<?php

namespace App\Service\business;

/**
 * 把预设的紧凑规格展开成完整设计令牌
 *
 * 20 套模板真正的差异在四条轴上：配色、字体与字号梯度、圆角与阴影、动效曲线与时长。
 * 这里把后三条做成可复用的档位，预设只需要挑档位，避免 20 份 JSON 手抄跑偏，
 * 也让「再加一套模板」变成加十几行配置而不是重写一份主题。
 */
class WxTemplatePresetService
{
    private static mixed $_instance;

    /**
     * 字体与字号梯度档位（单位 rpx，小程序习惯用 rpx）
     */
    private const SCALES = [
        'serif-elegant' => [
            'family' => 'Songti SC, Noto Serif SC, serif',
            'family_title' => 'Songti SC, Noto Serif SC, serif',
            'size_xs' => '20rpx', 'size_sm' => '24rpx', 'size_md' => '28rpx',
            'size_lg' => '34rpx', 'size_xl' => '42rpx', 'size_title' => '52rpx',
            'weight_normal' => '400', 'weight_bold' => '600',
            'line_height' => '1.7', 'letter_spacing' => '1rpx',
        ],
        'serif-book' => [
            'family' => 'Noto Serif SC, Georgia, serif',
            'family_title' => 'Noto Serif SC, Georgia, serif',
            'size_xs' => '22rpx', 'size_sm' => '26rpx', 'size_md' => '30rpx',
            'size_lg' => '34rpx', 'size_xl' => '40rpx', 'size_title' => '48rpx',
            'weight_normal' => '400', 'weight_bold' => '700',
            'line_height' => '1.8', 'letter_spacing' => '0',
        ],
        'sans-refined' => [
            'family' => 'PingFang SC, HarmonyOS Sans, sans-serif',
            'family_title' => 'PingFang SC, HarmonyOS Sans, sans-serif',
            'size_xs' => '20rpx', 'size_sm' => '24rpx', 'size_md' => '28rpx',
            'size_lg' => '32rpx', 'size_xl' => '40rpx', 'size_title' => '48rpx',
            'weight_normal' => '400', 'weight_bold' => '600',
            'line_height' => '1.6', 'letter_spacing' => '0',
        ],
        'sans-compact' => [
            'family' => 'PingFang SC, Roboto, sans-serif',
            'family_title' => 'PingFang SC, Roboto, sans-serif',
            'size_xs' => '18rpx', 'size_sm' => '22rpx', 'size_md' => '26rpx',
            'size_lg' => '30rpx', 'size_xl' => '36rpx', 'size_title' => '42rpx',
            'weight_normal' => '400', 'weight_bold' => '700',
            'line_height' => '1.5', 'letter_spacing' => '0',
        ],
        'sans-wide' => [
            'family' => 'PingFang SC, Inter, sans-serif',
            'family_title' => 'PingFang SC, Inter, sans-serif',
            'size_xs' => '22rpx', 'size_sm' => '26rpx', 'size_md' => '30rpx',
            'size_lg' => '36rpx', 'size_xl' => '44rpx', 'size_title' => '56rpx',
            'weight_normal' => '400', 'weight_bold' => '700',
            'line_height' => '1.6', 'letter_spacing' => '2rpx',
        ],
    ];

    private const RADIUS = [
        'none' => ['none' => '0', 'sm' => '0', 'md' => '0', 'lg' => '0', 'xl' => '0', 'pill' => '0'],
        'sharp' => ['none' => '0', 'sm' => '2rpx', 'md' => '4rpx', 'lg' => '8rpx', 'xl' => '12rpx', 'pill' => '999rpx'],
        'soft' => ['none' => '0', 'sm' => '8rpx', 'md' => '12rpx', 'lg' => '20rpx', 'xl' => '28rpx', 'pill' => '999rpx'],
        'round' => ['none' => '0', 'sm' => '12rpx', 'md' => '20rpx', 'lg' => '32rpx', 'xl' => '44rpx', 'pill' => '999rpx'],
        'pill' => ['none' => '0', 'sm' => '20rpx', 'md' => '32rpx', 'lg' => '48rpx', 'xl' => '64rpx', 'pill' => '999rpx'],
    ];

    private const SHADOW = [
        'flat' => ['none' => 'none', 'sm' => 'none', 'md' => 'none', 'lg' => 'none'],
        'airy' => ['none' => 'none', 'sm' => '0 2rpx 8rpx rgba(0,0,0,0.04)', 'md' => '0 8rpx 24rpx rgba(0,0,0,0.06)', 'lg' => '0 16rpx 48rpx rgba(0,0,0,0.08)'],
        'soft' => ['none' => 'none', 'sm' => '0 2rpx 8rpx rgba(0,0,0,0.06)', 'md' => '0 8rpx 20rpx rgba(0,0,0,0.10)', 'lg' => '0 16rpx 40rpx rgba(0,0,0,0.14)'],
        'deep' => ['none' => 'none', 'sm' => '0 4rpx 12rpx rgba(0,0,0,0.16)', 'md' => '0 12rpx 32rpx rgba(0,0,0,0.24)', 'lg' => '0 24rpx 64rpx rgba(0,0,0,0.32)'],
    ];

    private const MOTION = [
        'snappy' => ['fast' => '120ms', 'base' => '180ms', 'slow' => '260ms', 'easing' => 'cubic-bezier(0.4,0,0.2,1)', 'easing_in' => 'cubic-bezier(0.4,0,1,1)', 'easing_out' => 'cubic-bezier(0,0,0.2,1)'],
        'gentle' => ['fast' => '180ms', 'base' => '260ms', 'slow' => '400ms', 'easing' => 'cubic-bezier(0.25,0.1,0.25,1)', 'easing_in' => 'cubic-bezier(0.42,0,1,1)', 'easing_out' => 'cubic-bezier(0,0,0.58,1)'],
        'silk' => ['fast' => '220ms', 'base' => '320ms', 'slow' => '520ms', 'easing' => 'cubic-bezier(0.22,1,0.36,1)', 'easing_in' => 'cubic-bezier(0.55,0,1,0.45)', 'easing_out' => 'cubic-bezier(0.16,1,0.3,1)'],
        'bouncy' => ['fast' => '160ms', 'base' => '280ms', 'slow' => '460ms', 'easing' => 'cubic-bezier(0.34,1.56,0.64,1)', 'easing_in' => 'cubic-bezier(0.36,0,0.66,-0.56)', 'easing_out' => 'cubic-bezier(0.34,1.56,0.64,1)'],
    ];

    private const SPACE = [
        'xxs' => '4rpx', 'xs' => '8rpx', 'sm' => '16rpx',
        'md' => '24rpx', 'lg' => '32rpx', 'xl' => '48rpx', 'page' => '32rpx',
    ];

    public static function getInstance(): null|static
    {
        $name = get_called_class();
        if (!isset(self::$_instance[$name])) {
            self::$_instance[$name] = new static();
        }
        return self::$_instance[$name];
    }

    /**
     * 全部预设，已展开成入库可用的行
     *
     * @return array<int, array{code:string,name:string,style_tag:string,tokens:array,layout:array}>
     */
    public function all(): array
    {
        $rows = [];
        foreach ((array) config('wx_templates', []) as $index => $preset) {
            $rows[] = [
                'code' => (string) $preset['code'],
                'name' => (string) $preset['name'],
                'style_tag' => (string) ($preset['style_tag'] ?? ''),
                'sort' => $index,
                'tokens' => $this->expandTokens($preset),
                'layout' => (array) ($preset['layout'] ?? []),
            ];
        }
        return $rows;
    }

    /**
     * 展开单个预设的令牌
     */
    public function expandTokens(array $preset): array
    {
        $palette = (array) ($preset['palette'] ?? []);
        $primary = (string) ($palette['primary'] ?? '#B08D57');
        $isDark = $this->isDark((string) ($palette['bg'] ?? '#FFFFFF'));
        return [
            'color' => [
                'primary' => $primary,
                'primary_soft' => $this->mix($primary, $isDark ? '#000000' : '#FFFFFF', 0.7),
                'primary_strong' => $this->mix($primary, '#000000', 0.2),
                'accent' => (string) ($palette['accent'] ?? $primary),
                'bg' => (string) ($palette['bg'] ?? '#FFFFFF'),
                'bg_soft' => $this->mix((string) ($palette['bg'] ?? '#FFFFFF'), $isDark ? '#FFFFFF' : '#000000', 0.04),
                'surface' => (string) ($palette['surface'] ?? '#FFFFFF'),
                'surface_soft' => $this->mix((string) ($palette['surface'] ?? '#FFFFFF'), $isDark ? '#FFFFFF' : '#000000', 0.03),
                'text' => (string) ($palette['text'] ?? '#18181B'),
                'text_soft' => $this->mix((string) ($palette['text'] ?? '#18181B'), (string) ($palette['bg'] ?? '#FFFFFF'), 0.25),
                'text_muted' => $this->mix((string) ($palette['text'] ?? '#18181B'), (string) ($palette['bg'] ?? '#FFFFFF'), 0.5),
                'border' => (string) ($palette['border'] ?? '#E4E4E7'),
                // 价格用主色的强化版，保证在浅色与深色底上都够醒目
                'price' => $this->mix($primary, '#000000', $isDark ? 0 : 0.12),
                'success' => '#16A34A',
                'warning' => '#D97706',
                'danger' => '#DC2626',
                'mask' => $isDark ? 'rgba(0,0,0,0.72)' : 'rgba(0,0,0,0.45)',
            ],
            'font' => self::SCALES[$preset['scale'] ?? 'sans-refined'] ?? self::SCALES['sans-refined'],
            'radius' => self::RADIUS[$preset['radius'] ?? 'soft'] ?? self::RADIUS['soft'],
            'shadow' => self::SHADOW[$preset['shadow'] ?? 'soft'] ?? self::SHADOW['soft'],
            'space' => self::SPACE,
            'motion' => self::MOTION[$preset['motion'] ?? 'gentle'] ?? self::MOTION['gentle'],
        ];
    }

    /**
     * 两色按比例混合，用来派生 soft / strong 变体
     *
     * @param float $ratio target 的占比
     */
    private function mix(string $color, string $target, float $ratio): string
    {
        [$r1, $g1, $b1] = $this->toRgb($color);
        [$r2, $g2, $b2] = $this->toRgb($target);
        $ratio = max(0, min(1, $ratio));
        return sprintf(
            '#%02X%02X%02X',
            (int) round($r1 + ($r2 - $r1) * $ratio),
            (int) round($g1 + ($g2 - $g1) * $ratio),
            (int) round($b1 + ($b2 - $b1) * $ratio)
        );
    }

    private function isDark(string $color): bool
    {
        [$r, $g, $b] = $this->toRgb($color);
        // 感知亮度，低于 128 视作深色底
        return (0.299 * $r + 0.587 * $g + 0.114 * $b) < 128;
    }

    /**
     * @return array{0:int,1:int,2:int}
     */
    private function toRgb(string $color): array
    {
        $hex = ltrim(trim($color), '#');
        if (strlen($hex) === 3) {
            $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
        }
        if (strlen($hex) !== 6 || !ctype_xdigit($hex)) {
            return [255, 255, 255];
        }
        return [
            (int) hexdec(substr($hex, 0, 2)),
            (int) hexdec(substr($hex, 2, 2)),
            (int) hexdec(substr($hex, 4, 2)),
        ];
    }
}