<?php

namespace App\Utils;

class ImageAspectRatioDetector
{
    /**
     * Detect the aspect ratio of an image from its URL
     *
     * @param string $imageUrl The URL of the image to analyze
     * @return float|null The aspect ratio (width/height) or null if detection fails
     */
    public static function detectAspectRatio(string $imageUrl): ?float
    {
        if (empty($imageUrl)) {
            return null;
        }

        // Handle local images (relative URLs)
        if (!filter_var($imageUrl, FILTER_VALIDATE_URL)) {
            $imageUrl = self::resolveLocalImagePath($imageUrl);
        }

        try {
            // Get image dimensions
            $imageInfo = @getimagesize($imageUrl);

            if (!$imageInfo) {
                return null;
            }

            $width = $imageInfo[0];
            $height = $imageInfo[1];

            if ($width <= 0 || $height <= 0) {
                return null;
            }

            // Calculate aspect ratio (width/height)
            $aspectRatio = round($width / $height, 3);

            // Validate aspect ratio is reasonable (between 0.1 and 10)
            if ($aspectRatio < 0.1 || $aspectRatio > 10) {
                return null;
            }

            return $aspectRatio;

        } catch (\Exception $e) {
            // Log error but don't throw - aspect ratio detection should be non-blocking
            error_log("Failed to detect aspect ratio for image {$imageUrl}: " . $e->getMessage());
            return null;
        }
    }

    /**
     * Resolve local image path for getimagesize
     *
     * @param string $relativeUrl The relative URL of the image
     * @return string The absolute file path
     */
    private static function resolveLocalImagePath(string $relativeUrl): string
    {
        // Remove leading slash if present
        $relativeUrl = ltrim($relativeUrl, '/');

        // Define common image directories
        $possiblePaths = [
            __DIR__ . '/../../public/' . $relativeUrl,
            __DIR__ . '/../../public/images/' . $relativeUrl,
            __DIR__ . '/../../public/media/' . $relativeUrl,
            __DIR__ . '/../../storage/' . $relativeUrl,
        ];

        foreach ($possiblePaths as $path) {
            if (file_exists($path)) {
                return $path;
            }
        }

        // If no local file found, return the original URL (might be external)
        return $relativeUrl;
    }

    /**
     * Get a CSS aspect ratio class based on the aspect ratio value
     *
     * @param float|null $aspectRatio The aspect ratio value
     * @param string $defaultClass The default class to use if aspect ratio is null
     * @return string The CSS class for the aspect ratio
     */
    public static function getAspectRatioClass(?float $aspectRatio, string $defaultClass = 'aspect-[1/1]'): string
    {
        if ($aspectRatio === null) {
            return $defaultClass;
        }

        // Common aspect ratios with nice round numbers
        if (abs($aspectRatio - 1.333) < 0.05) { // 4:3
            return 'aspect-[4/3]';
        } elseif (abs($aspectRatio - 1.5) < 0.05) { // 3:2
            return 'aspect-[3/2]';
        } elseif (abs($aspectRatio - 1.667) < 0.05) { // 5:3
            return 'aspect-[5/3]';
        } elseif (abs($aspectRatio - 1.778) < 0.05) { // 16:9
            return 'aspect-[16/9]';
        } elseif (abs($aspectRatio - 0.667) < 0.05) { // 2:3
            return 'aspect-[2/3]';
        } elseif (abs($aspectRatio - 0.75) < 0.05) { // 3:4
            return 'aspect-[3/4]';
        } elseif (abs($aspectRatio - 1.0) < 0.05) { // 1:1
            return 'aspect-[1/1]';
        }

        // For other ratios, use a custom aspect ratio class
        // Tailwind doesn't support dynamic aspect ratios, so we'll use a data attribute approach
        return 'aspect-custom';
    }

    /**
     * Get inline styles for custom aspect ratios
     *
     * @param float|null $aspectRatio The aspect ratio value
     * @return string CSS style string for custom aspect ratios
     */
    public static function getCustomAspectRatioStyle(?float $aspectRatio): string
    {
        if ($aspectRatio === null) {
            return '';
        }

        // Convert aspect ratio to padding-bottom percentage for aspect ratio simulation
        $paddingBottom = (1 / $aspectRatio) * 100;
        return "padding-bottom: {$paddingBottom}%;";
    }

    /**
     * Batch detect aspect ratios for multiple images
     *
     * @param array $imageUrls Array of image URLs
     * @return array Array of aspect ratios corresponding to the input URLs
     */
    public static function batchDetectAspectRatios(array $imageUrls): array
    {
        $aspectRatios = [];

        foreach ($imageUrls as $url) {
            $aspectRatios[] = self::detectAspectRatio($url);
        }

        return $aspectRatios;
    }

    /**
     * Validate if an aspect ratio value is reasonable
     *
     * @param float $aspectRatio The aspect ratio to validate
     * @return bool True if the aspect ratio is valid
     */
    public static function isValidAspectRatio(float $aspectRatio): bool
    {
        return $aspectRatio > 0.1 && $aspectRatio < 10;
    }
}