import { spawn, type ChildProcess } from "node:child_process";
import fs from "node:fs";
import path from "node:path";
import * as readline from "node:readline";
import { Readable, Writable } from "node:stream";
import { fileURLToPath } from "node:url";
import {
  ClientSideConnection,
  PROTOCOL_VERSION,
  ndJsonStream,
  type RequestPermissionRequest,
  type RequestPermissionResponse,
  type SessionNotification,
} from "@agentclientprotocol/sdk";
import { ensureOpenClawCliOnPath } from "../infra/path-env.js";
import {
  materializeWindowsSpawnProgram,
  resolveWindowsSpawnProgram,
} from "../plugin-sdk/windows-spawn.js";
import {
  listKnownProviderAuthEnvVarNames,
  omitEnvKeysCaseInsensitive,
} from "../secrets/provider-env-vars.js";
import { sanitizeTerminalText } from "../terminal/safe-text.js";
import { classifyAcpToolApproval, type AcpApprovalClass } from "./approval-classifier.js";

type PermissionOption = RequestPermissionRequest["options"][number];

type PermissionResolverDeps = {
  prompt?: (toolName: string | undefined, toolTitle?: string) => Promise<boolean>;
  log?: (line: string) => void;
  cwd?: string;
};

function resolveToolKindForPermission(
  toolName: string | undefined,
  approvalClass: AcpApprovalClass,
): string | undefined {
  if (!toolName && approvalClass === "unknown") {
    return undefined;
  }
  if (approvalClass === "readonly_scoped") {
    return "readonly_scoped";
  }
  if (approvalClass === "readonly_search") {
    return "readonly_search";
  }
  return approvalClass;
}

function pickOption(
  options: PermissionOption[],
  kinds: PermissionOption["kind"][],
): PermissionOption | undefined {
  for (const kind of kinds) {
    const match = options.find((option) => option.kind === kind);
    if (match) {
      return match;
    }
  }
  return undefined;
}

function selectedPermission(optionId: string): RequestPermissionResponse {
  return { outcome: { outcome: "selected", optionId } };
}

function cancelledPermission(): RequestPermissionResponse {
  return { outcome: { outcome: "cancelled" } };
}

function promptUserPermission(toolName: string | undefined, toolTitle?: string): Promise<boolean> {
  if (!process.stdin.isTTY || !process.stderr.isTTY) {
    console.error(`[permission denied] ${toolName ?? "unknown"}: non-interactive terminal`);
    return Promise.resolve(false);
  }
  return new Promise((resolve) => {
    let settled = false;
    const rl = readline.createInterface({
      input: process.stdin,
      output: process.stderr,
    });

    const finish = (approved: boolean) => {
      if (settled) {
        return;
      }
      settled = true;
      clearTimeout(timeout);
      rl.close();
      resolve(approved);
    };

    const timeout = setTimeout(() => {
      console.error(`\n[permission timeout] denied: ${toolName ?? "unknown"}`);
      finish(false);
    }, 30_000);

    const label = toolTitle
      ? toolName
        ? `${toolTitle} (${toolName})`
        : toolTitle
      : (toolName ?? "unknown tool");
    rl.question(`\n[permission] Allow "${label}"? (y/N) `, (answer) => {
      const approved = answer.trim().toLowerCase() === "y";
      console.error(`[permission ${approved ? "approved" : "denied"}] ${toolName ?? "unknown"}`);
      finish(approved);
    });
  });
}

export async function resolvePermissionRequest(
  params: RequestPermissionRequest,
  deps: PermissionResolverDeps = {},
): Promise<RequestPermissionResponse> {
  const log = deps.log ?? ((line: string) => console.error(line));
  const prompt = deps.prompt ?? promptUserPermission;
  const cwd = deps.cwd ?? process.cwd();
  const options = params.options ?? [];
  const toolTitle = sanitizeTerminalText(params.toolCall?.title ?? "tool");
  const classification = classifyAcpToolApproval({ toolCall: params.toolCall, cwd });
  const toolName = classification.toolName;
  const toolKind = resolveToolKindForPermission(toolName, classification.approvalClass);

  if (options.length === 0) {
    log(`[permission cancelled] ${toolName ?? "unknown"}: no options available`);
    return cancelledPermission();
  }

  const allowOption = pickOption(options, ["allow_once", "allow_always"]);
  const rejectOption = pickOption(options, ["reject_once", "reject_always"]);
  const promptRequired = !classification.autoApprove;

  if (!promptRequired) {
    const option = allowOption ?? options[0];
    if (!option) {
      log(`[permission cancelled] ${toolName}: no selectable options`);
      return cancelledPermission();
    }
    log(`[permission auto-approved] ${toolName} (${toolKind ?? "unknown"})`);
    return selectedPermission(option.optionId);
  }

  log(
    `\n[permission requested] ${toolTitle}${toolName ? ` (${toolName})` : ""}${toolKind ? ` [${toolKind}]` : ""}`,
  );
  const approved = await prompt(toolName, toolTitle);

  if (approved && allowOption) {
    return selectedPermission(allowOption.optionId);
  }
  if (!approved && rejectOption) {
    return selectedPermission(rejectOption.optionId);
  }

  log(
    `[permission cancelled] ${toolName ?? "unknown"}: missing ${approved ? "allow" : "reject"} option`,
  );
  return cancelledPermission();
}

export type AcpClientOptions = {
  cwd?: string;
  serverCommand?: string;
  serverArgs?: string[];
  serverVerbose?: boolean;
  verbose?: boolean;
};

export type AcpClientHandle = {
  client: ClientSideConnection;
  agent: ChildProcess;
  sessionId: string;
};

function toArgs(value: string[] | string | undefined): string[] {
  if (!value) {
    return [];
  }
  return Array.isArray(value) ? value : [value];
}

function buildServerArgs(opts: AcpClientOptions): string[] {
  const args = ["acp", ...toArgs(opts.serverArgs)];
  if (opts.serverVerbose && !args.includes("--verbose") && !args.includes("-v")) {
    args.push("--verbose");
  }
  return args;
}

type AcpClientSpawnEnvOptions = {
  stripKeys?: Iterable<string>;
};

export function resolveAcpClientSpawnEnv(
  baseEnv: NodeJS.ProcessEnv = process.env,
  options: AcpClientSpawnEnvOptions = {},
): NodeJS.ProcessEnv {
  const env = omitEnvKeysCaseInsensitive(baseEnv, options.stripKeys ?? []);
  env.OPENCLAW_SHELL = "acp-client";
  return env;
}

export function shouldStripProviderAuthEnvVarsForAcpServer(
  params: {
    serverCommand?: string;
    serverArgs?: string[];
    defaultServerCommand?: string;
    defaultServerArgs?: string[];
  } = {},
): boolean {
  const serverCommand = params.serverCommand?.trim();
  if (!serverCommand) {
    return true;
  }
  const defaultServerCommand = params.defaultServerCommand?.trim();
  if (!defaultServerCommand || serverCommand !== defaultServerCommand) {
    return false;
  }
  const serverArgs = params.serverArgs ?? [];
  const defaultServerArgs = params.defaultServerArgs ?? [];
  return (
    serverArgs.length === defaultServerArgs.length &&
    serverArgs.every((arg, index) => arg === defaultServerArgs[index])
  );
}

export function buildAcpClientStripKeys(params: {
  stripProviderAuthEnvVars?: boolean;
  activeSkillEnvKeys?: Iterable<string>;
}): Set<string> {
  const stripKeys = new Set<string>(params.activeSkillEnvKeys ?? []);
  if (params.stripProviderAuthEnvVars) {
    for (const key of listKnownProviderAuthEnvVarNames()) {
      stripKeys.add(key);
    }
  }
  return stripKeys;
}

type AcpSpawnRuntime = {
  platform: NodeJS.Platform;
  env: NodeJS.ProcessEnv;
  execPath: string;
};

const DEFAULT_ACP_SPAWN_RUNTIME: AcpSpawnRuntime = {
  platform: process.platform,
  env: process.env,
  execPath: process.execPath,
};

export function resolveAcpClientSpawnInvocation(
  params: { serverCommand: string; serverArgs: string[] },
  runtime: AcpSpawnRuntime = DEFAULT_ACP_SPAWN_RUNTIME,
): { command: string; args: string[]; shell?: boolean; windowsHide?: boolean } {
  const program = resolveWindowsSpawnProgram({
    command: params.serverCommand,
    platform: runtime.platform,
    env: runtime.env,
    execPath: runtime.execPath,
    packageName: "openclaw",
  });
  const resolved = materializeWindowsSpawnProgram(program, params.serverArgs);
  return {
    command: resolved.command,
    args: resolved.argv,
    shell: resolved.shell,
    windowsHide: resolved.windowsHide,
  };
}

function resolveSelfEntryPath(): string | null {
  // Prefer a path relative to the built module location (dist/acp/client.js -> dist/entry.js).
  try {
    const here = fileURLToPath(import.meta.url);
    const candidate = path.resolve(path.dirname(here), "..", "entry.js");
    if (fs.existsSync(candidate)) {
      return candidate;
    }
  } catch {
    // ignore
  }

  const argv1 = process.argv[1]?.trim();
  if (argv1) {
    return path.isAbsolute(argv1) ? argv1 : path.resolve(process.cwd(), argv1);
  }
  return null;
}

function printSessionUpdate(notification: SessionNotification): void {
  const update = notification.update;
  if (!("sessionUpdate" in update)) {
    return;
  }

  switch (update.sessionUpdate) {
    case "agent_message_chunk": {
      if (update.content?.type === "text") {
        process.stdout.write(update.content.text);
      }
      return;
    }
    case "tool_call": {
      console.log(`\n[tool] ${update.title} (${update.status})`);
      return;
    }
    case "tool_call_update": {
      if (update.status) {
        console.log(`[tool update] ${update.toolCallId}: ${update.status}`);
      }
      return;
    }
    case "available_commands_update": {
      const names = update.availableCommands?.map((cmd) => `/${cmd.name}`).join(" ");
      if (names) {
        console.log(`\n[commands] ${names}`);
      }
      return;
    }
    default:
      return;
  }
}

export async function createAcpClient(opts: AcpClientOptions = {}): Promise<AcpClientHandle> {
  const cwd = opts.cwd ?? process.cwd();
  const verbose = Boolean(opts.verbose);
  const log = verbose ? (msg: string) => console.error(`[acp-client] ${msg}`) : () => {};

  ensureOpenClawCliOnPath();
  const serverArgs = buildServerArgs(opts);

  const entryPath = resolveSelfEntryPath();
  const defaultServerCommand = entryPath ? process.execPath : "openclaw";
  const defaultServerArgs = entryPath ? [entryPath, ...serverArgs] : serverArgs;
  const serverCommand = opts.serverCommand ?? defaultServerCommand;
  const effectiveArgs = opts.serverCommand || !entryPath ? serverArgs : defaultServerArgs;
  const { getActiveSkillEnvKeys } = await import("../agents/skills/env-overrides.runtime.js");
  const stripProviderAuthEnvVars = shouldStripProviderAuthEnvVarsForAcpServer({
    serverCommand,
    serverArgs: effectiveArgs,
    defaultServerCommand,
    defaultServerArgs,
  });
  const stripKeys = buildAcpClientStripKeys({
    stripProviderAuthEnvVars,
    activeSkillEnvKeys: getActiveSkillEnvKeys(),
  });
  const spawnEnv = resolveAcpClientSpawnEnv(process.env, { stripKeys });
  const spawnInvocation = resolveAcpClientSpawnInvocation(
    { serverCommand, serverArgs: effectiveArgs },
    {
      platform: process.platform,
      env: spawnEnv,
      execPath: process.execPath,
    },
  );

  log(`spawning: ${spawnInvocation.command} ${spawnInvocation.args.join(" ")}`);

  const agent = spawn(spawnInvocation.command, spawnInvocation.args, {
    stdio: ["pipe", "pipe", "inherit"],
    cwd,
    env: spawnEnv,
    shell: spawnInvocation.shell,
    windowsHide: spawnInvocation.windowsHide,
  });

  if (!agent.stdin || !agent.stdout) {
    throw new Error("Failed to create ACP stdio pipes");
  }

  const input = Writable.toWeb(agent.stdin);
  const output = Readable.toWeb(agent.stdout) as unknown as ReadableStream<Uint8Array>;
  const stream = ndJsonStream(input, output);

  const client = new ClientSideConnection(
    () => ({
      sessionUpdate: async (params: SessionNotification) => {
        printSessionUpdate(params);
      },
      requestPermission: async (params: RequestPermissionRequest) => {
        return resolvePermissionRequest(params, { cwd });
      },
    }),
    stream,
  );

  log("initializing");
  await client.initialize({
    protocolVersion: PROTOCOL_VERSION,
    clientCapabilities: {
      fs: { readTextFile: true, writeTextFile: true },
      terminal: true,
    },
    clientInfo: { name: "openclaw-acp-client", version: "1.0.0" },
  });

  log("creating session");
  const session = await client.newSession({
    cwd,
    mcpServers: [],
  });

  return {
    client,
    agent,
    sessionId: session.sessionId,
  };
}

export async function runAcpClientInteractive(opts: AcpClientOptions = {}): Promise<void> {
  const { client, agent, sessionId } = await createAcpClient(opts);

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
  });

  console.log("OpenClaw ACP client");
  console.log(`Session: ${sessionId}`);
  console.log('Type a prompt, or "exit" to quit.\n');

  const prompt = () => {
    rl.question("> ", async (input) => {
      const text = input.trim();
      if (!text) {
        prompt();
        return;
      }
      if (text === "exit" || text === "quit") {
        agent.kill();
        rl.close();
        process.exit(0);
      }

      try {
        const response = await client.prompt({
          sessionId,
          prompt: [{ type: "text", text }],
        });
        console.log(`\n[${response.stopReason}]\n`);
      } catch (err) {
        console.error(`\n[error] ${String(err)}\n`);
      }

      prompt();
    });
  };

  prompt();

  agent.on("exit", (code) => {
    console.log(`\nAgent exited with code ${code ?? 0}`);
    rl.close();
    process.exit(code ?? 0);
  });
}