .selection
                            .as_ref()
                            .and_then(|x| x.to_range(&raw.term))
                        {
                            if selection.contains(position) {
                                let mut clipboard = SystemClipboard::new();
                                let content = raw.term.bounds_to_string(
                                    selection.start,
                                    selection.end,
                                );
                                if !content.is_empty() {
                                    clipboard.put_string(content);
                                }
                            }
                            clear_selection = true;
                        }
                    }
                    _ => {
                        clear_selection = true;
                    }
                }
                if clear_selection {
                    self.raw.write().term.selection = None;
                    _cx.app_state_mut().request_paint(self.data.id());
                }
            }
            _ => {}
        }
        EventPropagation::Continue
    }

    fn update(
        &mut self,
        cx: &mut floem::context::UpdateCx,
        state: Box<dyn std::any::Any>,
    ) {
        if let Ok(state) = state.downcast() {
            match *state {
                TerminalViewState::Config => {}
                TerminalViewState::Focus(is_focused) => {
                    self.is_focused = is_focused;
                }
                TerminalViewState::Raw(raw) => {
                    self.raw = raw;
                }
            }
            cx.app_state_mut().request_paint(self.data.id());
        }
    }

    fn layout(
        &mut self,
        cx: &mut floem::context::LayoutCx,
    ) -> floem::taffy::prelude::NodeId {
        cx.layout_node(self.data.id(), false, |_cx| Vec::new())
    }

    fn compute_layout(
        &mut self,
        cx: &mut floem::context::ComputeLayoutCx,
    ) -> Option<Rect> {
        let layout = cx.get_layout(self.data.id()).unwrap();
        let size = layout.size;
        let size = Size::new(size.width as f64, size.height as f64);
        if size.is_empty() {
            return None;
        }
        if size != self.size {
            self.size = size;
            let (width, height) = self.terminal_size();
            let term_size = TermSize::new(width, height);
            self.raw.write().term.resize(term_size);
            self.proxy.terminal_resize(self.term_id, width, height);
        }

        None
    }

    fn paint(&mut self, cx: &mut floem::context::PaintCx) {
        let config = self.config.get_untracked();
        let mode = self.mode.get_untracked();
        let line_height = config.terminal_line_height() as f64;
        let font_family = config.terminal_font_family();
        let font_size = config.terminal_font_size();
        let char_size = self.char_size();
        let char_width = char_size.width;

        let family: Vec<FamilyOwned> =
            FamilyOwned::parse_list(font_family).collect();
        let attrs = Attrs::new().family(&family).font_size(font_size as f32);

        if let Some(error) = self.launch_error.get() {
            let mut text_layout = TextLayout::new();
            text_layout.set_text(
                &format!("Terminal failed to launch. Error: {error}"),
                AttrsList::new(
                    attrs.color(config.color(LapceColor::EDITOR_FOREGROUND)),
                ),
            );
            cx.draw_text(
                &text_layout,
                Point::new(6.0, 0.0 + (line_height - char_size.height) / 2.0),
            );
            return;
        }

        let raw = self.raw.read();
        let term = &raw.term;
        let content = term.renderable_content();

        // let mut search = RegexSearch::new("[\\w\\\\?]+\\.rs:\\d+:\\d+").unwrap();
        // self.hyper_matches = visible_regex_match_iter(term, &mut search).collect();

        if let Some(selection) = content.selection.as_ref() {
            let start_line = selection.start.line.0 + content.display_offset as i32;
            let start_line = if start_line < 0 {
                0
            } else {
                start_line as usize
            };
            let start_col = selection.start.column.0;

            let end_line = selection.end.line.0 + content.display_offset as i32;
            let end_line = if end_line < 0 { 0 } else { end_line as usize };
            let end_col = selection.end.column.0;

            for line in start_line..end_line + 1 {
                let left_col = if selection.is_block || line == start_line {
                    start_col
                } else {
                    0
                };
                let right_col = if selection.is_block || line == end_line {
                    end_col + 1
                } else {
                    term.last_column().0
                };
                let x0 = left_col as f64 * char_width;
                let x1 = right_col as f64 * char_width;
                let y0 = line as f64 * line_height;
                let y1 = y0 + line_height;
                cx.fill(
                    &Rect::new(x0, y0, x1, y1),
                    config.color(LapceColor::EDITOR_SELECTION),
                    0.0,
                );
            }
        } else if mode != Mode::Terminal {
            let y = (content.cursor.point.line.0 as f64
                + content.display_offset as f64)
                * line_height;
            cx.fill(
                &Rect::new(0.0, y, self.size.width, y + line_height),
                config.color(LapceColor::EDITOR_CURRENT_LINE),
                0.0,
            );
        }

        self.paint_content(cx, content, line_height, char_size, &config);
        // if data.find.visual {
        //     if let Some(search_string) = data.find.search_string.as_ref() {
        //         if let Ok(dfas) = RegexSearch::new(&regex::escape(search_string)) {
        //             let mut start = alacritty_terminal::index::Point::new(
        //                 alacritty_terminal::index::Line(
        //                     -(content.display_offset as i32),
        //                 ),
        //                 alacritty_terminal::index::Column(0),
        //             );
        //             let end_line = (start.line + term.screen_lines())
        //                 .min(term.bottommost_line());
        //             let mut max_lines = (end_line.0 - start.line.0) as usize;

        //             while let Some(m) = term.search_next(
        //                 &dfas,
        //                 start,
        //                 Direction::Right,
        //                 Side::Left,
        //                 Some(max_lines),
        //             ) {
        //                 let match_start = m.start();
        //                 if match_start.line.0 < start.line.0
        //                     || (match_start.line.0 == start.line.0
        //                         && match_start.column.0 < start.column.0)
        //                 {
        //                     break;
        //                 }
        //                 let x = match_start.column.0 as f64 * char_width;
        //                 let y = (match_start.line.0 as f64
        //                     + content.display_offset as f64)
        //                     * line_height;
        //                 let rect = Rect::ZERO
        //                     .with_origin(Point::new(x, y))
        //                     .with_size(Size::new(
        //                         (m.end().column.0 - m.start().column.0
        //                             + term.grid()[*m.end()].c.width().unwrap_or(1))
        //                             as f64
        //                             * char_width,
        //                         line_height,
        //                     ));
        //                 cx.stroke(
        //                     &rect,
        //                     config.get_color(LapceColor::TERMINAL_FOREGROUND),
        //                     1.0,
        //                 );
        //                 start = *m.end();
        //                 if start.column.0 < term.last_column() {
        //                     start.column.0 += 1;
        //                 } else if start.line.0 < term.bottommost_line() {
        //                     start.column.0 = 0;
        //                     start.line.0 += 1;
        //                 }
        //                 max_lines = (end_line.0 - start.line.0) as usize;
        //             }
        //         }
        //     }
        // }
    }
}

#[derive(Debug, Default, Copy, Clone)]
enum MouseAction {
    #[default]
    None,
    LeftDown {
        pos: Point,
    },
    LeftOnce {
        pos: Point,
        time: SystemTime,
    },
    LeftSelect {
        start_pos: Point,
        end_pos: Point,
    },
    LeftOnceAndDown {
        pos: Point,
        time: SystemTime,
    },
    LeftDouble {
        pos: Point,
    },
    RightDown {
        pos: Point,
    },
    RightOnce {
        pos: Point,
    },
}
