"use client";

import { useState } from "react";
import useSWR from "swr";
import AppShell from "@/components/AppShell";
import { PageHeader } from "@/components/ui";
import { api, fetcher } from "@/lib/api";
import { useAuth } from "@/lib/auth";

type RulesResponse = {
  yaml: string;
  parsed: { rules?: { id: string; name: string; priority?: number }[] };
  path_hint: string;
};

export default function RulesPage() {
  const { user } = useAuth();
  const isAdmin = user?.role === "admin";
  const { data, mutate } = useSWR<RulesResponse>("/api/rules/troubleshooting", fetcher);
  const [yaml, setYaml] = useState<string | null>(null);
  const [previewTitle, setPreviewTitle] = useState("Asterisk health status");
  const [previewIssue, setPreviewIssue] = useState("Check voip pjsip registration on GeneseasX");
  const [preview, setPreview] = useState<{ matched: Record<string, unknown> | null } | null>(null);
  const [saving, setSaving] = useState(false);
  const [msg, setMsg] = useState<string | null>(null);

  const content = yaml ?? data?.yaml ?? "";

  const [msgKind, setMsgKind] = useState<"ok" | "err">("ok");

  const save = async () => {
    setSaving(true);
    setMsg(null);
    try {
      await api("/api/rules/troubleshooting", { method: "PUT", body: JSON.stringify({ yaml: content }) });
      setMsgKind("ok");
      setMsg("Rules saved — next task run will use them.");
      setYaml(null);
      mutate();
    } catch (err: unknown) {
      setMsgKind("err");
      setMsg(err instanceof Error ? err.message : "Save failed");
    } finally {
      setSaving(false);
    }
  };

  const runPreview = async () => {
    setPreview(null);
    try {
      const res = await api<{ matched: Record<string, unknown> | null }>("/api/rules/troubleshooting/preview", {
        method: "POST",
        body: JSON.stringify({ title: previewTitle, issue: previewIssue }),
      });
      setPreview(res);
    } catch (err: unknown) {
      setMsg(err instanceof Error ? err.message : "Preview failed");
    }
  };

  return (
    <AppShell>
      <PageHeader
        title="Troubleshooting rules"
        subtitle="Standardize which devices to check and investigation order — YAML editable by admins"
      />

      <div className="mb-6 grid gap-4 lg:grid-cols-2">
        <div className="card">
          <h3 className="mb-2 text-sm font-semibold">Rule preview</h3>
          <p className="mb-3 text-xs text-muted">Test which rule matches a task title + issue.</p>
          <input
            className="input mb-2 w-full"
            value={previewTitle}
            onChange={(e) => setPreviewTitle(e.target.value)}
            placeholder="Task title"
          />
          <textarea
            className="input mb-2 min-h-[80px] w-full"
            value={previewIssue}
            onChange={(e) => setPreviewIssue(e.target.value)}
            placeholder="Issue description"
          />
          <button type="button" className="btn-secondary" onClick={runPreview}>
            Preview match
          </button>
          {preview?.matched && (
            <pre className="mt-3 overflow-x-auto rounded-lg bg-panel2 p-3 text-xs">
              {JSON.stringify(preview.matched, null, 2)}
            </pre>
          )}
          {preview && !preview.matched && (
            <p className="mt-3 text-sm text-muted">No specific rule — keyword fallback / all devices.</p>
          )}
        </div>

        <div className="card">
          <h3 className="mb-2 text-sm font-semibold">Defined rules</h3>
          <ul className="space-y-2 text-sm">
            {(data?.parsed?.rules || []).map((r) => (
              <li key={r.id} className="flex justify-between gap-2 border-b border-edge/50 py-2">
                <span>{r.name}</span>
                <span className="text-xs text-muted">priority {r.priority ?? 0}</span>
              </li>
            ))}
          </ul>
          <p className="mt-3 text-xs text-muted">File: {data?.path_hint}</p>
        </div>
      </div>

      <div className="card">
        <div className="mb-2 flex items-center justify-between">
          <h3 className="text-sm font-semibold">YAML editor</h3>
          {!isAdmin && <span className="text-xs text-muted">Read-only (admin can edit)</span>}
        </div>
        <textarea
          className="input min-h-[420px] w-full font-mono text-xs leading-relaxed"
          value={content}
          onChange={(e) => isAdmin && setYaml(e.target.value)}
          readOnly={!isAdmin}
          spellCheck={false}
        />
        {msg && (
          <p className={`mt-2 text-sm ${msgKind === "ok" ? "text-good" : "text-bad"}`}>{msg}</p>
        )}
        {isAdmin && (
          <button type="button" className="btn-primary mt-4" disabled={saving} onClick={save}>
            {saving ? "Saving…" : "Save rules"}
          </button>
        )}
      </div>
    </AppShell>
  );
}