import type { ProjectResponse } from "@/lib/api/types";

export type ProjectFilter =
  | "all"
  | "with_genre"
  | "uncategorized"
  | "pending_review";
export type ProjectSort = "updated_at" | "title" | "genre";
export type ProjectViewMode = "cards" | "compact";

export interface ProjectQuery {
  search: string;
  filter: ProjectFilter;
  sort: ProjectSort;
}

export function filterProjects(
  projects: readonly ProjectResponse[],
  query: ProjectQuery,
): ProjectResponse[] {
  const needle = query.search.trim().toLocaleLowerCase();
  const filtered = projects.filter((project) => {
    if (query.filter === "with_genre" && !project.genre) return false;
    if (query.filter === "uncategorized" && project.genre) return false;
    if (query.filter === "pending_review" && pendingReviewCount(project) === 0) {
      return false;
    }
    if (needle.length === 0) return true;

    return [project.title, project.genre, project.logline, project.theme]
      .filter((value): value is string => typeof value === "string")
      .some((value) => value.toLocaleLowerCase().includes(needle));
  });

  return [...filtered].sort((a, b) => compareProject(a, b, query.sort));
}

function compareProject(
  a: ProjectResponse,
  b: ProjectResponse,
  sort: ProjectSort,
): number {
  if (sort === "updated_at") {
    const byUpdated = timestamp(b.updated_at) - timestamp(a.updated_at);
    if (byUpdated !== 0) return byUpdated;
  }
  if (sort === "genre") {
    if (a.genre && !b.genre) return -1;
    if (!a.genre && b.genre) return 1;
    const byGenre = label(a.genre).localeCompare(label(b.genre), "zh-Hans-CN");
    if (byGenre !== 0) return byGenre;
  }
  return label(a.title).localeCompare(label(b.title), "zh-Hans-CN");
}

export function pendingReviewCount(project: ProjectResponse): number {
  return Math.max(0, project.pending_review_count ?? 0);
}

export function formatProjectUpdatedAt(value: string | null | undefined): string {
  if (!value) return "暂无编辑记录";
  const date = new Date(value);
  if (Number.isNaN(date.getTime())) return "暂无编辑记录";
  return new Intl.DateTimeFormat("zh-CN", {
    month: "2-digit",
    day: "2-digit",
    hour: "2-digit",
    minute: "2-digit",
  }).format(date);
}

function label(value: string | null | undefined): string {
  return value?.trim() || "未命名";
}

function timestamp(value: string | null | undefined): number {
  if (!value) return 0;
  const time = new Date(value).getTime();
  return Number.isNaN(time) ? 0 : time;
}