/* eslint-disable no-undef */

"use strict";

const {
  SERVICE_LIST_PS_COMMAND,
  buildServiceActionPsCommand,
} = require("./windowsPowerShell.cjs");

/**
 * systemd service management over SSH exec.
 * List/status via systemctl; mutate with optional sudo (same session password
 * pattern as dockerOps).
 */

function shQuote(str) {
  return `'${String(str).replace(/'/g, `'\"'\"'`)}'`;
}

function sanitizeUnitName(name) {
  const trimmed = String(name || "").trim().slice(0, 256);
  // systemd unit names: letters, digits, : . _ @ - and must end with a type suffix ideally
  if (!trimmed || !/^[A-Za-z0-9:._@\\-]+$/.test(trimmed)) return null;
  return trimmed;
}

const ALLOWED_ACTIONS = new Set(["start", "stop", "restart", "enable", "disable", "reload"]);

function normalizeActiveState(raw) {
  const text = String(raw || "").trim().toLowerCase();
  if (
    text === "active"
    || text === "inactive"
    || text === "failed"
    || text === "activating"
    || text === "deactivating"
    || text === "reloading"
  ) {
    return text;
  }
  return "unknown";
}

function normalizeLoadState(raw) {
  const text = String(raw || "").trim().toLowerCase();
  if (
    text === "loaded"
    || text === "not-found"
    || text === "bad-setting"
    || text === "error"
    || text === "masked"
  ) {
    return text;
  }
  return "unknown";
}

function parseSystemctlListUnits(stdout, scope) {
  const units = [];
  for (const line of String(stdout || "").split("\n")) {
    const trimmed = line.trim();
    if (!trimmed) continue;
    const cleaned = trimmed.replace(/^●\s*/, "");
    if (!cleaned || /^UNIT\b/i.test(cleaned) || /^Legend:/i.test(cleaned)) continue;
    if (/^\d+ loaded units listed/i.test(cleaned)) continue;
    if (/^To show all/i.test(cleaned)) continue;
    // UNIT LOAD ACTIVE SUB [DESCRIPTION] — description may be empty
    const m = cleaned.match(/^(\S+)\s+(\S+)\s+(\S+)\s+(\S+)(?:\s+(.*))?$/);
    if (!m) continue;
    const name = m[1];
    if (!name.includes(".")) continue;
    units.push({
      name,
      loadState: normalizeLoadState(m[2]),
      activeState: normalizeActiveState(m[3]),
      subState: m[4],
      description: (m[5] || "").trim(),
      scope,
    });
  }
  return units;
}

function getSessionSudoPassword(session) {
  return typeof session?.systemManagerSudoPassword === "string" && session.systemManagerSudoPassword.length > 0
    ? session.systemManagerSudoPassword
    : null;
}

function isSuccessfulCommandResult(result) {
  return result?.success && (result.code === 0 || result.code === null || result.code === undefined);
}

function commandError(result, fallback) {
  return (result?.stderr || result?.error || "").trim() || fallback;
}

function isPermissionDenied(result) {
  const text = `${result?.stderr || ""}\n${result?.stdout || ""}\n${result?.error || ""}`.toLowerCase();
  return text.includes("permission denied")
    || text.includes("access denied")
    || text.includes("authentication is required")
    || text.includes("interactive authentication required")
    || text.includes("not authorized");
}

const LIST_UNITS_INNER = [
  'printf "%s\\n" "__NC_SERVICES_BEGIN__"; ',
  'if command -v systemctl >/dev/null 2>&1; then ',
  'printf "%s\\n" "__NC_SYSTEM__"; ',
  // --plain needs systemd >= ~230; fall back for RHEL/CentOS 7-era hosts.
  "systemctl list-units --type=service --all --no-pager --no-legend --plain 2>/dev/null ",
  "|| systemctl list-units --type=service --all --no-pager --no-legend 2>/dev/null ",
  "|| true; ",
  'printf "%s\\n" "__NC_USER__"; ',
  "systemctl --user list-units --type=service --all --no-pager --no-legend --plain 2>/dev/null ",
  "|| systemctl --user list-units --type=service --all --no-pager --no-legend 2>/dev/null ",
  "|| true; ",
  "fi; ",
  'printf "%s\\n" "__NC_SERVICES_END__"',
].join("");

const LIST_UNITS_SCRIPT = `exec sh -c ${JSON.stringify(LIST_UNITS_INNER)}`;

function extractBetween(stdout, startMarker, endMarkers) {
  const text = String(stdout || "");
  const begin = text.indexOf(startMarker);
  if (begin < 0) return "";
  const after = text.slice(begin + startMarker.length);
  let end = -1;
  for (const marker of endMarkers) {
    const idx = after.indexOf(marker);
    if (idx >= 0 && (end < 0 || idx < end)) end = idx;
  }
  return end >= 0 ? after.slice(0, end) : after;
}

function parseServiceList(stdout) {
  const text = String(stdout || "");
  const systemPart = extractBetween(text, "__NC_SYSTEM__", ["__NC_USER__", "__NC_SERVICES_END__"]);
  const userPart = extractBetween(text, "__NC_USER__", ["__NC_SERVICES_END__"]);
  const systemUnits = parseSystemctlListUnits(systemPart, "system");
  const userUnits = parseSystemctlListUnits(userPart, "user");
  // Prefer system unit when names collide
  const seen = new Set(systemUnits.map((u) => u.name));
  const merged = systemUnits.slice();
  for (const unit of userUnits) {
    if (seen.has(unit.name)) continue;
    seen.add(unit.name);
    merged.push(unit);
  }
  merged.sort((a, b) => {
    if (a.activeState === "failed" && b.activeState !== "failed") return -1;
    if (b.activeState === "failed" && a.activeState !== "failed") return 1;
    return a.name.localeCompare(b.name);
  });
  return merged;
}

/** Parse Windows Get-Service JSON output (from SERVICE_LIST_PS_COMMAND). */
function parseWindowsServices(stdout) {
  const text = String(stdout || "").trim();
  if (!text) return [];
  let raw;
  try {
    raw = JSON.parse(text);
  } catch {
    return [];
  }
  const list = Array.isArray(raw) ? raw : raw ? [raw] : [];

  // Windows ServiceControllerStatus enum:
  //   0=Stopped, 1=StartPending, 2=StopPending, 3=Running,
  //   4=ContinuePending, 5=PausePending, 6=Paused
  const STATUS_NUMBER_TO_NAME = {
    0: "stopped",
    1: "startpending",
    2: "stoppending",
    3: "running",
    4: "continuepending",
    5: "pausepending",
    6: "paused",
  };

  const units = list.map((s) => {
    const name = String(s.Name || "");
    if (!name) return null;
    let status = String(s.Status || "").toLowerCase();
    // Handle numeric enum values from ConvertTo-Json (older PS / direct enum cast)
    if (!status || /^\d+$/.test(status)) {
      const num = Number(status);
      status = STATUS_NUMBER_TO_NAME[num] || "unknown";
    }
    const startType = String(s.StartType || "").toLowerCase();
    let activeState = "unknown";
    if (status === "running" || status === "continuepending") activeState = "active";
    else if (status === "stopped" || status === "stoppending" || status === "paused" || status === "pausepending" || status === "startpending") activeState = "inactive";
    let loadState = "loaded";
    if (startType === "disabled") loadState = "loaded";
    const subState = status || "unknown";
    return {
      name,
      loadState,
      activeState,
      subState,
      description: String(s.DisplayName || ""),
      scope: "system",
    };
  }).filter(Boolean);
  units.sort((a, b) => {
    if (a.activeState === "failed" && b.activeState !== "failed") return -1;
    if (b.activeState === "failed" && a.activeState !== "failed") return 1;
    return a.name.localeCompare(b.name);
  });
  return units;
}

function createServiceOpsApi({
  execOnSession,
  getSession,
}) {
  async function listServices(event, sessionId) {
    if (!sessionId) return { success: false, error: "Missing sessionId" };

    // POSIX first (systemd).
    const posixResult = await execOnSession(event, sessionId, LIST_UNITS_SCRIPT, 20000, {
      maxBuffer: 16 * 1024 * 1024,
    });
    if (posixResult.pending) return { success: false, pending: true };
    const posixOk = posixResult.success;
    const posixUnits = posixOk ? parseServiceList(posixResult.stdout) : [];

    // POSIX gave zero services — try Windows PowerShell Get-Service.
    if (!posixOk || posixUnits.length === 0) {
      console.log(`[Services] POSIX failed=${!posixOk}, got ${posixUnits.length} units → trying PowerShell fallback.`);
      const psResult = await execOnSession(event, sessionId, SERVICE_LIST_PS_COMMAND, 15000, {
        maxBuffer: 16 * 1024 * 1024,
      });
      if (psResult.pending) return { success: false, pending: true };
      console.log(`[Services] PowerShell result: success=${psResult.success}, code=${psResult.code}, error=${JSON.stringify(psResult.error||'').slice(0,120)}, stdoutSnippet=${JSON.stringify((psResult.stdout||'').slice(0,300))}`);
      if (psResult.success) {
        const winUnits = parseWindowsServices(psResult.stdout);
        console.log(`[Services] PowerShell parsed ${winUnits.length} services.`);
        if (winUnits.length > 0) {
          return { success: true, units: winUnits };
        }
      }
    }

    if (!posixOk) return { success: false, error: posixResult.error || "Failed to list services" };
    return { success: true, units: posixUnits };
  }

  async function serviceAction(event, payload) {
    const sessionId = payload?.sessionId;
    const unitName = sanitizeUnitName(payload?.unitName);
    const action = String(payload?.action || "").toLowerCase();
    const scope = payload?.scope === "user" ? "user" : "system";
    if (!sessionId || !unitName) return { success: false, error: "Missing sessionId or unitName" };
    if (!ALLOWED_ACTIONS.has(action)) return { success: false, error: "Invalid action" };

    const userFlag = scope === "user" ? "--user " : "";
    const baseCmd = `systemctl ${userFlag}${action} ${shQuote(unitName)}`;
    const wrapped = `exec sh -c ${JSON.stringify(baseCmd)}`;

    let result = await execOnSession(event, sessionId, wrapped, 30000);
    if (result.pending) return { success: false, pending: true };
    if (isSuccessfulCommandResult(result)) return { success: true };

    // User-scope units should not escalate via sudo.
    if (scope !== "user" && isPermissionDenied(result)) {
      const sudoPassword = getSessionSudoPassword(getSession?.(sessionId));
      const passwordless = `exec sh -c ${JSON.stringify(`sudo systemctl ${action} ${shQuote(unitName)}`)}`;
      const passwordlessResult = await execOnSession(event, sessionId, passwordless, 30000);
      if (passwordlessResult.pending) return { success: false, pending: true };
      if (isSuccessfulCommandResult(passwordlessResult)) return { success: true };

      if (sudoPassword) {
        const withPassword = `exec sh -c ${JSON.stringify(`sudo -S -p '' systemctl ${action} ${shQuote(unitName)}`)}`;
        const sudoResult = await execOnSession(event, sessionId, withPassword, 30000, {
          stdin: `${sudoPassword}\n`,
        });
        if (sudoResult.pending) return { success: false, pending: true };
        if (isSuccessfulCommandResult(sudoResult)) return { success: true };
        return { success: false, error: commandError(sudoResult, `sudo systemctl ${action} failed`) };
      }

      return {
        success: false,
        error: commandError(
          passwordlessResult.success === false ? passwordlessResult : result,
          `systemctl ${action} failed (sudo required)`,
        ),
      };
    }

    // systemctl failed for a non-POSIX reason (Windows host, systemctl not found).
    // Try Windows PowerShell service action.
    if (!isPermissionDenied(result)) {
      const psCmd = buildServiceActionPsCommand(action, unitName);
      if (psCmd) {
        const psResult = await execOnSession(event, sessionId, psCmd, 30000);
        if (psResult.pending) return { success: false, pending: true };
        if (isSuccessfulCommandResult(psResult)) return { success: true };
        if (!psResult.success) {
          return {
            success: false,
            error: commandError(psResult, `PowerShell ${action} service failed`),
          };
        }
      }
    }

    return { success: false, error: commandError(result, `systemctl ${action} failed`) };
  }

  return {
    listServices,
    serviceAction,
    parseServiceList,
    parseSystemctlListUnits,
    parseWindowsServices,
    sanitizeUnitName,
  };
}

module.exports = {
  createServiceOpsApi,
  parseServiceList,
  parseSystemctlListUnits,
  parseWindowsServices,
  sanitizeUnitName,
  LIST_UNITS_SCRIPT,
};