//! Color emoji rendering with COLR/CPAL support
//!
//! Implements layered color emoji rendering using OpenType COLR and CPAL tables.
//! Note: Full COLR/CPAL support requires ttf-parser with these features enabled.

use super::Font;
use crate::Color;
use std::collections::HashMap;

/// A single color layer in a COLR glyph
#[derive(Debug, Clone)]
pub struct ColorLayer {
    /// Glyph ID for this layer
    pub glyph_id: u16,

    /// Color for this layer
    pub color: Color,

    /// Palette index (for dynamic palette switching)
    pub palette_index: u16,
}

/// Color emoji renderer handling COLR/CPAL tables
pub struct ColorEmojiRenderer {
    /// Cache of parsed color layers for glyphs
    layer_cache: HashMap<u16, Vec<ColorLayer>>,
}

impl ColorEmojiRenderer {
    /// Create a new color emoji renderer
    pub fn new() -> Self {
        Self {
            layer_cache: HashMap::new(),
        }
    }

    /// Check if a glyph has color layers (stub - requires extended ttf-parser features)
    pub fn has_color_layers(&self, _font: &Font, _glyph_id: u16) -> bool {
        // Note: Full implementation requires ttf-parser with COLR table support
        // This is a stub for now
        false
    }

    /// Extract color layers for a glyph using COLR/CPAL tables
    ///
    /// Note: This is a stub implementation. Full COLR/CPAL support requires
    /// additional ttf-parser features or a custom table parser.
    pub fn get_color_layers(
        &mut self,
        _font: &Font,
        _glyph_id: u16,
        _palette_index: u16,
    ) -> Option<Vec<ColorLayer>> {
        // Stub - would parse COLR/CPAL tables here
        None
    }

    /// Get number of available color palettes (stub)
    pub fn num_palettes(&self, _font: &Font) -> u16 {
        // Stub - would check CPAL table
        0
    }

    /// Clear the layer cache
    pub fn clear_cache(&mut self) {
        self.layer_cache.clear();
    }
}

impl Default for ColorEmojiRenderer {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_color_emoji_renderer() {
        let renderer = ColorEmojiRenderer::new();
        assert_eq!(renderer.layer_cache.len(), 0);
    }
}
