import fs from "node:fs";
import path from "node:path";
import AdmZip from "adm-zip";
import { APP_VERSION } from "./constants";
import { getAuditLogPath } from "./audit-log";
import { getLogFilePath } from "./logger";
import { getPackageLogPath } from "./package-log";
import { getSessionLogPath } from "./session-log";
import { createStoragePaths, loadHistory, loadSettings } from "./storage";
import { buildAccountSummary, buildRedactedSettingsPayload, buildStatsPayload, summarizeHistoryEntry } from "./support-data";
import { getTraceConfig, getTraceConfigPath, getTraceLogPath } from "./trace-log";
import { getWindowsHostDiagnostics } from "./windows-host-diagnostics";
import type { DownloadManager } from "./download-manager";

const AI_MANIFEST_FILE = "debug_ai_manifest.json";

function safeReadJson(filePath: string): unknown {
  try {
    return JSON.parse(fs.readFileSync(filePath, "utf8")) as unknown;
  } catch {
    return null;
  }
}

function addJson(zip: AdmZip, zipPath: string, value: unknown): void {
  zip.addFile(zipPath, Buffer.from(`${JSON.stringify(value, null, 2)}\n`, "utf8"));
}

function addFileIfExists(zip: AdmZip, sourcePath: string | null, zipPath: string): void {
  if (!sourcePath || !fs.existsSync(sourcePath)) {
    return;
  }
  zip.addLocalFile(sourcePath, path.posix.dirname(zipPath), path.posix.basename(zipPath));
}

function addDirectoryIfExists(zip: AdmZip, dirPath: string, zipRoot: string): void {
  if (!fs.existsSync(dirPath)) {
    return;
  }
  const entries = fs.readdirSync(dirPath, { withFileTypes: true });
  for (const entry of entries) {
    const fullPath = path.join(dirPath, entry.name);
    const zipPath = path.posix.join(zipRoot, entry.name);
    if (entry.isDirectory()) {
      addDirectoryIfExists(zip, fullPath, zipPath);
      continue;
    }
    zip.addLocalFile(fullPath, path.posix.dirname(zipPath), path.posix.basename(zipPath));
  }
}

function formatTimestampForFileName(date: Date): string {
  const y = date.getFullYear();
  const mo = String(date.getMonth() + 1).padStart(2, "0");
  const d = String(date.getDate()).padStart(2, "0");
  const h = String(date.getHours()).padStart(2, "0");
  const mi = String(date.getMinutes()).padStart(2, "0");
  const s = String(date.getSeconds()).padStart(2, "0");
  return `${y}-${mo}-${d}_${h}-${mi}-${s}`;
}

export function getSupportBundleDefaultFileName(): string {
  return `rd-support-bundle-${formatTimestampForFileName(new Date())}.zip`;
}

export function buildSupportBundle(manager: DownloadManager, baseDir: string): Buffer {
  const zip = new AdmZip();
  const storagePaths = createStoragePaths(baseDir);
  const settings = loadSettings(storagePaths);
  const history = loadHistory(storagePaths);
  const snapshot = manager.getSnapshot();
  const packageIds = Object.keys(snapshot.session.packages);
  const itemIds = Object.keys(snapshot.session.items);

  addJson(zip, "overview/meta.json", {
    appVersion: APP_VERSION,
    generatedAt: new Date().toISOString(),
    runtimeBaseDir: baseDir,
    packageCount: packageIds.length,
    itemCount: itemIds.length
  });
  addJson(zip, "overview/status.json", snapshot.session);
  addJson(zip, "overview/settings.json", buildRedactedSettingsPayload(settings));
  addJson(zip, "overview/accounts.json", buildAccountSummary(settings));
  addJson(zip, "overview/stats.json", {
    ...buildStatsPayload(snapshot),
    allTime: {
      totalDownloadedAllTime: settings.totalDownloadedAllTime,
      totalCompletedFilesAllTime: settings.totalCompletedFilesAllTime
    }
  });
  addJson(zip, "overview/history.json", {
    total: history.length,
    entries: history.map((entry) => summarizeHistoryEntry(entry))
  });
  addJson(zip, "overview/packages.json", {
    count: packageIds.length,
    packages: packageIds.map((packageId) => snapshot.session.packages[packageId]).filter(Boolean)
  });
  addJson(zip, "overview/items.json", {
    count: itemIds.length,
    items: itemIds.map((itemId) => snapshot.session.items[itemId]).filter(Boolean)
  });
  addJson(zip, "overview/host-diagnostics.json", getWindowsHostDiagnostics());
  addJson(zip, "overview/trace-config.json", getTraceConfig());

  addFileIfExists(zip, path.join(baseDir, AI_MANIFEST_FILE), `runtime/${AI_MANIFEST_FILE}`);
  addFileIfExists(zip, path.join(baseDir, "debug_host.txt"), "runtime/debug_host.txt");
  addFileIfExists(zip, path.join(baseDir, "debug_port.txt"), "runtime/debug_port.txt");
  addFileIfExists(zip, storagePaths.configFile, "runtime/rd_downloader_config.json");
  addFileIfExists(zip, storagePaths.sessionFile, "runtime/rd_session_state.json");
  addFileIfExists(zip, storagePaths.historyFile, "runtime/rd_history.json");
  addFileIfExists(zip, getTraceConfigPath(), "runtime/trace_config.json");

  addFileIfExists(zip, getLogFilePath(), "logs/rd_downloader.log");
  addFileIfExists(zip, `${getLogFilePath()}.old`, "logs/rd_downloader.log.old");
  addFileIfExists(zip, getAuditLogPath(), "logs/audit.log");
  addFileIfExists(zip, getSessionLogPath(), "logs/session.log");
  addFileIfExists(zip, getTraceLogPath(), "logs/trace.log");

  addDirectoryIfExists(zip, path.join(baseDir, "session-logs"), "logs/session-logs");
  addDirectoryIfExists(zip, path.join(baseDir, "package-logs"), "logs/package-logs");
  addDirectoryIfExists(zip, path.join(baseDir, "item-logs"), "logs/item-logs");

  for (const packageId of packageIds) {
    addFileIfExists(zip, manager.getPackageLogPath(packageId) || getPackageLogPath(packageId), `logs/live/package-${packageId}.txt`);
  }
  for (const itemId of itemIds) {
    addFileIfExists(zip, manager.getItemLogPath(itemId), `logs/live/item-${itemId}.txt`);
  }

  const aiManifest = safeReadJson(path.join(baseDir, AI_MANIFEST_FILE));
  if (aiManifest) {
    addJson(zip, "overview/ai-manifest.json", aiManifest);
  }

  return zip.toBuffer();
}