import { getErrorMessage } from "@minikura/shared/errors";
import { Elysia } from "elysia";
import { k8sService } from "../application/di-container";
import { logger } from "../infrastructure/logger";

type TerminalWsData = {
  query?: Record<string, string>;
  k8sWs?: WebSocket;
};

type TerminalWs = {
  data: TerminalWsData;
  send: (message: string) => void;
  close: () => void;
};

type TerminalMessage =
  | { type: "input"; data: string }
  | { type: "resize"; cols: number; rows: number };

type BunTlsOptions = {
  rejectUnauthorized: boolean;
  cert?: string;
  key?: string;
  ca?: string;
};

export const terminalRoutes = new Elysia({ prefix: "/terminal" }).ws("/exec", {
  open: async (ws: TerminalWs) => {
    const podName = ws.data.query?.podName;
    const container = ws.data.query?.container;
    const shell = ws.data.query?.shell || "/bin/sh";
    const mode = ws.data.query?.mode || "shell";

    logger.debug(
      `Opening terminal for pod: ${podName}, container: ${container}, shell: ${shell}, mode: ${mode}`
    );

    if (!podName) {
      ws.send(
        JSON.stringify({
          type: "error",
          data: "Pod name is required",
        })
      );
      ws.close();
      return;
    }

    try {
      if (!k8sService.isInitialized()) {
        ws.send(
          JSON.stringify({
            type: "error",
            data: "Kubernetes client not initialized",
          })
        );
        ws.close();
        return;
      }

      const kc = k8sService.getKubeConfig();
      const namespace = k8sService.getNamespace();
      const cluster = kc.getCurrentCluster();
      const user = kc.getCurrentUser();

      if (!cluster) {
        throw new Error("No current cluster configured");
      }

      const server = cluster.server;
      const isAttach = mode === "attach";
      const apiPath = isAttach
        ? `/api/v1/namespaces/${namespace}/pods/${podName}/attach`
        : `/api/v1/namespaces/${namespace}/pods/${podName}/exec`;

      const params = new URLSearchParams({
        stdout: "true",
        stderr: "true",
        stdin: "true",
        tty: "true",
      });

      if (!isAttach) {
        params.append("command", shell);
      }

      if (container) {
        params.append("container", container);
      }

      const wsUrl = `${server}${apiPath}?${params.toString()}`
        .replace("https://", "wss://")
        .replace("http://", "ws://");

      logger.debug(`Connecting to Kubernetes: ${wsUrl}`);

      const headers: Record<string, string> = {
        Connection: "Upgrade",
        Upgrade: "websocket",
        "Sec-WebSocket-Version": "13",
        "Sec-WebSocket-Key": Buffer.from(Math.random().toString())
          .toString("base64")
          .substring(0, 24),
        "Sec-WebSocket-Protocol": "v4.channel.k8s.io",
      };

      if (user?.token) {
        headers.Authorization = `Bearer ${user.token}`;
      } else if (user?.username && user?.password) {
        const auth = Buffer.from(`${user.username}:${user.password}`).toString("base64");
        headers.Authorization = `Basic ${auth}`;
      }

      const tlsOptions: BunTlsOptions = {
        rejectUnauthorized: cluster.skipTLSVerify !== true,
      };

      if (user?.certData) {
        tlsOptions.cert = Buffer.from(user.certData, "base64").toString();
      }
      if (user?.keyData) {
        tlsOptions.key = Buffer.from(user.keyData, "base64").toString();
      }
      if (cluster.caData) {
        tlsOptions.ca = Buffer.from(cluster.caData, "base64").toString();
      }

      const wsOptions = { headers, tls: tlsOptions };
      const k8sWs = new WebSocket(wsUrl, wsOptions as unknown as string | string[]);
      ws.data.k8sWs = k8sWs;

      k8sWs.onopen = async () => {
        logger.debug(`Connected to Kubernetes ${isAttach ? "attach" : "exec"}`);

        if (isAttach) {
          try {
            const coreApi = k8sService.getCoreApi();
            const logs = await coreApi.readNamespacedPodLog({
              name: podName,
              namespace: namespace,
              container: container,
            });

            if (logs) {
              const lines = logs.split("\n");
              for (const line of lines) {
                ws.send(
                  JSON.stringify({
                    type: "output",
                    data: `${line}\r\n`,
                  })
                );
              }
            }

            ws.send(
              JSON.stringify({
                type: "ready",
                data: "Attached to container (showing logs since start)",
              })
            );
          } catch (logError) {
            logger.error("Failed to fetch historical logs:", logError);
            ws.send(
              JSON.stringify({
                type: "ready",
                data: "Attached to container",
              })
            );
          }
        } else {
          ws.send(
            JSON.stringify({
              type: "ready",
              data: "Shell ready",
            })
          );
        }
      };

      k8sWs.onmessage = (event: MessageEvent) => {
        try {
          const data = event.data;

          let buffer: Uint8Array;

          if (data instanceof Uint8Array) {
            buffer = data;
          } else if (data instanceof ArrayBuffer) {
            buffer = new Uint8Array(data);
          } else if (Buffer.isBuffer(data)) {
            buffer = new Uint8Array(data);
          } else if (data instanceof Blob) {
            data.arrayBuffer().then((ab) => {
              const uint8 = new Uint8Array(ab);
              processBuffer(uint8);
            });
            return;
          } else if (typeof data === "string") {
            ws.send(JSON.stringify({ type: "output", data }));
            return;
          } else {
            logger.debug(
              "Unknown data type:",
              typeof data,
              "constructor:",
              data?.constructor?.name
            );
            buffer = new Uint8Array(data);
          }

          processBuffer(buffer);
        } catch (err) {
          logger.error("Error processing Kubernetes message:", err);
        }
      };

      function processBuffer(buffer: Uint8Array): void {
        if (buffer.length === 0) {
          return;
        }

        const channel = buffer[0];
        const message = new TextDecoder().decode(buffer.slice(1));

        if (channel === 1 || channel === 2) {
          ws.send(JSON.stringify({ type: "output", data: message }));
        } else if (channel === 3) {
          logger.error("Kubernetes error channel:", message);
          ws.send(JSON.stringify({ type: "error", data: message }));
        }
      }

      k8sWs.onerror = (error: Event) => {
        logger.error("Kubernetes WebSocket error:", error);
        const message = getErrorMessage(error);
        ws.send(
          JSON.stringify({
            type: "error",
            data: `Connection error: ${message}`,
          })
        );
      };

      k8sWs.onclose = (event: CloseEvent) => {
        logger.debug(`Kubernetes WebSocket closed: ${event.code} ${event.reason}`);
        ws.send(
          JSON.stringify({
            type: "close",
            data: event.reason || "Connection closed",
          })
        );
        ws.close();
      };
    } catch (error: unknown) {
      logger.error("Error setting up terminal:", error);
      if (error instanceof Error) {
        logger.error("Error stack:", error.stack);
      }
      ws.send(
        JSON.stringify({
          type: "error",
          data: `Failed to connect: ${getErrorMessage(error)}`,
        })
      );
      ws.close();
    }
  },

  message: async (ws: TerminalWs, message: unknown) => {
    try {
      const data = parseTerminalMessage(message);
      if (!data) {
        return;
      }

      const k8sWs = ws.data.k8sWs;

      if (!k8sWs || k8sWs.readyState !== WebSocket.OPEN) {
        logger.error("Kubernetes WebSocket not ready, state:", k8sWs?.readyState);
        return;
      }

      if (data.type === "input") {
        logger.debug("Sending input to k8s:", data.data);
        const encoder = new TextEncoder();
        const textData = encoder.encode(data.data);
        const buffer = new Uint8Array(1 + textData.length);
        buffer[0] = 0;
        buffer.set(textData, 1);
        k8sWs.send(buffer.buffer);
      } else if (data.type === "resize") {
        const resizeMsg = JSON.stringify({
          Width: data.cols,
          Height: data.rows,
        });
        const encoder = new TextEncoder();
        const textData = encoder.encode(resizeMsg);
        const buffer = new Uint8Array(1 + textData.length);
        buffer[0] = 4;
        buffer.set(textData, 1);
        k8sWs.send(buffer.buffer);
      }
    } catch (error: unknown) {
      logger.error("Error handling terminal message:", error);
      ws.send(
        JSON.stringify({
          type: "error",
          data: `Error: ${getErrorMessage(error)}`,
        })
      );
    }
  },

  close: (ws: TerminalWs) => {
    logger.debug("Client WebSocket closed");
    const k8sWs = ws.data.k8sWs;
    if (k8sWs && k8sWs.readyState === WebSocket.OPEN) {
      k8sWs.close();
    }
  },
});

function parseTerminalMessage(message: unknown): TerminalMessage | null {
  if (typeof message === "string") {
    try {
      const parsed = JSON.parse(message) as unknown;
      return isTerminalMessage(parsed) ? parsed : null;
    } catch {
      logger.error("Failed to parse message as JSON:", message);
      return null;
    }
  }
  return null;
}

function isTerminalMessage(value: unknown): value is TerminalMessage {
  if (!value || typeof value !== "object") {
    return false;
  }
  if (!("type" in value)) {
    return false;
  }
  const type = (value as { type?: unknown }).type;
  if (type === "input") {
    return typeof (value as { data?: unknown }).data === "string";
  }
  if (type === "resize") {
    const cols = (value as { cols?: unknown }).cols;
    const rows = (value as { rows?: unknown }).rows;
    return typeof cols === "number" && typeof rows === "number";
  }
  return false;
}