//! Item detail screen — view/edit item fields, versions, publish status.

use ratatui::Frame;
use ratatui::layout::{Constraint, Layout};
use ratatui::style::{Color, Modifier, Style};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Borders, Paragraph, Row};

use crate::api::ItemDetail;
use crate::format;
use crate::staging;

use super::App;
use super::widgets;

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

    let item = match &app.item_detail {
        Some(d) => d,
        None => {
            let loading = Paragraph::new("  Loading...");
            frame.render_widget(loading, area);
            return;
        }
    };

    let status_label = if item.is_public { "Published" } else { "Draft" };

    let title = Line::from(vec![
        Span::styled(" Makenot.work ", Style::default().add_modifier(Modifier::BOLD)),
        Span::raw(" -- "),
        Span::styled(&item.title, Style::default().add_modifier(Modifier::BOLD)),
        Span::raw(format!(" -- {} -- {} ", format::format_item_type(&item.item_type), status_label)),
    ]);

    let block = Block::default()
        .title(title)
        .borders(Borders::ALL)
        .border_style(Style::default().fg(Color::Gray));

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

    let chunks = Layout::vertical([
        Constraint::Length(1), // spacer
        Constraint::Length(7), // item info (6 fields + tags)
        Constraint::Length(1), // spacer
        Constraint::Length(1), // versions header
        Constraint::Min(3),   // versions list
        Constraint::Length(1), // status line
        Constraint::Length(1), // keybindings
    ])
    .split(inner);

    // Item info
    render_item_info(frame, app, item, chunks[1]);

    // Versions header
    let version_count = app.item_versions.len();
    let version_header = Paragraph::new(Line::from(vec![
        Span::raw("  "),
        Span::styled("Versions", Style::default().add_modifier(Modifier::BOLD)),
        if version_count == 0 {
            Span::raw("")
        } else {
            Span::raw(format!(" ({})", version_count))
        },
    ]));
    frame.render_widget(version_header, chunks[3]);

    // Versions list
    if app.loading {
        let loading = Paragraph::new("  Loading...");
        frame.render_widget(loading, chunks[4]);
    } else if app.item_versions.is_empty() {
        let empty = Paragraph::new("  No versions.");
        frame.render_widget(empty, chunks[4]);
    } else {
        render_versions_table(frame, app, chunks[4]);
    }

    // Status line
    if let Some(ref status) = app.item_status {
        let style = if status.starts_with("Error") {
            Style::default().fg(Color::Red)
        } else {
            Style::default().fg(Color::Green)
        };
        let status_line = Paragraph::new(Line::from(vec![
            Span::raw("  "),
            Span::styled(status.as_str(), style),
        ]));
        frame.render_widget(status_line, chunks[5]);
    }

    // Keybindings
    let mut key_spans = vec![Span::raw("  ")];

    if app.item_editing.is_some() {
        key_spans.extend([
            Span::styled("[Enter]", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" Confirm  "),
            Span::styled("[Esc]", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" Cancel"),
        ]);
    } else {
        key_spans.extend([
            Span::styled("[e]", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" Edit  "),
        ]);
        if item.is_public {
            key_spans.extend([
                Span::styled("[u]", Style::default().add_modifier(Modifier::BOLD)),
                Span::raw(" Unpublish  "),
            ]);
        } else {
            key_spans.extend([
                Span::styled("[p]", Style::default().add_modifier(Modifier::BOLD)),
                Span::raw(" Publish  "),
            ]);
        }
        key_spans.extend([
            Span::styled("[d]", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" Delete  "),
            Span::styled("[t]", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" Tag  "),
            Span::styled("[l]", Style::default().add_modifier(Modifier::BOLD)),
            Span::raw(" Keys  "),
            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(Color::DarkGray));
    frame.render_widget(keys, chunks[6]);
}

fn render_item_info(
    frame: &mut Frame,
    app: &App,
    item: &ItemDetail,
    area: ratatui::layout::Rect,
) {
    let price = format::format_price(item.price_cents);
    let desc_preview = item
        .description
        .as_deref()
        .unwrap_or("(no description)")
        .chars()
        .take(60)
        .collect::<String>();

    // Show edit indicator for editing field
    let editing = app.item_editing;
    let edit_marker = |field: ItemEditField| -> &str {
        if editing == Some(field) {
            "> "
        } else {
            "  "
        }
    };

    let lines = vec![
        Line::from(vec![
            Span::raw(edit_marker(ItemEditField::Title)),
            Span::styled("Title: ", Style::default().fg(Color::DarkGray)),
            if editing == Some(ItemEditField::Title) {
                Span::styled(
                    format!("{}_", app.edit_buffer),
                    Style::default().add_modifier(Modifier::UNDERLINED),
                )
            } else {
                Span::raw(item.title.clone())
            },
        ]),
        Line::from(vec![
            Span::raw(edit_marker(ItemEditField::Description)),
            Span::styled("Description: ", Style::default().fg(Color::DarkGray)),
            if editing == Some(ItemEditField::Description) {
                Span::styled(
                    format!("{}_", app.edit_buffer),
                    Style::default().add_modifier(Modifier::UNDERLINED),
                )
            } else {
                Span::raw(desc_preview)
            },
        ]),
        Line::from(vec![
            Span::raw(edit_marker(ItemEditField::Price)),
            Span::styled("Price: ", Style::default().fg(Color::DarkGray)),
            if editing == Some(ItemEditField::Price) {
                Span::styled(
                    format!("${}_", app.edit_buffer),
                    Style::default().add_modifier(Modifier::UNDERLINED),
                )
            } else {
                Span::raw(price)
            },
        ]),
        Line::from(vec![
            Span::raw("  "),
            Span::styled("Type: ", Style::default().fg(Color::DarkGray)),
            Span::raw(format::format_item_type(&item.item_type)),
            Span::raw("    "),
            Span::styled("Slug: ", Style::default().fg(Color::DarkGray)),
            Span::raw(item.slug.clone()),
        ]),
        Line::from(vec![
            Span::raw("  "),
            Span::styled("Sales: ", Style::default().fg(Color::DarkGray)),
            Span::raw(item.sales_count.to_string()),
            Span::raw("    "),
            Span::styled("Downloads: ", Style::default().fg(Color::DarkGray)),
            Span::raw(item.download_count.to_string()),
            if item.play_count > 0 {
                Span::raw(format!("    Plays: {}", item.play_count))
            } else {
                Span::raw("")
            },
        ]),
        Line::from(vec![
            Span::raw("  "),
            Span::styled("Audio: ", Style::default().fg(Color::DarkGray)),
            Span::raw(if item.has_audio { "yes" } else { "no" }),
            Span::raw("    "),
            Span::styled("Cover: ", Style::default().fg(Color::DarkGray)),
            Span::raw(if item.has_cover { "yes" } else { "no" }),
        ]),
        Line::from({
            let mut spans = vec![
                Span::raw("  "),
                Span::styled("Tags: ", Style::default().fg(Color::DarkGray)),
            ];
            if app.item_tags.is_empty() {
                spans.push(Span::styled("(none)", Style::default().fg(Color::DarkGray)));
            } else {
                for (i, tag) in app.item_tags.iter().enumerate() {
                    if i > 0 { spans.push(Span::raw(", ")); }
                    if tag.is_primary {
                        spans.push(Span::styled(&tag.name, Style::default().add_modifier(Modifier::BOLD)));
                    } else {
                        spans.push(Span::raw(&tag.name));
                    }
                }
            }
            spans
        }),
    ];

    let info = Paragraph::new(lines);
    frame.render_widget(info, area);
}

fn render_versions_table(frame: &mut Frame, app: &App, area: ratatui::layout::Rect) {
    let rows: Vec<Row> = app
        .item_versions
        .iter()
        .map(|v| {
            let current = if v.is_current { "*" } else { " " };
            let size = v
                .file_size_bytes
                .map(|b| staging::format_bytes(b as u64))
                .unwrap_or_else(|| "--".to_string());
            let name = v.file_name.as_deref().unwrap_or("--");
            let date = v.created_at.get(..10).unwrap_or(&v.created_at);

            Row::new(vec![
                format!("  {}{}", current, v.version_number),
                name.to_string(),
                size,
                v.download_count.to_string(),
                date.to_string(),
            ])
        })
        .collect();

    let widths = [
        Constraint::Length(12),
        Constraint::Min(16),
        Constraint::Length(10),
        Constraint::Length(10),
        Constraint::Length(12),
    ];

    widgets::render_table(frame, area, &["  Version", "File", "Size", "Downloads", "Date"], &widths, rows);
}

/// Which field is being edited on the item detail screen.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ItemEditField {
    Title,
    Description,
    Price,
}