// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

package notify

import (
	"image"
	_ "image/gif"
	_ "image/jpeg"
	_ "image/png"
	"os"
	"path/filepath"
	"strings"
)

// IconMaxPixels is the long-side bound at or below which a content image is
// treated as an icon rather than a preview. A themed icon or an application
// logo is 256 or less; a screenshot is far larger.
const IconMaxPixels = 256

// IsIconImage reports whether a content image should fill the app-icon slot
// instead of the large preview. Clients disagree about where the icon goes:
// kitty, mail and opencode send it through the content-image hint, while a
// screenshot uses the same hint. The hint is one of the icon forms when the
// client sent a theme name, when the resolved file is an SVG, or when a raster
// is small on both sides. raw is the value before ResolveIcon; resolved is the
// path it resolved to.
func IsIconImage(raw, resolved string) bool {
	if raw != "" && !strings.Contains(raw, "/") && !strings.HasPrefix(raw, "file:") {
		return true
	}
	if resolved == "" {
		return false
	}
	if strings.EqualFold(filepath.Ext(resolved), ".svg") {
		return true
	}
	f, err := os.Open(resolved)
	if err != nil {
		return false
	}
	defer f.Close()
	cfg, _, err := image.DecodeConfig(f)
	if err != nil {
		// A format without a registered decoder is not something we can size,
		// so it stays a preview rather than being silently dropped.
		return false
	}
	return cfg.Width <= IconMaxPixels && cfg.Height <= IconMaxPixels
}