//! Collections management screen — list collections.

use makeover_tui::makeover_layout::{Column, Priority, Width};
use makeover_tui::table::{self, Cell, Sizing, TableStyle};
use ratatui::Frame;
use ratatui::layout::{Constraint, Layout};
use ratatui::style::{Modifier, Style};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Borders, Paragraph, TableState};

use super::App;

/// The collection columns. The title names the collection; whether it is public
/// is the next thing asked of it. The slug and the count drop first.
const COLLECTION_COLUMNS: [Column<'static>; 4] = [
    Column {
        name: "Title",
        width: Width::Fill,
        priority: Priority::Essential,
        sortable: false,
        sorted: None,
    },
    Column {
        name: "Slug",
        width: Width::Fixed,
        priority: Priority::Optional,
        sortable: false,
        sorted: None,
    },
    Column {
        name: "Status",
        width: Width::Fixed,
        priority: Priority::Secondary,
        sortable: false,
        sorted: None,
    },
    Column {
        name: "Items",
        width: Width::Fixed,
        priority: Priority::Optional,
        sortable: false,
        sorted: None,
    },
];

/// The tracks the hand-written `Constraint`s carried.
const COLLECTION_SIZING: Sizing<'static> = Sizing {
    lengths: &[("Title", 20), ("Slug", 20), ("Status", 8), ("Items", 6)],
    fallback: 8,
};

pub(crate) fn render(frame: &mut Frame, app: &App) {
    let area = frame.area();

    let title = Line::from(vec![
        Span::styled(
            " Makenot.work ",
            Style::default().add_modifier(Modifier::BOLD),
        ),
        Span::raw(" -- "),
        Span::styled("Collections", Style::default().add_modifier(Modifier::BOLD)),
        Span::raw(" "),
    ]);

    let block = Block::default()
        .title(title)
        .borders(Borders::ALL)
        .border_style(Style::default().fg(app.theme.line_border));

    let inner = block.inner(area);
    frame.render_widget(block, area);

    let chunks = Layout::vertical([
        Constraint::Length(1), // spacer
        Constraint::Length(1), // section header
        Constraint::Min(3),    // list
        Constraint::Length(1), // status line
        Constraint::Length(1), // keybindings
    ])
    .split(inner);

    let count = app.collections.len();
    let header = Paragraph::new(Line::from(vec![
        Span::raw("  "),
        Span::styled("Collections", Style::default().add_modifier(Modifier::BOLD)),
        if count == 0 {
            Span::raw("")
        } else {
            Span::raw(format!(" ({count})"))
        },
    ]));
    frame.render_widget(header, chunks[1]);

    if app.loading {
        let loading = Paragraph::new("  Loading...");
        frame.render_widget(loading, chunks[2]);
    } else if app.collections.is_empty() {
        let empty =
            Paragraph::new("  No collections. Manage collections at makenot.work/dashboard");
        frame.render_widget(empty, chunks[2]);
    } else {
        let area = super::indent(chunks[2], 2);
        let rows: Vec<Vec<Cell>> = app
            .collections
            .iter()
            .map(|c| {
                vec![
                    Cell::new("Title", c.title.as_str()),
                    Cell::new("Slug", c.slug.as_str()),
                    Cell::new("Status", if c.is_public { "public" } else { "draft" }),
                    Cell::new("Items", c.item_count.to_string()),
                ]
            })
            .collect();

        let style = TableStyle::from_theme(&app.theme);
        let table = table::table(
            &COLLECTION_COLUMNS,
            &rows,
            &COLLECTION_SIZING,
            &style,
            area.width,
        );
        let mut state = TableState::default().with_selected(Some(app.selected_index));
        frame.render_stateful_widget(table, area, &mut state);
    }

    if let Some(ref status) = app.collections_status {
        let style = if status.starts_with("Error") {
            Style::default().fg(app.theme.status_danger)
        } else {
            Style::default().fg(app.theme.status_success)
        };
        let status_line = Paragraph::new(format!("  {status}")).style(style);
        frame.render_widget(status_line, chunks[3]);
    }

    let key_spans = vec![
        Span::raw("  "),
        Span::styled("[j/k]", Style::default().add_modifier(Modifier::BOLD)),
        Span::raw(" Nav  "),
        Span::styled("[r]", Style::default().add_modifier(Modifier::BOLD)),
        Span::raw(" Refresh  "),
        Span::styled("[Esc]", Style::default().add_modifier(Modifier::BOLD)),
        Span::raw(" Back"),
    ];

    let keys =
        Paragraph::new(Line::from(key_spans)).style(Style::default().fg(app.theme.content_muted));
    frame.render_widget(keys, chunks[4]);
}