"use client";

import { useState, useTransition, useEffect, useRef } from "react";
import { grantCourseAccess, getPublishedCourses } from "@/app/admin/users/enroll-action";

interface Course {
  id: string;
  title: string;
}

interface Props {
  userId: string;
  userName: string;
}

export function QuickEnrollButton({ userId, userName }: Props) {
  const [open, setOpen] = useState(false);
  const [courses, setCourses] = useState<Course[]>([]);
  const [loadingCourses, setLoadingCourses] = useState(false);
  const [courseId, setCourseId] = useState("");
  const [expiresAt, setExpiresAt] = useState("");
  const [status, setStatus] = useState<"idle" | "success" | "error">("idle");
  const [errorMsg, setErrorMsg] = useState("");
  const [pending, startTransition] = useTransition();
  const dialogRef = useRef<HTMLDivElement>(null);

  // Load courses when modal opens
  useEffect(() => {
    if (!open) return;
    setLoadingCourses(true);
    getPublishedCourses()
      .then((data) => {
        setCourses(data);
        if (data.length > 0) setCourseId(data[0].id);
      })
      .finally(() => setLoadingCourses(false));
  }, [open]);

  // Close on Escape
  useEffect(() => {
    if (!open) return;
    const handler = (e: KeyboardEvent) => {
      if (e.key === "Escape") handleClose();
    };
    window.addEventListener("keydown", handler);
    return () => window.removeEventListener("keydown", handler);
  }, [open]);

  function handleOpen() {
    setStatus("idle");
    setErrorMsg("");
    setExpiresAt("");
    setCourseId("");
    setOpen(true);
  }

  function handleClose() {
    if (pending) return;
    setOpen(false);
  }

  function handleSubmit() {
    if (!courseId) return;
    const expiry = expiresAt ? new Date(expiresAt) : null;
    startTransition(async () => {
      const result = await grantCourseAccess(userId, courseId, expiry);
      if ("error" in result) {
        setStatus("error");
        setErrorMsg(result.error);
      } else {
        setStatus("success");
        setTimeout(() => setOpen(false), 1200);
      }
    });
  }

  return (
    <>
      {/* Trigger button */}
      <button
        type="button"
        onClick={handleOpen}
        className="text-xs px-2 py-1 transition-colors"
        style={{
          border: "1px solid var(--border)",
          color: "var(--foreground)",
          background: "transparent",
          fontWeight: 600,
          whiteSpace: "nowrap",
        }}
        title={`Выдать доступ к курсу — ${userName}`}
      >
        + Доступ
      </button>

      {/* Modal overlay */}
      {open && (
        <div
          className="fixed inset-0 z-50 flex items-center justify-center"
          style={{ background: "rgba(50,50,50,0.45)" }}
          onClick={(e) => {
            if (e.target === e.currentTarget) handleClose();
          }}
        >
          <div
            ref={dialogRef}
            className="w-full max-w-sm p-6 space-y-4"
            style={{
              background: "var(--background)",
              border: "2px solid var(--foreground)",
              boxShadow: "6px 6px 0 0 var(--foreground)",
            }}
          >
            {/* Header */}
            <div className="flex items-start justify-between gap-2">
              <div>
                <p
                  className="text-xs font-bold uppercase tracking-widest"
                  style={{ color: "var(--muted-foreground)" }}
                >
                  Выдать доступ
                </p>
                <p className="text-sm font-semibold mt-0.5" style={{ color: "var(--foreground)" }}>
                  {userName}
                </p>
              </div>
              <button
                type="button"
                onClick={handleClose}
                disabled={pending}
                className="text-xs leading-none"
                style={{ color: "var(--muted-foreground)", fontSize: "18px", lineHeight: 1 }}
              >
                ×
              </button>
            </div>

            {/* Course select */}
            <div>
              <label
                className="block text-xs font-bold uppercase tracking-widest mb-1.5"
                style={{ color: "var(--muted-foreground)" }}
              >
                Курс
              </label>
              {loadingCourses ? (
                <p className="text-xs" style={{ color: "var(--muted-foreground)" }}>
                  Загрузка…
                </p>
              ) : courses.length === 0 ? (
                <p className="text-xs" style={{ color: "var(--muted-foreground)" }}>
                  Нет опубликованных курсов
                </p>
              ) : (
                <select
                  value={courseId}
                  onChange={(e) => setCourseId(e.target.value)}
                  disabled={pending}
                  style={{
                    width: "100%",
                    border: "2px solid var(--border)",
                    background: "var(--background)",
                    color: "var(--foreground)",
                    padding: "0.4rem 0.5rem",
                    fontSize: "13px",
                    fontFamily: "inherit",
                    outline: "none",
                  }}
                  onFocus={(e) => (e.currentTarget.style.borderColor = "var(--foreground)")}
                  onBlur={(e) => (e.currentTarget.style.borderColor = "var(--border)")}
                >
                  {courses.map((c) => (
                    <option key={c.id} value={c.id}>
                      {c.title}
                    </option>
                  ))}
                </select>
              )}
            </div>

            {/* Expiry date (optional) */}
            <div>
              <label
                className="block text-xs font-bold uppercase tracking-widest mb-1.5"
                style={{ color: "var(--muted-foreground)" }}
              >
                Срок доступа (необязательно)
              </label>
              <input
                type="date"
                value={expiresAt}
                onChange={(e) => setExpiresAt(e.target.value)}
                disabled={pending}
                min={new Date().toISOString().slice(0, 10)}
                style={{
                  width: "100%",
                  border: "2px solid var(--border)",
                  background: "var(--background)",
                  color: expiresAt ? "var(--foreground)" : "var(--muted-foreground)",
                  padding: "0.4rem 0.5rem",
                  fontSize: "13px",
                  fontFamily: "inherit",
                  outline: "none",
                }}
                onFocus={(e) => (e.currentTarget.style.borderColor = "var(--foreground)")}
                onBlur={(e) => (e.currentTarget.style.borderColor = "var(--border)")}
              />
              <p className="text-xs mt-1" style={{ color: "var(--muted-foreground)" }}>
                Оставьте пустым для бессрочного доступа
              </p>
            </div>

            {/* Error message */}
            {status === "error" && (
              <p className="text-xs" style={{ color: "oklch(0.577 0.245 27.325)" }}>
                {errorMsg}
              </p>
            )}

            {/* Success message */}
            {status === "success" && (
              <p className="text-xs font-semibold" style={{ color: "#3A6A3A" }}>
                Доступ выдан
              </p>
            )}

            {/* Actions */}
            <div className="flex items-center gap-2 pt-1">
              <button
                type="button"
                onClick={handleSubmit}
                disabled={pending || loadingCourses || !courseId || status === "success"}
                className="btn-aubade btn-aubade-accent text-xs px-4 py-2"
              >
                {pending ? "Выдаю…" : "Выдать"}
              </button>
              <button
                type="button"
                onClick={handleClose}
                disabled={pending}
                className="btn-aubade text-xs px-4 py-2"
                style={{ color: "var(--muted-foreground)" }}
              >
                Отмена
              </button>
            </div>
          </div>
        </div>
      )}
    </>
  );
}