//! Play-mode status sidebar widget for kiln-tui.
//!
//! [`StatusSidebarWidget`] draws the player's persistent stats (health + gems)
//! in a bordered block on the left of the screen during play. It is purely
//! presentational: it reads `health`/`gems` values handed in at construction and
//! never mutates game state.

use crate::utils::rgba8_to_color;
use kiln_core::Archetype;
use kiln_core::cp437::tile_to_char;
use ratatui::buffer::Buffer;
use ratatui::layout::Rect;
use ratatui::style::{Color, Style};
use ratatui::symbols::merge::MergeStrategy;
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Paragraph, Widget};

/// How many hearts the health row always shows (the player's max health).
const MAX_HEARTS: u32 = 5;
/// A filled heart: bright red.
const HEART_FULL: Color = Color::Rgb(255, 0, 0);
/// A depleted heart: dark red.
const HEART_EMPTY: Color = Color::Rgb(90, 0, 0);

/// A ratatui widget that renders the play-mode status sidebar.
///
/// Shows a `Health:` label above a row of [`MAX_HEARTS`] heart glyphs (the first
/// `health` filled bright red, the rest dark red) and a `Gems: ♦ N` line.
pub struct StatusSidebarWidget {
    /// The player's current health, clamped to [`MAX_HEARTS`] when drawn.
    health: u32,
    /// The number of gems collected, shown as a count.
    gems: u32,
}

impl StatusSidebarWidget {
    /// Builds a sidebar widget for the given player stats.
    pub fn new(health: u32, gems: u32) -> Self {
        Self { health, gems }
    }
}

impl Widget for StatusSidebarWidget {
    fn render(self, area: Rect, buf: &mut Buffer) {
        // One bright-red span per filled heart, dark-red for the rest, so a
        // partly-depleted bar reads at a glance.
        let filled = self.health.min(MAX_HEARTS);
        let hearts: Vec<Span> = (0..MAX_HEARTS)
            .map(|i| {
                let color = if i < filled { HEART_FULL } else { HEART_EMPTY };
                Span::styled("♥", Style::default().fg(color))
            })
            .collect();

        // Draw the gem indicator from the gem archetype's default glyph, so the
        // sidebar matches what gems look like on the board (no hardcoded ♦/color).
        let gem_glyph = Archetype::Gem.default_glyph();
        let gem_char = tile_to_char(gem_glyph.tile).to_string();
        let gem_style = Style::default().fg(rgba8_to_color(gem_glyph.fg));

        let lines = vec![
            Line::from("Health:"),
            Line::from(hearts),
            Line::from(""),
            Line::from(vec![
                Span::raw("Gems: "),
                Span::styled(gem_char, gem_style),
                Span::raw(format!(" {}", self.gems)),
            ]),
        ];

        // A bordered block; `merge_borders` joins its right edge with the board
        // block's left edge where the layout overlaps them by one column.
        let block = Block::bordered()
            .title(" Status (tab) ")
            .merge_borders(MergeStrategy::Exact);
        Paragraph::new(lines).block(block).render(area, buf);
    }
}