import { useState, useEffect } from "react";
import { KeyRound, UserPen } from "lucide-react";

export default function Settings() {
  const [username, setUsername] = useState("");
  const [newUsername, setNewUsername] = useState("");
  const [usernameError, setUsernameError] = useState("");
  const [usernameSuccess, setUsernameSuccess] = useState(false);
  const [usernameLoading, setUsernameLoading] = useState(false);

  const [pwForm, setPwForm] = useState({
    current_password: "",
    new_password: "",
    confirm_password: "",
  });
  const [pwError, setPwError] = useState("");
  const [pwSuccess, setPwSuccess] = useState(false);
  const [pwLoading, setPwLoading] = useState(false);

  useEffect(() => {
    fetch("/api/auth/me")
      .then((r) => r.json())
      .then((d) => {
        setUsername(d.username);
        setNewUsername(d.username);
      });
  }, []);

  const saveUsername = async (e: React.FormEvent) => {
    e.preventDefault();
    setUsernameError("");
    setUsernameSuccess(false);
    if (newUsername.trim() === username) return;
    setUsernameLoading(true);
    const res = await fetch("/api/auth/change-username", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ new_username: newUsername.trim() }),
    });
    setUsernameLoading(false);
    if (res.ok) {
      setUsername(newUsername.trim());
      setUsernameSuccess(true);
    } else {
      const data = await res.json();
      setUsernameError(data.error || "Failed to update username");
    }
  };

  const savePassword = async (e: React.FormEvent) => {
    e.preventDefault();
    setPwError("");
    setPwSuccess(false);
    if (pwForm.new_password !== pwForm.confirm_password) {
      setPwError("New passwords do not match");
      return;
    }
    setPwLoading(true);
    const res = await fetch("/api/auth/change-password", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        current_password: pwForm.current_password,
        new_password: pwForm.new_password,
      }),
    });
    setPwLoading(false);
    if (res.ok) {
      setPwSuccess(true);
      setPwForm({ current_password: "", new_password: "", confirm_password: "" });
    } else {
      const data = await res.json();
      setPwError(data.error || "Failed to change password");
    }
  };

  return (
    <div className="space-y-6">
      <h1 className="text-xl font-semibold">Settings</h1>

      {/* Username */}
      <section className="bg-gray-900 border border-gray-800 rounded-lg p-5 space-y-4 max-w-md">
        <div className="flex items-center gap-2">
          <UserPen className="w-4 h-4 text-gray-400" />
          <h2 className="text-sm font-medium text-gray-400 uppercase tracking-wider">
            Change Username
          </h2>
        </div>
        <form onSubmit={saveUsername} className="space-y-3">
          <div className="space-y-1">
            <label className="text-xs text-gray-400">Username</label>
            <input
              value={newUsername}
              onChange={(e) => setNewUsername(e.target.value)}
              className="w-full bg-gray-800 border border-gray-700 rounded-md px-3 py-2 text-sm outline-none focus:border-blue-500"
            />
          </div>
          {usernameError && <p className="text-xs text-red-400">{usernameError}</p>}
          {usernameSuccess && <p className="text-xs text-green-400">Username updated successfully.</p>}
          <button
            type="submit"
            disabled={usernameLoading || newUsername.trim() === username}
            className="bg-blue-600 hover:bg-blue-500 disabled:opacity-50 text-white text-sm px-4 py-2 rounded-md transition-colors"
          >
            {usernameLoading ? "Saving..." : "Save"}
          </button>
        </form>
      </section>

      {/* Password */}
      <section className="bg-gray-900 border border-gray-800 rounded-lg p-5 space-y-4 max-w-md">
        <div className="flex items-center gap-2">
          <KeyRound className="w-4 h-4 text-gray-400" />
          <h2 className="text-sm font-medium text-gray-400 uppercase tracking-wider">
            Change Password
          </h2>
        </div>
        <form onSubmit={savePassword} className="space-y-3">
          <div className="space-y-1">
            <label className="text-xs text-gray-400">Current Password</label>
            <input
              type="password"
              value={pwForm.current_password}
              onChange={(e) => setPwForm((f) => ({ ...f, current_password: e.target.value }))}
              className="w-full bg-gray-800 border border-gray-700 rounded-md px-3 py-2 text-sm outline-none focus:border-blue-500"
            />
          </div>
          <div className="space-y-1">
            <label className="text-xs text-gray-400">New Password</label>
            <input
              type="password"
              value={pwForm.new_password}
              onChange={(e) => setPwForm((f) => ({ ...f, new_password: e.target.value }))}
              className="w-full bg-gray-800 border border-gray-700 rounded-md px-3 py-2 text-sm outline-none focus:border-blue-500"
            />
          </div>
          <div className="space-y-1">
            <label className="text-xs text-gray-400">Confirm New Password</label>
            <input
              type="password"
              value={pwForm.confirm_password}
              onChange={(e) => setPwForm((f) => ({ ...f, confirm_password: e.target.value }))}
              className="w-full bg-gray-800 border border-gray-700 rounded-md px-3 py-2 text-sm outline-none focus:border-blue-500"
            />
          </div>
          {pwError && <p className="text-xs text-red-400">{pwError}</p>}
          {pwSuccess && <p className="text-xs text-green-400">Password changed successfully.</p>}
          <button
            type="submit"
            disabled={pwLoading}
            className="bg-blue-600 hover:bg-blue-500 disabled:opacity-50 text-white text-sm px-4 py-2 rounded-md transition-colors"
          >
            {pwLoading ? "Saving..." : "Save"}
          </button>
        </form>
      </section>
    </div>
  );
}