use ratatui::style::{Color, Modifier, Style};
use ratatui::text::{Line, Span, Text};
use ratatui::widgets::{Block, Borders, List, ListItem, Paragraph, Tabs};
use ratatui::layout::{Alignment, Rect};
use ratatui::Frame;

use crate::domain::models::*;
use super::NetworkStatus;

const TAB_COLOR: Color = Color::Cyan;
const FOCUS_COLOR: Color = Color::Yellow;
const SELECTED_COLOR: Color = Color::Green;
const DETAIL_COLOR: Color = Color::White;
const STATUS_ONLINE: Color = Color::Green;
const STATUS_OFFLINE: Color = Color::Red;
const STATUS_SYNC: Color = Color::Yellow;
const POPUP_BG: Color = Color::Black;
const POPUP_BORDER: Color = Color::Cyan;

pub fn render_tabs_bar(
    frame: &mut Frame,
    area: Rect,
    lists: &[TaskList],
    selected: usize,
    focused: bool,
) {
    let tab_titles: Vec<&str> = lists.iter().map(|l| l.title.as_str()).collect();

    let block = Block::default()
        .borders(Borders::ALL)
        .border_style(Style::default().fg(if focused { FOCUS_COLOR } else { TAB_COLOR }))
        .title(" Lists ")
        .title_alignment(Alignment::Left);

    let tabs = if tab_titles.is_empty() {
        Tabs::new(vec![Line::from(" No lists ")])
            .block(block)
            .highlight_style(Style::default().add_modifier(Modifier::BOLD))
            .select(selected)
    } else {
        Tabs::new(tab_titles.into_iter().map(|t| Line::from(Span::raw(t))).collect::<Vec<_>>())
            .block(block)
            .divider(Span::raw(" | "))
            .highlight_style(Style::default().fg(FOCUS_COLOR).add_modifier(Modifier::BOLD))
            .select(selected)
    };

    frame.render_widget(tabs, area);
}

pub fn render_task_list(
    frame: &mut Frame,
    area: Rect,
    tasks: &[Task],
    selected: usize,
    focused: bool,
    _scroll: u16,
) {
    let items: Vec<ListItem> = tasks
        .iter()
        .map(|task| {
            let checkbox = match task.status {
                TaskStatus::Completed => "[\u{2713}]",
                TaskStatus::NeedsAction => "[ ]",
            };

            let due_str = task
                .due
                .map(|d| d.format(" %d/%m/%Y %H:%M").to_string())
                .unwrap_or_default();

            let content = Line::from(vec![
                Span::styled(
                    format!("{} ", checkbox),
                    Style::default().fg(if task.status == TaskStatus::Completed {
                        Color::Green
                    } else {
                        Color::DarkGray
                    }),
                ),
                Span::styled(
                    &task.title,
                    Style::default().fg(DETAIL_COLOR).add_modifier(
                        if task.status == TaskStatus::Completed {
                            Modifier::CROSSED_OUT
                        } else {
                            Modifier::empty()
                        },
                    ),
                ),
                Span::styled(
                    due_str,
                    Style::default().fg(Color::DarkGray),
                ),
            ]);
            ListItem::new(content)
        })
        .collect();

    let block = Block::default()
        .borders(Borders::ALL)
        .border_style(Style::default().fg(if focused { FOCUS_COLOR } else { Color::DarkGray }))
        .title(" Tasks ")
        .title_alignment(Alignment::Left);

    let list = List::new(items)
        .block(block)
        .highlight_style(
            Style::default()
                .bg(if focused { Color::DarkGray } else { Color::Black })
                .fg(SELECTED_COLOR)
                .add_modifier(Modifier::BOLD),
        )
        .highlight_symbol(">> ");

    frame.render_stateful_widget(list, area, &mut ratatui::widgets::ListState::default().with_selected(Some(selected)));
}

pub fn render_detail(
    frame: &mut Frame,
    area: Rect,
    task: Option<&Task>,
    focused: bool,
    scroll: u16,
) {
    let block = Block::default()
        .borders(Borders::ALL)
        .border_style(Style::default().fg(if focused { FOCUS_COLOR } else { Color::DarkGray }))
        .title(" Details ")
        .title_alignment(Alignment::Left);

    if let Some(task) = task {
        let mut lines = Vec::new();

        let status_text = match task.status {
            TaskStatus::Completed => "Completed",
            TaskStatus::NeedsAction => "Needs Action",
        };

        lines.push(Line::from(Span::styled(
            format!("Title: {}", task.title),
            Style::default().fg(DETAIL_COLOR).add_modifier(Modifier::BOLD),
        )));
        lines.push(Line::from(Span::styled(
            format!("Status: {}", status_text),
            Style::default().fg(Color::Cyan),
        )));

        if let Some(due) = task.due {
            lines.push(Line::from(Span::styled(
                format!("Due: {}", due.format("%d/%m/%Y %H:%M")),
                Style::default().fg(Color::Yellow),
            )));
        }

        if let Some(notes) = &task.notes {
            if !notes.is_empty() {
                lines.push(Line::from(""));
                lines.push(Line::from(Span::styled(
                    "Notes:",
                    Style::default().fg(Color::Cyan).add_modifier(Modifier::BOLD),
                )));
                for note_line in notes.lines() {
                    lines.push(Line::from(Span::raw(note_line.to_string())));
                }
            }
        }

        let paragraph = Paragraph::new(Text::from(lines))
            .block(block)
            .scroll((scroll, 0));
        frame.render_widget(paragraph, area);
    } else {
        let paragraph = Paragraph::new(Text::from(Line::from(Span::styled(
            "Select a task to view details",
            Style::default().fg(Color::DarkGray),
        ))))
        .block(block)
        .alignment(Alignment::Center);
        frame.render_widget(paragraph, area);
    }
}

pub fn render_status_bar(
    frame: &mut Frame,
    area: Rect,
    status: &NetworkStatus,
) {
    let (text, color) = match status {
        NetworkStatus::Online => (" ONLINE ", STATUS_ONLINE),
        NetworkStatus::Offline => (" OFFLINE ", STATUS_OFFLINE),
        NetworkStatus::Syncing => (" SYNCING... ", STATUS_SYNC),
    };

    let block = Block::default()
        .style(Style::default().bg(color).fg(Color::Black));

    let paragraph = Paragraph::new(Line::from(Span::styled(
        text,
        Style::default().fg(Color::Black).add_modifier(Modifier::BOLD),
    )))
    .block(block)
    .alignment(Alignment::Left);

    frame.render_widget(paragraph, area);
}

pub fn render_input_popup(
    frame: &mut Frame,
    area: Rect,
    input: &str,
    cursor: usize,
) {
    let popup_area = centered_rect(60, 3, area);
    let block = Block::default()
        .borders(Borders::ALL)
        .style(Style::default().bg(POPUP_BG))
        .border_style(Style::default().fg(POPUP_BORDER))
        .title(" Input ")
        .title_alignment(Alignment::Left);

    let paragraph = Paragraph::new(Text::from(Line::from(Span::raw(input))))
        .block(block);

    frame.render_widget(paragraph, popup_area);
    frame.set_cursor_position(ratatui::layout::Position::new(
        popup_area.x + 1 + cursor as u16,
        popup_area.y + 1,
    ));
}

pub fn render_date_picker(
    frame: &mut Frame,
    area: Rect,
    date: chrono::NaiveDateTime,
) {
    let popup_area = centered_rect(50, 7, area);
    let block = Block::default()
        .borders(Borders::ALL)
        .style(Style::default().bg(POPUP_BG))
        .border_style(Style::default().fg(POPUP_BORDER))
        .title(" Date Picker ")
        .title_alignment(Alignment::Left);

    let date_str = date.format("%Y-%m-%d %H:%M").to_string();
    let text = Text::from(vec![
        Line::from(Span::raw("Edit date/time:")),
        Line::from(""),
        Line::from(Span::styled(
            format!("  {}  ", date_str),
            Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD),
        )),
        Line::from(""),
        Line::from(Span::styled(
            " Tab:next field  Up/Down:change  Enter:ok  Esc:cancel",
            Style::default().fg(Color::DarkGray),
        )),
    ]);

    let paragraph = Paragraph::new(text)
        .block(block)
        .alignment(Alignment::Center);

    frame.render_widget(paragraph, popup_area);
}

pub fn render_confirm_popup(frame: &mut Frame, area: Rect) {
    let popup_area = centered_rect(40, 5, area);
    let block = Block::default()
        .borders(Borders::ALL)
        .style(Style::default().bg(POPUP_BG))
        .border_style(Style::default().fg(Color::Red))
        .title(" Confirm ")
        .title_alignment(Alignment::Left);

    let text = Text::from(vec![
        Line::from(""),
        Line::from(Span::styled(
            " Delete this item? ",
            Style::default().fg(Color::Red).add_modifier(Modifier::BOLD),
        )),
        Line::from(""),
        Line::from(Span::styled(
            " Enter:confirm  Esc:cancel ",
            Style::default().fg(Color::DarkGray),
        )),
    ]);

    let paragraph = Paragraph::new(text)
        .block(block)
        .alignment(Alignment::Center);

    frame.render_widget(paragraph, popup_area);
}

pub fn render_device_auth_popup(
    frame: &mut Frame,
    area: Rect,
    url: &str,
    _code: &str,
    error: Option<&str>,
) {
    let popup_area = centered_rect(80, 13, area);

    let border_color = if error.is_some() {
        Color::Red
    } else if url == "starting..." || !url.is_empty() {
        Color::Yellow
    } else {
        POPUP_BORDER
    };

    let block = Block::default()
        .borders(Borders::ALL)
        .style(Style::default().bg(POPUP_BG))
        .border_style(Style::default().fg(border_color))
        .title(" Google Tasks - Authorization ")
        .title_alignment(Alignment::Left);

    let mut lines = Vec::new();

    if let Some(err) = error {
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " Authorization Error ",
            Style::default().fg(Color::Red).add_modifier(Modifier::BOLD),
        )));
        lines.push(Line::from(""));
        let wrapped = textwrap(&err, 50);
        for line in wrapped {
            lines.push(Line::from(Span::styled(
                line,
                Style::default().fg(Color::White),
            )));
        }
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " Press Enter to retry | Esc to cancel ",
            Style::default().fg(Color::DarkGray),
        )));
    } else if url == "starting..." || !url.is_empty() {
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " Authorization in progress... ",
            Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD),
        )));
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " A browser tab should open automatically. ",
            Style::default().fg(Color::White),
        )));
        lines.push(Line::from(Span::styled(
            " If not, check that GOOGLE_CLIENT_ID and ",
            Style::default().fg(Color::DarkGray),
        )));
        lines.push(Line::from(Span::styled(
            " GOOGLE_CLIENT_SECRET are set correctly. ",
            Style::default().fg(Color::DarkGray),
        )));
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " (Esc to cancel) ",
            Style::default().fg(Color::DarkGray),
        )));
    } else {
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " Google Tasks Authorization ",
            Style::default().fg(Color::White).add_modifier(Modifier::BOLD),
        )));
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " This app needs access to your Google Tasks. ",
            Style::default().fg(Color::White),
        )));
        lines.push(Line::from(""));
        lines.push(Line::from(Span::styled(
            " Press Enter to start ",
            Style::default().fg(Color::Cyan),
        )));
        lines.push(Line::from(Span::styled(
            " Press Esc to skip ",
            Style::default().fg(Color::DarkGray),
        )));
    }

    let paragraph = Paragraph::new(Text::from(lines))
        .block(block)
        .alignment(Alignment::Left);

    frame.render_widget(paragraph, popup_area);
}

/// Simple word wrap: splits text at word boundaries to fit max_width chars per line
fn textwrap(text: &str, max_width: usize) -> Vec<String> {
    let mut result = Vec::new();
    let mut current = String::new();
    for word in text.split_whitespace() {
        if current.len() + word.len() + 1 > max_width && !current.is_empty() {
            result.push(current.clone());
            current.clear();
        }
        if !current.is_empty() {
            current.push(' ');
        }
        current.push_str(word);
    }
    if !current.is_empty() {
        result.push(current);
    }
    result
}

fn centered_rect(percent_x: u16, percent_y: u16, area: Rect) -> Rect {
    let popup_layout = ratatui::layout::Layout::default()
        .direction(ratatui::layout::Direction::Vertical)
        .constraints([
            ratatui::layout::Constraint::Length((area.height.saturating_sub(percent_y)) / 2),
            ratatui::layout::Constraint::Length(percent_y),
            ratatui::layout::Constraint::Min(0),
        ])
        .split(area);

    ratatui::layout::Layout::default()
        .direction(ratatui::layout::Direction::Horizontal)
        .constraints([
            ratatui::layout::Constraint::Length((area.width.saturating_sub(percent_x)) / 2),
            ratatui::layout::Constraint::Length(percent_x),
            ratatui::layout::Constraint::Min(0),
        ])
        .split(popup_layout[1])[1]
}