import React, { useCallback, useEffect, useMemo, useState } from "react";
import type { Meta, StoryObj } from "@storybook/react";

const meta: Meta = {
  title: "Layout/Editor",
  parameters: {
    layout: "fullscreen",
  },
};

export default meta;
type Story = StoryObj;

const SERVER_URL = "http://localhost:4001/layout";

function LayoutEditor() {
  const [value, setValue] = useState("");
  const [status, setStatus] = useState("Idle");
  const [error, setError] = useState("");

  const isJsonValid = useMemo(() => {
    try {
      JSON.parse(value);
      return true;
    } catch {
      return false;
    }
  }, [value]);

  const load = useCallback(async () => {
    setStatus("Loading...");
    setError("");
    try {
      const res = await fetch(SERVER_URL);
      if (!res.ok) {
        throw new Error(`Load failed (${res.status})`);
      }
      const json = await res.json();
      setValue(JSON.stringify(json, null, 2));
      setStatus("Loaded");
    } catch (err) {
      setError(err instanceof Error ? err.message : "Load failed");
      setStatus("Error");
    }
  }, []);

  const save = useCallback(async () => {
    if (!isJsonValid) {
      setError("JSON is invalid. Fix it before saving.");
      setStatus("Error");
      return;
    }
    setStatus("Saving...");
    setError("");
    try {
      const res = await fetch(SERVER_URL, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: value,
      });
      if (!res.ok) {
        const text = await res.text();
        throw new Error(`Save failed (${res.status}): ${text}`);
      }
      setStatus("Saved");
    } catch (err) {
      setError(err instanceof Error ? err.message : "Save failed");
      setStatus("Error");
    }
  }, [isJsonValid, value]);

  useEffect(() => {
    load();
  }, [load]);

  return (
    <div
      style={{
        minHeight: "100vh",
        background: "#f2efe9",
        color: "#1f1f1f",
        fontFamily: "Georgia, serif",
        padding: "40px",
        boxSizing: "border-box",
      }}
    >
      <div style={{ maxWidth: 900, margin: "0 auto" }}>
        <h1 style={{ fontSize: 36, margin: 0 }}>Layout Editor</h1>
        <p style={{ marginTop: 8, fontSize: 16 }}>
          Edit the JSON layout config and save it back to the repo.
        </p>
        <div style={{ display: "flex", gap: 12, margin: "16px 0" }}>
          <button
            type="button"
            onClick={load}
            style={{
              padding: "10px 16px",
              background: "#1f1f1f",
              color: "#fff",
              border: "none",
              cursor: "pointer",
            }}
          >
            Reload
          </button>
          <button
            type="button"
            onClick={save}
            disabled={!isJsonValid}
            style={{
              padding: "10px 16px",
              background: isJsonValid ? "#d95040" : "#b9b3ab",
              color: "#fff",
              border: "none",
              cursor: isJsonValid ? "pointer" : "not-allowed",
            }}
          >
            Save
          </button>
          <div style={{ display: "flex", alignItems: "center" }}>
            <strong>Status:</strong>&nbsp;{status}
          </div>
        </div>
        {error ? (
          <div
            style={{
              background: "#fff0ee",
              border: "1px solid #d95040",
              color: "#a83a2d",
              padding: "10px 12px",
              marginBottom: 12,
            }}
          >
            {error}
          </div>
        ) : null}
        <textarea
          value={value}
          onChange={(event) => setValue(event.target.value)}
          spellCheck={false}
          style={{
            width: "100%",
            minHeight: "65vh",
            padding: 16,
            border: "1px solid #c9c3bb",
            background: "#fffdf9",
            fontFamily: "ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace",
            fontSize: 14,
            lineHeight: 1.5,
            boxSizing: "border-box",
          }}
        />
      </div>
    </div>
  );
}

export const Editor: Story = {
  render: () => <LayoutEditor />,
};