import { exec as execCallback } from "child_process";
import { promisify } from "util";
import { v4 as uuidv4 } from "uuid";

const exec = promisify(execCallback);

// Basic interfaces for tmux objects
export interface TmuxSession {
  id: string;
  name: string;
  attached: boolean;
  windows: number;
}

export interface TmuxWindow {
  id: string;
  name: string;
  active: boolean;
  sessionId: string;
}

export interface TmuxPane {
  id: string;
  windowId: string;
  active: boolean;
  title: string;
}

interface CommandExecution {
  id: string;
  paneId: string;
  command: string;
  status: "pending" | "completed" | "error";
  startTime: Date;
  result?: string;
  exitCode?: number;
  rawMode?: boolean;
}

export type ShellType = "bash" | "zsh" | "fish";

let shellConfig: { type: ShellType } = { type: "bash" };

export function setShellConfig(config: { type: string }): void {
  // Validate shell type
  const validShells: ShellType[] = ["bash", "zsh", "fish"];

  if (validShells.includes(config.type as ShellType)) {
    shellConfig = { type: config.type as ShellType };
  } else {
    shellConfig = { type: "bash" };
  }
}

/**
 * Execute a tmux command and return the result
 */
export async function executeTmux(tmuxCommand: string): Promise<string> {
  try {
    const { stdout } = await exec(`tmux ${tmuxCommand}`);
    return stdout.trim();
  } catch (error: any) {
    throw new Error(`Failed to execute tmux command: ${error.message}`);
  }
}

/**
 * Check if tmux server is running
 */
export async function isTmuxRunning(): Promise<boolean> {
  try {
    await executeTmux("list-sessions -F '#{session_name}'");
    return true;
  } catch (error) {
    return false;
  }
}

/**
 * List all tmux sessions
 */
export async function listSessions(): Promise<TmuxSession[]> {
  const format =
    "#{session_id}:#{session_name}:#{?session_attached,1,0}:#{session_windows}";
  const output = await executeTmux(`list-sessions -F '${format}'`);

  if (!output) return [];

  return output.split("\n").map((line) => {
    const [id, name, attached, windows] = line.split(":");
    return {
      id,
      name,
      attached: attached === "1",
      windows: parseInt(windows, 10),
    };
  });
}

/**
 * Find a session by name
 */
export async function findSessionByName(
  name: string
): Promise<TmuxSession | null> {
  try {
    const sessions = await listSessions();
    return sessions.find((session) => session.name === name) || null;
  } catch (error) {
    return null;
  }
}

/**
 * List windows in a session
 */
export async function listWindows(sessionId: string): Promise<TmuxWindow[]> {
  const format = "#{window_id}:#{window_name}:#{?window_active,1,0}";
  const output = await executeTmux(
    `list-windows -t '${sessionId}' -F '${format}'`
  );

  if (!output) return [];

  return output.split("\n").map((line) => {
    const [id, name, active] = line.split(":");
    return {
      id,
      name,
      active: active === "1",
      sessionId,
    };
  });
}

/**
 * List panes in a window
 */
export async function listPanes(windowId: string): Promise<TmuxPane[]> {
  const format = "#{pane_id}:#{pane_title}:#{?pane_active,1,0}";
  const output = await executeTmux(
    `list-panes -t '${windowId}' -F '${format}'`
  );

  if (!output) return [];

  return output.split("\n").map((line) => {
    const [id, title, active] = line.split(":");
    return {
      id,
      windowId,
      title: title,
      active: active === "1",
    };
  });
}

/**
 * Capture content from a specific pane, by default the latest 200 lines.
 */
export async function capturePaneContent(
  paneId: string,
  lines: number = 200,
  includeColors: boolean = false
): Promise<string> {
  const colorFlag = includeColors ? "-e" : "";
  return executeTmux(
    `capture-pane -p ${colorFlag} -t '${paneId}' -S -${lines} -E -`
  );
}

/**
 * Create a new tmux session
 */
export async function createSession(name: string): Promise<TmuxSession | null> {
  await executeTmux(`new-session -d -s "${name}"`);
  return findSessionByName(name);
}

/**
 * Create a new window in a session
 */
export async function createWindow(
  sessionId: string,
  name: string,
  command?: string
): Promise<(TmuxWindow & { paneId: string; output?: string }) | null> {
  const output = await executeTmux(`new-window -t '${sessionId}' -n '${name}'`);
  const windows = await listWindows(sessionId);
  const window = windows.find((window) => window.name === name);

  if (!window) return null;

  // Get the default pane created with the window
  const panes = await listPanes(window.id);
  const defaultPane = panes[0];

  let commandOutput: string | undefined;

  // If command is provided, execute it in the new pane
  if (command && defaultPane) {
    await sendText({
      paneId: defaultPane.id,
      text: command,
      pressEnter: true,
    });

    // Sleep for 1 second to allow command to execute
    await new Promise((resolve) => setTimeout(resolve, 1000));

    // Capture the pane content
    commandOutput = await capturePaneContent(defaultPane.id, 200, false);
  }

  return {
    ...window,
    paneId: defaultPane?.id || "",
    output: commandOutput,
  };
}

/**
 * Kill a tmux session by ID
 */
export async function killSession(sessionId: string): Promise<void> {
  await executeTmux(`kill-session -t '${sessionId}'`);
}

/**
 * Kill a tmux window by ID
 */
export async function killWindow(windowId: string): Promise<void> {
  await executeTmux(`kill-window -t '${windowId}'`);
}

/**
 * Kill a tmux pane by ID
 */
export async function killPane(paneId: string): Promise<void> {
  await executeTmux(`kill-pane -t '${paneId}'`);
}

/**
 * Rename a tmux window by ID
 */
export async function renameWindow(
  windowId: string,
  name: string
): Promise<void> {
  await executeTmux(`rename-window -t '${windowId}' '${name}'`);
}

/**
 * Split a tmux pane horizontally or vertically
 */
export async function splitPane(
  targetPaneId: string,
  direction: "horizontal" | "vertical" = "vertical",
  size?: number
): Promise<TmuxPane | null> {
  // Build the split-window command
  let splitCommand = "split-window";

  // Add direction flag (-h for horizontal, -v for vertical)
  if (direction === "horizontal") {
    splitCommand += " -h";
  } else {
    splitCommand += " -v";
  }

  // Add target pane
  splitCommand += ` -t '${targetPaneId}'`;

  // Add size if specified (as percentage)
  if (size !== undefined && size > 0 && size < 100) {
    splitCommand += ` -p ${size}`;
  }

  // Execute the split command
  await executeTmux(splitCommand);

  // Get the window ID from the target pane to list all panes
  const windowInfo = await executeTmux(
    `display-message -p -t '${targetPaneId}' '#{window_id}'`
  );

  // List all panes in the window to find the newly created one
  const panes = await listPanes(windowInfo);

  // The newest pane is typically the last one in the list
  return panes.length > 0 ? panes[panes.length - 1] : null;
}

// Map to track ongoing command executions
const activeCommands = new Map<string, CommandExecution>();

const startMarkerText = "TMUX_MCP_START";
const endMarkerPrefix = "TMUX_MCP_DONE_";

// Execute a command in a tmux pane and track its execution
export async function executeCommand(
  paneId: string,
  command: string,
  rawMode?: boolean,
  noEnter?: boolean
): Promise<string> {
  // Generate unique ID for this command execution
  const commandId = uuidv4();

  let fullCommand: string;
  if (rawMode || noEnter) {
    fullCommand = command;
  } else {
    const endMarkerText = getEndMarkerText();
    fullCommand = `echo "${startMarkerText}"; ${command}; echo "${endMarkerText}"`;
  }

  // Store command in tracking map
  activeCommands.set(commandId, {
    id: commandId,
    paneId,
    command,
    status: "pending",
    startTime: new Date(),
    rawMode: rawMode || noEnter,
  });

  // Send the command to the tmux pane
  if (noEnter) {
    // Check if this is a special key or key combination
    // Special keys in tmux are typically capitalized or have special names
    const specialKeys = [
      "Up",
      "Down",
      "Left",
      "Right",
      "Escape",
      "Tab",
      "Enter",
      "Space",
      "BSpace",
      "Delete",
      "Home",
      "End",
      "PageUp",
      "PageDown",
      "F1",
      "F2",
      "F3",
      "F4",
      "F5",
      "F6",
      "F7",
      "F8",
      "F9",
      "F10",
      "F11",
      "F12",
      "BTab",
    ];

    // Split the command into parts to handle combinations like "C-b" or "M-x"
    const parts = fullCommand.split("-");
    const isSpecialKey = parts.length === 1 && specialKeys.includes(parts[0]);
    const isKeyCombo =
      parts.length > 1 &&
      (parts[0] === "C" || // Control
        parts[0] === "M" || // Meta/Alt
        parts[0] === "S"); // Shift

    if (isSpecialKey || isKeyCombo) {
      // Send special key or key combination as-is
      await executeTmux(`send-keys -t '${paneId}' ${fullCommand}`);
    } else {
      // For regular text, send each character individually to ensure proper processing
      // This handles both single characters (like 'q', 'f') and strings (like 'beam')
      for (const char of fullCommand) {
        await executeTmux(
          `send-keys -t '${paneId}' '${char.replace(/'/g, "'\\''")}'`
        );
      }
    }
  } else {
    await executeTmux(
      `send-keys -t '${paneId}' '${fullCommand.replace(/'/g, "'\\''")}' Enter`
    );
  }

  return commandId;
}

export async function checkCommandStatus(
  commandId: string
): Promise<CommandExecution | null> {
  const command = activeCommands.get(commandId);
  if (!command) return null;

  if (command.status !== "pending") return command;

  const content = await capturePaneContent(command.paneId, 1000);

  if (command.rawMode) {
    command.result =
      "Status tracking unavailable for rawMode commands. Use capture-pane to monitor interactive apps instead.";
    return command;
  }

  // Find the last occurrence of the markers
  const startIndex = content.lastIndexOf(startMarkerText);
  const endIndex = content.lastIndexOf(endMarkerPrefix);

  if (startIndex === -1 || endIndex === -1 || endIndex <= startIndex) {
    command.result = "Command output could not be captured properly";
    return command;
  }

  // Extract exit code from the end marker line
  const endLine = content.substring(endIndex).split("\n")[0];
  const endMarkerRegex = new RegExp(`${endMarkerPrefix}(\\d+)`);
  const exitCodeMatch = endLine.match(endMarkerRegex);

  if (exitCodeMatch) {
    const exitCode = parseInt(exitCodeMatch[1], 10);

    command.status = exitCode === 0 ? "completed" : "error";
    command.exitCode = exitCode;

    // Extract output between the start and end markers
    const outputStart = startIndex + startMarkerText.length;
    const outputContent = content.substring(outputStart, endIndex).trim();

    command.result = outputContent
      .substring(outputContent.indexOf("\n") + 1)
      .trim();

    // Update in map
    activeCommands.set(commandId, command);
  }

  return command;
}

// Get command by ID
export function getCommand(commandId: string): CommandExecution | null {
  return activeCommands.get(commandId) || null;
}

// Get all active command IDs
export function getActiveCommandIds(): string[] {
  return Array.from(activeCommands.keys());
}

// Clean up completed commands older than a certain time
export function cleanupOldCommands(maxAgeMinutes: number = 60): void {
  const now = new Date();

  for (const [id, command] of activeCommands.entries()) {
    const ageMinutes =
      (now.getTime() - command.startTime.getTime()) / (1000 * 60);

    if (command.status !== "pending" && ageMinutes > maxAgeMinutes) {
      activeCommands.delete(id);
    }
  }
}

function getEndMarkerText(): string {
  return shellConfig.type === "fish"
    ? `${endMarkerPrefix}$status`
    : `${endMarkerPrefix}$?`;
}

// New consolidated API functions

export type ListScope = "all" | "sessions" | "session" | "window" | "pane";

interface SessionWithWindows extends TmuxSession {
  windowDetails?: WindowWithPanes[];
}

interface WindowWithPanes extends TmuxWindow {
  paneDetails?: TmuxPane[];
}

export async function list({
  scope,
  target,
}: {
  scope: ListScope;
  target?: string;
}): Promise<
  | SessionWithWindows[]
  | TmuxSession[]
  | TmuxWindow[]
  | TmuxPane[]
  | TmuxSession
  | TmuxWindow
  | TmuxPane
> {
  if (scope === "all") {
    const sessions = await listSessions();
    const sessionsWithDetails: SessionWithWindows[] = [];

    for (const session of sessions) {
      const windows = await listWindows(session.id);
      const windowsWithPanes: WindowWithPanes[] = [];

      for (const window of windows) {
        const panes = await listPanes(window.id);
        windowsWithPanes.push({
          ...window,
          paneDetails: panes,
        });
      }

      sessionsWithDetails.push({
        ...session,
        windowDetails: windowsWithPanes,
      });
    }

    return sessionsWithDetails;
  }

  if (scope === "sessions") {
    return listSessions();
  }

  if (scope === "session") {
    if (!target) {
      throw new Error("target is required for scope 'session'");
    }
    return listWindows(target);
  }

  if (scope === "window") {
    if (!target) {
      throw new Error("target is required for scope 'window'");
    }
    return listPanes(target);
  }

  if (scope === "pane") {
    if (!target) {
      throw new Error("target is required for scope 'pane'");
    }
    const windowId = await executeTmux(
      `display-message -p -t '${target}' '#{window_id}'`
    );
    const panes = await listPanes(windowId);
    const pane = panes.find((p) => p.id === target);
    if (!pane) {
      throw new Error(`Pane not found: ${target}`);
    }
    return pane;
  }

  throw new Error(`Invalid scope: ${scope}`);
}

export type KillScope = "session" | "window" | "pane";

export async function kill({
  scope,
  target,
}: {
  scope: KillScope;
  target: string;
}): Promise<void> {
  if (scope === "session") {
    return killSession(target);
  }

  if (scope === "window") {
    return killWindow(target);
  }

  if (scope === "pane") {
    return killPane(target);
  }

  throw new Error(`Invalid scope: ${scope}`);
}

export interface ShellCommandResult {
  command: string;
  status: "completed" | "error";
  exitCode: number;
  output: string;
}

export async function executeShellCommand({
  paneId,
  command,
  timeout = 30000,
}: {
  paneId: string;
  command: string;
  timeout?: number;
}): Promise<ShellCommandResult> {
  const commandId = uuidv4();
  const endMarkerText = getEndMarkerText();
  const fullCommand = `echo "${startMarkerText}"; ${command}; echo "${endMarkerText}"`;

  activeCommands.set(commandId, {
    id: commandId,
    paneId,
    command,
    status: "pending",
    startTime: new Date(),
    rawMode: false,
  });

  await executeTmux(
    `send-keys -t '${paneId}' '${fullCommand.replace(/'/g, "'\\''")}' Enter`
  );

  // Poll for completion
  const startTime = Date.now();
  const pollInterval = 100;

  while (Date.now() - startTime < timeout) {
    await new Promise((resolve) => setTimeout(resolve, pollInterval));

    const result = await checkCommandStatus(commandId);

    if (result && result.status !== "pending") {
      // Cleanup
      activeCommands.delete(commandId);

      return {
        command: result.command,
        status: result.status,
        exitCode: result.exitCode!,
        output: result.result || "",
      };
    }
  }

  // Timeout
  activeCommands.delete(commandId);
  throw new Error(
    `Command timed out after ${timeout}ms. Use capture-pane to check pane state.`
  );
}

export async function sendKeys({
  paneId,
  keys,
  repeat = 1,
  return_output,
}: {
  paneId: string;
  keys: string;
  repeat?: number;
  return_output?: { lines?: number; wait?: number };
}): Promise<string | void> {
  // Repeat the key press the specified number of times
  for (let i = 0; i < repeat; i++) {
    // Raw pass-through, no validation or processing
    await executeTmux(`send-keys -t '${paneId}' ${keys}`);
  }

  // If return_output is requested, wait and capture pane content
  if (return_output) {
    await new Promise((resolve) =>
      setTimeout(resolve, return_output.wait ?? 500)
    );
    const lines = return_output.lines || 200;
    return capturePaneContent(paneId, lines, false);
  }
}

export async function sendText({
  paneId,
  text,
  pressEnter = false,
  return_output,
}: {
  paneId: string;
  text: string;
  pressEnter?: boolean;
  return_output?: { lines?: number; wait?: number };
}): Promise<string | void> {
  // Send each character with -l flag for literal interpretation
  for (const char of text) {
    await executeTmux(
      `send-keys -l -t '${paneId}' '${char.replace(/'/g, "'\\''")}'`
    );
  }

  if (pressEnter) {
    await new Promise((resolve) => setTimeout(resolve, 300));
    await executeTmux(`send-keys -t '${paneId}' Enter`);
  }

  // If return_output is requested, wait and capture pane content
  if (return_output) {
    if (return_output.wait) {
      await new Promise((resolve) => setTimeout(resolve, return_output.wait));
    }
    const lines = return_output.lines || 200;
    return capturePaneContent(paneId, lines, false);
  }
}