import Link from "next/link";
import { BookOpen, PenLine, Plus } from "lucide-react";

import { AppShell } from "@/components/AppShell";
import { BackendDownNotice } from "@/components/BackendDownNotice";
import { ProjectLibrary } from "@/components/projects/ProjectLibrary";
import { EmptyState } from "@/components/ui/EmptyState";
import { PageContainer } from "@/components/ui/PageContainer";
import { PageHeader } from "@/components/ui/PageHeader";
import { fetchProjects } from "@/lib/api/server";
import type { ProjectResponse } from "@/lib/api/types";
import { buttonClass } from "@/lib/ui/variants";

// 作品库（Dashboard 入口，UX §6.1）。Server Component 读取。
export default async function DashboardPage() {
  let projects: ProjectResponse[] = [];
  let loadError = false;
  try {
    const data = await fetchProjects();
    projects = data.projects ?? [];
  } catch {
    loadError = true;
  }

  return (
    <AppShell>
      <PageContainer>
        <PageHeader
          title="我的作品"
          description="从一个灵感进入正文、设定、审稿与验收闭环。"
          actions={
            <div className="flex flex-wrap items-center gap-2">
              <Link
                href="/write"
                className={buttonClass({ variant: "primary" })}
              >
                <PenLine className="h-4 w-4" aria-hidden="true" />
                直接开始写
              </Link>
              <Link
                href="/projects/new"
                className={buttonClass({ variant: "secondary" })}
              >
                <Plus className="h-4 w-4" aria-hidden="true" />
                先立项
              </Link>
            </div>
          }
        />

        {loadError ? (
          <BackendDownNotice />
        ) : projects.length === 0 ? (
          <EmptyState
            icon={BookOpen}
            title="还没有作品"
            description="直接开始写，落笔即成书；或先立项，从一句灵感搭好设定、大纲再动笔。"
            action={
              <div className="flex flex-wrap items-center justify-center gap-2">
                <Link
                  href="/write"
                  className={buttonClass({ variant: "primary" })}
                >
                  <PenLine className="h-4 w-4" aria-hidden="true" />
                  直接开始写
                </Link>
                <Link
                  href="/projects/new"
                  className={buttonClass({ variant: "secondary" })}
                >
                  <Plus className="h-4 w-4" aria-hidden="true" />
                  先立项
                </Link>
              </div>
            }
          />
        ) : (
          <ProjectLibrary projects={projects} />
        )}
      </PageContainer>
    </AppShell>
  );
}
