use std::io::{Stdout, Write};

use termion::{clear, cursor, raw::RawTerminal};

use super::{
    compose::{Component, Components, HorizontalAlignment, Text},
    frame::Frame,
    theme::ColorSet,
    Environment, Event, Page,
};

type Result<T> = std::result::Result<T, anyhow::Error>;

#[derive(Debug, Clone)]
pub enum Body {
    Echo,
    Signin(SigninPage),
}

impl Body {
    fn echo(
        env: Environment,
        screen: &mut RawTerminal<Stdout>,
        event: Event,
    ) -> Result<()> {
        let echo_comps =
            Components::break_into(format!("Event: {}", event))
                .nextline_after_text(
                    0,
                    HorizontalAlignment::Left,
                    env.frame.inner_size().0,
                );
        write!(screen, "{}", env.frame.make(echo_comps))?;
        screen.flush()?;
        Ok(())
    }

    fn echo_init(
        &self,
        env: Environment,
        screen: &mut RawTerminal<Stdout>,
    ) -> Result<()> {
        write!(
            screen,
            "{hide}{clear}{fr}{cursor}",
            clear = clear::All,
            hide = cursor::Hide,
            fr = env.frame.frame_str(env.theme.windows.primary),
            cursor = env.frame.goto(0, 0),
        )?;
        screen.flush()?;
        Ok(())
    }
}

impl Page for Body {
    fn receive_event(
        &mut self,
        env: Environment,
        screen: &mut RawTerminal<Stdout>,
        event: Event,
    ) -> Result<()> {
        match self {
            Body::Signin(b) => b.receive_event(env, screen, event)?,
            Body::Echo => Body::echo(env, screen, event)?,
        };
        Ok(())
    }

    fn init(
        &mut self,
        env: Environment,
        screen: &mut RawTerminal<Stdout>,
    ) -> Result<()> {
        match self {
            Body::Echo => self.echo_init(env, screen),
            Body::Signin(signin) => signin.init(env, screen),
        }
    }
}

#[derive(Debug, Clone, Default)]
pub struct SigninPage {
    hostname: String,
    token: String,
    cursor: SigninCursorLocation,
    frame: Option<Frame>,
}

#[derive(Debug, Clone)]
enum SigninCursorLocation {
    Hostname,
    Token,
    Ok,
}

impl Default for SigninCursorLocation {
    fn default() -> Self {
        Self::Hostname
    }
}

impl SigninPage {
    #[inline]
    fn next(&mut self) {
        self.cursor = match self.cursor {
            SigninCursorLocation::Hostname => {
                SigninCursorLocation::Token
            }
            SigninCursorLocation::Token => SigninCursorLocation::Ok,
            SigninCursorLocation::Ok => {
                SigninCursorLocation::Hostname
            }
        }
    }

    #[inline]
    fn previous(&mut self) {
        self.cursor = match self.cursor {
            SigninCursorLocation::Hostname => {
                SigninCursorLocation::Ok
            }
            SigninCursorLocation::Token => {
                SigninCursorLocation::Hostname
            }
            SigninCursorLocation::Ok => SigninCursorLocation::Token,
        }
    }

    fn draw(
        &self,
        highlight: ColorSet,
        normal: ColorSet,
    ) -> Components {
        const HEADER_Y: u16 = 1;
        const HOSTNAME_Y: u16 = 3;
        const TOKEN_Y: u16 = 4;
        const OK_Y: u16 = 6;
        let frame = self.frame.unwrap();
        let (w, _) = frame.inner_size();
        let exp_w = w - (w / 3);

        let (hostname_theme, token_theme, ok_theme) = match self
            .cursor
        {
            SigninCursorLocation::Hostname => {
                (highlight, normal, normal)
            }
            SigninCursorLocation::Token => {
                (normal, highlight, normal)
            }
            SigninCursorLocation::Ok => (normal, normal, highlight),
        };

        vec![
            frame
                .prefix_centered_goto(
                    vec![Component::String(Text::Normal(
                        "login kk".into(),
                    ))]
                    .into(),
                    HEADER_Y,
                )
                .0,
            frame
                .prefix_centered_goto(
                    self.field(
                        hostname_theme,
                        normal,
                        exp_w,
                        "hostname",
                        &self.hostname,
                    ),
                    HOSTNAME_Y,
                )
                .0,
            frame
                .prefix_centered_goto(
                    self.field(
                        token_theme,
                        normal,
                        exp_w,
                        "token",
                        &self.token,
                    ),
                    TOKEN_Y,
                )
                .0,
            vec![Component::Theme(ok_theme)],
            HorizontalAlignment::Center
                .align(Text::Normal("[ok]".into()), w, OK_Y)
                .0,
            vec![Component::Theme(normal)],
        ]
        .into_iter()
        .flatten()
        .collect::<Vec<Component>>()
        .into()
    }

    #[inline]
    fn field<C>(
        &self,
        color: ColorSet,
        normal: ColorSet,
        exp_width: u16,
        field: C,
        field_content: C,
    ) -> Components
    where
        C: Into<String>,
    {
        let (field, field_content) =
            (field.into(), field_content.into());
        let budget_for_content = exp_width - field.len() as u16 - 3;
        vec![
            Component::String((field + &": ").into()),
            Component::Theme(color),
            Component::String(Text::LimitedOrPadded(
                field_content,
                '_',
                budget_for_content,
            )),
            Component::Theme(normal),
        ]
        .into()
    }

    fn del(&mut self) {
        match self.cursor {
            SigninCursorLocation::Hostname => {
                self.hostname.pop();
            }
            SigninCursorLocation::Token => {
                self.token.pop();
            }
            SigninCursorLocation::Ok => {}
        }
    }

    #[inline]
    fn char(&mut self, c: char) {
        if ['\t', '\n', '\r'].contains(&c) {
            return;
        }
        match self.cursor {
            SigninCursorLocation::Hostname => {
                self.hostname.push(c);
            }
            SigninCursorLocation::Token => {
                self.token.push(c);
            }
            SigninCursorLocation::Ok => {}
        }
    }
}

impl Page for SigninPage {
    fn receive_event(
        &mut self,
        env: Environment,
        screen: &mut RawTerminal<Stdout>,
        event: Event,
    ) -> Result<()> {
        match event {
            Event::Key(key) => match key {
                termion::event::Key::Char(c) => self.char(c),
                termion::event::Key::Up => self.previous(),
                termion::event::Key::Down => self.next(),
                termion::event::Key::Backspace => self.del(),
                termion::event::Key::Delete => {}
                termion::event::Key::Left => {}
                termion::event::Key::Right => {}
                //
                _ => {}
            },
        }

        let fr = self.frame.unwrap();
        write!(
            screen,
            "{}{}{}",
            env.primary_frame(),
            fr.frame_str(env.theme.windows.subwin),
            fr.make(self.draw(
                env.theme.windows.highlight,
                env.theme.windows.subwin
            ))
        )?;
        screen.flush()?;

        Ok(())
    }

    fn init(
        &mut self,
        env: Environment,
        screen: &mut RawTerminal<Stdout>,
    ) -> Result<()> {
        self.frame = Some(env.frame.sub(
            env.theme.frames.inner,
            super::frame::FrameSize::ByAbsolute(70, 10),
        ));
        write!(
            screen,
            "{frame}{subframe}{content}{hide_cursor}",
            frame = env.frame.frame_str(env.theme.windows.primary),
            subframe = self
                .frame
                .unwrap()
                .frame_str(env.theme.windows.subwin),
            hide_cursor = cursor::Hide,
            content = self.frame.unwrap().make(self.draw(
                env.theme.windows.highlight,
                env.theme.windows.subwin
            ))
        )?;
        screen.flush()?;

        Ok(())
    }
}