#!/usr/bin/env node
import process from "node:process";
import readline from "node:readline";

const args = process.argv.slice(2);

if (args.includes("about")) {
  process.stdout.write(
    `${JSON.stringify({
      cliVersion: "tutti-perf-fixture",
      subscriptionTier: "Fixture",
      userEmail: "performance-fixture@localhost"
    })}\n`
  );
} else if (args.includes("--version") || args.includes("version")) {
  process.stdout.write("cursor-agent tutti-perf-fixture\n");
} else if (args.includes("acp")) {
  runACPFixture();
} else {
  process.stdout.write("Logged in as performance-fixture@localhost\n");
}

function runACPFixture() {
  const input = readline.createInterface({ input: process.stdin });
  let canceled = false;
  let activeSessionId = "tutti-perf-cursor-session";
  input.on("line", (line) => {
    void handleMessage(line).catch((error) => {
      process.stderr.write(`${error.stack ?? error.message}\n`);
      process.exitCode = 1;
    });
  });

  async function handleMessage(line) {
    const message = JSON.parse(line);
    switch (message.method) {
      case "initialize":
        respond(message.id, {
          protocolVersion: 1,
          agentInfo: { name: "tutti-perf-cursor", title: "Tutti Perf Cursor" },
          agentCapabilities: { loadSession: true }
        });
        return;
      case "session/new":
        activeSessionId =
          message.params?.sessionId?.trim?.() || activeSessionId;
        respond(message.id, {
          configOptions: [],
          sessionId: activeSessionId
        });
        return;
      case "session/load":
      case "session/resume":
        activeSessionId =
          message.params?.sessionId?.trim?.() || activeSessionId;
        respond(message.id, { configOptions: [] });
        return;
      case "session/set_mode":
      case "session/set_config_option":
        respond(message.id, { configOptions: [] });
        return;
      case "session/cancel":
        canceled = true;
        return;
      case "session/prompt":
        activeSessionId =
          message.params?.sessionId?.trim?.() || activeSessionId;
        canceled = false;
        await streamPrompt(message.id, fixtureExpectedToken(message.params));
        return;
      default:
        if (message.id !== undefined) {
          write({
            jsonrpc: "2.0",
            id: message.id,
            error: {
              code: -32601,
              message: `method not found: ${message.method}`
            }
          });
        }
    }
  }

  async function streamPrompt(promptID, expectedToken) {
    const oversizedToolCallCount = Number.parseInt(
      process.env.TUTTI_PERF_OVERSIZED_TOOL_CALLS ?? "",
      10
    );
    if (Number.isFinite(oversizedToolCallCount) && oversizedToolCallCount > 0) {
      await streamOversizedToolCalls(promptID, oversizedToolCallCount);
      return;
    }
    for (let index = 0; index < 48 && !canceled; index += 1) {
      notify("session/update", {
        sessionId: activeSessionId,
        update: {
          sessionUpdate: "agent_message_chunk",
          content: {
            type: "text",
            text: `Virtualized streaming fixture chunk ${String(index + 1).padStart(2, "0")}: ${"layout-safe-content ".repeat(8)}\n\n`
          }
        }
      });
      await new Promise((resolve) => setTimeout(resolve, 30));
    }
    if (expectedToken && !canceled) {
      notify("session/update", {
        sessionId: activeSessionId,
        update: {
          sessionUpdate: "agent_message_chunk",
          content: { type: "text", text: expectedToken }
        }
      });
    }
    respond(promptID, { stopReason: canceled ? "canceled" : "end_turn" });
  }

  async function streamOversizedToolCalls(promptID, toolCallCount) {
    for (let index = 0; index < toolCallCount && !canceled; index += 1) {
      const toolCallId = `tutti-perf-oversized-tool-${index}`;
      const title = `Inspect fixture path ${index + 1}`;
      notify("session/update", {
        sessionId: activeSessionId,
        update: {
          sessionUpdate: "tool_call",
          toolCallId,
          title,
          kind: "execute",
          status: "pending",
          rawInput: {
            command: `printf oversized-tool-${index + 1}`
          }
        }
      });
      notify("session/update", {
        sessionId: activeSessionId,
        update: {
          sessionUpdate: "tool_call_update",
          toolCallId,
          title,
          kind: "execute",
          status: "completed",
          rawOutput: {
            output: `oversized tool ${index + 1} completed`
          }
        }
      });
      await new Promise((resolve) => setTimeout(resolve, 12));
    }
    for (let index = 0; index < 100 && !canceled; index += 1) {
      await new Promise((resolve) => setTimeout(resolve, 100));
    }
    respond(promptID, { stopReason: canceled ? "canceled" : "end_turn" });
  }
}

function fixtureExpectedToken(params) {
  const prefix = "Reply with exactly this text: ";
  const text = collectText(params?.prompt ?? params?.content);
  const index = text.indexOf(prefix);
  return index < 0 ? "" : text.slice(index + prefix.length).trim();
}

function collectText(value) {
  if (typeof value === "string") return value;
  if (Array.isArray(value)) return value.map(collectText).join("");
  if (!value || typeof value !== "object") return "";
  if (typeof value.text === "string") return value.text;
  return Object.values(value).map(collectText).join("");
}

function respond(id, result) {
  write({ jsonrpc: "2.0", id, result });
}

function notify(method, params) {
  write({ jsonrpc: "2.0", method, params });
}

function write(value) {
  process.stdout.write(`${JSON.stringify(value)}\n`);
}