use std::cell::RefCell;
use std::thread;
use std::collections::HashMap;
use std::string::String;

use rmp::Value;
use rmp::value::Integer;

use cairo;
use cairo::TextExtents;
use cairo::enums::{FontWeight, FontSlant};
use gtk;
use gtk::prelude::*;
use gtk::{Window, WindowType, DrawingArea, Grid, ToolButton, ButtonBox, Orientation, Image};
use gdk::{EventKey, EventConfigure};
use glib;
use glib_sys;
use neovim_lib::{Neovim, NeovimApi};

use ui_model::{UiModel, Attrs, Color, COLOR_BLACK, COLOR_WHITE};
use nvim::RedrawEvents;

use input::convert_key;

#[cfg(target_os = "linux")]
const FONT_NAME: &'static str = "Droid Sans Mono for Powerline";
#[cfg(target_os = "windows")]
const FONT_NAME: &'static str = "Droid Sans Mono";
const FONT_SIZE: f64 = 16.0;

thread_local!(pub static UI: RefCell<Ui> = {
    let thread = thread::current();
    let current_thread_name = thread.name();
    if current_thread_name != Some("<main>") {
        panic!("Can create UI  only from main thread, {:?}", current_thread_name);
    }
    RefCell::new(Ui::new())
});

pub struct Ui {
    pub model: UiModel,
    nvim: Option<Neovim>,
    drawing_area: DrawingArea,
    cur_attrs: Option<Attrs>,
    bg_color: Color,
    fg_color: Color,
    line_height: Option<f64>,
    char_width: Option<f64>,
    resize_timer: Option<u32>,
}

impl Ui {
    pub fn new() -> Ui {
        Ui {
            model: UiModel::empty(),
            drawing_area: DrawingArea::new(),
            nvim: None,
            cur_attrs: None,
            bg_color: COLOR_BLACK,
            fg_color: COLOR_WHITE,
            line_height: None,
            char_width: None,
            resize_timer: None,
        }
    }

    pub fn set_nvim(&mut self, nvim: Neovim) {
        self.nvim = Some(nvim);
    }

    pub fn nvim(&mut self) -> &mut Neovim {
        self.nvim.as_mut().unwrap()
    }

    pub fn init(&mut self) {

        let window = Window::new(WindowType::Toplevel);

        let grid = Grid::new();

        let button_bar = ButtonBox::new(Orientation::Horizontal);
        button_bar.set_hexpand(true);
        button_bar.set_layout(gtk::ButtonBoxStyle::Start);

        let open_image = Image::new_from_icon_name("document-open", 50);
        let open_btn = ToolButton::new(Some(&open_image), None);
        button_bar.add(&open_btn);

        let save_image = Image::new_from_icon_name("document-save", 50);
        let save_btn = ToolButton::new(Some(&save_image), None);
        button_bar.add(&save_btn);

        let exit_image = Image::new_from_icon_name("application-exit", 50);
        let exit_btn = ToolButton::new(Some(&exit_image), None);
        exit_btn.connect_clicked(|_| gtk::main_quit());
        button_bar.add(&exit_btn);

        grid.attach(&button_bar, 0, 0, 1, 1);

        self.drawing_area.set_size_request(500, 300);
        self.drawing_area.set_hexpand(true);
        self.drawing_area.set_vexpand(true);
        grid.attach(&self.drawing_area, 0, 1, 1, 1);
        self.drawing_area.connect_draw(gtk_draw);

        window.add(&grid);
        window.show_all();
        window.connect_key_press_event(gtk_key_press);
        window.connect_delete_event(|_, _| {
            gtk::main_quit();
            Inhibit(false)
        });
        self.drawing_area.connect_configure_event(gtk_configure_event);
    }
}

fn gtk_key_press(_: &Window, ev: &EventKey) -> Inhibit {
    if let Some(input) = convert_key(ev) {
        UI.with(|ui_cell| {
            let mut ui = ui_cell.borrow_mut();
            ui.nvim().input(&input).expect("Error run input command to nvim");
        });
    }
    Inhibit(false)
}

fn calc_char_bounds(ctx: &cairo::Context) -> TextExtents {
    let font_face = cairo::FontFace::toy_create(FONT_NAME, FontSlant::Normal, FontWeight::Normal);
    ctx.set_font_size(FONT_SIZE);
    ctx.set_font_face(font_face);
    ctx.text_extents("A")
}

fn gtk_draw(drawing_area: &DrawingArea, ctx: &cairo::Context) -> Inhibit {
    UI.with(|ui_cell| {
        let mut ui = ui_cell.borrow_mut();

        let char_bounds = calc_char_bounds(ctx);
        let font_extents = ctx.font_extents();
        ui.line_height = Some(font_extents.height.round());
        ui.char_width = Some(char_bounds.width.round());

        draw(&*ui, ctx);
        request_width(&drawing_area, &*ui);

    });

    Inhibit(false)
}

fn gtk_configure_event(_: &DrawingArea, ev: &EventConfigure) -> Inhibit {
    UI.with(|ui_cell| {
        let mut ui = ui_cell.borrow_mut();
        let (width, height) = ev.get_size();

        if let Some(timer) = ui.resize_timer {
            unsafe { glib_sys::g_source_remove(timer) };
        }
        if let Some(line_height) = ui.line_height {
            if let Some(char_width) = ui.char_width {

                ui.resize_timer = Some(glib::timeout_add(250, move || {
                    UI.with(|ui_cell| {
                        let mut ui = ui_cell.borrow_mut();
                        ui.resize_timer = None;

                        let rows = (height as f64 / line_height).trunc() as usize;
                        let columns = (width as f64 / char_width).trunc() as usize;
                        if ui.model.rows != rows || ui.model.columns != columns {
                            if let Err(err) = ui.nvim().ui_try_resize(columns as u64, rows as u64) {
                                println!("Error trying resize nvim {}", err);
                            }
                        }
                    });
                    Continue(false)
                }));
            }
        }
    });
    Inhibit(false)
}

fn draw(ui: &Ui, ctx: &cairo::Context) {
    ctx.set_source_rgb(ui.bg_color.0, ui.bg_color.1, ui.bg_color.2);
    ctx.paint();

    let font_extents = ctx.font_extents();
    let line_height = ui.line_height.unwrap();
    let char_width = ui.char_width.unwrap();

    let mut line_y = line_height;
    for line in ui.model.model() {
        ctx.move_to(0.0, line_y - font_extents.descent);
        for cell in line {
            let slant = if cell.attrs.italic {
                FontSlant::Italic
            } else {
                FontSlant::Normal
            };

            let weight = if cell.attrs.bold {
                FontWeight::Bold
            } else {
                FontWeight::Normal
            };

            let font_face = cairo::FontFace::toy_create(FONT_NAME, slant, weight);
            ctx.set_font_face(font_face);
            ctx.set_font_size(FONT_SIZE);

            let current_point = ctx.get_current_point();

            if let Some(ref bg) = cell.attrs.background {
                ctx.set_source_rgb(bg.0, bg.1, bg.2);
                ctx.rectangle(current_point.0,
                              line_y - line_height,
                              char_width,
                              line_height);
                ctx.fill();

                ctx.move_to(current_point.0, current_point.1);
            }
            let fg = if let Some(ref fg) = cell.attrs.foreground {
                fg
            }
            else {
                &ui.fg_color
            };
            ctx.set_source_rgb(fg.0, fg.1, fg.2);
            ctx.show_text(&cell.ch.to_string());
            ctx.move_to(current_point.0 + char_width, current_point.1);
        }
        line_y += line_height;
    }

}

fn request_width(drawing_area: &DrawingArea, ui: &Ui) {
    let width = drawing_area.get_allocated_width();
    let height = drawing_area.get_allocated_height();
    let request_height = (ui.model.rows as f64 * ui.line_height.unwrap()) as i32;
    let request_width = (ui.model.columns as f64 * ui.char_width.unwrap()) as i32;

    if width != request_width || height != request_height {
        drawing_area.set_size_request(request_width, request_height);
    }
}

impl RedrawEvents for Ui {
    fn on_cursor_goto(&mut self, row: u64, col: u64) {
        self.model.set_cursor(row, col);
    }

    fn on_put(&mut self, text: &str) {
        self.model.put(text, &self.cur_attrs);
    }

    fn on_clear(&mut self) {
        self.model.clear();
    }

    fn on_eol_clear(&mut self) {
        self.model.eol_clear();
    }

    fn on_resize(&mut self, columns: u64, rows: u64) {
        self.model = UiModel::new(rows, columns);
    }

    fn on_redraw(&self) {
        self.drawing_area.queue_draw();
    }

    fn on_set_scroll_region(&mut self, top: u64, bot: u64, left: u64, right: u64) {
        self.model.set_scroll_region(top, bot, left, right);
    }

    fn on_scroll(&mut self, count: i64) {
        self.model.scroll(count);
    }

    fn on_highlight_set(&mut self, attrs: &HashMap<String, Value>) {
        let mut model_attrs = Attrs::new();
        if let Some(&Value::Integer(Integer::U64(fg))) = attrs.get("foreground") {
            model_attrs.foreground = Some(split_color(fg));
        }
        if let Some(&Value::Integer(Integer::U64(bg))) = attrs.get("background") {
            model_attrs.background = Some(split_color(bg));
        }
        if attrs.contains_key("reverse") {
            let fg = if let Some(ref fg) = model_attrs.foreground {
                fg.clone()
            } else {
                self.fg_color.clone()
            };
            let bg = if let Some(ref bg) = model_attrs.background {
                bg.clone()
            } else {
                self.bg_color.clone()
            };
            model_attrs.foreground = Some(bg);
            model_attrs.background = Some(fg);
        }
        model_attrs.bold = attrs.contains_key("bold");
        model_attrs.italic = attrs.contains_key("italic");
        self.cur_attrs = Some(model_attrs);
    }

    fn on_update_bg(&mut self, bg: i64) {
        if bg >= 0 {
            self.bg_color = split_color(bg as u64);
        }
        else {
            self.bg_color = COLOR_BLACK;
        }
    }

    fn on_update_fg(&mut self, fg: i64) {
        if fg >= 0 {
            self.fg_color = split_color(fg as u64);
        }
        else {
            self.fg_color = COLOR_WHITE;
        }
    }

}

fn split_color(indexed_color: u64) -> Color {
    let r = ((indexed_color >> 16) & 0xff) as f64;
    let g = ((indexed_color >> 8) & 0xff) as f64;
    let b = (indexed_color & 0xff) as f64;
    Color(r / 255.0, g / 255.0, b / 255.0)
}