/**
 * 站点配置结构化表单纯函数模块（docs/09 §3.1；docs/20 F6 扩展参数分区退役）。
 * 已知键与模板/Java 实际消费方对齐（docs/09 §0 键清单表）；
 * 未知键（字符串与非字符串）一律无损入 preserved 静默保留——不再提供「扩展参数」编辑区
 * （后端对未知键的宽容策略不变：不拦截、不渲染、不丢失）。
 * vitest 单测对象：siteConfigForm.spec.ts，不依赖组件挂载基建。
 */

export type SiteConfigGroup = "display" | "footer" | "seo" | "domain";

export interface SiteConfigFieldDef {
    key: string;
    label: string;
    group: SiteConfigGroup;
    placeholder?: string;
    tip?: string;
    multiline?: boolean;
    /** url: http(s) URL；host: 域名（不带协议）；asset: / 开头路径或 http(s) URL；text: 仅长度 */
    kind?: "text" | "url" | "host" | "asset";
    /** F5（docs/20）：asset 类字段的预览/占位框比例（favicon 1:1、二维码 4:3） */
    aspect?: "1:1" | "4:3";
    maxLength?: number;
}

/** 与后端 SiteService.validateConfigJson 的已知键约束保持一致 */
export const SITE_CONFIG_FIELD_DEFS: SiteConfigFieldDef[] = [
    {
        key: "logo", label: "站点 Logo", group: "display", kind: "asset", maxLength: 500,
        placeholder: "如 /yschcms/upload/2026/06/logo.png 或 https://…",
        tip: "门户顶栏与页脚品牌位展示；建议先在「附件管理」上传，复制路径填到这里。",
    },
    {
        key: "favicon", label: "浏览器图标 favicon", group: "display", kind: "asset", maxLength: 500, aspect: "1:1",
        placeholder: "如 /yschcms/upload/…/favicon.png（留空用主题内置图标）",
        tip: "浏览器标签页与收藏夹的小图标，不显示在页面正文中。",
    },
    {
        key: "slogan", label: "首页标语", group: "display", kind: "text", maxLength: 200,
        placeholder: "门户顶栏展示的一句话标语（可选）",
    },
    {
        key: "colleges_label", label: "院系下拉文案", group: "display", kind: "text", maxLength: 50,
        placeholder: "留空默认「专业院系」",
        tip: "门户右上「专业院系」下拉的文案；仅主站有效（下拉由院系子站生成）。",
    },
    {
        key: "contact", label: "联系方式", group: "footer", kind: "text", maxLength: 200, multiline: true,
        placeholder: "如：电话 0571-88888888 · 地址杭州市 XX 路 100 号",
        tip: "显示在页脚品牌区（页脚第一行位置）。",
    },
    {
        key: "footer_addresses", label: "多校区地址", group: "footer", kind: "text", maxLength: 500, multiline: true,
        placeholder: "一行一个校区，如：\nXX校区：杭州市 XX 路 100 号 邮编：310000",
        tip: "逐行展示在页脚品牌区旁；换行即分行（最多 500 字）。",
    },
    {
        key: "qr_wechat", label: "微信二维码", group: "footer", kind: "asset", maxLength: 500, aspect: "4:3",
        placeholder: "如 /yschcms/upload/…/qr-wechat.png（留空不展示）",
        tip: "页脚二维码，悬停放大预览；建议先在「附件管理」上传。",
    },
    {
        key: "qr_weibo", label: "微博二维码", group: "footer", kind: "asset", maxLength: 500, aspect: "4:3",
        placeholder: "如 /yschcms/upload/…/qr-weibo.png（留空不展示）",
        tip: "显示在页脚右侧二维码区，与微信二维码并排，悬停放大预览。",
    },
    {
        key: "social_wechat", label: "微信公众号", group: "footer", kind: "url", maxLength: 500,
        placeholder: "微信公众号主页链接，如 https://mp.weixin.qq.com/…（留空不展示图标）",
        tip: "页脚社媒图标行（点击跳转链接地址）。",
    },
    {
        key: "social_weibo", label: "微博", group: "footer", kind: "url", maxLength: 500,
        placeholder: "微博主页链接 https://weibo.com/…（留空不展示图标）",
        tip: "页脚社媒图标行（点击跳转链接地址）。",
    },
    {
        key: "social_douyin", label: "抖音", group: "footer", kind: "url", maxLength: 500,
        placeholder: "抖音主页链接 https://www.douyin.com/…（留空不展示图标）",
        tip: "页脚社媒图标行（点击跳转链接地址）。",
    },
    {
        key: "social_bilibili", label: "哔哩哔哩", group: "footer", kind: "url", maxLength: 500,
        placeholder: "B 站主页链接 https://space.bilibili.com/…（留空不展示图标）",
        tip: "页脚社媒图标行（点击跳转链接地址）。",
    },
    {
        key: "copyright", label: "版权文字", group: "footer", kind: "text", maxLength: 200,
        placeholder: "如：XX学校 · 版权所有 © 2026",
        tip: "页脚最底行的版权声明文字。",
    },
    {
        key: "beian", label: "备案号", group: "footer", kind: "text", maxLength: 100,
        placeholder: "如：浙ICP备XXXXXXXX号-1",
        tip: "页脚最底行版权文字旁的 ICP 备案号（可点击性质由模板决定，通常为纯文字）。",
    },
    {
        key: "seo_description", label: "SEO 描述", group: "seo", kind: "text", maxLength: 500, multiline: true,
        placeholder: "搜索引擎摘要（meta description，建议 80~160 字）",
    },
    {
        key: "domain", label: "绑定域名", group: "domain", kind: "host", maxLength: 200,
        placeholder: "如 www.xxx.edu.cn（不带 https://）",
        tip: "学校独立域名台账；DNS 解析生效后需配合填写对外基地址。",
    },
    {
        key: "public_base_url", label: "对外基地址", group: "domain", kind: "url", maxLength: 500,
        placeholder: "如 https://www.xxx.edu.cn",
        tip: "绑定独立域名后必填；未填时全站链接走 base 域子路径形态（/yschcms/portal/{站点编码}）。",
    },
    {
        key: "svc_hall_base", label: "服务大厅基地址", group: "domain", kind: "url", maxLength: 500,
        placeholder: "如 https://svhall.xxx.edu.cn（留空不生成「我要办理」链接）",
        tip: "事项指南页「我要办理」按钮：事项单独配置的外链优先；未单独配置时用本地址生成服务大厅发起页（/#/apply?siteCode=…&itemCode=…）。",
    },
];

export const SITE_CONFIG_GROUPS: { name: SiteConfigGroup; title: string }[] = [
    { name: "display", title: "基础展示" },
    { name: "footer", title: "页脚信息" },
    { name: "seo", title: "SEO" },
    { name: "domain", title: "域名与访问" },
];

/**
 * 系统托管键：不进表单，解析时原样保留、序列化时无损回写（theme_params 由主题参数表单维护；
 * custom_css 由站点设置「皮肤与外观」分区维护）。
 */
export const RESERVED_SITE_CONFIG_KEYS = ["theme_params", "custom_css"];

/**
 * docs/16 D4 被吸收的旧键：画廊标题/副题、新闻卡背景图改由首页布局区块属性承载（home_layout），
 * 分区表单不再展示；存量值静默保留（渲染端仍作区块未设 title/background 时的默认值）。
 */
export const ABSORBED_LEGACY_KEYS = ["gallery_title", "gallery_subtitle", "news_bg_image"];

/** 扩展键名约束（与后端 CONFIG_KEY_PATTERN 一致；供后续功能键落位时复用） */
export const EXTRA_KEY_RE = /^[A-Za-z_][A-Za-z0-9_]*$/;

export const HOST_RE = /^(\*\.)?[A-Za-z0-9]([A-Za-z0-9-]*[A-Za-z0-9])?(\.[A-Za-z0-9]([A-Za-z0-9-]*[A-Za-z0-9])?)+$/;
export const URL_RE = /^https?:\/\/\S+$/;
export const ASSET_RE = /^(\/.+|https?:\/\/\S+)$/;

export interface SiteConfigFormModel {
    fields: Record<string, string>;
    /** 非已知键（含系统托管键与未知键）无损保留 */
    preserved: Record<string, unknown>;
}

/** configJson → 表单模型：已知键入 fields，其余（系统托管键/旧键/未知键）无损入 preserved */
export function parseSiteConfig(configJson: string | undefined | null): SiteConfigFormModel {
    const model: SiteConfigFormModel = { fields: {}, preserved: {} };
    if (!configJson || !configJson.trim()) {
        return model;
    }
    let parsed: Record<string, unknown> | null = null;
    try {
        const obj = JSON.parse(configJson);
        if (obj && typeof obj === "object" && !Array.isArray(obj)) {
            parsed = obj;
        }
    } catch {
        // 非法 JSON 按空配置处理（与后端 ExtJsonUtils.parse 语义一致）
    }
    if (!parsed) {
        return model;
    }
    const known = new Set(SITE_CONFIG_FIELD_DEFS.map(f => f.key));
    Object.keys(parsed).forEach(k => {
        const v = parsed![k];
        if (known.has(k) && typeof v === "string") {
            model.fields[k] = v;
        } else {
            model.preserved[k] = v;
        }
    });
    return model;
}

/** 表单模型 → configJson：空值剔除；preserved 原样回写（永不丢失） */
export function serializeSiteConfig(model: SiteConfigFormModel): string {
    const out: Record<string, unknown> = {};
    SITE_CONFIG_FIELD_DEFS.forEach(def => {
        const v = (model.fields[def.key] || "").trim();
        if (v) {
            out[def.key] = v;
        }
    });
    Object.keys(model.preserved || {}).forEach(k => {
        out[k] = model.preserved[k];
    });
    return JSON.stringify(out);
}

/**
 * F1（docs/20）Tab 独立保存：服务端事实源 base + 本 Tab 增量 patch 合并——
 * patch 值为空串/null/undefined = 删除该键；其余键原样保留。
 * 各 Tab 只提交自己的键空间，其他 Tab 未保存的内存修改不会被连带提交。
 */
export function mergeConfigPatch(base: string | undefined | null, patch: Record<string, unknown>): string {
    let obj: Record<string, unknown>;
    try {
        const parsed = base && base.trim() ? JSON.parse(base) : {};
        obj = parsed && typeof parsed === "object" && !Array.isArray(parsed) ? { ...parsed } : {};
    } catch {
        obj = {};
    }
    Object.entries(patch).forEach(([k, v]) => {
        if (v === undefined || v === null || (typeof v === "string" && !v.trim())) {
            delete obj[k];
        } else {
            obj[k] = v;
        }
    });
    return JSON.stringify(obj);
}

/** 已知字段值校验：返回错误消息，空串=通过（与后端 validateConfigJson 同语义） */
export function validateFieldValue(def: SiteConfigFieldDef, value: string): string {
    const v = (value || "").trim();
    if (!v) {
        return "";
    }
    switch (def.kind) {
        case "url":
            return URL_RE.test(v) ? "" : "须为完整的 http(s):// 地址";
        case "host":
            return HOST_RE.test(v) ? "" : "须为域名形式（如 www.xxx.edu.cn，不带协议）";
        case "asset":
            return ASSET_RE.test(v) ? "" : "须为站点上传路径（/ 开头）或 http(s) 地址";
        default:
            return def.maxLength && v.length > def.maxLength ? `不能超过 ${def.maxLength} 字` : "";
    }
}