/**
 * Model Sharing — Mock Fixtures（平行開發用）
 *
 * 對 API 契約 mock（api-model-sharing.md 的 response 形狀），不依賴後端跑起來。
 * 形狀為契約定義的 snake_case，經 model-sharing.ts 的 normalize 後才成前端型別。
 *
 * 用途：
 *   1. store 在 `NEXT_PUBLIC_USE_MODEL_SHARING_MOCK=1` 時走 mock（見 model-sharing-store）
 *   2. 元件測試 fixture 來源
 *
 * ⚠️ mock owner 資料刻意不含 email（對齊契約 §4：非擁有者不該看到他人 email）。
 *   shares 的 email 是 owner 授權目標，才有 email。
 */

/** 契約 §1 library item 的原始（snake_case）形狀。 */
export interface RawLibraryItem {
  id: string;
  name: string;
  description?: string;
  target_chip: string;
  file_size: number;
  source: string;
  status: string;
  visibility: string;
  owner: { id: string; name: string; is_me: boolean };
  shared_with_me: boolean;
  my_access: string;
  created_at: string;
  updated_at: string;
}

/** 契約 §1 分頁 response 原始形狀。 */
export interface RawLibraryPage {
  items: RawLibraryItem[];
  next_cursor: string | null;
  has_more: boolean;
}

const NOW = "2026-08-01T00:00:00Z";

/**
 * 一個較大的 mock 資料集（30 筆），用來驗證 cursor 無限捲動分頁。
 * 混合三種可見性、owner/非 owner、shared_with_me 各態，覆蓋 UI 分支。
 */
export const MOCK_LIBRARY_ITEMS: RawLibraryItem[] = Array.from({ length: 30 }).map(
  (_, i) => {
    const isMine = i % 3 === 0;
    const visibility = isMine ? "private" : i % 3 === 1 ? "public" : "tenant";
    const sharedWithMe = !isMine && i % 4 === 0;
    const chips = ["kl520", "kl720", "kl630", "kl730"];
    const sources = ["converted", "uploaded", "preset"];
    return {
      id: `mock-model-${String(i + 1).padStart(2, "0")}`,
      name: `mock-model-${i + 1} ${["yolov5s", "resnet50", "mobilenet", "ssd"][i % 4]}`,
      description: i % 2 === 0 ? `Mock 模型 ${i + 1} 的描述` : undefined,
      target_chip: chips[i % chips.length],
      file_size: (i + 1) * 1024 * 1024,
      source: isMine ? "converted" : sources[i % sources.length],
      status: "ready",
      visibility,
      owner: isMine
        ? { id: "me", name: "我", is_me: true }
        : { id: `owner-${i}`, name: `Owner ${(i % 5) + 1}`, is_me: false },
      shared_with_me: sharedWithMe,
      my_access: isMine ? "owner" : sharedWithMe ? "viewer" : "viewer",
      created_at: `2026-07-${String((i % 28) + 1).padStart(2, "0")}T00:00:00Z`,
      updated_at: NOW,
    };
  },
);

/**
 * 對 MOCK_LIBRARY_ITEMS 套用 query（搜尋 / filter / 排序 / cursor 分頁）產生一頁。
 * cursor = 已消費筆數的 base64（不透明；mock 只需能往下切）。
 */
export function mockLibraryPage(query: {
  cursor?: string;
  limit?: number;
  q?: string;
  targetChip?: string;
  source?: string;
  visibility?: string;
  owned?: boolean;
  sort?: string;
  order?: string;
}): RawLibraryPage {
  let items = [...MOCK_LIBRARY_ITEMS];

  // filter
  if (query.q) {
    const q = query.q.toLowerCase();
    items = items.filter(
      (m) =>
        m.name.toLowerCase().includes(q) ||
        (m.description ?? "").toLowerCase().includes(q),
    );
  }
  if (query.targetChip) {
    items = items.filter((m) => m.target_chip === query.targetChip);
  }
  if (query.source) {
    items = items.filter((m) => m.source === query.source);
  }
  if (query.visibility) {
    items = items.filter((m) => m.visibility === query.visibility);
  }
  if (query.owned === true) {
    items = items.filter((m) => m.owner.is_me);
  } else if (query.owned === false) {
    items = items.filter((m) => !m.owner.is_me);
  }

  // sort
  const order = query.order === "asc" ? 1 : -1;
  const sortKey = query.sort ?? "created_at";
  items.sort((a, b) => {
    if (sortKey === "name") return a.name.localeCompare(b.name) * order;
    if (sortKey === "file_size") return (a.file_size - b.file_size) * order;
    return a.created_at.localeCompare(b.created_at) * order;
  });

  // cursor 分頁
  const limit = Math.min(Math.max(query.limit ?? 20, 1), 100);
  const start = query.cursor ? Number(atob(query.cursor)) : 0;
  const slice = items.slice(start, start + limit);
  const nextStart = start + slice.length;
  const hasMore = nextStart < items.length;
  return {
    items: slice,
    next_cursor: hasMore ? btoa(String(nextStart)) : null,
    has_more: hasMore,
  };
}

/** 依 id 產生一筆 profile 原始形狀（找不到回 null，模擬 404）。 */
export function mockProfile(id: string): Record<string, unknown> | null {
  const item = MOCK_LIBRARY_ITEMS.find((m) => m.id === id);
  if (!item) return null;
  return {
    ...item,
    input_shape: [1, 3, 224, 224],
    classes: ["person", "car", "dog", "cat"],
    framework: "onnx",
    can_download: item.my_access !== "none",
    uploaded_at: item.created_at,
  };
}

/** mock shares 清單（owner 檢視自己模型的授權對象）。 */
export const MOCK_SHARES: Record<string, Array<{ user_id: string; email: string; role: string; created_at: string }>> = {
  "mock-model-01": [
    { user_id: "u-alice", email: "alice@corp.com", role: "viewer", created_at: NOW },
    { user_id: "u-bob", email: "bob@corp.com", role: "viewer", created_at: NOW },
  ],
};