import { HeartHandshake, Sparkles, UserRoundCheck, UserRoundPlus } from "lucide-react";
import { type FormEvent, useEffect, useMemo, useState } from "react";

import { platformApiClient } from "../api/client";
import type { UserCreateRequest, UserResponse, UserStatus } from "../api/types";
import { EmptyState, ErrorState, LoadingState, ResultBadge } from "../components/StateViews";
import { PageFrame } from "../components/PageFrame";
import type { PageComponentProps } from "../contracts/page";
import { userAccess } from "../contracts/shell";
import { isPlatformAdmin } from "../contracts/workspace";
import { cx } from "../utils/classes";

const roleOptions = [
  { value: "platform-admin", label: "平台管理员" },
  { value: "server-owner", label: "服主" },
  { value: "server-admin", label: "服务器管理员" }
];

const statusOptions: Array<{ value: UserStatus; label: string }> = [
  { value: "active", label: "启用" },
  { value: "pending", label: "待审核" },
  { value: "disabled", label: "停用" }
];

const fallbackUsers: UserResponse[] = userAccess.map((user, index) => ({
  id: user.id,
  displayName: user.displayName,
  email: `${user.id}@local.example.test`,
  status: user.status,
  roles: user.roles,
  profile: {
    phone: index === 0 ? "13800000000" : "",
    qq: index === 0 ? "10001" : "",
    contactNote: user.review
  },
  createdAt: "2026-07-03T00:00:00Z",
  updatedAt: "2026-07-03T00:00:00Z"
}));

export function UsersPage({ session, operations }: PageComponentProps) {
  const [users, setUsers] = useState<UserResponse[]>(fallbackUsers);
  const [loading, setLoading] = useState(true);
  const [source, setSource] = useState<"api" | "local">("local");
  const [loadError, setLoadError] = useState("");
  const [result, setResult] = useState<{ status: "pending" | "succeeded" | "failed"; label: string }>();
  const [draft, setDraft] = useState<UserCreateRequest>({
    displayName: "",
    email: "",
    roles: ["server-admin"],
    status: "pending",
    profile: { phone: "", qq: "", contactNote: "" }
  });

  useEffect(() => {
    let cancelled = false;
    void platformApiClient
      .listUsers()
      .then((response) => {
        if (!cancelled) {
          setUsers(response.items);
          setSource("api");
          setLoadError("");
        }
      })
      .catch(() => {
        if (!cancelled) {
          setUsers(fallbackUsers);
          setSource("local");
          setLoadError("账号 API 加载失败，当前显示本地样例；创建与状态更新仍会尝试平台 API。");
        }
      })
      .finally(() => {
        if (!cancelled) {
          setLoading(false);
        }
      });
    return () => {
      cancelled = true;
    };
  }, []);

  const counts = useMemo(
    () => ({
      active: users.filter((user) => user.status === "active").length,
      pending: users.filter((user) => user.status === "pending").length,
      roleCount: new Set(users.flatMap((user) => user.roles)).size
    }),
    [users]
  );

  async function createUser(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    const request: UserCreateRequest = {
      ...draft,
      displayName: draft.displayName.trim(),
      email: draft.email?.trim(),
      roles: draft.roles.length ? draft.roles : ["server-admin"],
      profile: {
        phone: draft.profile?.phone?.trim(),
        qq: draft.profile?.qq?.trim(),
        contactNote: draft.profile?.contactNote?.trim()
      }
    };
    const operationId = operations.begin({ intent: "创建用户", targetKind: "platform", targetId: "users", requester: session.displayName });
    setResult({ status: "pending", label: `正在创建用户 ${operationId}` });
    try {
      const created = await platformApiClient.createUser(request);
      setUsers((current) => [created, ...current.filter((user) => user.id !== created.id)]);
      operations.succeed(operationId, `用户已创建：${created.id}`);
      setSource("api");
      setLoadError("");
      setResult({ status: "succeeded", label: `已创建 ${created.displayName}` });
    } catch (error) {
      operations.fail(operationId, error instanceof Error ? error.message : "用户创建失败");
      setResult({ status: "failed", label: "用户创建失败，未写入数据库" });
    }
    setDraft({ displayName: "", email: "", roles: ["server-admin"], status: "pending", profile: { phone: "", qq: "", contactNote: "" } });
  }

  async function setUserStatus(user: UserResponse, status: UserStatus) {
    const operationId = operations.begin({ intent: "更新用户状态", targetKind: "platform", targetId: user.id, requester: session.displayName });
    setResult({ status: "pending", label: `正在更新 ${user.displayName}` });
    try {
      const updated = await platformApiClient.updateUser(user.id, { status });
      setUsers((current) => current.map((item) => (item.id === updated.id ? updated : item)));
      operations.succeed(operationId, `用户状态已更新：${updated.id}`);
      setSource("api");
      setLoadError("");
      setResult({ status: "succeeded", label: `${updated.displayName} 已${statusLabel(updated.status)}` });
    } catch (error) {
      operations.fail(operationId, error instanceof Error ? error.message : "用户状态更新失败");
      setResult({ status: "failed", label: "状态更新失败，未写入数据库" });
    }
  }

  function toggleRole(role: string) {
    setDraft((current) => {
      const nextRoles = current.roles.includes(role) ? current.roles.filter((item) => item !== role) : [...current.roles, role];
      return { ...current, roles: nextRoles };
    });
  }

  if (!isPlatformAdmin(session)) {
    return (
      <div className="console-page">
        <PageFrame kicker="身份" title="用户管理" status="无访问权限" metrics={[]} />
        <section className="console-panel">
          <div className="state-view state-error" role="alert">
            <HeartHandshake size={24} />
            <strong>当前账号不能管理用户</strong>
            <p>服务器用户不会看到用户管理导航；直接访问该页时应返回角色默认工作区。</p>
          </div>
        </section>
      </div>
    );
  }

  return (
    <div className="console-page">
      <PageFrame
        kicker="身份"
        title="用户管理"
        status={source === "api" ? "账号 API 已连接" : "本地回退"}
        metrics={[
          { label: "用户", value: `${users.length}`, tone: "success" },
          { label: "角色", value: `${counts.roleCount}`, tone: "neutral" },
          { label: "待审核", value: `${counts.pending}`, tone: "warning" }
        ]}
      />

      {loading && <LoadingState label="正在加载用户列表…" />}
      {loadError && <ErrorState title="用户 API 暂不可用" reason={loadError} diagnosticId="user-management:fallback" compact />}

      <section className="console-panel">
        <div className="panel-header">
          <h2>创建用户</h2>
          {loading ? <ResultBadge status="pending" label="加载用户…" /> : result && <ResultBadge status={result.status} label={result.label} />}
        </div>
        <form className="management-form" onSubmit={createUser}>
          <label>
            <span>显示名称</span>
            <input value={draft.displayName} required onChange={(event) => setDraft((current) => ({ ...current, displayName: event.target.value }))} />
          </label>
          <label>
            <span>邮箱</span>
            <input value={draft.email} type="email" onChange={(event) => setDraft((current) => ({ ...current, email: event.target.value }))} />
          </label>
          <label>
            <span>手机号</span>
            <input
              value={draft.profile?.phone ?? ""}
              inputMode="tel"
              onChange={(event) => setDraft((current) => ({ ...current, profile: { ...current.profile, phone: event.target.value } }))}
            />
          </label>
          <label>
            <span>QQ</span>
            <input
              value={draft.profile?.qq ?? ""}
              inputMode="numeric"
              onChange={(event) => setDraft((current) => ({ ...current, profile: { ...current.profile, qq: event.target.value } }))}
            />
          </label>
          <label>
            <span>备注</span>
            <input
              value={draft.profile?.contactNote ?? ""}
              onChange={(event) => setDraft((current) => ({ ...current, profile: { ...current.profile, contactNote: event.target.value } }))}
            />
          </label>
          <label>
            <span>状态</span>
            <select value={draft.status} onChange={(event) => setDraft((current) => ({ ...current, status: event.target.value as UserStatus }))}>
              {statusOptions.map((option) => (
                <option key={option.value} value={option.value}>
                  {option.label}
                </option>
              ))}
            </select>
          </label>
          <div className="role-selector" aria-label="角色">
            {roleOptions.map((role) => (
              <button key={role.value} type="button" className={cx("role-chip", draft.roles.includes(role.value) && "role-chip-active")} onClick={() => toggleRole(role.value)}>
                <Sparkles size={13} />
                <span>{role.label}</span>
              </button>
            ))}
          </div>
          <button type="submit" className="profile-save-button">
            <UserRoundPlus size={14} />
            <span>创建用户</span>
          </button>
        </form>
      </section>

      <section className="console-panel">
        <div className="panel-header">
          <h2>访问列表</h2>
          <span className="page-status">{source === "api" ? "平台数据" : "本地样例 / 待同步"}</span>
        </div>
        {users.length === 0 ? (
          <EmptyState title="暂无用户" description="平台暂未返回可管理账号。创建用户后会在这里显示 API 连接结果。" />
        ) : (
          <div className="resource-list user-management-list">
            {users.map((user) => (
              <article key={user.id} className="resource-list-item user-management-item">
                <div>
                  <strong>{user.displayName}</strong>
                  <span className="provider-id">{user.email ?? user.id}</span>
                </div>
                <span className={cx("status-pill", statusClass(user.status))}>
                  <UserRoundCheck size={13} />
                  {statusLabel(user.status)}
                </span>
                <span>{user.roles.map(roleLabel).join(" / ")}</span>
                <span>{profileSummary(user)}</span>
                <div className="user-actions" aria-label={`${user.displayName} 状态操作`}>
                  {statusOptions.map((option) => (
                    <button
                      key={option.value}
                      type="button"
                      className="theme-upload"
                      disabled={user.status === option.value}
                      aria-label={`将 ${user.displayName} 设为${option.label}`}
                      onClick={() => void setUserStatus(user, option.value)}
                    >
                      {option.label}
                    </button>
                  ))}
                </div>
              </article>
            ))}
          </div>
        )}
      </section>
    </div>
  );
}

function statusLabel(status: UserStatus): string {
  return status === "active" ? "启用" : status === "pending" ? "待审核" : "停用";
}

function statusClass(status: UserStatus): string {
  return status === "active" ? "status-active" : status === "pending" ? "status-pending" : "status-disabled";
}

function roleLabel(role: string): string {
  const matched = roleOptions.find((option) => option.value === role || option.value.replace("-", "") === role.toLowerCase());
  return matched?.label ?? role;
}

function profileSummary(user: UserResponse): string {
  const parts = [user.profile?.phone, user.profile?.qq ? `QQ ${user.profile.qq}` : undefined, user.profile?.contactNote].filter(Boolean);
  return parts.length > 0 ? parts.join(" · ") : "暂无联系方式";
}