import { useState, useRef } from "react";
import { useMutation } from "@tanstack/react-query";
import {
  Upload,
  Download,
  FileJson,
  CheckCircle,
  XCircle,
  AlertTriangle,
  Loader2,
  ChevronDown,
  ChevronUp,
} from "lucide-react";
import { importRT, type RTImportPayload, type RTTechniqueEntry } from "../api/tests";

/* ── Template JSON ─────────────────────────────────────────────────── */

const TEMPLATE_JSON: RTImportPayload = {
  name: "Red Team Q1 2024",
  date: new Date().toISOString().slice(0, 10),
  description: "External red team engagement — perimeter assessment",
  operator: "SecTeam Red",
  techniques: [
    {
      mitre_id: "T1059.001",
      result: "detected",
      attack_success: true,
      platform: "windows",
      notes: "PowerShell execution caught by Defender for Endpoint within 2 min",
    },
    {
      mitre_id: "T1078",
      result: "not_detected",
      attack_success: true,
      platform: "windows",
      notes: "Credential reuse via stolen credentials — undetected for 48h",
    },
    {
      mitre_id: "T1486",
      result: "not_detected",
      attack_success: false,
      platform: "windows",
      notes: "Ransomware blocked by AppLocker before execution",
    },
    {
      mitre_id: "T1190",
      result: "partially_detected",
      attack_success: true,
      platform: "linux",
      notes: "Exploit worked but only a partial alert fired — no full incident created",
    },
  ],
};

/* ── helpers ─────────────────────────────────────────────────────── */

const RESULT_CONFIG: Record<string, { label: string; badge: string }> = {
  detected:           { label: "Detected",          badge: "bg-green-500/10 text-green-400 border-green-500/20" },
  not_detected:       { label: "Not Detected",       badge: "bg-red-500/10 text-red-400 border-red-500/20" },
  partially_detected: { label: "Partial",            badge: "bg-yellow-500/10 text-yellow-400 border-yellow-500/20" },
};

function downloadTemplate() {
  const blob = new Blob([JSON.stringify(TEMPLATE_JSON, null, 2)], { type: "application/json" });
  const a = document.createElement("a");
  a.href = URL.createObjectURL(blob);
  a.download = "rt_import_template.json";
  a.click();
  URL.revokeObjectURL(a.href);
}

function parseJson(raw: string): { payload: RTImportPayload | null; error: string | null } {
  try {
    const parsed = JSON.parse(raw);
    if (!parsed.name) return { payload: null, error: "Missing required field: name" };
    if (!Array.isArray(parsed.techniques)) return { payload: null, error: "Missing required field: techniques (array)" };
    for (const t of parsed.techniques) {
      if (!t.mitre_id) return { payload: null, error: `Technique missing mitre_id: ${JSON.stringify(t)}` };
      if (!["detected", "not_detected", "partially_detected"].includes(t.result)) {
        return { payload: null, error: `Invalid result '${t.result}' for ${t.mitre_id}. Must be: detected | not_detected | partially_detected` };
      }
    }
    return { payload: parsed as RTImportPayload, error: null };
  } catch (e) {
    return { payload: null, error: `Invalid JSON: ${(e as Error).message}` };
  }
}

/* ── Component ────────────────────────────────────────────────────── */

export default function ImportRTPage() {
  const fileRef = useRef<HTMLInputElement>(null);
  const [jsonText, setJsonText] = useState("");
  const [showFormat, setShowFormat] = useState(false);
  const [parseError, setParseError] = useState<string | null>(null);
  const [preview, setPreview] = useState<RTImportPayload | null>(null);

  const importMutation = useMutation({
    mutationFn: (payload: RTImportPayload) => importRT(payload),
  });

  const handleTextChange = (value: string) => {
    setJsonText(value);
    setParseError(null);
    importMutation.reset();
    if (!value.trim()) {
      setPreview(null);
      return;
    }
    const { payload, error } = parseJson(value);
    if (error) {
      setParseError(error);
      setPreview(null);
    } else {
      setPreview(payload);
    }
  };

  const handleFile = (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;
    const reader = new FileReader();
    reader.onload = (ev) => {
      const text = ev.target?.result as string;
      setJsonText(text);
      handleTextChange(text);
    };
    reader.readAsText(file);
    e.target.value = "";
  };

  const handleImport = () => {
    if (!preview) return;
    importMutation.mutate(preview);
  };

  const result = importMutation.data;

  return (
    <div className="space-y-6 max-w-4xl">
      {/* Header */}
      <div>
        <h1 className="text-2xl font-bold text-white flex items-center gap-2">
          <Upload className="h-7 w-7 text-orange-400" />
          Import Red Team Results
        </h1>
        <p className="mt-1 text-sm text-gray-400">
          Upload findings from a real Red Team engagement. Each technique becomes a validated test
          with its detection result, maintaining full coverage history.
        </p>
      </div>

      {/* Format toggle */}
      <div className="rounded-xl border border-gray-800 bg-gray-900">
        <button
          onClick={() => setShowFormat(!showFormat)}
          className="flex w-full items-center justify-between px-5 py-4 text-left"
        >
          <div className="flex items-center gap-2">
            <FileJson className="h-4 w-4 text-cyan-400" />
            <span className="text-sm font-medium text-gray-300">JSON Format Reference</span>
          </div>
          {showFormat ? <ChevronUp className="h-4 w-4 text-gray-500" /> : <ChevronDown className="h-4 w-4 text-gray-500" />}
        </button>

        {showFormat && (
          <div className="border-t border-gray-800 px-5 pb-5 pt-4 space-y-4">
            <div className="grid gap-4 sm:grid-cols-2">
              {/* Required fields */}
              <div>
                <p className="mb-2 text-xs font-semibold uppercase tracking-wider text-gray-500">Required fields</p>
                <table className="w-full text-xs">
                  <tbody className="divide-y divide-gray-800">
                    {[
                      ["name", "string", "Engagement name"],
                      ["techniques[].mitre_id", "string", "e.g. T1059.001"],
                      ["techniques[].result", "enum", "detected | not_detected | partially_detected"],
                      ["techniques[].attack_success", "boolean", "Was the attack successful?"],
                    ].map(([field, type, desc]) => (
                      <tr key={field}>
                        <td className="py-1.5 pr-3 font-mono text-cyan-400">{field}</td>
                        <td className="py-1.5 pr-3 text-gray-500 italic">{type}</td>
                        <td className="py-1.5 text-gray-400">{desc}</td>
                      </tr>
                    ))}
                  </tbody>
                </table>
              </div>
              {/* Optional fields */}
              <div>
                <p className="mb-2 text-xs font-semibold uppercase tracking-wider text-gray-500">Optional fields</p>
                <table className="w-full text-xs">
                  <tbody className="divide-y divide-gray-800">
                    {[
                      ["date", "string", "ISO date (YYYY-MM-DD)"],
                      ["description", "string", "Engagement description"],
                      ["operator", "string", "Team or company"],
                      ["techniques[].platform", "string", "windows | linux | macos"],
                      ["techniques[].notes", "string", "What happened, how it was used"],
                    ].map(([field, type, desc]) => (
                      <tr key={field}>
                        <td className="py-1.5 pr-3 font-mono text-gray-400">{field}</td>
                        <td className="py-1.5 pr-3 text-gray-500 italic">{type}</td>
                        <td className="py-1.5 text-gray-400">{desc}</td>
                      </tr>
                    ))}
                  </tbody>
                </table>
              </div>
            </div>

            <button
              onClick={downloadTemplate}
              className="flex items-center gap-2 rounded-lg border border-cyan-500/30 bg-cyan-500/10 px-4 py-2 text-sm font-medium text-cyan-400 hover:bg-cyan-500/20 transition-colors"
            >
              <Download className="h-4 w-4" />
              Download template JSON
            </button>
          </div>
        )}
      </div>

      {/* Input area */}
      <div className="rounded-xl border border-gray-800 bg-gray-900 p-5 space-y-4">
        <div className="flex items-center justify-between">
          <h2 className="text-sm font-semibold text-white">Paste or upload your JSON</h2>
          <div className="flex items-center gap-2">
            <input ref={fileRef} type="file" accept=".json" onChange={handleFile} className="hidden" />
            <button
              onClick={() => fileRef.current?.click()}
              className="flex items-center gap-1.5 rounded-lg border border-gray-700 px-3 py-1.5 text-xs text-gray-400 hover:bg-gray-800 hover:text-white transition-colors"
            >
              <Upload className="h-3.5 w-3.5" />
              Upload file
            </button>
          </div>
        </div>

        <textarea
          value={jsonText}
          onChange={(e) => handleTextChange(e.target.value)}
          placeholder={`Paste your JSON here or use the template…\n\n{\n  "name": "Red Team Q1 2024",\n  "techniques": [\n    {\n      "mitre_id": "T1059.001",\n      "result": "detected",\n      "attack_success": true\n    }\n  ]\n}`}
          rows={14}
          className="w-full rounded-lg border border-gray-700 bg-gray-800 px-3 py-2.5 font-mono text-xs text-gray-200 placeholder-gray-600 focus:border-cyan-500 focus:outline-none resize-none"
        />

        {parseError && (
          <div className="flex items-start gap-2 rounded-lg border border-red-500/30 bg-red-900/20 p-3 text-sm text-red-400">
            <XCircle className="h-4 w-4 mt-0.5 shrink-0" />
            {parseError}
          </div>
        )}
      </div>

      {/* Preview */}
      {preview && !parseError && (
        <div className="rounded-xl border border-gray-800 bg-gray-900 p-5 space-y-4">
          <div className="flex items-center justify-between">
            <div>
              <h2 className="text-sm font-semibold text-white">{preview.name}</h2>
              <p className="mt-0.5 text-xs text-gray-500">
                {preview.date && <span>{preview.date} · </span>}
                {preview.operator && <span>{preview.operator} · </span>}
                <span className="text-amber-400">{preview.techniques.length} techniques</span>
              </p>
              {preview.description && (
                <p className="mt-1 text-xs text-gray-400">{preview.description}</p>
              )}
            </div>
            <button
              onClick={handleImport}
              disabled={importMutation.isPending}
              className="flex items-center gap-2 rounded-lg bg-orange-600 px-4 py-2 text-sm font-medium text-white hover:bg-orange-500 disabled:opacity-50 transition-colors"
            >
              {importMutation.isPending
                ? <><Loader2 className="h-4 w-4 animate-spin" /> Importing…</>
                : <><Upload className="h-4 w-4" /> Import {preview.techniques.length} Techniques</>
              }
            </button>
          </div>

          <div className="overflow-x-auto rounded-lg border border-gray-800">
            <table className="w-full text-xs">
              <thead>
                <tr className="border-b border-gray-800 text-gray-500 uppercase tracking-wider">
                  <th className="px-4 py-2.5 text-left">MITRE ID</th>
                  <th className="px-4 py-2.5 text-left">Result</th>
                  <th className="px-4 py-2.5 text-left">Attack</th>
                  <th className="px-4 py-2.5 text-left">Platform</th>
                  <th className="px-4 py-2.5 text-left">Notes</th>
                </tr>
              </thead>
              <tbody className="divide-y divide-gray-800/50">
                {preview.techniques.map((t: RTTechniqueEntry, i) => (
                  <tr key={i} className="hover:bg-gray-800/20">
                    <td className="px-4 py-2.5 font-mono text-cyan-400 font-semibold">{t.mitre_id}</td>
                    <td className="px-4 py-2.5">
                      <span className={`inline-flex rounded-full border px-2 py-0.5 font-medium ${RESULT_CONFIG[t.result]?.badge ?? ""}`}>
                        {RESULT_CONFIG[t.result]?.label ?? t.result}
                      </span>
                    </td>
                    <td className="px-4 py-2.5">
                      {t.attack_success
                        ? <span className="text-orange-400">Success</span>
                        : <span className="text-gray-500">Blocked</span>
                      }
                    </td>
                    <td className="px-4 py-2.5 text-gray-400 capitalize">{t.platform ?? "—"}</td>
                    <td className="px-4 py-2.5 text-gray-500 max-w-xs truncate">{t.notes ?? "—"}</td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        </div>
      )}

      {/* Import result */}
      {result && (
        <div className="rounded-xl border border-green-500/30 bg-green-500/5 p-5 space-y-3">
          <div className="flex items-center gap-2">
            <CheckCircle className="h-5 w-5 text-green-400" />
            <h2 className="text-sm font-semibold text-green-400">
              Import complete — {result.created} tests created
            </h2>
          </div>
          <p className="text-xs text-gray-400">
            Engagement: <span className="text-white">{result.engagement}</span>
            {" · "}Created: <span className="text-green-400">{result.created}</span>
            {result.skipped > 0 && <>{" · "}<span className="text-yellow-400">{result.skipped} skipped</span></>}
          </p>

          {result.warnings.length > 0 && (
            <div className="space-y-1">
              <p className="text-xs font-medium text-yellow-400 flex items-center gap-1">
                <AlertTriangle className="h-3.5 w-3.5" /> Skipped entries
              </p>
              {result.warnings.map((w, i) => (
                <p key={i} className="text-xs text-gray-500 ml-5">
                  <span className="font-mono text-gray-400">{w.mitre_id}</span>: {w.reason}
                </p>
              ))}
            </div>
          )}
        </div>
      )}

      {importMutation.isError && (
        <div className="flex items-start gap-2 rounded-xl border border-red-500/30 bg-red-900/20 p-4 text-sm text-red-400">
          <XCircle className="h-4 w-4 mt-0.5 shrink-0" />
          {(importMutation.error as Error)?.message || "Import failed"}
        </div>
      )}
    </div>
  );
}