export type Locale = "en" | "zh";

const STORAGE_KEY = "wh-locale";

type Dict = Record<string, string>;

const en: Dict = {
  "app.tagline": "CONFIG CONSOLE",
  "app.newRoute": "+ New Route",
  "app.newGroup": "+ New Group",
  "app.signOut": "Sign out",
  "app.langToggle": "中文",
  "login.title": "Config Console",
  "login.forbidden": "Access denied — this GitHub account is not an admin or group admin.",
  "login.prompt": "Sign in with GitHub to manage routes.",
  "login.button": "Sign in with GitHub",
  "tab.groups": "Groups",
  "tab.logs": "Send Logs",
  "status.loading": "loading",
  "status.connected": "connected",
  "kpi.groups": "GROUPS",
  "kpi.routes": "ROUTES",
  "groups.empty": "No groups yet. Groups scope routes by org/user and delegate access.",
  "groups.createFirst": "Create your first group",
  "groups.admins": "ADMINS",
  "groups.owners": "OWNERS",
  "groups.any": "any",
  "groups.open": "Open →",
  "group.back": "← Groups",
  "group.routesIn": "Routes in {name}",
  "routes.emptyGroup": "No routes in this group yet.",
  "routes.createFirst": "Create your first route",
  "route.untitled": "(untitled)",
  "route.noFilters": "no filters",
  "route.channel": "CHANNEL",
  "route.thread": "THREAD",
  "filter.event": "Event",
  "filter.repo": "Repo",
  "filter.actor": "Actor",
  "filter.action": "Action",
  "filter.branch": "Branch",
  "filter.keyword": "Keyword",
  "routeEditor.editTitle": "Edit route",
  "routeEditor.newTitle": "New route",
  "routeEditor.close": "Close",
  "routeEditor.name": "Name",
  "routeEditor.namePlaceholder": "My Route",
  "routeEditor.id": "ID",
  "routeEditor.idHint": "Unique, use a-z / 0-9 / dashes",
  "routeEditor.language": "Language",
  "routeEditor.langPlaceholder": "en",
  "routeEditor.langHint": "en or zh; custom via KV i18n:<lang>",
  "routeEditor.enabled": "Route enabled",
  "routeEditor.filters": "Filters",
  "routeEditor.filtersNote": "(all must match · AND)",
  "routeEditor.matchPlaceholder": "match value",
  "routeEditor.not": "NOT",
  "routeEditor.addFilter": "+ Add filter",
  "routeEditor.channel": "Channel ID",
  "routeEditor.channelPlaceholder": "Discord channel ID",
  "routeEditor.thread": "Thread ID",
  "routeEditor.threadNote": "(optional)",
  "routeEditor.threadPlaceholder": "Optional thread ID",
  "routeEditor.cancel": "Cancel",
  "routeEditor.save": "Save route",
  "routeEditor.errFilterMatch": "Filter {n} needs a match value",
  "routeEditor.errAddFilter": "Add at least one filter",
  "routeEditor.errIdFormat": "ID must be a-z / 0-9 / dashes",
  "routeEditor.errName": "Name is required",
  "routeEditor.errChannel": "Channel ID is required",
  "groupEditor.editTitle": "Edit group",
  "groupEditor.newTitle": "New group",
  "groupEditor.close": "Close",
  "groupEditor.name": "Name",
  "groupEditor.namePlaceholder": "My Team",
  "groupEditor.id": "ID",
  "groupEditor.idPlaceholder": "my-team",
  "groupEditor.idHint": "Unique, use a-z / 0-9 / dashes",
  "groupEditor.admins": "Group admins",
  "groupEditor.adminsNote": "(GitHub login or user id, comma-separated)",
  "groupEditor.adminsPlaceholder": "octocat, 12345",
  "groupEditor.adminsHint": "These users can view logs and edit this group's routes.",
  "groupEditor.owners": "Owner scope",
  "groupEditor.ownersNote": "(GitHub org / user logins, comma-separated)",
  "groupEditor.ownersPlaceholder": "my-org, some-user",
  "groupEditor.ownersHint":
    "Only webhook events from these orgs/users enter this group's routes. Leave empty for no restriction.",
  "groupEditor.cancel": "Cancel",
  "groupEditor.save": "Save group",
  "groupEditor.errIdFormat": "ID must be a-z / 0-9 / dashes",
  "groupEditor.errName": "Name is required",
  "logs.lastSends": "LAST {n} SENDS",
  "logs.refresh": "⟳ Refresh",
  "logs.empty": "No send records yet — trigger a webhook to see results.",
  "logs.repo": "REPO",
  "logs.target": "TARGET",
  "toast.routesSaved": "Routes saved",
  "toast.routeDeleted": "Route deleted",
  "toast.groupSaved": "Groups saved",
  "toast.groupDeleted": "Group deleted",
  "toast.routeIdExists": "Route ID already exists",
  "toast.groupIdExists": "Group ID already exists",
  "toast.saveFailed": "Save failed: {msg}",
  "toast.deleteFailed": "Delete failed: {msg}",
  "confirm.deleteRoute": 'Delete route "{name}"?',
  "confirm.deleteGroup": 'Delete group "{name}"?',
  "confirm.deleteGroupWarn": " {n} route(s) reference it and will lose their group.",
};

const zh: Dict = {
  "app.tagline": "配置控制台",
  "app.newRoute": "+ 新建路由",
  "app.newGroup": "+ 新建分组",
  "app.signOut": "退出登录",
  "app.langToggle": "EN",
  "login.title": "配置控制台",
  "login.forbidden": "访问被拒绝 —— 该 GitHub 账号不是超级管理员或分组管理员。",
  "login.prompt": "使用 GitHub 登录以管理路由。",
  "login.button": "使用 GitHub 登录",
  "tab.groups": "分组",
  "tab.logs": "发送日志",
  "status.loading": "加载中",
  "status.connected": "已连接",
  "kpi.groups": "分组",
  "kpi.routes": "路由",
  "groups.empty": "还没有分组。分组按组织/用户限定路由并委派访问权限。",
  "groups.createFirst": "创建第一个分组",
  "groups.admins": "管理员",
  "groups.owners": "来源",
  "groups.any": "任意",
  "groups.open": "进入 →",
  "group.back": "← 返回分组",
  "group.routesIn": "{name} 的路由",
  "routes.emptyGroup": "该分组还没有路由。",
  "routes.createFirst": "创建第一个路由",
  "route.untitled": "（未命名）",
  "route.noFilters": "无过滤器",
  "route.channel": "频道",
  "route.thread": "子区",
  "filter.event": "事件",
  "filter.repo": "仓库",
  "filter.actor": "操作者",
  "filter.action": "动作",
  "filter.branch": "分支",
  "filter.keyword": "关键词",
  "routeEditor.editTitle": "编辑路由",
  "routeEditor.newTitle": "新建路由",
  "routeEditor.close": "关闭",
  "routeEditor.name": "名称",
  "routeEditor.namePlaceholder": "我的路由",
  "routeEditor.id": "ID",
  "routeEditor.idHint": "唯一，使用 a-z / 0-9 / 短横线",
  "routeEditor.language": "语言",
  "routeEditor.langPlaceholder": "zh",
  "routeEditor.langHint": "en 或 zh；可通过 KV i18n:<lang> 自定义",
  "routeEditor.enabled": "启用路由",
  "routeEditor.filters": "过滤器",
  "routeEditor.filtersNote": "（全部匹配 · AND）",
  "routeEditor.matchPlaceholder": "匹配值",
  "routeEditor.not": "取反",
  "routeEditor.addFilter": "+ 添加过滤器",
  "routeEditor.channel": "频道 ID",
  "routeEditor.channelPlaceholder": "Discord 频道 ID",
  "routeEditor.thread": "子区 ID",
  "routeEditor.threadNote": "（可选）",
  "routeEditor.threadPlaceholder": "可选的子区 ID",
  "routeEditor.cancel": "取消",
  "routeEditor.save": "保存路由",
  "routeEditor.errFilterMatch": "第 {n} 个过滤器需要匹配值",
  "routeEditor.errAddFilter": "至少添加一个过滤器",
  "routeEditor.errIdFormat": "ID 只能是 a-z / 0-9 / 短横线",
  "routeEditor.errName": "名称为必填项",
  "routeEditor.errChannel": "频道 ID 为必填项",
  "groupEditor.editTitle": "编辑分组",
  "groupEditor.newTitle": "新建分组",
  "groupEditor.close": "关闭",
  "groupEditor.name": "名称",
  "groupEditor.namePlaceholder": "我的团队",
  "groupEditor.id": "ID",
  "groupEditor.idPlaceholder": "my-team",
  "groupEditor.idHint": "唯一，使用 a-z / 0-9 / 短横线",
  "groupEditor.admins": "分组管理员",
  "groupEditor.adminsNote": "（GitHub 登录名或用户 ID，逗号分隔）",
  "groupEditor.adminsPlaceholder": "octocat, 12345",
  "groupEditor.adminsHint": "这些用户可以查看日志并编辑本分组的路由。",
  "groupEditor.owners": "来源限定",
  "groupEditor.ownersNote": "（GitHub 组织 / 用户登录名，逗号分隔）",
  "groupEditor.ownersPlaceholder": "my-org, some-user",
  "groupEditor.ownersHint": "只有来自这些组织/用户的 webhook 事件才会进入本分组的路由。留空表示不限制。",
  "groupEditor.cancel": "取消",
  "groupEditor.save": "保存分组",
  "groupEditor.errIdFormat": "ID 只能是 a-z / 0-9 / 短横线",
  "groupEditor.errName": "名称为必填项",
  "logs.lastSends": "最近 {n} 条发送",
  "logs.refresh": "⟳ 刷新",
  "logs.empty": "还没有发送记录 —— 触发一次 webhook 即可查看结果。",
  "logs.repo": "仓库",
  "logs.target": "目标",
  "toast.routesSaved": "路由已保存",
  "toast.routeDeleted": "路由已删除",
  "toast.groupSaved": "分组已保存",
  "toast.groupDeleted": "分组已删除",
  "toast.routeIdExists": "路由 ID 已存在",
  "toast.groupIdExists": "分组 ID 已存在",
  "toast.saveFailed": "保存失败：{msg}",
  "toast.deleteFailed": "删除失败：{msg}",
  "confirm.deleteRoute": "确定删除路由“{name}”吗？",
  "confirm.deleteGroup": "确定删除分组“{name}”吗？",
  "confirm.deleteGroupWarn": " 有 {n} 条路由引用它，将失去所属分组。",
};

const messages: Record<Locale, Dict> = { en, zh };

function detectLocale(): Locale {
  if (typeof window === "undefined") return "zh";
  const stored = window.localStorage.getItem(STORAGE_KEY);
  if (stored === "en" || stored === "zh") return stored;
  const nav = (window.navigator.language || "").toLowerCase();
  return nav.startsWith("zh") ? "zh" : "en";
}

export function useI18n() {
  const locale = useState<Locale>("wh-locale", detectLocale);

  function setLocale(next: Locale): void {
    locale.value = next;
    if (typeof window !== "undefined") window.localStorage.setItem(STORAGE_KEY, next);
  }

  function toggle(): void {
    setLocale(locale.value === "zh" ? "en" : "zh");
  }

  function t(key: string, params?: Record<string, string | number>): string {
    const dict = messages[locale.value] ?? en;
    let str = dict[key] ?? en[key] ?? key;
    if (params) {
      for (const [k, v] of Object.entries(params)) {
        str = str.replace(`{${k}}`, String(v));
      }
    }
    return str;
  }

  return { locale, setLocale, toggle, t };
}